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Biogeographic patterns in life history traits of the Pan-American sandy beachisopodExcirolana braziliensis were analyzed to determine latitudinal variations along its distribution, from tropical (9°N) to temperate (39°S) sandy beaches in Atlantic and Pacific oceans. Population features exhibited systematic geographical patterns of variation: (1) an increase in individual sizes and growth rates towards temperate beaches, following an inverse relationship with mean water temperature of the surf zone; (2) a shift from almost continuous to seasonal growth from subtropical to temperate Atlantic beaches and a positive relationship between amplitude of intra-annual growth oscillations and temperature range; (3) a linear decrease in life span and an increase in natural mortality from temperate to subtropical beaches; and (4) an increase in the individual mass-at-size (length-mass relationship) from subtropical to temperate beaches. Analyses discriminated by sex were consistent with the patterns illustrated above. Local effects of temperature and beach morphodynamics are discussed. Our results demonstrate that the population dynamics of E. braziliensis is highly plastic over latitudinal gradients, with large-scale variations in temperature and concurrent environmental variables leading to an adjustment of the phenotype-environment relationship.
Spatial and temporal structural analysis of the isopodExcirolana armata Dana (Cirolanidae) was carried out at Barra del Chuy (Uruguay) during the period May 1988-April 1989. The role of environmental variables in controlling microspatial abundance and zonation was studied. Some aspects of the population dynamics were also determined. Greatest abundances were registered around the upper level of the swash zone. Quantitative analysis showed a strongly aggregated distribution of organisms and a differential length structure in relation to their level of occurrence in the beach; a tendency to occupy microhabitats in a narrow range of sediment penetrability and sediment water content values was also observed. E. armata showed seasonal growth with minimum growth rates during winter, increasing from spring onwards. Longevity was nearly 3 years. One recruitment event per year is suggested, with the main peak in late spring and summer.
The somatic and gonad productions of the cirolanid isopodExcirolana armata were analyzed by taking monthly samples from December 2003 to November 2005 on Una beach, São Paulo state (24°S), southeastern Brazil. Sampling was performed along three fixed transects established from the base of the foredunes to the waterline. Weight-specific growth rate was used to estimate the E. armata somatic production for 2004 and 2005, separately. The gonad production was estimated based on the monthly reproductive potential (mean number of eggs/embryos per female × monthly abundance of ovigerous females with near-release broods) for 2004. The annual somatic production of E. armata population varied from 15.57 to 17.25 g AFDW m-1 year-1 and the somatic production/biomass ratio ( P s/ B) from 3.55 to 3.14 year-1 for 2004 and 2005, respectively. The P s/ B ratios were higher for males (4.02 and 3.19 year-1 for 2004 and 2005) than for females (3.10 year-1 for both years). The annual gonad production ( P g = 1.07 g AFDW m-1 year-1) contributed about 15 and 6% to the total production ( P s + P g) of females and the population, respectively. The proportion of gonad to somatic production of females ( P g/ P s) increased with individual size (ca 90% in the 7.5 mm size class), and the annual weight-specific gonad production ( P g/ B ratio) was estimated to 0.24 year-1. The high P s/ B ratios estimated for E. armata derive from the fast growth of individuals and show the importance of this population to the energy flow on Una beach ecosystem. However, the low percentage of juveniles verified in this population and in other studies of populations of the genus Excirolana is discussed as an important source of underestimation of P s/ B ratio.
The stimuli which normally synchronize the endogenous tidal rhythm of the isopodExcirolana chiltoni arise from turbulent waves moving across the beach. A phase-response curve for two-h pulses of similar stimuli has been derived from experiments in which individual isopods were treated with vigorous intermittent shaking in a flask of seawater. This response curve differs qualitatively from all results previously obtained
The supralittoral isopod Armadillidium album Dollfus is common, although patchily distributed, under driftwood on the foreshore of broad sandy beaches on the outer coast of the Delta area in the SW Netherlands. The isopods are very tolerant of immersion in seawater, but are nevertheless confined to a narrow zone just above normal spring tides. A. album is a sexually reproducing isopod, with a single well-defined reproductive period in summer and a lifespan of two years. In spite of its very specialized biotope, the life cycle and reproductive strategy of A. album do not deviate substantially from those of related ubiquitous terrestrial isopods.
In this outdoor activity, learners dig for and collect isopods (sometimes known as "roly-poly bugs" or "potato bugs" and other names). Learners have fun discovering that there are two species of isopodsâpill bugs and sow bugsâwith different body structures and self-defense behaviors. One way they learn is by racing the bugs on a circular track drawn with chalk on asphalt or pavement. Extensions include racing the bugs on other surfaces such as gravel or grass and keeping them in a see-through container for a week to observe their feeding behavior. At the end of the races, or the observation week, isopods should be returned to a natural environment.
Large scale industrial development has taken place in the Coatzacoalcos river estuary, SE Mexico, over the last 32 years, and the area is now regarded as the most polluted coastal area of Mexico. A series of sediment cores were taken from the lower Coatzacoalcos river and the estuary, and the concentrations of trace elements (Zn, Co, Cu, Cr, Ni, Pb, V), major elements (Al, Si, Mn, Fe, Ti, Ca, Mg, Na, K, P) and organic matter determined. Heavy metal concentration seems to be largely dependant on proximity to industrial areas, with highest metal concentrations (particularly for Zn, Ni and Cu) found at Teapa, the most heavily industrialized site, and lowest values found at Jicaro, upstream of the main industrial areas. At all of the sites examined, heavy metals either show a relatively uniform distribution with depth, or subsurface maxima, which reflect changes in sediment composition. There is little evidence for significant early-diagenetic remobilization at any of the sites studied. 210Pb and 137Cs data at Teapa indicate that the sediments have accreted rapidly and may be vigorously mixed, and so these sediment cores cannot be used to reliably reconstruct temporal changes in pollutant input.
Rosales-Hoz, L.; Cundy, A. B.; Bahena-Manjarrez, J. L.
Ten exposed sandy sites covering a range from reflective to dissipative beaches were sampled in south-central Chile to evaluate: (1) spatial changes in species richness, abundance and biomass of the intertidal macroinfauna in response to changes in mean grain size, beach face slope and beach type, and (2) spatial changes in abundance, biomass and body sizes of the most abundant species in response to changes in the physical factors. The number of species, abundance and biomass per beach in general decreased with increasing particle size and beach face slope (steeper beaches) and increased from reflective to dissipative conditions. The best fit for number of species was with Dean's parameter, a measure of beach type, whereas for abundance and biomass the best fits were found with particle size. The isopodExcirolana braziliensis and the anomuran Emerita analoga increased in abundance and biomass towards dissipative conditions, whereas Excirolana hirsuticauda showed the opposite trend in biomass and was significantly larger in beaches with steeper profiles. It is concluded that responses to changes in beach type are more pronounced at community level than within species populations.
Dilute solutions of ethyl alcohol lengthen the free-running period of the endogenous tidal rhythmicity of the isopod, Excirolana chiltoni. One-half percent alcohol increases the period, on the average, by about an hour, and the dosage dependence is apparently linear up to 1% alcohol. Since alcohol has also been shown to slow the circadian leaf-movement rhythm of the bean plant, Phaseolus,
Exposed sandy beaches have been defined as physically stressful environments, so that benthic populations living there are thought to be regulated mainly by physical factors, biological interactions being minimal. However, recent long-term studies indicate that potential intra- and interspecific interactions should also play a role in structuring populations and communities. This paper evaluates the role of sediment characteristics and potential
The digestive tracts of Cylisticus corvexus isopods were homogenized in distilled water and diluted with absolute ethanol and distilled water. The homogenate was extracted, and the extracts were then boiled for five minutes, at which time the precipitated...
Deuterium oxide lengthens the period of the endogenous tidal activity rhythm of the sand-beachisopod, Excirolana chiltoni. Heavy water has also been shown to retard the circadian rhythm of deer mice, when added to the animals' drinking water. The average dosage dependence of the effect can be estimated with high precision for both isopod and mouse, and the two values
At the High Energy Benthic Boundary Layer Experiment (HEBBLE) site (4820 m depth in the western North Atlantic) periods of strong currents and sediment erosion alternate with periods of weak flow and massive deposition. We investigated the impact of this atypical hydrodynamic environment on the isopod fauna by testing for a difference in composition between the HEBBLE site and a tranquil location, the Deep Ocean Mining Environmental Study (DOMES) site A ( ca. 5000 m) in the equatorial Pacific. Epifaunal isopods were significantly less abundant at the HEBBLE site than at the comparison site despite significantly greater total isopod numbers at the HEBBLE site. We suggest that the hydrodynamic regime puts epifaunal isopods at risk, making them rare at the HEBBLE site.
The Madison Cave isopod, Antrolana lira, is a subterranean freshwater crustacean. It belongs to the family Cirolanidae, which consists of mostly marine and a small number of freshwater species. In common with other freshwater cirolanids, A. lira is restri...
... have been reported for ocean, bay, and Great Lakes beaches, but these problems are not limited to ... safety of swimming beaches at rivers and other lakes across the country. A primary goal of the ...
A method is described for assessing the effects of metals on the food consumption rate of isopods from measurements of fecal production. The effects of zinc in the diets of two isopod species, Porcellio scaber and Oniscus asellus, were tested. The metal was fed to the isopods on leaves of field maple (Acer campestre) contaminated with concentrations ranging between 1000
Little is known of the physiology of isopods, and although much work has been done on the osmoregulation of other crustacean groups in both marine and fresh- water environments, the isopods have been rarely studied. The occurrence of related isopod species in marine, fresh-water and terrestrial habitats should provide interesting material for comparative physiological study. Ligia oceanica (L.) is the
Have you ever wondered what sand is made of? Where does it come from? How can we keep our beaches clean? Let's work together using the internet to find out a little bit more about the beach. Web Quest Links Introduction Task Resources Evaluation Conclusion Teacher Guide TASK Dear students, Miss Kaysha was at the beach last week and she saw lots of sand. She wants to know how it got there and what it is made of. She also saw ...
This activity provides students with an in-class practice of landscape interpretation using slides of beaches shown by the instructor. Students view a select number of slides and are asked to classify each beach shown using the Wright and Short Beach Classification: dissipative, reflexive, and intermediate by visually identifying landforms and processes of each beach type. The outcome of this activity is that students have practice identifying landforms and processes and applying their observations and interpretations of geomorphic features and processes for an applied purpose. Designed for a geomorphology course Has minimal/no quantitative component
The Environmental Protection Agency has released data from the third annual National Health Protection Survey of Beaches for the 1999 swimming season. Based on voluntarily returned surveys, the site offers information on water quality at 1,891 beaches in the US. Using an interactive map, users can find out if the water at a selected beach is being monitored, who is responsible for monitoring, and if any advisories or closures have been issued. Initial entries for each beach include basic monitoring information, contact information, and a map. Users can also read the submitted survey form in full. Additional resources at the BEACH Watch site include summary results from the survey, a fact sheet, technical reports and reference, brochures amd pamphlets, a FAQ, and related links.
The white-spotted colour morph of the marine isopod Idotea baltica appears cryptic on the brown alga Fucus vesiculosus with its white-coloured epizoites Electra crustulenta and Balanus improvisus. This study shows that the crypsis of this coloration is achieved through disruptive coloration rather than through background matching. Crypsis through background matching requires that the sizes and the shapes of the pattern
Résumé Des chromosomes sexuels, inconnus jusqu'à présent chez les Isopodes, ont été trouvés dans 4 espèces de la superespèceJaera marina (Janiridae, Asellota). Il s'agit d'un système multiple de chromosomes sexuels, ce qui aboutit à la formation d'un trivalent sexuel dans la méiose femelle. Les femelles — hétérogamétiques — ont la constitution XY1Y2, les mâles étant XX. D'après les données chromosomiques
The Beach Erosion site of the WhyFiles (last mentioned in the August 9, 1996 Scout Report), a project funded by the graduate school of the University of Wisconsin-Madison, has been recently updated. Its newest addition includes a story about the population of the tiny Pacific Island nation of Tuvalu that is preparing to abandon its home due to rising sea levels. The site takes a look at this subject and the resulting increased beach erosion that takes place around the world. Visitors can read about the physical processes of beach erosion, view a QuickTime movie of a house falling into the ocean, and more. The site includes good descriptions, photographs, and links to additional information (although some were broken at the time of this annotation), giving interested readers insight into this widespread phenomenon.
Two miles of beach at Cape Canaveral eroded by construction of a port and jetties was recently restored. Such work in harbors of many cities often disrupts normal flow of sand for many miles along coasts. Brevard County, FL residents now enjoy a 400 ft. wide public beach in an area in imminent danger of destructive erosion just a year previously. Before and after aerial photos show how more than two miles of beach were rebuilt with 2.7 million cubic yards of sand helping abate the erosion problem caused by construction of jetties. NASA volunteered its remote-sensing technology and instrumented aircraft to provide low-altitude color infrared photography about every three months since 1972.
Far from threatening the persistence and geographic extent of red mangrove (Rhizophora mangle) in Florida, wood-boring marine isopods may aid the plant to survive wave action by initiating branching of aerial prop roots. Evidence for a recent, sudden increase in density or range of one such isopod, Sphaeroma terebrans, is anecdotal and weak. Insect damage to mangrove aerial roots even
Daniel Simberloff; Becky Jean Brown; Stuart Lowrie
In order to test three hypotheses on digestive constraints that may have affected the colonization of land by isopods, two marine isopods and one semi-terrestrial species were screened for their ability to oxidize phenolic compounds and digest cellulose in natural and artificial diets. Ligia pallasii (Isopoda: Oniscidea) and Gnorimosphaeroma oregonense (Isopoda: Sphaeromatidea) oxidized dietary phenolics, but Idotea wosnesenskii (Isopoda: Valvifera)
M. Zimmer; J. P. Danko; S. C. Pennings; A. R. Danford; T. Carefoot; A. Ziegler; R. F. Uglow
The purpose of this assessment probe is to elicit students' ideas about weathering, erosion, deposition, and landforms. It is designed to determine if students recognize that sand on a beach may have come from distant mountains and landforms as a result of the weathering of rock, subsequent erosion, and deposition.
Freshly collected samples of Tylos europaeus from Korba beach (northeast of Tunisia) were housed in an environmental cabinet at controlled temperature (18°C?±?.5°C) and photoperiod. Locomotor activity was recorded under two photoperiodic regimens by infrared actography every 20?min by multichannel data loggers. One regimen simulated the natural light-dark cycle on the day of collection, whereas the second imposed a state of continuous darkness on all individuals. Under entraining conditions, the animals displayed rhythmic activity, in phase with the period of darkness, whereas in continuous darkness these isopods exhibited a strong endogenous rhythm with circadian and semidiurnal components at mean periods of ? (h:min)?=?25:09?±?01:02?h and ??=?12:32?±?00:26?h, respectively. Under free-running conditions, this endogenous rhythm showed significant intraspecific variability. PMID:22324555
The Lee County cave isopod, Lirceus usdagalun, is a subterranean freshwater crustacean belonging to the family Asellidae. The family is represented in North America by several ganera, including Caecidotea and Lirceus. While Caecidotea is known to occur in...
Beach profiles from selected Oahu and Maui beaches quantitatively document beach volume variation and change between 1994 and 1999. Along exposed, high-energy beaches, large fluctuations in beach volume, characterized primarily by the formation and erosion of extensive berms, dominate the seasonal changes. Beaches along more protected stretches of coastline show much less variation in profile morphology. Beaches on the west (leeward) coast of Oahu experienced the most seasonal variation in profile volume, followed by the north shore, east (windward) shore, and south shore. Similar to Oahu, beaches along the west coast of Maui showed the greatest overall profile variation. However, the mean variation for profiles along a single coastal reach showed little difference compared to other coastal segments. Although some beaches showed net gain or loss during the study period, most beaches remained relatively stable with change limited to a finite envelope. No island-wide trends in beach erosion or accretion were observed during the study period. However, no extreme events, such as tropical storms or hurricanes, directly influenced the Hawaiian Islands during the study period. This data set should therefore be considered as representative of typical annual beach activity. Greater variation and possible long-term change would be expected during extreme events.
Most isopod crustaceans in the North Atlantic deep sea belong to the suborder Asellota. In contrast, South Atlantic isopod faunas have a significant component of flabelliferan isopods, a phylogenetic clade that contains suborders derived evolutionarily later than the Asellota. The flabelliferans decrease diversity from shallow water to deep water and on a south-to-north latitudinal gradient. Although many asellote families are
The supralittoral environment, at the transition between sea and land, is characterized by harsh conditions for life. Nonetheless, evolution of terrestrial isopods (Oniscidea), the only group of Crustacea fully adapted to live on land, appears to have involved a transitional step within the supralittoral. The two most basal oniscidean lineages (Ligiidae and Tylidae) have representatives that successfully colonized the supralittoral. One of them is the genus Tylos, which is found exclusively in supralittoral sandy beaches from tropical and subtropical coasts around the world. Comprehensive phylogenetic hypotheses for this genus are lacking, which are necessary for understanding the evolution and biogeography of a lineage that successfully diversified in the harsh sea-land interface. Herein, we studied the phylogenetic relationships among 17 of the 21 currently recognized species of the genus Tylos, based on sequences from four mitochondrial genes (Cytochrome Oxidase I, Cytochrome b, 16S rDNA, and 12S rDNA). Maximum Likelihood and Bayesian phylogenetic analyses identified several lineages with deep divergences and discrete geographic distributions. Phylogenetic and distributional patterns of Tylos provide important clues on the biogeography and evolution of this group. Large divergences among the most basal clades are consistent with ancient splits. Due to the biological characteristics of Tylos, which likely prevent dispersal of these isopods across vast oceanic scales, we argue that tectonic events rather than trans-oceanic dispersal explain the distribution of Tylos in different continents. Overwater dispersal, however, likely enabled range expansions within some basins, and explains the colonization of volcanic oceanic islands. Present-day distributions were also likely influenced by sea level and climate changes. High levels of allopatric cryptic genetic differentiation are observed in different regions of the world, implying that the dispersal abilities of Tylos isopods are more limited than previously thought. Our results indicate that a taxonomic revision of this group is necessary. PMID:24736501
Hurtado, Luis A; Lee, Eun J; Mateos, Mariana; Taiti, Stefano
The supralittoral environment, at the transition between sea and land, is characterized by harsh conditions for life. Nonetheless, evolution of terrestrial isopods (Oniscidea), the only group of Crustacea fully adapted to live on land, appears to have involved a transitional step within the supralittoral. The two most basal oniscidean lineages (Ligiidae and Tylidae) have representatives that successfully colonized the supralittoral. One of them is the genus Tylos, which is found exclusively in supralittoral sandy beaches from tropical and subtropical coasts around the world. Comprehensive phylogenetic hypotheses for this genus are lacking, which are necessary for understanding the evolution and biogeography of a lineage that successfully diversified in the harsh sea-land interface. Herein, we studied the phylogenetic relationships among 17 of the 21 currently recognized species of the genus Tylos, based on sequences from four mitochondrial genes (Cytochrome Oxidase I, Cytochrome b, 16S rDNA, and 12S rDNA). Maximum Likelihood and Bayesian phylogenetic analyses identified several lineages with deep divergences and discrete geographic distributions. Phylogenetic and distributional patterns of Tylos provide important clues on the biogeography and evolution of this group. Large divergences among the most basal clades are consistent with ancient splits. Due to the biological characteristics of Tylos, which likely prevent dispersal of these isopods across vast oceanic scales, we argue that tectonic events rather than trans-oceanic dispersal explain the distribution of Tylos in different continents. Overwater dispersal, however, likely enabled range expansions within some basins, and explains the colonization of volcanic oceanic islands. Present-day distributions were also likely influenced by sea level and climate changes. High levels of allopatric cryptic genetic differentiation are observed in different regions of the world, implying that the dispersal abilities of Tylos isopods are more limited than previously thought. Our results indicate that a taxonomic revision of this group is necessary.
Hurtado, Luis A.; Lee, Eun J.; Mateos, Mariana; Taiti, Stefano
Resource Purpose: The annual Beach Survey is designed to gather information about beach water quality, standards, monitoring, and beach health advisories or closures issued during the previous year's bathing season. Each year the survey updates previously submitted beach i...
Nineteen intermediate exposed sandy beaches, located along the northern coast of Spain, were sampled during the summer 1999. Data from 10 of the beaches, located at the eastern part of this coast, were previously reported to evaluate environmental factors affecting benthic macrofauna. Data from nine of the beaches, located at the western part of this coast, were included to compare community structure and intertidal zonation of the macroinfauna on intermediate sandy beaches in temperate latitudes. Morphodynamic parameters such as Dean's parameter ( ?), Beach State Index (BSI) and relative tide range (RTR) were estimated at each beach. Beach length, width, intertidal slope, medium grain size, sorting, swash amplitude and wave characteristics were also analyzed. The highest macroinfaunal densities and biomass occurred at the mid and lower shore levels of each beach. Crustaceans, mainly cirolanid isopods, were the dominant group found on these beaches, whereas molluscs were the least representative. In general, the relationship between community structure and beach morphodynamics was similar to that found for the macroinfauna worldwide suggesting that macroinfauna in intermediate sandy beaches is affected, in the same way, by the physical processes associated with different beach types. Histograms and kite diagrams representing the intertidal distribution of the macroinfauna and multivariate analysis were used to show the zonation pattern on these exposed beaches. Intertidal slope values and beach profile pattern were found similar in all the beaches sampled. We hypothesized that this particular beach profile could influence the pattern of macroinfauna zonation. All the 19 beaches have two zones in common: the supralittoral zone of air breathers present on all shores at and above the drift line and the littoral zone extending from the drift line down the midshore to just above the water table outcrop. Ordination analyses identified two possible zones within the lower beach levels on seven of the beaches, but this cannot be clearly established. The Monte Carlo permutation test was used to select beach slope, length and wave height as the best predictor variables of macroinfaunal characteristics and it seems that the species most affected by the main variables showed the clearest zonation on the beaches.
Baterial samples were taken at swimming beaches (primarily freshwater beaches) in Region 10 while evaluating potential bacterial sources (e.g., people, cattle, pets, septic systems, runoff, birds). For each beach selected, the preferred sampling is: background, low/no use period...
The antennal tips of the isopod Ligia oceanica each bear approximately one hundred specialized sensory hairs. Their structure has been analysed by scanning and transmission electron microscopy and electrophysiological methods used to investigate some of their functions. Each hair has a double outer sheath protecting the inner structures which are only in contact with the external environment through a laterally
Environmental pollution by toxic metals is widespread in urban areas. In contrast to many industrialized sites, however, metal pollution in most urban regions occurs at low or moderately elevated levels. Reliable criteria of environmental quality have therefore to be established, with the consequence that there is an increasing need for sensitive monitoring of pollution. In this present study, the isopod
Reinhard Dallinger; Burkhard Berger; Stefan Birkel
Laboratory determination of temperature stress levels and assessment of their ecological consequences was carried out for selected zooplankton species to develop data for ecological impact associated with industrial use of natural water for cooling. An included literature search revealed substantial fish and benthos data, but little on stress temperature effects on zooplankton. Information was gathered on two cladocerans, four copepods and an isopod.
During our researches on systematics and ecology of terrestrial isopods, carried out in western Sicily, some specimens showing a blue-purple coloration were collected; they belonged to four species: Armadillidium decorum Brandt, 1833, Trichoniscus panormidensis Montesanto et al., 2011, Philoscia affinis Verhoeff, 1908, Porcellio siculoccidentalis Viglianisi et al., 1992. We hypothesized that such coloration could be due, as reported in literature, to characteristic paracrystalline arrays of virions inside the tissues of blue colored specimens. Ultrastructural observations by transmission electron microscopy, on tissues of A. decorum, showed the presence of electron-dense viral particles, with a diameter of nearly 0.12?m. Dual-axis tomography, performed on specimens of A. decorum, evidenced an icosahedral structure of viral particles matching with that of Isopod Iridescent Virus (IIV). Molecular analysis, on 254bp portion of the major capsid protein (MCP) gene, allowed to place the virus into IIV-31 group, already known for other oniscidean species. The symptoms of infected individuals and the course of the disease were followed in laboratory, indicating similarities with other studies on Isopod Iridoviruses. Moreover, some notes on reproduction of infected ovigerous females are reported. Our data support unequivocal and direct evidences for the first case of IIV infection in terrestrial isopods reported in Italy. PMID:23756498
Several times per year, the High Energy Benthic Boundary Layer Experiment (HEBBLE) site (4820 m depth, 40°27'N 62°20'W) experiences benthic storms during which near-bottom flows can erode millimeters of sediment. Thistle and Wilson ( Deep-Sea Research, 34 1987, 73-87) predicted that isopods that inhabited the surface of the sediment would be relatively rare at the HEBBLE site compared to those at quiescent deep-sea sites. They tested this prediction by comparing the composition of the HEBBLE isopod fauna to that of a quiescent site and found a significant difference in the predicted direction. Although this result was encouraging, the strength of their inference was limited because only one site from each type of environment had been compared. We performed a second test of Thistle and Wilson's hypothesis by comparing the composition of the isopod fauna from two additional physically quiescent locations (4500 m depth, 14°40'N 125°26'W, and 4800 m depth, 12°57'N 128°19.5'W) to that of the HEBBLE site. Those isopods that are thought to be exposed to the erosion caused by storms occurred in a significantly greater proportion of the samples at the quiescent sites than at the HEBBLE site, a result consistent with Thistle and Wilson's hypothesis.
Identifying mechanisms behind assortative mating is central to the understanding of ecological divergence and speciation. Recent studies show that populations of the freshwater isopod Asellus aquaticus can rapidly become locally differentiated when submerged Chara vegetation expands in lakes. In the novel Chara habitat, isopods have become lighter pigmented and smaller than in ancestral reed stands. In this study, we used a laboratory multiple-choice experiment to investigate assortative mating as a possible prezygotic reproductive barrier between Chara and reed isopods. Mating was assortative when Chara isopods were experimentally mixed with isopods from an adjacent reed site with large-size individuals, suggesting a partial prezygotic reproductive barrier. No deviation from random mating could, however, be detected when Chara isopods were mixed with smaller sized isopods from another reed site. In both experiments, assortative mating was apparently based on size, as Chara isopods were larger and reed isopods smaller in mixed pairs than in assortative pairs. Pigmentation did not have any clear influence on mating. We suggest that divergence in pigmentation evolved through natural selection in conjunction with size-assortative mating indirectly causing assortative mating between Chara and reed isopods. Size-assortative mating is likely a by-product of natural selection, but its importance may hypothetically be transient, if selection erodes the correlation between pigmentation and size over time. PMID:17040388
The cirolanid isopod Cirolana harfordi is described as a scavenger and a predator that lives in the intertidal region. In order to understand the microanatomy of the mouthparts and the setae that allow this animal to handle and eat its food, a scanning electron microscopy study was conducted. C. harfordi displays a variety in the types of setae distributed on its mouthparts in a site-specific fashion, including complex setae placed on the medial edge of the maxilliped and maxilla. Terminal pores in some setae were found to contain a cupule, which is a hemispherical structure, housed in the concave recess of the pore, which demonstrates that the pore is more than merely a thinning of the cuticle as has been proposed. Future studies on setal morphology are needed for comparative microanatomy of cirolanid isopods. PMID:24032633
Summary Energetics of the populations of three isopods,Armadillidium vulgare, Porcellio scaber andLigidium japonicum were studied in a warm-temperate evergreen broadleaved forest of Mt. Kiyosumi in central Japan. The study deals with age\\u000a composition, survivorship curves, relations of body size to number of eggs or young, and mean growth curves of the populations.\\u000a Respiratory rates, calorific values and food consumptions of the
Data on isopods processed by the author and the literature available on the subject have made it possible to provide specific lists of isopods for coastal zones of cold and cold-temperate regions in both hemispheres and for isopods from depths of more than 2000 m for the entire World Ocean. A comparative analysis shows both faunas to be very similar
The in vivo effects of parathion and endosulfan on the isopod Porcellio dilatatus were investigated. Feeding parameters (food consumption and assimilation rates), growth, and energy reserves (glycogen, lipid, and protein contents) of pesticide-exposed isopods were compared with those of control animals. Isopods were exposed to a wide range of concentrations of parathion or endosulfan (0.1, 1, 10, 25, 50, 100,
Sónia Ribeiro; J. P. Sousa; A. J. A. Nogueira; A. M. V. M. Soares
The flora, vegetation, and microenvironment of beach and dune are sufficiently different to warrant their separate treatment in this chapter. Beach is defined here as the expanse of sandy substrate between mean tide and the foredune or, in the absence of ...
The hypothesis that faeces recycling in isopods evolved as an adaption to facilitate maintenance of an adequate copper balance in terrestrial environments is examined. Experimental observations on the consumption, absorption and growth rates of Porcellio scaber fed Betula pendula leaf litter varying in copper content and extent of microbial decay are reported. Preventing the isopods from reingesting their faeces caused
The comparative biology of four species of fresh-water isopods was investigated. Isopods are known to be part of the 'pollution fauna' that can inhabit badly polluted areas. The species studies inhabit a temporaty pond, a drainage ditch, a small permanent...
Terrestrial isopods are suitable invertebrates for testing the relative toxicities of chemicals present in the terrestrial environment. Terrestrial isopods respond in numerous ways to elevated concentrations of chemicals in their food, but only a few of these responses can be used as toxicological endpoints. The most suitable are changes in reproduction, food consumption, moult cycle duration, and structure of the
The influence of mode of life and habitat characteristics on the evolution of body size in isopods was investigated in a comparative analysis based on data from 746 free-living and parasitic species. The phylogeny of isopods allowed 24 independent comparisons to be made between higher taxa (families or superfamilies), each corresponding to a separate branching event. The evolution of parasitism
Most of the year the isopod crustacean Hemilepistus reaumuri depends for survival on the protection of a permanent shelter (i.e., the burrow occupied by its family), despite its remarkable physiological adaptations to its desert habitat. If an isopod gets lost after an excursion from the burrow, it has to find it as quickly as possible.
The indirect contribution terrestrial isopods make to decomposition processes by stimulating microbial activites has been quantified in laboratory experiments. The extent to which microbial metabolism is enhanced as a result of the passage of Betula pendula leaf litter through the alimentary system of isopods was measured for both freshly fallen and decayed leaves. Faeces derived from 1 g freshly fallen
Eutrophication of shallow coastal waters often leads to blooms of macroalgae. Grazing by crustaceans, such as amphipods and isopods, can reduce macroalgal biomass accumulation. At the same time, growth of the macroalgae can be stimulated by epiphyte removal. The role of grazing by isopods and amphipods on Ulva spp. biomass development was investigated in the Veerse Meer, a brackish lagoon
Pauline Kamermans; Erik-Jan Malta; Jacobus M. Verschuure; Lonneke Schrijvers; L. Franca Lentz; Angela Tjin A. Lien
Terrestrial isopods are widely infected with Wolbachia. However, little is known about the presence of bacteria in the Neotropical species. The objective of this study was to test the hypothesis of presence of Wolbachia infection in the native species of terrestrial isopods, Atlantoscia floridana and Circoniscus bezzii, and in the introduced species Burmoniscus meeusei.
Beach locational data for BEACH Act. Beach locations are coded onto route.drain (Transport and Coastline Reach) feature of NHD to create Point Events and Linear Events. Beach locations are coded onto region.rch (Waterbody Reach) feature of NHD to create NHD Waterbody Shapefiles...
This annual Surfrider Foundation report surveys the state of the beaches in coastal and Great Lakes states that are home to Foundation chapters. Each state is rated based on the availability of information and status of eight indicators, including beach access, Website access, surf zone water quality, and beach erosion, among others. The report is written from the perspective of a "concerned local citizen" and aimed at "the people who use and care most about this precious resource." The online report contains six sections, including an executive summary, an explanation of the indicators, conclusions, and recommendations.
Hydrologic and beach dynamics studies were conducted in and near Rookery Bay Sanctuary south of Naples on the southwest coast of Florida. These studies determined water exchange rates, tidal range variations, the characteristics of the tidal prism, bottom...
\\u000a This chapter summarizes the rationale for using microbial source tracking (MST) methods at beach sites and coastal water bodies\\u000a (Sect. 20.1), as MST methods are especially useful for evaluating waters impacted by nonpoint sources of pollution. This chapter\\u000a also describes the most common traditional and alternative MST markers used at beach sites (Sect. 20.2). Two case studies\\u000a are presented (Sect.
Helena M. Solo-Gabriele; Alexandria B. Boehm; Troy M. Scott; Christopher D. Sinigalliano
A method of separating oil and other floatatable debris from the sand on a beach by localized flooding of the beach is disclosed. Suitable large diameter conduits are provided to introduce large quantities of water to a selected area of the beach, the water mixing with the sand and causing oil and other debris on or buried in the sand to float, and thus to rise toward the surface of the sand. A second flooding operation refloats the debris and a skimmer mechanism then removes the floating oil and other material while allowing the water to return to the beach area. The water supply is provided by means of suitable conduits carried by a truck, tractor, or other beach vehicle. In the preferred embodiment, the water required for flooding is obtained from the ocean by an extension of the supply conduits, with the forward motion of the tractor providing the required water flow through the conduits to the area to be cleaned. Alternatively, the desired water flow can be obtained by means of a low lift pump in the conduits, the pumps being hydraulically operated from the beach vehicle. The first flooding operation provides water to move the oil and other debris toward a center line, while the second provides water to refloat the material in the vicinity of the intake for the skimmer.
The problems involved in the interaction between waves and beaches are complex and it is not yet possible to predict on empirical grounds, let alone theoretical grounds, the shape of a beach after it is subjected to given wave conditions. This investigation began as a study of the use of crushed coal as a model beach material to represent natural beaches of quartz sand but subsequently developed into a more general study of the processes which determine the shape of beach profiles formed in beach materials with different permeabilities.
Dr. Stephen Leatherman, professor and director of the Laboratory for Coastal Research at the University of Maryland, College Park, has released his annual list of America's best beaches. "Dr. Beach" considered fifty different factors, including current, wave size, smell, views and vistas, and intensity of beach use, to rate the twenty finest public beaches of 650 nation wide. This site features photos of the winners, a complete list of the Beach Rating Scale Criteria, and Dr. Leatherman's selections for the five best Walking, Wild, and Romantic Beaches.
Coastal erosion is widespread and locally severe in Hawaii and other low-latitude areas. Typical erosion rates in Hawaii are in the range of 15 to 30 cm/yr (0.5 to 1 ft/yr; Hwang, 1981; Sea Engineering, Inc., 1988; Makai Ocean Engineering, Inc. and Sea Engineering, Inc.,1991). Recent studies on Oahu (Fletcher et al., 1997; Coyne et al., 1996) have shown that nearly 24%, or 27.5 km (17.1 mi) of an original 115 km (71.6 mi) of sandy shoreline (1940's) has been either significantly narrowed (17.2 km; 10.7 mi) or lost (10.3 km; 6.4 mi). Nearly one-quarter of the islands' beaches have been significantly degraded over the last half-century and all shorelines have been affected to some degree. Oahu shorelines are by far the most studied, however, beach loss has been identified on the other islands as well, with nearly 13 km (8 mi) of beach likely lost due to shoreline hardening on Maui (Makai Engineering, Inc. and Sea Engineering, Inc., 1991). Causes of coastal erosion and beach loss in Hawaii are numerous but, unfortunately, poorly understood and rarely quantified. Construction of shoreline protection structures limits coastal land loss, but does not alleviate beach loss and may actually accelerate the problem by prohibiting sediment deposition in front of the structures. Other factors contributing to beach loss include: a) reduced sediment supply; b) large storms; and, c) sea-level rise. Reduction in sand supply, either from landward or seaward (primarily reef) sources, can have a myriad of causes. Obvious causes such as beach sand mining and emplacement of structures that interrupt natural sediment transport pathways or prevent access to backbeach sand deposits, remove sediment from the active littoral system. More complex issues of sediment supply can be related to reef health and carbonate production which, in turn, may be linked to changes in water quality. Second, the accumulated effect of large storms is to transport sediment beyond the littoral system. Third, rising sea level leads to a natural landward migration of the shoreline. Dramatic examples of coastal erosion, such as houses and roads falling into the sea, are rare in Hawaii, but the impact of erosion is still very serious. The signs of erosion are much more subtle and typically start as a "temporary" hardening structure designed to mitigate an immediate problem which, eventually, results in a proliferation of structures along a stretch of coast. The natural ability of the sandy shoreline to respond to changes in wave climate is lost. The overall goals of this study are to document the coastal erosion history in Hawaii, determine the causal factors of that erosion, provide high-quality data for other "end-users" in applied studies (i.e. coastal engineers, planners, and managers), and increase our general understanding of low-latitude coastal geologic development. This project involves close cooperation between the USGS Coastal and Marine Geology Program and the University of Hawaii.
Gibbs, Ann E.; Richmond, Bruce M.; Fletcher, Charles H.; Hillman, Kindra P.
In crustaceans, the androgenic gland (AG), thanks to the synthesis of the androgenic gland hormone (AGH), controls the differentiation of the primary and secondary male sexual characters. In this study, we amplified 12 new AGH cDNAs in species belonging to five different families of the infra-order Ligiamorpha of terrestrial isopods. Putative essential amino acids for the production of a functional AGH protein exhibit signatures of negative selection and are strictly conserved including typical proteolytic cleavage motifs, a putative N-linked glycosylation motif on the A chains and the eight Cys positions. An insulin-like growth factor motif was also identified in Armadillidium AGH sequences. The phylogenetic relationships of AGH sequences allowed one to distinguish two main clades, corresponding to members of the Armadillidiidae and the Porcellionidae families which are congruent with the narrow specificity of AG heterospecific grafting. An in-depth understanding of the regulation of AGH expression would help deciphering the interaction between Wolbachia, widespread feminizing endosymbiotic bacteria in isopods, and the sex differentiation of their hosts. PMID:24561051
Cerveau, Nicolas; Bouchon, Didier; Bergès, Thierry; Grève, Pierre
Safe beaches meet water quality standards and are valued for their aesthetics and the recreational opportunities that they afford. In the United States recreational water quality assessments and beach closure decisions are presently based on samples of enterococci or Escherichia ...
The purpose of this report is to synthesize information about the geomorphology and dynamics of Puget Sound's beaches. It summarizes important peer-reviewed literature relevant to these beach environments and assemblies background information that should ...
The Great Lakes Information Network developed this website to "broadcast critical information about beach closings and educational content on human health concerns." The website provides the latest news on erosion control projects, contamination and cleanup efforts, beach testing efforts, and other environmental news. Users can explore monitoring data and maps by location. The website also contains the proceedings from the Great Lakes Beach Conferences from 2001 and 2002 and the US EPA's Beach Program activities.
Virtual Beach version 3 (VB3) is a decision support tool that constructs site-specific statistical models to predict fecal indicator bacteria (FIB) concentrations at recreational beaches. VB3 is primarily designed for beach managers responsible for making decisions regarding beac...
The quantitative significance of bacterial biomass in the nutrition of detritivores remains equivocal. We have used tritiated thymidine to specifically label stable macromolecules in natural assemblages of sediment-associated and detritus-associated bacteria. This material was presented to the isopod (Lirceus sp.) and incorporation of bacterial biomass measured. The isopod incorporated roughly 1 ng bacterial carbon (mg wet wt.)-1 h-1 from leaf
In two species of isopods (mainlyTracheoniscus rathkei, plus a fewOniscus asellus) total copper content as well as the amount of copper extractable with zinc-dibenzyldithiocarbamate in CCl4 (CTC) were determined. Both copper fractions show near perfect relationship with total copper concentration of the litter collected in the isopods' habitats. Between copperrich and copper-poor sites in Tirol, Austria, mean total copper content
The crustacean order Isopoda (excluding Asellota, crustacean symbionts and freshwater taxa) comprise 3154 described marine species in 379 genera in 37 families according to the WoRMS catalogue. The history of taxonomic discovery over the last two centuries is reviewed. Although a well defined order with the Peracarida, their relationship to other orders is not yet resolved but systematics of the major subordinal taxa is relatively well understood. Isopods range in size from less than 1 mm to Bathynomus giganteus at 365 mm long. They inhabit all marine habitats down to 7280 m depth but with few doubtful exceptions species have restricted biogeographic and bathymetric ranges. Four feeding categories are recognised as much on the basis of anecdotal evidence as hard data: detritus feeders and browsers, carnivores, parasites, and filter feeders. Notable among these are the Cymothooidea that range from predators and scavengers to external blood-sucking micropredators and parasites. Isopods brood 10–1600 eggs depending on individual species. Strong sexual dimorphism is characteristic of several families, notably in Gnathiidae where sessile males live with a harem of females while juvenile praniza stages are ectoparasites of fish. Protandry is known in Cymothoidae and protogyny in Anthuroidea. Some Paranthuridae are neotenous. About half of all coastal, shelf and upper bathyal species have been recorded in the MEOW temperate realms, 40% in tropical regions and the remainder in polar seas. The greatest concentration of temperate species is in Australasia; more have been recorded from temperate North Pacific than the North Atlantic. Of tropical regions, the Central Indo-Pacific is home to more species any other region. Isopods are decidedly asymmetrical latitudinally with 1.35 times as many species in temperate Southern Hemisphere than the temperate North Atlantic and northern Pacific, and almost four times as many Antarctic as Arctic species. More species are known from the bathyal and abyssal Antarctic than Arctic GOODS provinces, and more from the larger Pacific than Atlantic oceans. Two areas with many species known are the New Zealand-Kermadec and the Northern North Pacific provinces. Deep hard substrates such as found on seamounts and the slopes are underrepresented in samples. This, the documented numbers of undescribed species in recent collections and probable cryptic species suggest a large as yet undocumented fauna, potentially an order of magnitude greater than presently known.
Sound Beach Soccer Club, our local travel club of the Long Island Junior Soccer League, is proud to bring you the 2009 Summer Soccer Camp. For the 4th year running, the camp will once again be held at the North Shore Heritage Park (\\
Predicted changes in soil water availability regimes with climate and land-use change will impact the community of functionally important soil organisms, such as macro-detritivores. Identifying and quantifying the functional traits that underlie interspecific differences in desiccation resistance will enhance our ability to predict both macro-detritivore community responses to changing water regimes and the consequences of the associated species shifts for organic matter turnover. Using path analysis, we tested (1) how interspecific differences in desiccation resistance among 22 northwestern European terrestrial isopod species could be explained by three underlying traits measured under standard laboratory conditions, namely, body ventral surface area, water loss rate and fatal water loss; (2) whether these relationships were robust to contrasting experimental conditions and to the phylogenetic relatedness effects being excluded; (3) whether desiccation resistance and hypothesized underlying traits could explain species distribution patterns in relation to site water availability. Water loss rate and (secondarily) fatal water loss together explained 90% of the interspecific variation in desiccation resistance. Our path model indicated that body surface area affects desiccation resistance only indirectly via changes in water loss rate. Our results also show that soil moisture determines isopod species distributions by filtering them according to traits underpinning desiccation resistance. These findings reveal that it is possible to use functional traits measured under standard conditions to predict soil biota responses to water availability in the field over broad spatial scales. Taken together, our results demonstrate an increasing need to generate mechanistic models to predict the effect of global changes on functionally important organisms. PMID:23224790
Dias, André T C; Krab, Eveline J; Mariën, Janine; Zimmer, Martin; Cornelissen, Johannes H C; Ellers, Jacintha; Wardle, David A; Berg, Matty P
Beloniform fishes are infested by cymothoid isopods on the body surface, in the gill chambers, and in the mouth. Only flying fishes have these isopods on the body surface: Nerocila exocoeti Pillai, 1954, on Exocoetus brachypterus, and Nerocila trichiura (...
...Zone; Cocoa Beach Air Show, Atlantic Ocean, Cocoa Beach, FL AGENCY: Coast...safety zone on the waters of the Atlantic Ocean located east of Cocoa Beach...in aerobatic maneuvers over the Atlantic Ocean east of Cocoa Beach,...
Studies of microbial associations of intertidal isopods in the primitive genus Ligia (Oniscidea, Isopoda) can help our understanding of the formation of symbioses during sea-land transitions, as terrestrial Oniscidean isopods have previously been found to house symbionts in their hepatopancreas. Ligia pallasii and Ligia occidentalis co-occur in the high intertidal zone along the Eastern Pacific with a large zone of range overlap and both species showing patchy distributions. In 16S rRNA clone libraries mycoplasma-like bacteria (Firmicutes), related to symbionts described from terrestrial isopods, were the most common bacteria present in both host species. There was greater overall microbial diversity in Ligia pallasii compared with L. occidentalis. Populations of both Ligia species along an extensive area of the eastern Pacific coastline were screened for the presence of mycoplasma-like symbionts with symbiont-specific primers. Symbionts were present in all host populations from both species but not in all individuals. Phylogenetically, symbionts of intertidal isopods cluster together. Host habitat, in addition to host phylogeny appears to influence the phylogenetic relation of symbionts.
Interdisciplinary coastal education program from Surfrider Foundation incorporates science processes, oceanography, watershed ecology and environmental awareness in lessons for K-12 students and community groups. Include: teaching guides, classroom lectures, handouts, video, hands-on projects. Beachology, for grades K-6, studies sand processes, beach ecology, human impacts. Watershed Works, for grades 5-12, explains links between coast and watershed. The Snowrider Project educates alpine communities about hydrologic cycle. Available online as PDF documents.
Beach ridges are landforms commonly developed on prograded coasts with beach shorelines. A sequence of beach ridges, coupled with their subsurface deposits, can be regarded as a time series of coastal evolution. Methodological advances in field surveying and chronology applicable to beach ridges have led to detailed palaeoenvironmental reconstructions to be derived from such sequences. This paper reconsiders the basic aspects of beach ridges and deposits, which need to be properly understood for their comprehensive interpretation in a palaeo-environmental context. It also reviews case studies in which beach-ridge sequences have been used to unveil past sea-level history, catastrophic events, and climate changes. Proposed formative processes of beach ridges include: 1) progradation of sandy beach and berm formations in relation to fairweather waves, coupled with aeolian foredune accumulation; 2) building of gravel ridges by storm waves; 3) welding of longshore bars. Beach-ridge formation through sea-level oscillation is thought to be questionable and caution is suggested for this process when undertaking palaeoenvironmental reconstruction. Beach deposit stratification is known to dip either landwards or seawards, but landward dips are uncommon. Seaward dipping stratification is formed in relation to beachface progradation, and is usually dissected in places by erosion surfaces resulting from episodic beach retreat. The boundary between the foreshore and the underlying shoreface is well defined only in the case that longshore bars lead to complex bedding structure relative to that of the foreshore. Reliable chronology of beach ridges can be determined by radiocarbon and optically-stimulated luminescence (OSL) dating. Radiocarbon dating of articulated shells, which are considered not to be extensively reworked, provides robust results, but OSL dating is more useful as it enables direct dating of sediment grains. It is noted that there are restrictions in chronological resolution and continuity inherent to beach ridge and beach deposits. The plan-view geomorphic expression of beach ridges typically consists of ridge sets with multi-decadal intervals, whereas their internal sedimentary structures define shorter time scales. Records of beach sedimentation and erosion are likely to be reworked by episodic high-magnitude beach retreat, and the resultant record of the net progradation is likely to be sporadic and discontinuous. The height of sandy beach ridges is often variable due to differing degrees of aeolian sand accumulation, and they are thus not used as sea-level indicators unless purely wave-built. Gravel ridge height is a relatively reliable indicator of sea level, but can vary in response to storminess fluctuations. Subsurface sediment facies boundaries are preferred as sea-level indicators, and those proposed include: boundaries of aeolian/beach, foreshore/shoreface, and upper/lower shorefaces. Catastrophic events are expressed in both erosional and depositional records. Erosion surfaces, or scarp imprints, revealed in a cross section of beach deposits, indicate storm or tsunami events. However, erosional events are likely to rework previous records of sedimentation and even other erosional events, and thus the apparent history decoded from the resultant deposits tends to be biased. Several attempts for estimating the frequency and intensity of prehistoric cyclones rely on assumed relationships between the level of coarse sand beach ridges and cyclone inundation. The formative process of coarse sand ridges remains uncertain and needs to be clarified, as it constitutes the fundamental basis of these attempts. The growth rates of beach-ridge systems are expected to reflect fluctuations in river sediment discharge to the coast and in aeolian sand flux due to onshore winds, both of which are affected by climate change. Assessment of the growth rate is potentially improved by ground-penetrating radar survey of subsurface structure and by detailed chronology. Orientation of beach ridges reflects long-term trends in wave dir
Many boring isopods inhabit positively buoyant substrata (wood and algae), which float after detachment, permitting passive migration of inhabitants. Based on observations from previous studies, it was hypothesized that juvenile, subadult and male isopods migrate actively, and will rapidly abandon substrata after detachment. In contrast, reproductive females and small offspring were predicted to remain in floating substrata and thus have a high probability to disperse passively via rafting. In order to test this hypothesis, a colonization and an emigration experiment were conducted with giant kelp ( Macrocystis integrifolia), the holdfasts of which are inhabited by boring isopods from the genus Limnoria. A survey of benthic substrata in the kelp forest confirmed that limnoriids inhabited the holdfasts and did not occur in holdfast-free samples. Results of the colonization experiment showed that all life history stages of the boring isopods immigrated into young, largely uncolonized holdfasts, and after 16 weeks all holdfasts were densely colonized. In the emigration experiment, all life history stages of the isopods rapidly abandoned the detached holdfasts — already 5 min after detachment only few individuals remained in the floating holdfasts. After this initial rapid emigration of isopods, little changes in isopod abundance occurred during the following 24 h, and at the end of the experiment some individuals of all life history stages still remained in the holdfasts. These results indicate that all life history stages of Limnoria participate in both active migration and passive dispersal. It is discussed that storm-related dynamics within kelp forests may contribute to intense mixing of local populations of these burrow-dwelling isopods, and that most immigrants to young holdfasts probably are individuals emigrating from old holdfasts detached during storm events. The fact that some individuals of all life history stages and both sexes remain in floating holdfasts suggests that limnoriids could successfully reproduce during rafting journeys in floating kelp, facilitating long-distance dispersal. We propose that the coexistence of different modes of dispersal (short distance local migrations and long-distance regional dispersal) within these kelp-dwelling isopods might be advantageous in an environment where unpredictable El Niño events can cause extinction of local kelp forests.
Visiting the beach is a popular tourist activity worldwide. Unfortunately, the beach environment is abundant with hazards and potential danger to the unsuspecting tourist. While the traditional focus of beach safety has been water safety oriented, there is growing concern about the risks posed by the sand environment on beaches. This study reports on the death and near death experience of eight tourists in the collapse of sand holes, sand dunes, and sand tunnels. Each incident occurred suddenly and the complete burial in sand directly contributed to the victims injury or death in each case report. PMID:23290717
Most isopod crustaceans in the North Atlantic deep sea belong to the suborder Asellota. In contrast, South Atlantic isopod faunas have a significant component of flabelliferan isopods, a phylogenetic clade that contains suborders derived evolutionarily later than the Asellota. The flabelliferans decrease diversity from shallow water to deep water and on a south-to-north latitudinal gradient. Although many asellote families are endemic to the deep sea, none of the flabelliferan families appear to have evolved in the abyss. Recent colonisations of the deep sea, which may have been limited to the southern hemisphere by oceanographic conditions, have significant consequences for observed regional diversities of some taxa. Instability in oceanographic conditions owing to glaciation and benthic storms may have further limited benthic species richness of the North Atlantic deep-sea benthos.
The heart of animals is regulated through the central nervous system in response to external sensory stimuli. We found, however, that the adult neurogenic heart of the isopod crustacean Ligia exotica has photosensitivity. The beat frequency of the isolated heart decreased in response to a light stimulus. Magnitude of the response was stimulus intensity dependent and the heartbeat frequency decreased to less than 80% of the dark value during illumination of the white light with an intensity of 6.0?mW?cm?2. The spectral sensitivity curve of the heart photoresponse peaked at a wavelength around 520?nm. In response to 530?nm monochromatic light, the relationship between light intensity and response magnitude was linear and the threshold intensity was 7.26×1012?quanta?cm?2?s?1. Bursting activity of the cardiac ganglion, which is located in the heart and acts as the cardiac pacemaker deceased in frequency in response to illumination by white light. This fact suggests that the heart photoresponse of L. exotica results from the photosensitivity of the cardiac ganglion neurons. The photoresponse of the heart therefore contributes to regulation of cardiac output in addition to other regulatory systems.
The abundance and size composition of stream isopods Lirceus fontinalis were investigated from April 2001 to August 2002 in 3 streams in southern Ontario, Canada. Effects of current speed was released from the analysis by choosing slow flowing water. The effects of substrate, season and water depth on the abundance, distribution and size composition of the isopods were analyzed. It was found that substrate and season influence isopods the most. The rocky substrate with attached filamentous macro-algae contains an isopod abundance 7.05 times that of bare rock substrate and 14.6 times that of fine-sand and mud substrate. There was a large variation with respect to seasonality in both abundance and size composition of the isopods, with the highest abundance occurring in summer and the lowest in winter and spring; individual isopods also tend to be larger in the winter and spring. In all substrates, shallow areas tend to support higher densities of isopods than deeper areas.
Zhao, Xiaoxia; Fox, Michael G.; Lasenby, David C.; Armit, Alexis C.; Kothawala, Dolly N.
A hitherto undescribed association between the valviferan isopod, Edotia doellojuradoi, and the mussel, Mytilus edulis chilensis, in the Falkland Islands (South-west Atlantic) is reported. Isopods were recorded within the mantle cavity of mussels from an estuarine location, Camilla Creek, and from two coastal sites, Goose Green and Darwin. All the mussel populations sampled along the estuary harboured isopods, whereas only those from the low and low-mid shore sites at Darwin and Goose Green were infested. Overall infestation increased between October 1994 and December 1995 from 47, 9 and 2 to 51, 21 and 24% at Camilla Creek, Goose Green and Darwin, respectively. Infestation also increased with decreasing tidal elevation but declined with mussel size. There was no apparent correlation between the occurrence of the isopod and salinity along the estuary at Camilla Creek. Isopod abundance increased with mussel size at all sites and tidal levels, and the largest broods were generally present in mussels from the low shore. Length-frequency distributions of the isopod populations were distinctly bimodal and comprised a prominent mode of males and juvenile individuals, up to 9 mm in size, and a smaller mode containing the adult females, ranging from 5 to 14 mm. Never more than one female was found within any given mussel, and this was always the largest isopod present. No significant differences in condition were observed between mussels that were infested and those that were not.
Beach systems in Pacific Islands are Holocene deposits of reef-dervied and terrigenous sediment. Thus, geologic setting is important in determining the success at which beach systems are established. Generally, older islands exhibit better beach system development. Although modern beach systems are composed of Holocene sediment, development of suitable accommodation space requires more geologic time.
The use of Posidonia oceanica beach wrack by macroinvertebrates of the sandy beach at Burano (Tuscany, Italy) was assessed by following the colonisation dynamics of the wrack and analysing the stable isotopes 'scenario' of the main local carbon and nitrogen sources and consumers. One-hundred experimental cylinders, filled with P. oceanica wrack, were placed on the beach and sampled over a 1-month period. Abundance and species richness of macroinvertebrates in wracks varied through time. Wrack was colonised by crustaceans almost immediately after deployment of the experimental cylinders. The amphipod Talitrus saltator largely dominated the faunal assembly and, together with the isopod Tylos europaeus, occupied the wracks closer to the sealine. These were followed by dipterans, staphylinids, pselaphids and tenebrionids that occurred in drier wracks higher up on the eulittoral. Moisture content of the wrack and sand decreased through space and time. This was the primary factor explaining the spatial and temporal changes observed in macroinvertebrate abundance, with species colonising or abandoning wracks according to thresholds of environmental parameters. Isotopic analysis clearly established the absence of any direct dietary link between P. oceanica wrack and macroinvertebrates. Terrestrial food sources were also discarded. Both our experimental data and a literature search showed that the organic matter from seston as filtered by the sand is the most plausible carbon and nitrogen source for beach food webs. Even if P. oceanica wrack is not a trophic source for macroinvertebrates, it is vitally important as a physical structure that provides detritivorous and predatory species with refuge from environmentally stressful conditions.
Colombini, Isabella; Mateo, Miguel Ángel; Serrano, Oscar; Fallaci, Mario; Gagnarli, Elena; Serrano, Laura; Chelazzi, Lorenzo
This data tip from Bridge, the Ocean Sciences Education Teacher Resource Center archive, explores erosion and accretion of coastal sediments, the two processes that keep our beaches in a constant state of change. Both natural and not-so-natural factors influencing these processes are discussed. Learners can view a variety of weblinks on the topic and conduct their own beach profile investigation, or access profile data from a 1999 Ocean City, Maryland beach and plot the changes over time for a graphic illustration of these processes.
An account is given of the morphology of a new species of Temnocephala, named T. geonoma, associated with the Australian burrowing isopod Phreatoicopsis terricola. The temnocephalids are blind and unpigmented, and have five tentacles. The central tentacle is reduced in size and less mobile than the remainder. The intestine possesses lateral septal partitions. The penis tube has a pronounced curvature,
Variation in the birth size of offspring of the terrestrial isopod, Armadillidium vulgare, was observed in laboratory experiments and in field populations. In the laboratory, larger offspring were produced when the mother's food supply was reduced. In field populations, larger offspring were produced during the summer, a period of reduced food availability. Smaller offspring are produced in the spring, when
The alimentary canal of isopod crustaceans is comparable to that of most other Arthropoda in that three basic regions can be recognized. These are the foregut, derived from the ectodermal stomodaeum and consisting of an oesophagus and pro ventriculus, the endodermal midgut, and an ectodermal hindgut derived from the proctodaeum (Goodrich, 1939) . The midgut, though, is unusual in that
Platinum has been increasing in the environment as a result of emissions from catalytic converters. The platinum emitted is principally located in the vicinity of roads but might be transported to urban rivers through highway and urban run-off water. Platinum concentrations in the freshwater isopod Asellus aquaticus were measured for two urban rivers and a stormwater detention pond. Concentrations ranged
Individuals of the isopod species Porcellio scaber, Oniscus asellus and Philoscia muscorum and the earthworm species Lumbricus rubellus were collected at i0 sites with increasing distance from a blast furnace plant. PAH concentrations in the species decreased with increasing distance from the blast furnace plant. Each of the species contained a specific profile of PAHs. Animal concentrations correlated better with
T. C. Van Brummelen; R. A. Verweij; S. A. Wedzinga; C. A. M. Van Gestel
The deep sea is one of the largest ecosystems on Earth and is home to a highly diverse fauna, with polychaetes, molluscs and peracarid crustaceans as dominant groups. A number of studies have proposed that this fauna did not survive the anoxic events that occurred during the Mesozoic Era. Accordingly, the modern fauna is thought to be relatively young, perhaps having colonized the deep sea after the Eocene/Oligocene boundary. To test this hypothesis, we performed phylogenetic analyses of nuclear ribosomal 18S and 28S and mitochondrial cytochrome oxidase I and 16S sequences from isopod crustaceans. Using a molecular clock calibrated with multiple isopod fossils, we estimated the timing of deep-sea colonization events by isopods. Our results show that some groups have an ancient origin in the deep sea, with the earliest estimated dates spanning 232-314 Myr ago. Therefore, anoxic events at the Permian-Triassic boundary and during the Mesozoic did not cause the extinction of all the deep-sea fauna; some species may have gone extinct while others survived and proliferated. The monophyly of the 'munnopsid radiation' within the isopods suggests that the ancestors of this group evolved in the deep sea and did not move to shallow-water refugia during anoxic events. PMID:23054914
Lins, Luana S F; Ho, Simon Y W; Wilson, George D F; Lo, Nathan
Gut contents of three small (<6 mm) species of munnopsid asellote isopod crustaceans ( Echinozone arctica, Ilyarachna bergendali and I. torleivi) from bathyal depths in the Nordic Seas were examined. The species feed mainly on benthic foraminifers, and their gut contents reflect the functional capability of the mouthparts in partitioning the food. Fragments of small and fragile calcareous foraminifer protozoans and small hard agglutinating foraminifers were most important in the guts of Echinozone arctica, which has rounded mandibular molar process, suited for crunching the foraminifers. Dark- and light-gray stercomata (foraminifer fecal pellets) from soft agglutinating foraminifers were most important in the guts of Ilyarachna bergendali, whose molar process has a wide crunching cusp and a sharp cutting edge. The gut contents of Ilyarachna torleivi were similar to the contents of I. bergendali, but differed somewhat from those of E. arctica. The results indicate that foraminiferivory may be common among small munnopsid asellote isopods and that the isopods may specialize in certain foraminifer species or genera. The strength of the foraminifer test may be an important aid against predation. This study indicates that small, yet poorly known, soft-shelled and agglutinating foraminifers with a low nutritional value may be important as food for deep-water isopods and that foraminifers may be an important link between phytodetritus and the macrofauna.
Gudmundsson, Gudmundur; von Schmalensee, Menja; Svavarsson, Jörundur
Environmental variation in food resources modifies performance of herbivores, in addition to genetic variation and maternal effects. In marine benthic habitats, eutrophication may modify herbivores’ diets by changing host species composition or nutritional quality of algae for herbivores. We studied experimentally the effects of diet breadth and nutrient availability for the host algae on fitness components of the herbivorous isopod
Wolbachia are maternally inherited, intracellular, alpha proteobacteria that infect a wide range of arthropods. They cause three kinds of reproductive alterations in their hosts: cytoplasmic incompatibility, parthenogenesis and feminization. There have been many studies of the distribution of Wolbachia in arthropods, but very few crustacean species are known to be infected. We investigated the prevalence of Wolbachia in 85 species from five crustacean orders. Twenty-two isopod species were found to carry these bacteria. The bacteria were found mainly in terrestrial species, suggesting that Wolbachia came from a continental environment. The evolutionary relationships between these Wolbachia strains were determined by sequencing bacterial genes and by interspecific transfers. All the bacteria associated with isopods belonged to the Wolbachia B group, based on 16S rDNA sequence data. All the terrestrial isopod symbionts in this group except one formed an independent clade. The results of interspecific transfers show evidence of specialization of Wolbachia symbionts to their isopod hosts. They also suggest that host species plays a more important role than bacterial phylogeny in determining the phenotype induced by Wolbachia infection.
A variety of genetic elements encode traits beneficial to their own transmis- sion. Despite their 'selfish' behaviour, most of these elements are often found at relatively low frequencies in host populations. This is the case of intracytoplasmic Wolbachia bacteria hosted by the isopod Armadillidium vulgare that distort the host sex ratio towards females by feminizing the genetic males they infect.
Isopods of the family Gnathiidae have free-living adults and parasitic juveniles feeding on the blood and tissue fluids of teleost and elasmobranch fishes. When not feeding on fishes, gnathiids are cryptic and widely distributed, especially among marine habitats. Ten genera are recognized: Bathygnathia, Bythognathia, Caecognathia, Elaphognathia, Euneognathia, Gibbagnathia, Gnathia, Monodgnathia, Paragnathia and Thaumastognathia. Among these are 172 known species, the
Criteria for distinguishing introduced from endemic peracaridan crustaceans were used to deduce that a human-borne global invasion by the Oriental isopod Synidotea laevidorsalis (Meirs 1881) has occurred in the past 100 years. hese criteria concern the ecological, evolutionary, a...
The investigation of recently collected material of terrestrial isopods from Crete yielded 7 species new to science (Graeconiscus guanophilus n. sp., Graeconiscus kournasensis n. sp., Tra- chelipus cavaticus n. sp., Armadillidium lymberakisi n. sp., Platanosphaera kournasensis n. sp., Schizidium delmastroi n. sp., Trichodillidium mylonasi n. sp.). Further 7 species are recorded for the first time from the Cretan Archipelago (Armadilloniscus
HELMUT SCHMALFUSS; KALOUST PARAGAMIAN; SPYROS SFENTHOURAKIS
The old field mouse (Peromyscus polionotus) is distributed throughout northeastern Mississippi, Alabama, Georgia, South Carolina, and Florida. Certain subspecies occur on beaches and dunes of the Atlantic coast of Florida and the Gulf Coast of Alabama and...
A quantitative study of the movement behaviour of the brackish isopod Lekanesphaera hookeri was performed. Isopods were collected in late spring 2007 from an Italian lagoon and held in the laboratory under temperature-controlled conditions. We used a real-time video acquisition system to measure in resource-free arenas the mean step length, total path length, average movement speed and movement complexity of
The role of submerged macrophytes as refugia from fish predation and as possible food sources for the estuarine isopod Exosphaeroma hylocoetes ( Barnard, K.H., 1940) was investigated. Laboratory experiments tested the effectiveness of artificial vegetation, replicating submerged vegetation, in enabling isopods to elude selected fish predators Rhabdosargus holubi, Glossogobius callidus, Monodactylus falciformis and Clinus cottoides. Isopods preferentially hid in the vegetation (>90%), even in absence of fish. The predatory fish had varying success in finding isopods within the vegetation. Isopod mortality ranged from 2% ( R. holubi) to a maximum of 87% ( C. cottoides) within vegetation, depending on the fish predator present. Stable isotope and fatty acid analyses ruled out the submerged macrophyte Ruppia maritima and inundated fringing grasses as direct food sources, but highlighted the epiphytic biota (mainly diatoms) found on the submerged vegetation and sediments as more likely food sources. These findings are consistent with gut content analyses. The results suggest that the close association of E. hylocoetes with R. maritima is the result of the vegetation providing the isopod with a refuge against fish predation as well as areas of increased food availability.
Henninger, Tony O.; Froneman, P. William; Richoux, Nicole B.; Hodgson, Alan N.
Representatives of at least six crustacean taxa managed to establish a terrestrial life style during their evolutionary history and the Oniscidea (Isopoda) are currently held as the most successfully terrestrialized malacostracan crustaceans. The brain architecture of terrestrial isopods is fairly well understood and studies on this field suggest that the evolutionary transition from sea to land in isopods coincided with a considerable size reduction and functional loss of their first pair of antennae and associated brain areas. This finding suggests that terrestrial isopods may have no or poor abilities to detect volatile substances but that their chemosensory ecology is most likely restricted to contact chemoreception. In this study, we explored how the brain of a marine isopod and particularly its olfactory system compares to that of terrestrial relatives. Using histochemical and immunohistochemical labeling, brightfield and confocal laser-scan microscopy, we show that in the marine isopod Saduria entomon aesthetascs on the first pair of antennae provide input to a well defined deutocerebrum (DC). The deutocerebral chemosensory lobes (DCL) are divided into spherical neuropil compartments, the olfactory glomeruli (og). Secondary processing areas in the lateral protocerebrum (lPC) are supplied by a thin but distinct projection neuron tract (PNT) with a contralateral connection. Hence, contrary to terrestrial Isopoda, S. entomon has at least the neuronal substrate to perceive and process olfactory stimuli suggesting the originally marine isopod lineage had olfactory abilities comparable to that of other malacostracan crustaceans. PMID:24109435
Representatives of at least six crustacean taxa managed to establish a terrestrial life style during their evolutionary history and the Oniscidea (Isopoda) are currently held as the most successfully terrestrialized malacostracan crustaceans. The brain architecture of terrestrial isopods is fairly well understood and studies on this field suggest that the evolutionary transition from sea to land in isopods coincided with a considerable size reduction and functional loss of their first pair of antennae and associated brain areas. This finding suggests that terrestrial isopods may have no or poor abilities to detect volatile substances but that their chemosensory ecology is most likely restricted to contact chemoreception. In this study, we explored how the brain of a marine isopod and particularly its olfactory system compares to that of terrestrial relatives. Using histochemical and immunohistochemical labeling, brightfield and confocal laser-scan microscopy, we show that in the marine isopod Saduria entomon aesthetascs on the first pair of antennae provide input to a well defined deutocerebrum (DC). The deutocerebral chemosensory lobes (DCL) are divided into spherical neuropil compartments, the olfactory glomeruli (og). Secondary processing areas in the lateral protocerebrum (lPC) are supplied by a thin but distinct projection neuron tract (PNT) with a contralateral connection. Hence, contrary to terrestrial Isopoda, S. entomon has at least the neuronal substrate to perceive and process olfactory stimuli suggesting the originally marine isopod lineage had olfactory abilities comparable to that of other malacostracan crustaceans.
The aims of the present study were to establish a detailed and representative record of landing techniques (two-, left-, and right-footed landings) in professional beach volleyball and compare the data with those of indoor volleyball. Beach volleyball data was retrieved from videos taken at FIVB World Tour tournaments. Landing techniques were compared in the different beach and indoor volleyball skills serve, set, attack, and block with regard to sex, playing technique, and court position. Significant differences were observed between men and women in landings following block actions (?(2)(2) = 18.19, p < 0.01) but not following serve, set, and attack actions. Following blocking, men landed more often on one foot than women. Further differences in landings following serve and attack with regard to playing technique and position were mainly observed in men. The comparison with landing techniques in indoor volleyball revealed overall differences both in men (?(2)(2) = 161.4, p < 0.01) and women (?(2)(2) = 84.91, p < 0.01). Beach volleyball players land more often on both feet than indoor volleyball players. Besides the softer surface in beach volleyball, and therefore resulting lower loads, these results might be another reason for fewer injuries and overuse conditions compared to indoor volleyball. Key PointsAbout 1/3 of all jumping actions in beach volleyball result in a landing on one foot.Especially following block situations men land on one foot more often than women.Landing techniques are related to different techniques and positions.Landings on one foot are less common in beach volleyball than indoor volleyball. This could be a reason for fewer injuries and overuse conditions. PMID:24149150
The aims of the present study were to establish a detailed and representative record of landing techniques (two-, left-, and right-footed landings) in professional beach volleyball and compare the data with those of indoor volleyball. Beach volleyball data was retrieved from videos taken at FIVB World Tour tournaments. Landing techniques were compared in the different beach and indoor volleyball skills serve, set, attack, and block with regard to sex, playing technique, and court position. Significant differences were observed between men and women in landings following block actions (?2(2) = 18.19, p < 0.01) but not following serve, set, and attack actions. Following blocking, men landed more often on one foot than women. Further differences in landings following serve and attack with regard to playing technique and position were mainly observed in men. The comparison with landing techniques in indoor volleyball revealed overall differences both in men (?2(2) = 161.4, p < 0.01) and women (?2(2) = 84.91, p < 0.01). Beach volleyball players land more often on both feet than indoor volleyball players. Besides the softer surface in beach volleyball, and therefore resulting lower loads, these results might be another reason for fewer injuries and overuse conditions compared to indoor volleyball. Key Points About 1/3 of all jumping actions in beach volleyball result in a landing on one foot. Especially following block situations men land on one foot more often than women. Landing techniques are related to different techniques and positions. Landings on one foot are less common in beach volleyball than indoor volleyball. This could be a reason for fewer injuries and overuse conditions.
The action consists of restoration and periodic nourishment of 13,200 feet of ocean beach and a rubble stone terminal groin extending 800 feet seaward on Tybee Island, Georgia. Environmental impacts include the restoration and maintenance of scenic beach ...
...Beach Regatta, Powerboat Race, Atlantic Ocean, Long Beach, NY AGENCY: Coast...on the navigable waters of the Atlantic Ocean off Long Beach, NY during the...The event will be held on the Atlantic Ocean off Long Beach, NY and will...
Most water wave simulations use fixed boundaries. This simplification of course change the wave height prediction near the shore. In this paper, we will find a relation between reflected wave and incoming wave on a sloping beach. This result is important for later use in water wave simulations with moving boundaries. In this paper, we solve the 1-D nonlinear shallow water equation, using the conservative finite volume method. The scheme plus wet and dry procedure can simulate wave running up and down on a sloping beach. Comparison with Carrier and Greenspan analytical run up and down waves shows a good agreement. Then, we use this scheme to find a relation between reflected and incident wave on a sloping beach, incorporating the moving shoreline. And we obtain amplitude ratio and phase difference depending on wave frequency for moderate bottom slopes.
The sex differentiation in crustaceans is known to be controlled by a peptide hormone called androgenic gland hormone (AGH). AGH was extracted and purified from the androgenic glands (AGs) of the male isopod Armadillidium vulgare by high-performance liquid chromatography. AGH consisted of two peptide chains and their N-terminal amino acid sequences were determined. A cDNA encoding AGH was cloned by
In the stream-dwelling isopod, Lirceus fontinalis, mating contests between males and females occur prior to pair formation. We examined the relative contribution of male preference\\u000a and female resistance to contest outcomes. We first quantified male and female behavior during typical mating interactions\\u000a and examined the relationship between time until molt (TTM) and mating outcomes. We then examined the role of
Timothy C. Sparkes; Daniel P. Keogh; Kristin E. Haskins
Objective To carry out a comparative study of the mouthparts and the diet of eight isopod fish parasites. Methods A description of the mouthparts, together with their diet nature, was derived both by direct observation and an interpretation of their structure. The three-dimensional study of the mouthparts of the isopod parasites was done to reveal their morphology. Results Observations revealed that these species are wholly carnivorous. Result shows how they are adapted for tearing and bolting fish food material. The mouthparts consist of a labrum, paragnaths, paired mandibles, maxillules, maxillae and maxillipeds. The labrum and the paragnaths are the least developed but peculiarly the mandibles are asymmetrical, large, stout and highly modified. The analysis of gut contents indicated that Cymothoa indica and Joryma brachysoma diet consisted of 90% to 95% of animal blood. The diet of Mothocya renardi, Ryukyua circularis and Joryma hilsae were mainly composed of mucus (80%-90%). The stomach contents of Nerocila phaeopleura and Nerocila sundaica, were dominated by body muscles (75%-83%). Conclusions The possible functions of the mouthparts, especially in feeding are discussed in light of their structure. The morphology of the mouthparts of the isopod parasites are heavily modified with their feeding behavior.
Rameshkumar, Ganapathy; Ravichandran, Samuthirapandian; Allayie, Sartaj Ahmad
Little is known about the capacity of terrestrial invertebrates to transform organic soil pollutants such as polycyclic aromatic hydrocarbons (PAHs). Studies were designed to characterize microsomal mixed function oxygenase and accompanying conjugation enzymes from the hepatopancreas of the terrestrial isopods Porcellio scaber and Oniscus asellus using pyrene and 1-hydroxypyrene as model substrates. The hydroxylation of pyrene and the formation of pyreneglucoside and pyrenesulfate appeared to be sensitive measures for the activity of cytochrome P450 aryl hydrocarbon hydroxylase (AHH), uridinediphosphateglucosyltransferase (UDPGT), and aryl sulfotransferase (ST), respectively. Treatment with the antibiotic riphampicine demonstrated that the enzyme activities originate from the animals themselves and not from symbiotic microflora present in the hepatopancreas and the gut. In both species, ST has a very high affinity for 1-hydroxypyrene with Km values two orders of magnitude lower than that of UDPGT. The Vmax values of UDPGT, however, are 10- to 20-fold higher than that of ST. Taking the P450 activities into consideration, both species are expected to transform PAHs in an equally effective way. When the isopods were fed with food containing benz[a]pyrene and 3-methyl-cholanthrene, none of the enzyme activities appeared to be inducible except for a small enhancement of UDPGT in O. asellus. Our findings indicate that terrestrial isopods have a high, noninducible capacity for biotransformation of PAHs and that the sulfate conjugation pathway is as important as the carbohydrate conjugation pathway. This conclusion is consistent with the low body residues of parent PAHs found in the field. PMID:11434285
de Knecht, J A; Stroomberg, G J; Tump, C; Helms, M; Verweij, R A; Commandeur, J; van Gestel, C A; van Straalen, N M
Terrestrial isopods were studied in the Dubravica peat bog and surrounding forest in the northwestern Croatia. Sampling was conducted using pitfall traps over a two year period. Studied peat bog has a history of drastically decrease in area during the last five decades mainly due to the process of natural succession and changes in the water level. A total of 389 isopod individuals belonging to 8 species were captured. Species richness did not significantly differ between bog, edge and surrounding forest. High species richness at the bog is most likely the result of progressive vegetation succession, small size of the bog and interspecific relationships, such as predation. With spreading of Molinia grass on the peat bog, upper layers of Sphagnum mosses become less humid and probably more suitable for forest species that slowly colonise bog area. The highest diversity was found at the edge mainly due to the edge effect and seasonal immigration, but also possibly due to high abundance and predator pressure of the Myrmica ants and lycosid spiders at the bog site. The most abundant species were Trachelipus rathkii and Protracheoniscus politus, in the bog area and in the forest, respectively. Bog specific species were not recorded and the majority of the species collected belong to the group of tyrphoneutral species. However, Hyloniscus adonis could be considered as a tyrphoxenous species regarding its habitat preferences. Most of collected isopod species are widespread eurytopic species that usually inhabit various habitats and therefore indicate negative successive changes or degradation processes in the peat bog. PMID:22536107
The fine structure of the hepatopancreas of the isopod, Armadillidium vulgare was studied in intact and in experimentally treated animals. The gross anatomy of the hepatopancreas of this species is simpler than that of decapods, but microscopically the cells are similar in both. Accordingly, the function of this organ is probably the same in decapods and Armadillidium. Some phylogenetic considerations are also presented. In a previous paper Miyawaki et al. (1984), presented experimental results which indicated that the hepatopancreas of the crayfish, Procambarus clarki, had an important role in the absorption of digested food materials. These results confirmed earlier reports by Yonge (1924) and van Weel (1955) on the decapods, Nephrops norvegicus and Atya spinides, respectively. In the present study, we wished to determine whether the isopod hepatopancreas has a function like that of the decapods. A terrestrial isopod, Armadillidium vulgare collected on the University campus, and reared in the laboratory at room temperature was used. The methods of study were similar to those employed in the study with Procambarus clarki (Miyawaki et al., 1984). PMID:3986923
Field measurements of edge waves obtained on a narrow pocket beach are described. The beach (named Usgo) is located on the north coast of Spain immediately to the west of the city of Santander and is exposed to the Atlantic Ocean. The edge wave field on this beach is analyzed utilizing data from a longshore array of current meters located
H. Tuba Özkan-Haller; César Vidal; Iñigo J. Losada; Raúl Medina; Miguel A. Losada
This study attempts to establish a system for the sequential monitoring of beach litter using webcams placed at the Ookushi beach, Goto Islands, Japan, to establish the temporal variability in the quantities of beach litter every 90 min over a one and a half year period. The time series of the quantities of beach litter, computed by counting pixels with a greater lightness than a threshold value in photographs, shows that litter does not increase monotonically on the beach, but fluctuates mainly on a monthly time scale or less. To investigate what factors influence this variability, the time derivative of the quantity of beach litter is compared with satellite-derived wind speeds. It is found that the beach litter quantities vary largely with winds, but there may be other influencing factors. PMID:20392465
Spatial variation of macrofauna on a sandy beach was examined simultaneously over two scales across-shore (among and within zones) and three nested scales along-shore over the entire length of the beach. Prior to the main study, pilot studies were performed to determine: (1) the relative efficiency, accuracy and precision of combinations of core size, depth of sampling, and sieve mesh size; and (2) the likely distribution of macrofauna across-shore so that stratification of sampling in the main study would be meaningful. From this, three zones were defined across-shore, namely: (1) the high-shore zone which extended 10 m downshore of the drift line and was dominated by two species of isopod; (2) the mid-shore zone which extended across the beach from the bottom of the high-shore zone to the top of the swash zone and was dominated by the glycerid polychaete Hemipodussp.; and (3) the swash zone which contained more species than the other two zones and was dominated by amphipods, Hemipodussp., the bivalve Donax deltoidesand a species of cumacean. In the main study, multivariate analyses confirmed that assemblages of macrofauna varied significantly among zones despite smaller scale variation within zones and along-shore variation. Significant along-shore variation was detected in assemblages of macrofauna from each zone and occurred at different scales for different zones. Only assemblages in the swash zone showed a pattern of along-shore variation that was consistent with a gradient in wave exposure along the beach. Univariate analyses showed that significant variation in populations of individual taxa occurred at both large and small scales. Significant variation was detected across-shore within zones for nearly all variates and this demonstrated the importance of formally assessing variation withinzones when making comparisons amongzones. Significant variation was also detected along-shore in analyses of particular taxa, and interactions of across- and along-shore variation also occurred. These results illustrate the necessity of considering both across- and along-shore variation for describing spatial patterns in assemblages or individual species of macrofauna. Unfortunately, sampling a single transect across a beach, which is common in many published descriptions of spatial patterns, will not provide an adequate nor representative description of the macrofauna of that beach because this approach fails to consider all important sources of variation and confounds large- and small-scale variation. The authors conclude that a better understanding of small-scale variation, both along- and across-shore within beaches, is required in order to provide better descriptions of patterns, provide a basis for larger scale studies, allow unconfounded comparisons among beaches and, ultimately, to improve our understanding of the ecology of sandy beaches.
This site provides nesting data for loggerhead sea turtles (Caretta caretta) using this South Carolina beach. Entries include: location, date discovered, number of eggs, expected and actual hatch dates, percent hatched, and photos. Data archives extend back to 1998. Site also includes information: on what you can do to help nesting turtles, strandings, impacts of beachfront construction on sea turtles, and a photo collection of turtle nesting.
Parasitic isopods of Bopyroidea and Cryptoniscoidea (commonly referred to as epicarideans) are unique in using crustaceans as both intermediate and definitive hosts. In total, 795 epicarideans are known, representing ?7.7% of described isopods. The rate of description of parasitic species has not matched that of free-living isopods and this disparity will likely continue due to the more cryptic nature of these parasites. Distribution patterns of epicarideans are influenced by a combination of their definitive (both benthic and pelagic species) and intermediate (pelagic copepod) host distributions, although host specificity is poorly known for most species. Among epicarideans, nearly all species in Bopyroidea are ectoparasitic on decapod hosts. Bopyrids are the most diverse taxon (605 species), with their highest diversity in the North West Pacific (139 species), East Asian Sea (120 species), and Central Indian Ocean (44 species). The diversity patterns of Cryptoniscoidea (99 species, endoparasites of a diverse assemblage of crustacean hosts) are distinct from bopyrids, with the greatest diversity of cryptoniscoids in the North East Atlantic (18 species) followed by the Antarctic, Mediterranean, and Arctic regions (13, 12, and 8 species, respectively). Dajidae (54 species, ectoparasites of shrimp, mysids, and euphausids) exhibits highest diversity in the Antarctic (7 species) with 14 species in the Arctic and North East Atlantic regions combined. Entoniscidae (37 species, endoparasites within anomuran, brachyuran and shrimp hosts) show highest diversity in the North West Pacific (10 species) and North East Atlantic (8 species). Most epicarideans are known from relatively shallow waters, although some bopyrids are known from depths below 4000 m. Lack of parasitic groups in certain geographic areas is likely a sampling artifact and we predict that the Central Indian Ocean and East Asian Sea (in particular, the Indo-Malay-Philippines Archipelago) hold a wealth of undescribed species, reflecting our knowledge of host diversity patterns.
Background Most of crustacean immune responses are well described for the aquatic forms whereas almost nothing is known for the isopods that evolved a terrestrial lifestyle. The latter are also infected at a high prevalence with Wolbachia, an endosymbiotic bacterium which affects the host immune system, possibly to improve its transmission. In contrast with insect models, the isopod Armadillidium vulgare is known to harbor Wolbachia inside the haemocytes. Methodology/Principal Findings In A. vulgare we characterized three haemocyte types (TEM, flow cytometry): the hyaline and semi-granular haemocytes were phagocytes, while semi-granular and granular haemocytes performed encapsulation. They were produced in the haematopoietic organs, from central stem cells, maturing as they moved toward the edge (TEM). In infected individuals, live Wolbachia (FISH) colonized 38% of the haemocytes but with low, variable densities (6.45±0.46 Wolbachia on average). So far they were not found in hyaline haemocytes (TEM). The haematopoietic organs contained 7.6±0.7×103 Wolbachia, both in stem cells and differentiating cells (FISH). While infected and uninfected one-year-old individuals had the same haemocyte density, in infected animals the proportion of granular haemocytes in particular decreased by one third (flow cytometry, Pearson's test?=?12 822.98, df?=?2, p<0.001). Conclusions/Significance The characteristics of the isopod immune system fell within the range of those known from aquatic crustaceans. The colonization of the haemocytes by Wolbachia seemed to stand from the haematopoietic organs, which may act as a reservoir to discharge Wolbachia in the haemolymph, a known route for horizontal transfer. Wolbachia infection did not affect the haemocyte density, but the quantity of granular haemocytes decreased by one third. This may account for the reduced prophenoloxidase activity observed previously in these animals.
...100.736 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY REGATTAS AND MARINE PARADES SAFETY OF LIFE ON NAVIGABLE WATERS Â§ 100.736 Annual Fort Myers Beach air show; Fort Myers Beach, FL....
...coastal recreation waters, including the Great Lakes. EPA encourages coastal and Great Lakes states and tribes that have received BEACH...EPA also encourages eligible coastal and Great Lakes tribes to apply for BEACH Act grants to...
Summary form only given. Ocean Beach is a dissipative beach, which is associated with large powerful rip currents. The processes that cause these rip currents on Ocean Beach have not been studied. As well, the general dimension of size, shape and velocity (the 3-dimension seaward distance and vertical distance) of these rip currents are also unknown. This report looks at
...NRC-2010-0123] FPL Energy Point Beach, LLC; Point Beach Nuclear Plant, Units 1 and 2; Exemption 1.0 Background FPL Energy Point Beach, LLC (FPLE...NRC) to M. S. Fertel (Nuclear Energy Institute) dated June...
The tubular hindgut of the intertidal herbivorous isopod, Dynamene bidentata, consists of a long dorso-ventrally flattened anterior region, surrounded by a network of muscles, and a short muscular sphincter which grades into a pair of anal flaps. The monolayer of epithelial cells forming the wall of the hindgut appears to take no part in the production of digestive enzymes, food
...Isopod From Dominion Virginia Power; Low-Effect Habitat Conservation Plan AGENCY: Fish...Take Permit (ITP) and a proposed Low-Effect Habitat Conservation Plan (LEHCP) from...Conservation Plan (HCP) qualifies as a low-effect plan under NEPA. To make this...
Effective population size (N e) is one of the most important parameters in, ecology, evolutionary and conservation biology; however, few studies of N e in surface freshwater organisms have been published to date. Even fewer studies have been carried out in groundwater organisms, although their evolution has long been considered to be particularly constrained by small N e. In this study, we estimated the contemporary effective population size of the obligate groundwater isopod: Proaselluswalteri (Chappuis, 1948). To this end, a genomic library was enriched for microsatellite motifs and sequenced using 454 GS-FLX technology. A total of 54,593 reads were assembled in 10,346 contigs or singlets, of which 245 contained candidate microsatellite sequences with suitable priming sites. Ninety-six loci were tested for amplification, polymorphism and multiplexing properties, of which seven were finally selected for N e estimation. Linkage disequilibrium and approximate Bayesian computation methods revealed that N e in this small interstitial groundwater isopod could reach large sizes (> 585 individuals). Our results suggest that environmental conditions in groundwater, while often referred to as extreme, are not necessarily associated with small N e. PMID:24086709
Global environmental changes are nowadays one of the most important issues affecting terrestrial ecosystems. One of its most significant expressions is the increasing ultraviolet radiation (UVR) arising from the human-induced depletion in ozone layer. Therefore, to investigate the effects of UVR on the terrestrial isopod Porcellionides pruinosus a multiple biomarker approach was carried out. Two experiments were performed in order to analyze the importance of the exposure environment and the growth stage on the UV-induced damages. First, adult individuals were exposed to UVR in three exposure environments (soil, soil with leaves, and plaster). Thereafter, three growth stages using soil as the exposure condition were tested. Integrated biomarker responses (IBR) suggested that UV effects were higher in plaster, and mostly identified by changes in acetylcholinesterase and glutathione-S-transferases activities, lipid peroxidation rates, and total energy available. The effects in soil and soil with leaves were not so clear. In the growth stages' experiment, juveniles and pre-adults were found to be more affected than adults, with the greatest differences between irradiated and non-irradiated isopods occurring in energy-related parameters. Our findings suggest that soil surface-living macrofauna may be prone to deleterious effects caused by UVR, highlighting the importance of taking the media of exposure and growth stage in account. PMID:23899792
Morgado, Rui; Ferreira, Nuno G C; Tourinho, Paula; Ribeiro, Fabianne; Soares, Amadeu M V M; Loureiro, Susana
Robotic vehicles resembling large beach balls proposed for carrying scientific instruments. Conceived for use in exploring planet Mars, also useful on Earth to carry meteorological or pollution-monitoring equipment to remote locations across rough terrain and even across water. Each vehicle features approximately spherical balloonlike outer shell inflated to suitable pressure. Three diametral tethers approximately perpendicular to each other attached to shell. Control box moves itself along tethers to shift center of gravity, causing vehicle to roll. Alternatively, instead of shell, structure of approximately spherical outline made of twisted rods; of course, not suitable for traversing water or thick vegetation.
Similar to many places in the world, Taiwan's coastlines have experienced short term beach erosion arising from awesome waves and storm surges which have aggravated the long term erosion caused by various man-made factors. To combat beach erosion, hard structures using seawalls more than 500 km with protective precast concrete blocks have been installed throughout the island since the 1970s.
John R. C. Hsu; Melissa M. J. Yu; Shue-Ruey Liaw; Jyh-Cheng Chu; Chien-Chung Chen; Nan-Jing Wu
Several experiments aimed at characterising the hydrodynamics of megatidal beaches outside the surf zone were carried out between 1990 and 1994 on the Cotentin coast of the Cherbourg Peninsula in Normandy. The database was established from the records of several electromagnetic current meters and pressure sensors and from field surveys. The mean spring tidal range on these beaches varies between
A classical example of the failure of institutions and environmental technology to protect the nation's aesthetic, recreational, and public health values is represented by the July-August, 1999 Huntington Beach, California beach closure. This multi-million dollar regional public ...
We used results from a survey of horseshoe crab reproductive activity that was conducted in 1999 throughout Delaware Bay to examine the relationship between estimates of spawning females and egg deposition and analyze how that relationship varies with geography, time within a spawning season, beach morphology, and wave energy. We found that beach morphology and wave energy interacted with density of spawning females to explain variation in the density and distribution of eggs and larvae. For example, the quantity of eggs in surface sediment (i.e., eggs that are potentially available to foraging shorebirds) was associated with the density of spawning females, beach morphology, and wave energy. The association between beach morphology and live eggs in surface sediment was strong especially in late May (Percent Reduction in Error = 86% from regression tree model) where egg density was an order of magnitude higher on beaches <15 m wide (3.38*105 m-2; 90% CI: 2.29*105, 4.47*105) compared to wider beaches (1.49*104 m-2; 90% CI: 4.47*103, 2.53*104). Results also indicate that, among bay-front beaches, horseshoe crabs prefer to spawn on narrow beaches, possibly because of reduced wave energy. At peak periods of spawning activity, density of spawning females was inversely related to foreshore width on mid-latitude beaches within Delaware Bay (t = -2.68, 7 df, p = 0.03). Because the distribution of eggs across the foreshore varied with beach morphology and widened as the spawning season progressed, methods used to sample eggs need to be robust to variation in beach morphology and applicable regardless of when the samples are taken. Because beach morphology and wave energy were associated with the quantity of eggs in surface sediment, certain beach types may be critical to the conservation of shorebird foraging habitat.
Smith, D. R.; Pooler, P. S.; Loveland, R. E.; Botton, M. L.; Michels, S. F.; Weber, R. G.; Carter, D. B.
The U.S. EPA BEACH Program website describes how the public's health and environmental quality of our nation's beaches can be improved. It focuses on strengthening beach standards and testing, providing faster laboratory test methods, predicting pollution, investing in health and methods research, and informing the public about the environmental quality of our beaches.
Owing to Oman's geographic position and long coastal line, the coastal areas of Oman are particularly vulnerable to oil pollution from normal tanker operations, illegal discharges, and accidental spills as well as local sources of oil input. UNEP carried out a survey on the coasts of Oman to determine the major sources of oil pollution and concluded that the major shoreline pollution problems in Oman arose from operational discharges of oil from passing vessels traffic. The oil, because of the high sea and air temperatures in the area, was subjected to relatively high rates of evaporation and photo-oxidation and tended to arrive at the coast as heavy petroleum particulate residues (tar balls). The aim of the present study was to measure the loads of tar balls in Omani coastal areas and to identify the source of oil pollutants on beaches.
Badawy, M.I.; Al-Harthy, F.T. (National Research Center, Cairo (Egypt))
In agroecosystems, organisms may regularly be exposed to anthropogenic stressors, e.g. pesticides. Species' sensitivity to stress depends on toxicity, life-history, and landscape structure. We developed an individual-based model of an isopod, Asellus aquaticus, to explore how timing of stress events affects population dynamics in a seasonal environment. Furthermore, we tested the relevance of habitat connectivity and spatial distribution of stress for the recovery of a local and total population. The simulation results indicated that population recovery is mainly driven by reproductive periods. Furthermore, high habitat connectivity led to faster recovery both for local and total populations. However, effects of landscape structure disappeared for homogeneously stressed populations, where local survivors increased recovery rate. Finally, local populations recovered faster, implying that assessing recovery in the field needs careful consideration of spatial scale for sampling. We emphasize the need for a coherent definition of recovery for more relevant ecosystem risk assessment and management. PMID:22325436
Galic, Nika; Baveco, Hans; Hengeveld, Geerten M; Thorbek, Pernille; Bruns, Eric; van den Brink, Paul J
Infestation dynamics of parasitic gnathiid isopods on Caribbean reefs were studied throughout the 24-h diel cycle. Gnathiid infestation on caged longfin damselfish ( Stegastes diencaeus) peaked strongly at dawn, remained low during the remainder of the day, and increased again at night until about midnight. Gnathiids were less abundant during the pre-dawn period. Peak loads on fish retrieved at dawn were the highest reported in any study thus far. The dawn peak consisted almost exclusively of individuals from the smallest size class, whereas nocturnal activity consisted almost exclusively of individuals of the largest size class. Because of the high rates of infestation at night and dawn, and the high variation in parasite loads on fish collected during that time, reduction of parasite infestation may play an important role in the selection of nocturnal and crepuscular shelter holes and settlement sites by reef fishes.
Sikkel, Paul C.; Schaumburg, Collin S.; Mathenia, Jeremy K.
...Show at Jones Beach State Park, Atlantic Ocean off of Jones Beach, Wantagh...performing aerobatic maneuvers over the Atlantic Ocean off of Jones Beach State Park...aircraft over a specified area of the Atlantic Ocean off of Jones Beach State...
A field trip to the shore can engage students in real-world science and offer plentiful opportunities for interdisciplinary learning. This field trip "action plan" ensures that a day at the beach goes smoothly for students and chaperones alike.
Abstract Using a numerical model, we show that the surf zone of embayed beaches systematically flushes out more floating material (simulated using passive tracers) than on open beaches, with most exits occurring through the headland rips. For obliquely incident waves, a headland rip acts as a persistent conduit for transporting floating material out of the surf zone and into the inner shelf region. Wave angle and embayment size determine which headland rip (upwave or downwave) flushes out more the surf zone material. For narrow embayed beaches, passive drifters exit the surf zone through the upwave headland rip. For wider embayed beaches, the longshore current has enough room to develop and is further deflected against the downwave headland where most drifters exit the surf zone. Our results indicate that wave-exposed rugged coasts strongly enhance exchange of floating matter (e.g., pollutants and nutrients) at the ocean/continent interface.
Presents a marine education activity. Students construct a web of changes that shows potential problems caused by solid waste on beaches. They then determine whether each change is an increase or a decrease from previous conditions. (Author/SOE)
The need for rapid assessment of bacterial contamination at beaches is well known. Bacterial concentrations change rapidly (Bohm, Whitman et al. 1995, Olyphant and Whitman 2004, Whitman and Nevers 2008). The persistence model regulates todays swimming wit...
D. Rockwell D. J. Schwab G. Land G. Mann K. Campbell
Systematic measurement of barometric pressure, wind speed, wind direction, wave period, breaker height, angle of wave approach, and long-shore current velocity at Illinois Beach State Park in 1974 and Sheboygan, Wisconsin in summer 1972 shows the relation...
The rate of wave overtopping of a barrier beach is measured and modeled as a first step in modeling the breaching of a beach impounding an ephemeral river. Unique rate of wave overtopping data are obtained from the measure of the Carmel River, California, lagoon filling during a time when the lagoon is closed-off and there is no river inflow. Volume changes are calculated from measured lagoon height changes owing to wave overtopping by a stage-volume curve, then center differenced and averaged to provide volume rates of change in the lagoon. Wave height and period are obtained from CDIP MOPS directional wave spectra data in 15m fronting the beach. Beach morphology was measured by GPS walking surveys and interpolated for beach slopes and berm heights. Three empirical overtopping models by van der Meer and Janssen (1995), Hedges and Reis (1998) and Pullen et al. (2007) with differing parameterizations on wave height, period and beach slope and calibrated using extensive laboratory data obtained over plane, impermeable beaches are compared with the data. In addition, the run-up model by Stockdon et al. (2006) based on field data is examined. Three wave overtopping storm events are considered when morphology data were available less than 2 weeks prior to the event. The models are tuned to fit the data using a reduction factor to account for beach permeability, berm characteristics, non-normal wave incidence and surface roughness influence. It is concluded that the Stockdon et al. (2006) model underestimates run-up as no overtopping is predicted with this model. The three empirical overtopping models behaved similarly well with regression coefficients ranging 0.72 to 0.86 using a reasonable range of reduction factors 0.66 - 0.81 with an average of 0.74.
The effects of soil pH on the toxicity of ZnO nanoparticles (NPs) to the terrestrial isopod Porcellionides pruinosus were evaluated. Isopods were exposed to a natural soil amended with CaCO3 to reach 3 different pH(CaCl2) levels (4.5, 6.2, and 7.3) and to standard LUFA 2.2 soil (pH 5.5) spiked with ZnO NPs (30?nm), non-nano ZnO (200?nm), and ionic Zn as ZnCl?. Toxicity was expressed based on total Zn concentration in soil, as well as total Zn and free Zn²? ion concentrations in porewater. Compared with ZnO-spiked soils, the ZnCl?-spiked soils had lower pH and higher porewater Ca²? and Zn levels. Isopod survival did not differ between Zn forms and soils, but survival was higher for isopods exposed to ZnO NPs at pH 4.5. Median effect concentrations (EC50s) for biomass change showed similar trends for all Zn forms in all soils, with higher values at intermediate pH. Median lethal concentration (LC50) and EC50 values based on porewater Zn or free Zn ion concentrations were much lower for ZnO than for ionic zinc. Zn body concentrations increased in a dose-related manner, but no effect of soil pH was found. It is suggested not only that dissolved or free Zn in porewater contributed to uptake and toxicity, but also that oral uptake (i.e., ingestion of soil particles) could be an important additional route of exposure. PMID:23983054
Tourinho, Paula S; van Gestel, Cornelis A M; Lofts, Stephen; Soares, Amadeu M V M; Loureiro, Susana
Four species of isopod characteristic of salt marsh habitats, Tylos ponticus, Porcellio lamellatus, Halophiloscia couchii and Armadillidium album coexist in the upper reaches of the Ria Formosa lagoon salt marsh system in southern Portugal. In this locality, T. ponticus is the most abundant of the four species with mean annual densities of 2,950 m?2 and a peak density of 10,387 m?2 in
The complete amino acid sequence of a neuropeptide was established using gas-phase microsequencing, mass spectrometry, and reverse transcription–polymerase chain reaction. This peptide, stored in the sinus gland of the terrestrial isopod Armadillidium vulgare, inhibited vitellogenin synthesis by the fat tissue and inhibited the onset of secondary vitellogenesis when tested in homologous bioassays. This peptide, named Arv-VIH, has 83 amino acid
Pierre Grève; Odile Sorokine; Thierry Berges; Christian Lacombe; Alain Van Dorsselaer; Gilbert Martin
The effects of cadmium (3CdSO4·8H2O), zinc (ZnSO4·7H2O) and lead [Pb (NO3)2] on mortality, and cadmium, zinc and mercury (HgCl2) on osmoregulation, have been recorded for marine and estuarine species of isopods (Crustacea). The marine species studied were Idotea baltica, I. neglecta, I. emarginata and Eurydice pulchra, which were adapted to 100, 80, 60 and 40% sea water (SW) (100% SW
L'Isopode profond Cirolana borealis présente en milieu expérimental un rythme circadien endogène net d'émergence du sédiment, de géonégativité, et d'activité natatoire. Le rythme a pu être enregistré durant plus de 60 jours consécutifs en obscurité constante. Il se manifeste chez les animaux conditionnés à un éclairement de surface (100 à 10 ?W.cm), chez ceux conditionnés à éclairement très réduit (10
Describes an inquiry-based science activity in which students investigate the preferred food sources of sowbugs. Students design their own experiment, perform a first trial, and refine their procedure before conducting a second trial with more accurate results. (SAH)
Waterborne chemical cues are an important source of information for many aquatic organisms, in particular when assessing the current risk of predation. The ability to use chemical cues to detect and respond to potential predators before an actual encounter can improve prey chances of survival. We investigated predator recognition and the impact of chemical cues on predator avoidance in the freshwater isopod Asellus aquaticus. This isopod has recently colonised a novel habitat and diverged into two distinct ecotypes, which encounter different predator communities. Using laboratory-based choice experiments, we have quantified behavioural responses to chemical cues from predators typical of the two predator communities (larval dragonflies in the ancestral habitat, perch in the newly colonised habitat) in wild-caught and lab-reared Asellus of the two ecotypes. Individuals with prior experience of predators showed strong predator avoidance to cues from both predator types. Both ecotypes showed similar antipredator responses, but sexes differed in terms of threat-sensitive responses with males avoiding areas containing predator cues to a larger extent than females. Overall, chemical cues from fish elicited stronger predator avoidance than cues from larval dragonflies. Our results indicate that in these isopods, prior exposure to predators is needed to develop antipredator behaviour based on waterborne cues. Furthermore, the results emphasise the need to analyse predator avoidance in relation to waterborne cues in a sex-specific context, because of potential differences between males and females in terms of vulnerability and life history strategies. PMID:23636460
Harris, Sanna; Karlsson Green, Kristina; Pettersson, Lars B
...Atlantic Ocean, Virginia Beach, VA in the Federal Register (76 FR 13519). We received one comment on the proposed rule...Atlantic Ocean in Virginia Beach, VA. In recent years, there have...Changes The Coast Guard did receive one comment in response to the...
...Ocean in Virginia Beach, VA. This action is necessary...2012-0095 using any one of the following methods...If we determine that one would aid this rulemaking, we will hold one at a time and place announced...Ocean in Virginia Beach, VA. In recent years,...
Sediments exposed at low tide on the transgressive, hypertidal (>6 m tidal range) Waterside Beach, New Brunswick, Canada permit the scrutiny of sedimentary structures and textures that develop at water depths equivalent to the upper and lower shoreface. Waterside Beach sediments are grouped into eleven sedimentologically distinct deposits that represent three depositional environments: (1) sandy foreshore and shoreface; (2) tidal-creek
SHAHIN E. DASHTGARD; MURRAY K. GINGRAS; KARL E. BUTLER
The objective of this study was to identify the major factors that motivated visitors to attend the South Beach Wine and Food Festival in Miami Beach, Florida, and determine whether these factors varied among the visitors from the United States, Canada, South America, Europe, and Asia. A survey of 475 visitors to South Florida was conducted in February 2006. Forty?four
Virtual Beach is a free decision-support system designed to help beach managers and researchers construct, evaluate, and operate site-specific statistical models that can predict levels of fecal indicator bacteria (FIB) based on environmental conditions that are more readily mea...
The significance of sediment delivered via storm-associated stream discharge in altering sediment characteristics, beach form, and volume is evaluated on pocket beaches with different basin characteristics and wave exposures. The focus is on changes on three beaches on Elba Island, Italy caused by a flood event in September 2002 that had an estimated recurrence interval of 200 years. Beach profiles and foreshore sediment samples were gathered in 1999 and 2000 to identify pre-storm characteristics, in September 2002 to reveal the immediate effects of the storm, and in 2003 and 2004 to reveal post-storm recovery. Foreshore sediments were finer and better sorted and contained no pebbles prior to the flood. Coarsening of the sand and granule fraction was evident after the flood, along with pebble accumulations, especially near major streams. Mean size, sorting values and percent pebbles one and two years after the flood were generally greater than pre-flood conditions but less than immediately after the flood. Beach profiles reveal conspicuous erosion immediately after the flood, when sediment delivered by streams is transported to subaqueous deltas. Thereafter, sediment moves onshore and alongshore to adjacent beaches to restore subaerial volumes. The location of streams within a compartment, relative to the location of capes and headlands, is important in determining the movement of sediment added to the beach by streams. The sites are all sheltered from the highest-energy waves from the west, facilitating longshore transport to the west. Where the largest stream is located at the east end of a compartment, sediment discharged from it is source material for the downdrift beaches to the west. Where the largest stream is at the west end of the compartment, the ability to supply sediment to the beaches to the east is restricted. Hence, broad-scale geologic controls (headlands and capes) enhance or diminish the ability of streams to influence beach change throughout the pocket. The inability of beaches on two of the sites to migrate landward, due to human development of uplands, will be an issue in the future. Lack of sediment to replenish beaches through erosion of the upland, places increased emphasis on the role of coastal streams in the beach sediment budget. Changing watershed attributes to allow more sediment discharge during high-energy, low-frequency events (e.g. devoting more land to agriculture) would be a way of helping to restore beach sediment.
Pranzini, Enzo; Rosas, Valentina; Jackson, Nancy L.; Nordstrom, Karl F.
We provide a brief synopsis of the unique physical and ecological attributes of sandy beach ecosystems and review the main anthropogenic pressures acting on the world's single largest type of open shoreline. Threats to beaches arise from a range of stressors which span a spectrum of impact scales from localised effects (e.g. trampling) to a truly global reach (e.g. sea-level rise). These pressures act at multiple temporal and spatial scales, translating into ecological impacts that are manifested across several dimensions in time and space so that today almost every beach on every coastline is threatened by human activities. Press disturbances (whatever the impact source involved) are becoming increasingly common, operating on time scales of years to decades. However, long-term data sets that describe either the natural dynamics of beach systems or the human impacts on beaches are scarce and fragmentary. A top priority is to implement long-term field experiments and monitoring programmes that quantify the dynamics of key ecological attributes on sandy beaches. Because of the inertia associated with global climate change and human population growth, no realistic management scenario will alleviate these threats in the short term. The immediate priority is to avoid further development of coastal areas likely to be directly impacted by retreating shorelines. There is also scope for improvement in experimental design to better distinguish natural variability from anthropogenic impacts. Sea-level rise and other effects of global warming are expected to intensify other anthropogenic pressures, and could cause unprecedented ecological impacts. The definition of the relevant scales of analysis, which will vary according to the magnitude of the impact and the organisational level under analysis, and the recognition of a physical-biological coupling at different scales, should be included in approaches to quantify impacts. Zoning strategies and marine reserves, which have not been widely implemented in sandy beaches, could be a key tool for biodiversity conservation and should also facilitate spillover effects into adjacent beach habitats. Setback and zoning strategies need to be enforced through legislation, and all relevant stakeholders should be included in the design, implementation and institutionalisation of these initiatives. New perspectives for rational management of sandy beaches require paradigm shifts, by including not only basic ecosystem principles, but also incentives for effective governance and sharing of management roles between government and local stakeholders.
Defeo, Omar; McLachlan, Anton; Schoeman, David S.; Schlacher, Thomas A.; Dugan, Jenifer; Jones, Alan; Lastra, Mariano; Scapini, Felicita
So-called "typical" behavioural responses of coastal animals to particular stimuli have previously been shown often to vary cyclically in phase with diel or tidal cycles in the environment. Less well-studied are differences in the behaviour of adults and juveniles of the same species at the same time of day or tidal state, or in response to the same stimulus. Experimental studies of such differences in behaviour are reviewed and compared for three species of beach crustaceans, namely, the crab Carcinus maenas, the isopod Eurydice pulchra and the amphipod Orchestoidea tuberculata. Juvenile, but not adult, Carcinus will entrain circatidal rhythmicity after exposure to artificial tidal cycles of immersion/emersion; juvenile, but not adult, Eurydice express pronounced free-running circatidal swimming rhythms at neap tides as well as at springs; and, in Orchestoidea, juveniles and adults express patterns of daily locomotor activity that are complementary, both on the shore and in the laboratory. These ontogenetic differences are discussed in relation to distributional and behavioural differences between adults and juveniles in each species, drawing attention to their adaptive significance and wider implications for coastal management and conservation.
A study on the spatial distribution of two tenebrionids and an isopod species was conducted at a small extent. Two species of the genus Phaleria were chosen because of their sympatric distribution and apparently similar adaptations to the beach environment. These scavenger species were studied in association to Tylos europaeus. Distributions, both perpendicular and parallel to the shoreline, were studied simultaneously with a grid of 20 × 20 pitfall traps arranged at a distance of 1 m from each other. Faunal samples were collected at two different hours of the night and core samples of sand were taken next to each pitfall trap for successive laboratory analysis. An index of dispersion was applied to test for aggregation of all species and of environmental parameters on the total, across- and long-shore. Kolmogorov-Smirnov two-sample test was used to compare the distributions between species. Regression analyse were applied to evaluate relationships between environmental parameters and species distributions. The study showed that the distribution of Phaleria species and T. europaeus was scale-dependent. The species and the values of the environmental parameters showed aggregated distributions both across- and long-shore. Aggregations of each Phaleria species differed according to their resting and foraging phases. For all species, sand moisture and salinity were the most important parameters explaining distribution. Granulometric parameters were correlated with the choice of the resting areas of both Phaleria species, whereas the spatial distribution of T. europaeus was correlated to the distribution of the organic matter.
Colombini, Isabella; Fallaci, Mario; Chelazzi, Lorenzo
Monitoring beach waters for human health has led to an increase and evolution of science in the Great Lakes, which includes microbiology, limnology, hydrology, meteorology, epidemiology, and metagenomics, among others. In recent years, concerns over the accuracy of water quality standards at protecting human health have led to a significant interest in understanding the risk associated with water contact in both freshwater and marine environments. Historically, surface waters have been monitored for fecal indicator bacteria (fecal coliforms, Escherichia coli, enterococci), but shortcomings of the analytical test (lengthy assay) have resulted in a re-focusing of scientific efforts to improve public health protection. Research has led to the discovery of widespread populations of fecal indicator bacteria present in natural habitats such as soils, beach sand, and stranded algae. Microbial source tracking has been used to identify the source of these bacteria and subsequently assess their impact on human health. As a result of many findings, attempts have been made to improve monitoring efficiency and efficacy with the use of empirical predictive models and molecular rapid tests. All along, beach managers have actively incorporated new findings into their monitoring programs. With the abundance of research conducted and information gained over the last 25 years, “Beach Science” has emerged, and the Great Lakes have been a focal point for much of the ground-breaking work. Here, we review the accumulated research on microbiological water quality of Great Lakes beaches and provide a historic context to the collaborative efforts that have advanced this emerging science.
Nevers, Meredith B.; Byappanahalli, Murulee N.; Edge, Thomas A.; Whitman, Richard L.
Stretches of beach along popular Huntington Beach, California are occassionally closed to swimming due to high levels of bacteria. One hypothesized source is the treated wastewater plume from the Orange County Sanitation District's (OCSD) ocean outfall. While three independent sc...
...coastal recreation waters, including the Great Lakes. EPA encourages coastal and Great Lakes States and Tribes that have received BEACH...EPA also encourages eligible coastal and Great Lakes Tribes to apply for 2010 BEACH Act...
Beach widening and sand retention structures are proposed along 6,000 feet of shorefront at Sherwood Island State Park, Town of Westport, Fairfield County, Connecticut. Environmental impacts include restoration and protection of valuable beach fronting on...
The study is designed to provide information about the intertidal macrofauna of representative sandy beaches in southern California, along with the factors affecting their distribution. Nine beaches between Coal Oil Point in the north and Deheny State Par...
Isopods of the family Gnathiidae have free-living adults and parasitic juveniles feeding on the blood and tissue fluids of teleost and elasmobranch fishes. When not feeding on fishes, gnathiids are cryptic and widely distributed, especially among marine habitats. Ten genera are recognized: Bathygnathia, Bythognathia, Caecognathia, Elaphognathia, Euneognathia, Gibbagnathia, Gnathia, Monodgnathia, Paragnathia and Thaumastognathia. Among these are 172 known species, the majority in the genus Gnathia. Species descriptions rely on the morphology of adult male gnathiids. When juveniles or females are found, their identification can be difficult, a problem discussed in this review. Several gnathiids adapt well to laboratory culture and life cycles are generally similar, although variations in moulting behaviour, length of cycle and harem formation are observed. Praniza larvae are the feeding stages, and their mouthparts and digestion processes are examined. The effects of feeding on fishes in aquaria, in fisheries and in the wild are reported, and the role of gnathiids as vectors is assessed. Ecological interactions between gnathiid larvae, client and cleaner fishes are summarized. Identification of juveniles, host-finding behaviour, feeding and the digestion processes in larvae, feeding cycles among gnathiids of elasmobranchs, and the role of gnathiids as vectors, are among areas highlighted for further study. PMID:15603765
Analysis of gut contents of two deep-sea asellote isopod species, Ilyarachna hirticeps and Eurycope inermis (Munnopsidae, Asellota, Isopoda, Crustacea), showed that they were preying on benthic foraminifers. Benthic foraminifers with hard tests were more frequent in I. hirticeps guts than in E. inermis. I. hirticeps, having robust mandibles, is capable of crushing large calcareous and agglutinating foraminifers with hard tests. The presence of foraminiferal fecal pellets (stercomata), along with fine mineral particles and globigerinacean tests in I. hirticeps guts, shows that it was preying on the large, loosely agglutinating foraminifer, Oryctoderma sp. A. E. inermis swallowed whole, medium sized, calcareous foraminifers, which it apparently was unable to crush with its slender mandibles. The guts of E. inermis contained an abundance of mineral particles and globigerinacean tests. These are conjectured to be mashed remains of certain agglutinating foraminifers with soft tests, rather than being evidence of detritivory. It is suggested that feeding on foraminifers by asellotes may be common and may significantly affect the foraminiferal community.
Susceptibility to infestation by a gnathiid isopod (Gnathia marleyi: Crustacea: Isopoda) was examined among 16 species from 9 families and 3 orders of common Caribbean reef fishes off St. John, United States Virgin Islands. Fish were placed in cages during times of peak gnathiid activity. Individuals from most (n=14) species were compared against a single species (French Grunt, Haemulon flavolineatum) that served as a standard and effectively controlled for the effects of habitat and variation in gnathiid abundance on exposure to and the likelihood and intensity of host infestation by gnathiids. All species were susceptible to infestation by gnathiids, with individual hosts harbouring up to 368 gnathiids. However, there was significant variation in levels of infestation among the 14 comparison species. Controlling for body size, nocturnal species from the families Haemulidae and Lutjanidae had the highest gnathiid infestation. Our finding that haemulids and lutjanids are particularly susceptible has important implications for the role of gnathiids in Caribbean reef food webs, given the role members of these families play in trophic connectivity between reefs and associated habitats. To our knowledge this is the first manipulative field study to examine variation among potential hosts in susceptibility to an ectoparasite in any terrestrial or aquatic system and is the greatest number of teleost hosts documented for any gnathiid species. PMID:23506839
The amount of toxic and non-toxic elements assimilated by primary consumers from their environment depends as much on the form, as on concentration of these elements in the food. In superficially contaminated sites, the majority of elements detected in plant material are present as a blanket deposit of fine particles on leaf surfaces, and these are easily removed as the consumed material passes through the alimentary canal. In contrast, trace metals stored in the plant tissue are not readily available as they have been taken up via roots and are firmly bound within the plant tissue. Earlier studies have shown that mean concentrations of magnesium (Mg) and manganese (Mn) in whole woodlice are correlated with levels in their diet. Both metals are regulated by terrestrial isopods during their intermoult- and moult-cycles. The present study provides information on the regulation of Mg and Mn tissue concentrations during forced fasting in adult, intermoult male and female Porcellio spinicornis Say (Porcellionidae, Isopoda). Mg, the principal cation in the soft tissues is a well known activator of many enzymes of the glycolytic systems. Mn, on the other hand, plays a special role in digestive and catabolic processes.
Bercovitz, K.; Alikhan, M.A. (Laurentian Univ., Sudbury, Ontario (Canada))
Previously unreported males of a gnathiid isopod were found in reproductive aggregations of the harem-forming gnathiid Elaphognathia discolor. Although the male gnathiids were small in size and morphologically different from E. discolor males, the male sexual organ, appendix masculina, was similar to that of E. discolor males, and possible conspecific larvae and females of the small male gnathiid were never found. In the laboratory, the small male gnathiids as well as male E. discolor successfully copulated with female E. discolor, and the development of embryos in female brood pouches was observed. Offspring of small male gnathiids develop to adults of E. discolor after molting three times, or small male gnathiids after molting two times. Thus, the small male gnathiid was concluded to be an alternative male form compared to the regular large male form of E. discolor. This male polymorphism was thought to have a genetic basis, since no small male specimens appeared in offspring of regular E. discolor males. Field sampling showed that a regular large male formed a harem composed of one large male and several females and never coexisted with other large males as previously reported. However, small males were often found together with large males. Therefore, small males are thought to be sneakers intruding into harems dominated by large males. PMID:21800999
The alpha-proteobacteria Wolbachia are the most widespread endosymbionts in arthropods and nematodes. Mainly maternally inherited, these so-called sex parasites have selected several strategies that increase their vertical dispersion in host populations. However, the lack of congruence between the Wolbachia and their host phylogenies suggests frequent horizontal transfers. One way that could be used for horizontal Wolbachia transfers between individuals is predation. The aim of this study was to test whether horizontal passage of Wolbachia is possible when an uninfected terrestrial isopod eats an infected one. After having eaten Armadillidium vulgare harbouring Wolbachia, the predator-recipients (the two woodlice A. vulgare and Porcellio dilatatus dilatatus) that were initially Wolbachia-free were tested positive for the presence of Wolbachia both by quantitative PCR and Fluorescence in situ Hybridization (FISH). Even if the titers were low compared to vertically infected individuals, this constitutes the first demonstration of Wolbachia occurrence in various organs of an initially uninfected host after eating an infected one.
Maternally inherited Wolbachia (?-Proteobacteria) are widespread parasitic reproductive manipulators. A growing number of studies have described the presence of different Wolbachia strains within a same host. To date, no naturally occurring multiple infections have been recorded in terrestrial isopods. This is true for Armadillidium vulgare which is known to harbor non simultaneously three Wolbachia strains. Traditionally, such Wolbachia are detected by PCR amplification of the wsp gene and strains are characterized by sequencing. The presence of nucleotide deletions or insertions within the wsp gene, among these three different strains, provides the opportunity to test a novel genotyping method. Herein, we designed a new primer pair able to amplify products whose lengths are specific to each Wolbachia strain so as to detect the presence of multi-infections in A. vulgare. Experimental injections of Wolbachia strains in Wolbachia-free females were used to validate the methodology. We re-investigated, using this novel method, the infection status of 40 females sampled in 2003 and previously described as mono-infected based on the classical sequencing method. Among these females, 29 were identified as bi-infected. It is the first time that naturally occuring multiple infections of Wolbachia are detected within an individual A. vulgare host. Additionally, we resampled 6 of these populations in 2010 to check the infection status of females.
The life history and distribution of the intertidal isopod Idotea granulosa were investigated at five rocky shore biotopes in the Isle of Man. I. granulosa breeds throughout the year in the Irish Sea. The breeding activity is highest in the early summer after the sexual maturation of the overwintered animals. At that period about 4% of the females were infested by Clypeoniscus sp. (Isopoda) which destroys the brood. A small proportion of the juveniles released in the early summer mature and breed in the autumn. In the winter Idotea populations consisted of juveniles, immature adults and old individuals which produce another brood. These large sized animals die off before the summer. Consequently, the age and size of the breeding I. granulosa fluctuates seasonally. The number of eggs is linearly related to the female length. The fecundity is highest in the spring and lowest in the autumn in all female size classes. I. granulosa inhabits an array of structurally different intertidal algae including the filamentous Cladophora rupestris, understory turfs Gigartina stellata, Laurencia pinnatifida and Corallina officinalis and the fucoids Fucus serratus and Ascophyllum nodosum. The distribution pattern of I. granulosa in examined intertidal communities is modified by the physiognomy of the algal microhabitats, by seasonal and spatial variation in wave agitation and by the breeding cycle of the population itself. Both the life history characteristics and distribution patterns are explained as adaptations to the spatially and temporally heterogeneous intertidal shores.
Ecological factors modulate animal immunocompetence and potentially shape the evolution of their immune systems. Not only environmental parameters impact on immunocompetence: Aging is one major cause of variability of immunocompetence between individuals, and sex-specific levels of immunocompetence have also been frequently described. Moreover, a growing core of data put in light that vertically transmitted symbionts can dramatically modulate the immunocompetence of their hosts. In this study, we addressed the influence of gender, age and the feminising endosymbiont Wolbachia ( wVulC) on variations in haemocyte density, total PO activity and bacterial load in the haemolymph of the terrestrial isopod Armadillidium vulgare. This host-symbiont system is of particular interest to address this question since: (1) wVulC was previously shown as immunosuppressive in middle-aged females and (2) wVulC influences sex determination. We show that age, gender and Wolbachia modulate together immune parameters in A. vulgare. However, wVulC, which interacts with aging, appears to be the prominent factor interfering with both PO activity and haemocyte density. This interference with immune parameters is not the only aspect of wVulC virulence on its host, as reproduction and survival are also altered.
Background, Aim and Scope The distribution of sediments in estuarine beaches is controlled by the interactions between sediment supply, hydrodynamic\\u000a processes and human intervention. The main purpose of this study is to characterize the sediments of Tagus estuarine beaches\\u000a in order to understand their origin and to contribute to a better knowledge of the Tagus estuary sediment budget.\\u000a \\u000a \\u000a \\u000a Methods Surface sediment samples
This map represents the Health Status of beaches in the state of Washington. The interactive map allows users to click on counties, water bodies, and beaches to view seasons and limits. The page also includes links to text bulletins regarding beach closures, descriptions of marine biotoxins and associated health effects, and a factsheet of shellfish program publications.
Brief analysis of the geologic setting of the Grand Strand (Myrtle Beach, South Carolina, and vicinity) coast and the limited occurrence of sand suitable for beach re-nourishment. Students use a USGS Fact Sheet to examine the beach, near offshore, and edge of Coastal Plain geology.
103. VIEW OF BEACH STRUCTURES ON NORTHWEST SIDE OF PIER, LOOKING SOUTHEAST; PACIFIC ELECTRIC RAILWAY CAR (UPPER LEFT), CONCESSION STANDS (LOWER LEFT), BANDSHELL (RIGHT), AND PIER IN BACKGROUND Photograph #5352-HB. Photographer unknown, c. 1914 - Huntington Beach Municipal Pier, Pacific Coast Highway at Main Street, Huntington Beach, Orange County, CA
The terms "high energy" and "low energy" refer to the amount of energy a wave has that reaches the face of a beach. In this student guide, two types of beaches are investigated. The objective is to be able to identify whether a beach is of high or low energy. Background information is provided, as well as instructions and worksheets for activities…
Lee County School District, Ft. Myers, FL. Dept. of Environmental Education and Instructional Development Services.
Traditional beach monitoring has focused on water quality, with little attention paid to health risks associated with beach sand. Recent research has reported that fecal indicator bacteria, as well as human pathogens can be found in beach sand and may constitute a risk to human h...
The littoral in the vicinity of Nazaré (West Portuguese coast) is characterized by two distinct coastal stretches separated by Nazaré headland: a northern sector (Norte beach) characterized by a high energetic continuous sandy beach and a southern sector (Nazaré bay beach) that corresponds to an embayed beach, sheltered by the Nazaré headland. The bay is a geomorphological expression of the Nazaré canyon head, which acts as powerful sediment sink, capturing the large longshore net southward transport at Norte beach generated by the north Atlantic high energetic swell. The northern side of the canyon head is carved on highly resistant Cretaceous limestone sustaining an underwater vertical relief that emerges on the Nazaré headland, creating a unusual nearshore wave pattern. This wave pattern not only concentrates high energy levels at the Norte beach but also contributes to local complex longshore drift gradients capable of inducing beach seasonal cross-shore variations of more than 200 m. The main factors that influence local sediment budget are: (1) canyon head capturing and (2) headland sediment bypassing. To obtain a direct measure of the net longshore drift at Norte beach (upstream boundary of the system) a large scale fluorescent tracer experiment was performed. The data will be used to validate longshore transport formulas in a high energetic environment and to access Nazaré canyon head sediment loss. Considering the anticipation of high transport rates, approximately 10 tonnes of native sand where coated with orange fluorescent ink using a set of concrete mixers. The experiment took place on the 9th to 15th September 2013 period and followed the continuous injection method (CIM). The CIM approach was justified by the expected high energy levels that inhibits sediment sampling across the surf zone. During the tracer injection procedure (approx. 5 hours), sediment sampling was performed at 13 sites along a rectilinear coastal stretch extended through 600 m downdrift of the injection point. Tracer was injected at a rate of 16 kg each 30 sec and collected at a frequency of 10 min at each site. Complementary sampling was performed at the inner shelf and at the beach southern of the headland. In order to follow tracer downdrift movement and headland sediment bypassing low resolution sampling was extended through three more days. Oceanographic forcing throughout the experiment was measured by an offshore wave buoy and an ADCP specifically deployed for the experiment. During the first tidal cycle, data from field observations using a hand held UV light showed a southward tracer displacement of more than 600 m. After the second tidal cycle, sediment tracer was detected in the Nazaré bay beach showing headland bypassing. Further insights on the sediment transport at the Nazaré canyon head system will be supported by the analysis of sediment samples collected at the beach and inner shelf using an automated image analysis system. This work was done in the framework of the PTDC/MAR/114674/2009 program, financed by FCT which the authors acknowledge gratefully.
Beach cusps are crescentic morphological structures observed on the foreshore of beaches characterized by steep seaward protruding extensions, called cusp horns, and gently sloped landward extensions, called cusp embayments. Their formation depends on the grain size, beach slope, tidal range and incoming waves. Cusps are best developed on gravel or shingle beaches, small tidal range with a large slope for incoming waves generate a well-developed swash excursion. These structures are quickly responding to wave climate and tidal range, changing the position of the rhythmic features on the beach face. Beach cusps are favored by normal incoming waves, while oblique waves tend to wash these features out. This study aims to analyze the spatial distribution and temporal evolution of rhythmic features such as beach cusps in Massaguaçú embayment (Caraguatatuba, northern coast of São Paulo, Brazil). This embayment has an extension of 7.5 km with reflective beaches cusped mainly in its more exposed central portion. The data set for this study consists of a series of video images (Argus system), covering a stretch of the beach. Visible beach cusps were digitalized from these rectified images. Results obtained from the images were related to the wave climate, water level and the storm surges. Results show that the cusps on the upper portion of the foreshore were more regular and present than the cusps on the lower portion of the foreshore due to the tidal modulation of wave action. The cusp spacing on the upper portion of the foreshore is of about 38 m and the lower portion of the foreshore is of about 28 m and their presence was correlated with the wave direction and water elevation. As expected, waves approaching with shore-normal angles (southeast direction) were favorable to the formation of beach cusps while the waves from the southwest, south, east and northeast generated a longshore current that reduced or destroyed any rhythmic feature. Other important forcing was the influence of the water level. Waves acting at higher water levels are able to produce the less dynamic upper layer of cusps. During 31 consecutive days from 8 July 2011 to 8 August of the same year these features show four periods with the presence of cusps on the upper and lower portion of the foreshore with three periods with cups only on the upper portion of the foreshore. The analyzed dataset shows the highly dynamic behavior of cusps, with rapid generation and destruction, related directly to its forcing hydrodynamic conditions.
Beach cusps are rhythmic shoreline features made up of series of horns and embayments. Their build-up occurs in specific conditions (steep beachface, low-energy wave conditions...). These features can notably be characterized by the cusp spacing ? and their prominence ? (difference in beachface gradient between embayment and horn). At present, two main theories confront to explain the formation of such features on natural beaches : standing edge waves (special class of waves propagating longshore) and self-organisation hypothesis. - Standing edge wave theory proposes that the superimposition of incident waves and standing edge waves generates longshore variations of swash height linked with the position of edge wave nodes and anti-nodes. These variations of swash height result in regular zones of erosion. Depending on the context, different types of edge-waves may occur. The predicted beach cusp spacing is : ? = (g T^2 tan?) / ? for a sub-harmonic edge wave model ? = (g T^2 tan?) / 2? for a synchronous edge wave model with : ? : beach cusp spacing (m) g : gravitational acceleration (9.81 m/s) T : incident wave period (s) tan? : beach gradient - Self-organisation theory suggests that a combination of interactions and feedbacks between swash flow and beach topography leads to the growth of morphologic irregularities of a given wavelength (because of flow divergence or convergence), resulting in beach cusp formation and maintaining. The predicted beach cusp spacing is then : ? = f S with : ? : beach cusp spacing (m) S : horizontal extent of the swash flow (m) f : empirical constant (~1.5) Three multitemporal Terrestrial Laser Scan acquisitions have been carried out for three consecutive days on the sandy beach of Porsmilin (Brittany, France) with a spatial resolution varying from few centimetres to few metres. Moreover the hydrodynamic conditions have been obtained thanks to the Previmer project website (http://www.previmer.org/), notably based on WaveWatch3 and MARS-2D models. This study proposes to profit from the high resolution and accuracy of Terrestrial Laser data to measure the geometry and the spacing of beach cusps, to compare the measured parameters to the predicted ones (with both theories) and thus to attempt to identify the hydrodynamic process which sparks off their formation.
Chabrol, C.; Jaud, M.; Delacourt, C.; Allemand, P.; Augereau, E.; Cuq, V.
Phylogeographic studies of animals with low vagility and restricted to patchy habitats of the supralittoral zone, can uncover unknown diversity and shed light on processes that shaped evolution along a continent's edge. The Pacific coast between southern California and central Mexico, including the megadiverse Gulf of California, offers a remarkable setting to study biological diversification in the supralittoral. A complex geological history coupled with cyclical fluctuations in temperature and sea level provided ample opportunities for diversification of supralittoral organisms. Indeed, a previous phylogeographic study of Ligia, a supralittoral isopod that has limited dispersal abilities and is restricted to rocky patches, revealed high levels of morphologically cryptic diversity. Herein, we examined phylogeographic patterns of Tylos, another supralittoral isopod with limited dispersal potential, but whose habitat (i.e., sandy shores) appears to be more extensive and connected than that of Ligia. We conducted Maximum Likelihood and Bayesian phylogenetic analyses on mitochondrial and nuclear DNA sequences. These analyses revealed multiple highly divergent lineages with discrete regional distributions, despite the recognition of a single valid species for this region. A traditional species-diagnostic morphological trait distinguished several of these lineages. The phylogeographic patterns of Tylos inside the Gulf of California show a deep and complex history. In contrast, patterns along the Pacific region between southern California and the Baja Peninsula indicate a recent range expansion, probably postglacial and related to changes in sea surface temperature (SST). In general, the phylogeographic patterns of Tylos differed from those of Ligia. Differences in the extension and connectivity of the habitats occupied by Tylos and Ligia may account for the different degrees of population isolation experienced by these two isopods and their contrasting phylogeographic patterns. Identification of divergent lineages of Tylos in the study area is important for conservation, as some populations are threatened by human activities. PMID:23844103
Phylogeographic studies of animals with low vagility and restricted to patchy habitats of the supralittoral zone, can uncover unknown diversity and shed light on processes that shaped evolution along a continent’s edge. The Pacific coast between southern California and central Mexico, including the megadiverse Gulf of California, offers a remarkable setting to study biological diversification in the supralittoral. A complex geological history coupled with cyclical fluctuations in temperature and sea level provided ample opportunities for diversification of supralittoral organisms. Indeed, a previous phylogeographic study of Ligia, a supralittoral isopod that has limited dispersal abilities and is restricted to rocky patches, revealed high levels of morphologically cryptic diversity. Herein, we examined phylogeographic patterns of Tylos, another supralittoral isopod with limited dispersal potential, but whose habitat (i.e., sandy shores) appears to be more extensive and connected than that of Ligia. We conducted Maximum Likelihood and Bayesian phylogenetic analyses on mitochondrial and nuclear DNA sequences. These analyses revealed multiple highly divergent lineages with discrete regional distributions, despite the recognition of a single valid species for this region. A traditional species-diagnostic morphological trait distinguished several of these lineages. The phylogeographic patterns of Tylos inside the Gulf of California show a deep and complex history. In contrast, patterns along the Pacific region between southern California and the Baja Peninsula indicate a recent range expansion, probably postglacial and related to changes in sea surface temperature (SST). In general, the phylogeographic patterns of Tylos differed from those of Ligia. Differences in the extension and connectivity of the habitats occupied by Tylos and Ligia may account for the different degrees of population isolation experienced by these two isopods and their contrasting phylogeographic patterns. Identification of divergent lineages of Tylos in the study area is important for conservation, as some populations are threatened by human activities.
Beaches in the United States of (North) America are subject to closure when bacterial counts exceed water quality criteria. Many authorities base these decisions on water samples that typically require at least 18 hours to analyze. This persistence approach, or model, often leads to erroneous decisions due to the great variability in bacterial concentrations. Beaches are closed when they could be open and vice versa, their true status unknown until the next day. Studies show that mathematical models based on multi-variable linear regression (MLR) principles can produce better estimates, or nowcasts, using real-time explanatory variables, such as turbidity, cloud cover, and rainfall. To make such models generally available, the Environmental Protection Agency (EPA) is developing a program called Virtual Beach (VB). VB is public-domain software for developing site-specific predictive models. It features capabilities that make it possible with reasonable effort to develop, and compare the performance of, static and dynamic MLR models. The results of tests on 2006 Huntington Beach, Lake Erie beach data are presented. In addition to nowcasting, the work begins to address the question, can weather and water forecasts be used to forecast beach conditions in advance? A preliminary affirmative answer is provided based on an analysis of the Huntington Beach data, with weather forecasts for nearby Cleveland-Hopkins international airport, and NOAA lake condition forecasts. We encourage those engaged in beach monitoring and management to request VB, applying the nowcast and forecast models developed with it to their locations of interest. Disclaimer: Although this work was reviewed by EPA and approved for presentation, it may not necessarily reflect official Agency policy.
This report documents a 1-week long field monitoring effort conducted at Pickering Beach, Delaware. The purpose of the study was to gain information concerning mooring line response of a floating breakwater subjected to boat-generated waves. Data are comp...
Wayne Hu lectures on Secondary Anisotropy in the CMB. The lecture is the first in a series of 3 he delivered as part of the "Cosmology at the Beach" winter school organized by Berkeley Lab's George Smoot in Los Cabos, Mexico from Jan. 12-16, 2009.
The Division of Beaches and Shores contracted the services of the University of Florida, Department of Recreation, Parks and Tourism to inventory and map all public owned properties which front the Atlantic Ocean, Straits of Florida, and Gulf of Mexico, a...
This article presents an interview with Beatrice Beach Szekely, a comparative education scholar that specialized in the Soviet Union. She was editor of the journal "Soviet Education" from 1970 to 1989. During the interview, Szekely talked about how she became personally involved in Russian/Soviet studies of education. She related that her interest…
The proposal concerns restoration and periodic nourishment of 13,200 feet of ocean beach and a rubble stone terminal groin extending 800 feet seaward. Proposed for the future, when and if needed, is the placement of two additional rubble groins 760 feet a...
Beach erosion and inlet shoaling have been determined by both public and private authorities to be a serious problem for the economy and general welfare of the citizens and residents of Florida. To effectively cope with this problem, the state must develo...
The Fossil Preserve built as part of the Cliffwood Beach Shore Protection project in the mid 1970's is important to scientists. The Township of Aberdeen now wants the Preserve filled to halt further cliff erosion and avoid safety problems. Before filling ...
Wayne Hu lectures on Secondary Anisotropy in the CMB. The lecture is the first in a series of 3 he delivered as part of the "Cosmology at the Beach" winter school organized by Berkeley Lab's George Smoot in Los Cabos, Mexico from Jan. 12-16, 2009.
This guide introduces visitors to the sediments and geologic histories of Mile and Half Mile beaches in Reid State Park on the coast of Maine. Topics include the source of the sand presently found on the beaches, the origin and migration of beach deposits, dunes, and marsh peat deposits as sea level has risen, and some history of the area. Some suggested activities for visitors include observing grain size sorting of beach sands, observing the size and angle of waves washing ashore, and making measurements of beach cusps and berms. References and links to additional information are included.
The present study reported the first observation of isopod parasite, Nerocila phaiopleura infestation on Chirocentrus nudus an economically important fish from Cuddalore coast, Southeast coast of India. The maximum prevalence of 6.3 % and mean intensity of 3.2 were observed during pre-monsoon 2010 and monsoon 2010 respectively. The highest intensity 7 was observed in the single host during monsoon. The site of attachment leads to wound and offer the secondary infection. Two pathogenic bacteria Streptococcus aureus and E. coli were isolated from the wound. PMID:24808654
Biological introductions can alter the ecology of local assemblages and are an important driver of global environmental change. The first step towards understanding the impact of a non-indigenous species is to study its distribution and associations in the invaded area. In Sydney Harbour, the non-indigenous isopod Cirolana harfordi has been reported in densities up to 0.5 individuals per cm2 in mussel-beds. Abundances of this species have, however, been largely overlooked in other key habitats. The first aim of this study was to evaluate the abundances and distribution of C. harfordi across different habitats representative of Sydney Harbour. Results showed that C. harfordi occurred in oyster and mussel-beds, being particularly abundant in oyster-beds. We also aimed to determine the role of C. harfordi as a predator, scavenger and detritus feeder by investigating the relationships between densities of C. harfordi and (i) the structure of the resident assemblages, and (ii) deposited organic matter in oyster-beds. Densities of C. harfordi were not related to the structure of the assemblages, nor amounts of deposited organic matter. These findings suggested little or no ecological impacts of C. harfordi in oyster-beds. These relationships may, however, affect other variables such as growth of individuals, or be disguised by high variability of assemblages among different locations. Future studies should, therefore, test the impacts of C. harfordi on the size of organisms in the assemblage and use manipulative experiments to control for spatial variation. This study is the first published work on the ecology of the invasion of C. harfordi and provides the starting-point for the study of the impacts of this species in Sydney Harbour.
Bugnot, Ana B.; Coleman, Ross A.; Figueira, Will F.; Marzinelli, Ezequiel M.
Animal-bacterial symbioses are highly dynamic in terms of multipartite interactions, both between the host and its symbionts as well as between the different bacteria constituting the symbiotic community. These interactions will be reflected by the titres of the individual bacterial taxa, for example via host regulation of bacterial loads or competition for resources between symbionts. Moreover, different host tissues represent heterogeneous microhabitats for bacteria, meaning that host-associated bacteria might establish tissue-specific bacterial communities. Wolbachia are widespread endosymbiotic bacteria, infecting a large number of arthropods and filarial nematodes. However, relatively little is known regarding direct interactions between Wolbachia and other bacteria. This study represents the first quantitative investigation of tissue-specific Wolbachia-microbiota interactions in the terrestrial isopod Armadillidium vulgare. To this end, we obtained a more complete picture of the Wolbachia distribution patterns across all major host tissues, integrating all three feminizing Wolbachia strains (wVulM, wVulC, wVulP) identified to date in this host. Interestingly, the different Wolbachia strains exhibited strain-specific tissue distribution patterns, with wVulM reaching lower titres in most tissues. These patterns were consistent across different host genetic backgrounds and might reflect different co-evolutionary histories between the Wolbachia strains and A. vulgare. Moreover, Wolbachia-infected females carried higher total bacterial loads in several, but not all, tissues, irrespective of the Wolbachia strain. Taken together, this quantitative approach indicates that Wolbachia is part of a potentially more diverse bacterial community, as exemplified by the presence of highly abundant bacterial taxa in the midgut caeca of several A. vulgare populations. PMID:24750488
Dittmer, J; Beltran-Bech, S; Lesobre, J; Raimond, M; Johnson, M; Bouchon, D
In the present study about, 66 copepod parasites of Lernaeenicus hemiramphi of two Hemiramphus sp., H. far (17 copepod) and H. lutkei (49 copepod), and an isopod (Mothocya plagulophora) on the gill chamber were observed. H. lutkei was added as a new host for L. hemiramphi. The copepod infestation was almost on the ventral side of the hosts. PMID:25035596
Vijayakumar, R; Raja, K; Velvizhi, S; Sinduja, K; Gopalakrishnan, A
The isopod Sphaeroma terebrans, which bores into the prop roots of the red mangrove, Rhizophora mangle, can cause death and subsequent breakage of the inhabited root and, debatably, may reduce the support system of the tree. We examined whether different characteristics of a root or its physical setting, both of which may relate to habitat quality, influence the colonization of
The bluefish, Pomatomus saltatrix, is often a preferred host for infection by the isopod, gill ectoparasite Lironeca ovalis. Here we quantify the occurrence of infection by L. ovalis on young-of-the-year bluefish in the Hudson River estuary and evaluate whether there is a significant reduction in growth or foraging as a result of infection. Prevalence of L. ovalis on bluefish was
Rick E. Marks; Francis Juanes; Jonathan A. Hare; David O. Conover
Background: Evolutionary interpretations of life-history as well as physiological patterns require distinction between genotypic variations and environmentally induced phenotypic variation. Problem: We investigate the extent to which variation in life history and metabolism have an environmental or a genetic basis in an invasive species. Methods: We used the widely distributed isopod, Porcellio laevis, as a model. To examine the effects
Preference tests were performed over a two-week period in September 2001 in which isopods ( Idotea baltica) and amphipods ( Gammarus oceanicus) were offered choices of three common species of algae from the Baltic Sea: Enteromorpha intestinalis, Cladophora spp., and Fucus vesiculosus. After a 48-hour starvation period, 20 individuals of each grazer species were placed in aquaria containing approximately 1.0 g of each algal species. Fifteen trials for each grazer species were run for 20 hours. We found that G. oceanicus ate significantly more Cladophora spp. and E. intestinalis than F. vesiculosus (p<0.001), with a preference order of: Cladophora spp.> E. intestinalis> F. vesiculosus. Similarly, I. baltica ate significantly more of both the filamentous green algae than F. vesiculosus (p<0.001), with a preference order of: E. intestinalis> Cladophora spp.> F. vesiculosus. Given the preference of isopods and amphipods for filamentous green algae, we might expect these algae to be maintained at low biomass levels. However, this is clearly not the case in the Baltic Sea. Nutrient enrichment (bottom-up effects) is the accepted dominant reason for the non-controlling impact of algal grazers, but other reasons may include cascading trophic effects resulting from the removal of large piscivorous fish (top-down effects).
The issue-focused, peer-reviewed article addresses how beach closings are on the rise, but the public is not being given accurate information to help them get involved in solving the problem. The media, the publics primary information source, must provide information based on factual scientific evidence, not be swayed by economic and political factors, and work with scientists to obtain data and facts.
Erika Jensen and Sandra McLellan (Great Lakes WATER Institute;)
Two types of cemented beach deposits occur on reef islands off the coast of Belize. These are (1) intertidal beachrock that is dominantly cemented by marine aragonite and high-magnesium-calcite cements, and (2) supratidal cayrock that is cemented mainly by vadose low-magnesium-calcite cements. Besides differences in position relative to present sea level and resulting early diagenesic features, beachrock and cayrock can
Wave reflection was measured during the RIPEX/SteepBeach experiment conducted at the Sand City Beach in Monterey Bay, California during April/May 2001. The morphology is a barred shoreline, cut by rip channels spaced 100-200 m apart. The beach slope is steep at 1:5, and the slope offshore of the bar is 1:20. Measuring wave reflection in the dissipative surf zone is complicated because the wave field is not spatially homogeneous and the nodes of the reflected waves pose difficulties in analysis. The inverse approach by Dickson et.al. (1995) is extended to the case of local pressure/velocity (puv) measurements, to avoid having to assume spatial homogeniety. In this inverse approach, the various expected puv cross-spectra and energy density spectra are modeled for a reflective wave field and compared with actual measurements. The unknown coefficients as a function of frequency are reflection coefficient, phase difference, mean incident wave direction, and incident wave energy of the model, and are determined iteratively in a least square sense. The estimated reflection coefficients increase towards the shoreline inside the surf zone, decrease with increasing frequency and vary with the tidal stage. Dickson, W.S., T.H.C. Herbers, and E.B. Thornton, 1995, Wave Reflection from Breakwater, J. Waterway, Port, Coastal and Ocean Engineering, Vol. 121 (5), 262-268.
Nott (2013) argued that Tamura's (2012) review of beach ridges as palaeoenvironment records comprises an incorrect interpretation of the processes of building coarse sand beach ridges in NE Australia. Nott (2013) stressed no possibility of aeolian transport of coarse sand onto beach ridges during both cyclone and non-cyclone conditions. The facts presented by Nott (2013) however fail to completely rule out the possibility that aeolian transport could be at least contributing to the building of the beach ridges. This reply aims to clarify the original intentions of Tamura (2012), which Nott (2013) appears to have misunderstood, and further examines the possibility of aeolian transport of coarse sand onto the beach ridges from incipient ridges. If this does occur, then it is appropriate to question how this might affect the theory and algorithm employed by Nott et al. (2009) and Forsyth et al. (2010) to assess the intensity and frequency of prehistoric cyclone landfall.
Microorganisms associated with coastal sands serve as a natural biofilter, providing essential nutrient recycling in nearshore environments and acting to maintain coastal ecosystem health. Anthropogenic stressors often impact these ecosystems, but little is known about whether these disturbances can be identified through microbial community change. The blowout of the Macondo Prospect reservoir on April 20, 2010, which released oil hydrocarbons into the Gulf of Mexico, presented an opportunity to examine whether microbial community composition might provide a sensitive measure of ecosystem disturbance. Samples were collected on four occasions, beginning in mid-June, during initial beach oiling, until mid-November from surface sand and surf zone waters at seven beaches stretching from Bay St. Louis, MS to St. George Island, FL USA. Oil hydrocarbon measurements and NOAA shoreline assessments indicated little to no impact on the two most eastern beaches (controls). Sequence comparisons of bacterial ribosomal RNA gene hypervariable regions isolated from beach sands located to the east and west of Mobile Bay in Alabama demonstrated that regional drivers account for markedly different bacterial communities. Individual beaches had unique community signatures that persisted over time and exhibited spatial relationships, where community similarity decreased as horizontal distance between samples increased from one to hundreds of meters. In contrast, sequence analyses detected larger temporal and less spatial variation among the water samples. Superimposed upon these beach community distance and time relationships, was increased variability in bacterial community composition from oil hydrocarbon contaminated sands. The increased variability was observed among the core, resident, and transient community members, indicating the occurrence of community-wide impacts rather than solely an overprinting of oil hydrocarbon-degrading bacteria onto otherwise relatively stable sand population structures. Among sequences classified to genus, Alcanivorax, Alteromonas, Marinobacter, Winogradskyella, and Zeaxanthinibacter exhibited the largest relative abundance increases in oiled sands. PMID:24040219
Newton, Ryan J; Huse, Susan M; Morrison, Hilary G; Peake, Colin S; Sogin, Mitchell L; McLellan, Sandra L
Microorganisms associated with coastal sands serve as a natural biofilter, providing essential nutrient recycling in nearshore environments and acting to maintain coastal ecosystem health. Anthropogenic stressors often impact these ecosystems, but little is known about whether these disturbances can be identified through microbial community change. The blowout of the Macondo Prospect reservoir on April 20, 2010, which released oil hydrocarbons into the Gulf of Mexico, presented an opportunity to examine whether microbial community composition might provide a sensitive measure of ecosystem disturbance. Samples were collected on four occasions, beginning in mid-June, during initial beach oiling, until mid-November from surface sand and surf zone waters at seven beaches stretching from Bay St. Louis, MS to St. George Island, FL USA. Oil hydrocarbon measurements and NOAA shoreline assessments indicated little to no impact on the two most eastern beaches (controls). Sequence comparisons of bacterial ribosomal RNA gene hypervariable regions isolated from beach sands located to the east and west of Mobile Bay in Alabama demonstrated that regional drivers account for markedly different bacterial communities. Individual beaches had unique community signatures that persisted over time and exhibited spatial relationships, where community similarity decreased as horizontal distance between samples increased from one to hundreds of meters. In contrast, sequence analyses detected larger temporal and less spatial variation among the water samples. Superimposed upon these beach community distance and time relationships, was increased variability in bacterial community composition from oil hydrocarbon contaminated sands. The increased variability was observed among the core, resident, and transient community members, indicating the occurrence of community-wide impacts rather than solely an overprinting of oil hydrocarbon-degrading bacteria onto otherwise relatively stable sand population structures. Among sequences classified to genus, Alcanivorax, Alteromonas, Marinobacter, Winogradskyella, and Zeaxanthinibacter exhibited the largest relative abundance increases in oiled sands.
Newton, Ryan J.; Huse, Susan M.; Morrison, Hilary G.; Peake, Colin S.; Sogin, Mitchell L.; McLellan, Sandra L.
The beaches on the west coast of Cotentin, on the Cherbourg Peninsula in Normandy, France, experience mean spring tidal ranges of 9.3–11.4m. A study of the morphology, hydrodynamics and grain-size characteristics of these beaches was carried out in order to highlight the influence of large tidally induced water level fluctuations on their morphodynamics. These beaches are herein referred to as
F. Levoy; E. J. Anthony; O. Monfort; C. Larsonneur
A new semi-empirical model for tailings beach slope prediction is presented. The model is based on existing non-Newtonian rheology theory combined with some well-established turbulent channel flow equations. It is shown that solid particles do not deposit from the self-formed channels of the tailings slurry as it flows down the beach, and that the slope of the beach is dictated
This paper compares shoreline and beach morphology changes and responses to storms from 1985 to 1988 along sections of a rapidly eroding coast at the Bayou Lafourche headland, Louisiana. A beach consisting of a cement-filled bag seawall and nourishment was compared with natural beaches to the west and east of the project. Local patterns of beach response could be attributed to several recent processes and historical conditions. Hurricane Gilbert, which made landfall in Mexico, caused about 70% of the sediment loss on both the artificially-stablized and the natural shorelines over this three-year period.
Beach debris abundance and weight were estimated from surveys on 11 beaches of the Gulf of Oman along the Omani coast. Debris were collected on two occasions from 100 m transects, sorted and categorized by origin and type. Overall contaminations ranged from 0.43 to 6.01 items m(-1) of beach front on different beaches with a mean value of 1.79+/-1.04 gm(-1) (95% C.I). In terms of weight, contamination levels ranged from 7.8 to 75.44 gm(-1) of beach front with a mean contamination of 27.02+/-14.48 gm(-1) (95% C.I). In terms of numbers of items, plastic debris ranked first on all beaches followed by either wood items or other organic materials such as cigarette butts. Industrial debris remained few on all beaches (<10%). Most debris had a local origin and, in terms of numbers, were associated with beach recreational activities whereas fishing debris represented the largest proportion of the debris in terms of weight. There were notable differences between beaches in the relative abundance of recreation-related and fishing-related debris. PMID:15530520
... samples taken annually at beaches around the country, Great Lakes beaches have the highest failure rate, with excessively ... Main Street Beach in Chautauqua County In the Great Lakes, 13 percent of samples failed to meet federal ...
Ecological monitoring of algae, invertebrates, and fishes was conducted in the southeast Florida coast in connection with offshore dredging and beach nourishment projects. The Pompano Beach to Lauderdale-by-the-Sea segment of the Broward County Beach Eros...
D. J. Harrema J. van Montfrans M. J. Thompson W. P. Azzinaro W. R. Courtenay
... Anaheim Bay Harbor, Calif.; Naval Weapons Station, Seal Beach. 334.930 Section... Anaheim Bay Harbor, Calif.; Naval Weapons Station, Seal Beach. (a) The restricted...west jetties at the United States Naval Weapons Station, Seal Beach, California,...
Detailed Project Report present results of an analysis of beach erosion problems at Sherwood Island State Park, and investigated several alternative plans of erosion control for West Beach, the Sherwood Island State Park. Recommended beach widening by pla...
...Special Local Regulations; Palm Beach World Championship, Atlantic Ocean; Jupiter...Jupiter, Florida during the Palm Beach World Championship, a high speed power boat race. The Palm Beach World Championship is scheduled to take...
...the 2011 Wrightsville Beach/Quintiles Marathon will be transiting across the bridge...the 2011 Wrightsville Beach/Quintiles Marathon. DATES: This deviation is effective...The Wrightsville Beach/Quintiles Marathon Committee on behalf of the North...
...Intracoastal Waterway, West Palm Beach, FL AGENCY: Coast Guard...Intracoastal Waterway, in West Palm Beach, Florida, during the West Palm Beach Triathlon Championship...designated representative. DATES: Comments and related...
...Intracoastal Waterway; West Palm Beach, FL AGENCY: Coast Guard...Intracoastal Waterway, in West Palm Beach, Florida, during the West Palm Beach Triathlon Championship...designated representative. DATES: This rule is effective...
...Miami Super Boat Grand Prix, Atlantic Ocean; Miami Beach, FL AGENCY: Coast...special local regulation on the Atlantic Ocean east of Miami Beach, Florida...will be held on the waters of the Atlantic Ocean east of Miami Beach,...
...Jacksonville Sea and Sky Spectacular, Atlantic Ocean; Jacksonville Beach, FL AGENCY...safety zone on the waters of the Atlantic Ocean east of Jacksonville Beach, Florida...host an air show event over the Atlantic Ocean in Jacksonville Beach, FL....
Beaches are subject to closure when bacterial counts exceed water quality criteria. Many authorities base these decisions on sample counts, which typically require a day or more to analyze. Sometimes called the persistence model, because conditions are assumed to persist, experie...
Studies of coastal morphodynamics are becoming increasingly more focused on quantification of relationships between processes, form and function of dynamic landform systems because wave climates (e.g., wave height, wave period, seasonality, cyclical patterns) and sediments (i.e., composition, size, and shape) interact in various ways to collectively produce distinctive types of beaches. This paper identifies criteria and boundary conditions that characterize
Lindino Benedet; Charles W. Finkl; Thomas Campbell; Antonio Klein
OBJECTIVES. The purpose of the study was to determine the health risks of swimming at ocean beaches in Sydney, Australia. METHODS. From people attending 12 Sydney beaches in the period from December 5, 1989 to February 26, 1990, we recruited a cohort of 8413 adults who agreed to participate in this study. Of these, 4424 were excluded either because they had been swimming in the previous 5 days or because they reported a current illness. Of the remainder, 2839 successfully completed a follow-up telephone interview conducted within 10 days after recruitment. We recorded reported respiratory, gastrointestinal, eye, and ear symptoms and fever that occurred within the 10 days between initial interview on the beach and the follow-up interview. RESULTS. A total of 683 participants (24.0%) reported experiencing symptoms in the 10 days following initial interview. Of these, 435 (63.7%) reported respiratory symptoms. Swimmers were almost twice as likely as nonswimmers to report symptoms. There was a linear relationship between water pollution and all reported symptoms with the exception of gastrointestinal complaints. CONCLUSIONS. Swimmers at Sydney ocean beaches are more likely to report respiratory, ear, and eye symptoms than beachgoers who do not swim. The incidence of these symptoms increases slightly with increasing levels of pollution.
Corbett, S J; Rubin, G L; Curry, G K; Kleinbaum, D G
Beaches in the United States of (North) America are subject to closure when bacterial counts exceed water quality criteria. Many authorities base these decisions on water samples that typically require at least 18 hours to analyze. This persistence approach, or model, often leads...
Summary On Kos island, Greece, along an investigated coastal segment 3 km in length, four adjacent sectors were distinguished, (1)\\u000a Empros beach, a rocky shore with plunging cliffs and a steeply dipping, submarine talus, (2) Thermi beach, a „coarse-clastic\\u000a beach” with a subaerial cliff fringed by a bouldery to coarse gravelly beach with poorly developed zonation, (3) Dimitra beach,\\u000a a gravelly
Compared to the striking diversification and levels of endemism observed in many terrestrial groups within the Hawaiian Archipelago, marine invertebrates exhibit remarkably lower rates of endemism and diversification. Supralittoral invertebrates restricted to specific coastal patchy habitats, however, have the potential for high levels of allopatric diversification. This is the case of Ligia isopods endemic to the Hawaiian Archipelago, which most likely arose from a rocky supralittoral ancestor that colonized the archipelago via rafting, and diversified into rocky supralittoral and inland lineages. A previous study on populations of this isopod from O'ahu and Kaua'i revealed high levels of allopatric differentiation, and suggested inter-island historical dispersal events have been rare. To gain a better understanding on the diversity and evolution of this group, we expanded prior phylogeographic work by incorporating populations from unsampled main Hawaiian Islands (Maui, Moloka'i, Lana'i, and Hawai'i), increasing the number of gene markers (four mitochondrial and two nuclear genes), and conducting Maximum likelihood and Bayesian phylogenetic analyses. Our study revealed new lineages and expanded the distribution range of several lineages. The phylogeographic patterns of Ligia in the study area are complex, with Hawai'i, O'ahu, and the Maui-Nui islands sharing major lineages, implying multiple inter-island historical dispersal events. In contrast, the oldest and most geographically distant of the major islands (Kaua'i) shares no lineages with the other islands. Our results did not support the monophyly of all the supralittoral lineages (currently grouped into L. hawaiensis), or the monophyly of the terrestrial lineages (currently grouped into L. perkinsi), implying more than one evolutionary transition between coastal and inland forms. Geometric-morphometric analyses of three supralittoral clades revealed significant body shape differences among them. A taxonomic revision of Hawaiian Ligia is warranted. Our results are relevant for the protection of biodiversity found in an environment subject to high pressure from disturbances. PMID:24386463
Santamaria, Carlos A; Mateos, Mariana; Taiti, Stefano; DeWitt, Thomas J; Hurtado, Luis A
Models for the evolution of cannibalism highlight the importance of asymmetries between individuals in initiating cannibalistic attacks. Studies may include measures of body size but typically group individuals into size/age classes or compare populations. Such broad comparisons may obscure the details of interactions that ultimately determine how socially contingent characteristics evolve. We propose that understanding cannibalism is facilitated by using an interacting phenotypes perspective that includes the influences of the phenotype of a social partner on the behaviour of a focal individual and focuses on variation in individual pairwise interactions. We investigated how relative body size, a composite trait between a focal individual and its social partner, and the sex of the partners influenced precannibalistic aggression in the endangered Socorro isopod, Thermosphaeroma thermophilum. We also investigated whether differences in mating interest among males and females influenced cannibalism in mixed sex pairs. We studied these questions in three populations that differ markedly in range of body size and opportunities for interactions among individuals. We found that relative body size influences the probability of and latency to attack. We observed differences in the likelihood of and latency to attack based on both an individual's sex and the sex of its partner but found no evidence of sexual conflict. The instigation of precannibalistic aggression in these isopods is therefore a property of both an individual and its social partner. Our results suggest that interacting phenotype models would be improved by incorporating a new conditional ?, which describes the strength of a social partner's influence on focal behaviour. PMID:23516960
Bleakley, B H; Welter, S M; McCauley-Cole, K; Shuster, S M; Moore, A J
Background Ligia isopods are widely distributed in the Pacific rocky intertidal shores from central California to central Mexico, including the Gulf of California. Yet, their biological characteristics restrict them to complete their life cycles in a very narrow range of the rocky intertidal supralittoral. Herein, we examine phylogeographic patterns of Ligia isopods from 122 localities between central California and central Mexico. We expect to find high levels of allopatric diversity. In addition, we expect the phylogeographic patterns to show signatures of past vicariant events that occurred in this geologically dynamic region. Methodology/Principal Findings We sequenced two mitochondrial genes (Cytochrome Oxidase I and 16S ribosomal DNA). We conducted Maximum Likelihood and Bayesian phylogenetic analyses. We found many divergent clades that, in general, group according to geography. Some of the most striking features of the Ligia phylogeographic pattern include: (1) deep mid-peninsular phylogeographic breaks on the Pacific and Gulf sides of Baja peninsula; (2) within the Gulf lineages, the northern peninsula is most closely related to the northern mainland, while the southern peninsula is most closely related to the central-southern mainland; and, (3) the southernmost portion of the peninsula (Cape Region) is most closely related to the southernmost portion of mainland. Conclusions/Significance Our results shed light on the phylogenetic relationships of Ligia populations in the study area. This study probably represents the finest-scale phylogeographic examination for any organism to date in this region. Presence of highly divergent lineages suggests multiple Ligia species exist in this region. The phylogeographic patterns of Ligia in the Gulf of California and Baja peninsula are incongruent with a widely accepted vicariant scenario among phylogeographers, but consistent with aspects of alternative geological hypotheses and phylo- and biogeographic patterns of several other taxa. Our findings contribute to the ongoing debate regarding the geological origin of this important biogeographic region.
Hurtado, Luis A.; Mateos, Mariana; Santamaria, Carlos A.
Compared to the striking diversification and levels of endemism observed in many terrestrial groups within the Hawaiian Archipelago, marine invertebrates exhibit remarkably lower rates of endemism and diversification. Supralittoral invertebrates restricted to specific coastal patchy habitats, however, have the potential for high levels of allopatric diversification. This is the case of Ligia isopods endemic to the Hawaiian Archipelago, which most likely arose from a rocky supralittoral ancestor that colonized the archipelago via rafting, and diversified into rocky supralittoral and inland lineages. A previous study on populations of this isopod from O?ahu and Kaua?i revealed high levels of allopatric differentiation, and suggested inter-island historical dispersal events have been rare. To gain a better understanding on the diversity and evolution of this group, we expanded prior phylogeographic work by incorporating populations from unsampled main Hawaiian Islands (Maui, Moloka?i, Lana?i, and Hawai?i), increasing the number of gene markers (four mitochondrial and two nuclear genes), and conducting Maximum likelihood and Bayesian phylogenetic analyses. Our study revealed new lineages and expanded the distribution range of several lineages. The phylogeographic patterns of Ligia in the study area are complex, with Hawai?i, O?ahu, and the Maui-Nui islands sharing major lineages, implying multiple inter-island historical dispersal events. In contrast, the oldest and most geographically distant of the major islands (Kaua?i) shares no lineages with the other islands. Our results did not support the monophyly of all the supralittoral lineages (currently grouped into L. hawaiensis), or the monophyly of the terrestrial lineages (currently grouped into L. perkinsi), implying more than one evolutionary transition between coastal and inland forms. Geometric-morphometric analyses of three supralittoral clades revealed significant body shape differences among them. A taxonomic revision of Hawaiian Ligia is warranted. Our results are relevant for the protection of biodiversity found in an environment subject to high pressure from disturbances.
Santamaria, Carlos A.; Mateos, Mariana; Taiti, Stefano; DeWitt, Thomas J.; Hurtado, Luis A.
Field experiments have been conducted on arctic beaches to asses the effectiveness of dispersants for the cleanup of stranded oil. The application of two commercially available chemical dispersants to aged and emulsified oil plots, in the intertidal zone on a semi-sheltered beach, resulted in a significant reduction of oil loadings immediately following the experiment as compared to loadings on adjacent
...Navigable Waters 1 2009-07-01 2009-07-01 false Apollo Beach, Fla. 110.74b Section 110.74b Navigation...ANCHORAGE REGULATIONS Special Anchorage Areas Â§ 110.74b Apollo Beach, Fla. Beginning at a point approximately 300 feet south of...
...Navigable Waters 1 2010-07-01 2010-07-01 false Apollo Beach, Fla. 110.74b Section 110.74b Navigation...ANCHORAGE REGULATIONS Special Anchorage Areas Â§ 110.74b Apollo Beach, Fla. Beginning at a point approximately 300 feet south of...
The stability of three-dimensional edge waves along a sloping beach described in the Lagrangian framework is investigated by the theory of short-wavelength perturbations. We prove that the edge waves with the steepness parameter higher than 7/18 sin?, ? being the sloping angle of the beach, are unstable.
Characteristics of a two-dimensional model beach subjected to wave action and with initial slope 1:60 were investigated. The hypothesis that the beach profile reaches a repeatable equilibrium form was tested. It was found that the entire profile did not h...
Bioremediation of oil spills on tidally influenced beaches commonly involves the addition of a nutrient solution to the contaminated region of the beach at low tide to stimulate the growth of indigenous oil-degrading bacteria. Maximizing the residentce time of nutrients in the be...
The public swimming beach at Maumee Bay State Park (MBSP) on Lake Erie is often posted for occurrences of unsafe levels of bacteria. The main source of bacteria derives from a drainage ditch that discharges near the beach. We have conducted a comprehensive study to determine the feasibility of using a constructed wetland to filter the ditch water, prior to
Sebastain N. Awondo; Kevin J. Egan; Daryl F. Dwyer
A biological and inorganic assessment of five beaches on Lake Texoma was conducted from September 1999 through July 2001. Water samples for each beach site were divided into two groups, a swimming season and non-swimming season. Water properties such as temperature, alkalinity,...
270. OFFICERS' QUARTERS (FORMER SUMMER COTTAGES) AT DOG PATCH BEACH, C. 1939. VIEW NORTH DOWN GREENWICH ROAD TOWARD FORMER SUMMER COTTAGES, CONVERTED TO OFFICER'S QUARTERS, OVER-LOOKING DOG PATCH BEACH. - Quonset Point Naval Air Station, Roger Williams Way, North Kingstown, Washington County, RI
Virtual Beach version 2.2 (VB 2.2) is a decision support tool. It is designed to construct site-specific Multi-Linear Regression (MLR) models to predict pathogen indicator levels (or fecal indicator bacteria, FIB) at recreational beaches. MLR analysis has outperformed persisten...
This report summarizes the information provided by grantees that pilot tested a beach sanitary survey tool for identifying sources of bacteria to Great Lakes beaches in 2007. The purpose of the project was to improve the tool so that it could be used by b...
This assessment of the climate of racial and ethnic attitudes in Howard Beach (New York) was conducted at John Adams High School, the public school attended by the greatest number of high school children in the Howard Beach community. The survey of 1,217 students was administered in December, 1986, several weeks before the incident in which a…
We investigated if the differences in density and nematode communities of intertidal sediments from two Brazilian sheltered sandy beaches were related to environmental characteristics. The upper tide level (UTL) and the low tide level (LTL) of both beaches were surveyed in January (austral summer) and June 2001 (austral winter) during low-spring tides, by collecting samples of nematodes and sediments. Differences in density between beaches, tidal level and seasons, and nematode community structure were investigated. Sediments from both beaches were composed of medium to very coarse sand. The highest nematode densities were found at the UTL, and significant differences between beaches, tidal levels and months were found. A total of 54 genera were found and the genera composition on both sheltered beaches was similar to other exposed worldwide sandy beaches. The density and structure of the nematode community at both beaches clearly varied along the spatial and temporal scales. Gravel percentage was the most important variable explaining the spatial distribution of the nematodes, determining the four sub-communities; this suggests that the sediment characteristics influence the nematode community, rather than physical hydrodynamic forces. Temperature and salinity were suggested to be important variables affecting the temporal variation. PMID:23460426
Maria, Tatiana F; Paiva, Paulo; Vanreusel, Ann; Esteves, André M
Grande Riviere Beach in Trinidad and Tobago is an important nesting site in the Caribbean for the Critically Endangered leatherback sea turtle, Dermochelys coriacea. Community members were concerned that beach erosion and seasonal river flooding were destroying many of the nests deposited annually and thought that a hatchery was a possible solution. Over the 2001 turtle nesting season, the Institute of Marine Affairs (IMA) assessed the spatial and temporal distribution of nests using the Global Positioning System recorded to reference points, and beach dynamics using permanent bench mark profile stations, to determine areas of high risk and more stable areas for nesting. A total of 1449 leatherback nests were positioned. It was evident that at the start of the season in March, the majority of leatherback nests were deposited at the eastern section of the beach. After May, there was a continuing westward shift in nest distribution as the season progressed until August and beach erosion in the eastern section became predominant. The backshore remained relatively stable along the entire beach throughout the nesting season, and erosion was predominant in the foreshore at the eastern section of the beach, from the middle to the end of the season. Similar trends in accretion and erosion were observed in 2000. River flooding did not occur during the study period or in the previous year. With both high risk and more stable regions for turtle nesting available at Grande Riviere Beach, there was no compelling evidence to justify the need for a hatchery. PMID:17465163
Several experiments aimed at characterising the hydrodynamics of megatidal beaches outside the surf zone were carried out between 1990 and 1994 on the Cotentin coast of the Cherbourg Peninsula in Normandy. The database was established from the records of several electromagnetic current meters and pressure sensors and from field surveys. The mean spring tidal range on these beaches varies between 9.3 and 11.4 m. The results show the prevalence of strong longshore currents, with velocities up to 0.5 m s -1, on the low- and mid-tidal beach zones. Mostly oriented northward, these currents reflect both a progressive tidal wave and a strong longshore gradient in water level between the Channel Islands embayment and the English Channel. While varying largely during a typical tidal cycle, these longshore velocities are maximum at high tide, reflecting the progressive nature of the tides. This high-tide maximum velocity increases by a factor of 1.5 between the mean tide and mean spring tide, and between the mid- and low-tidal zones due to bed friction effects. Cross-shore velocities are generally weak (<0.1 m s -1), but sometimes stronger in smaller water depths. In the low-tidal zone, they are commonly oriented onshore at the beginning of the rising tide and offshore during the falling tide. This circulation results from a west-east cross-shore gradient in water level that is particularly important around the mean water level. Towards high tides, weak offshore steady flows were observed in the presence of waves. Site-specific relationships were defined in order to characterise the modulation of significant wave height by sea level fluctuations both on the shoreface and in the intertidal zone. The water depth variability during the tidal cycle induces fluctuations in the dissipation by bottom friction, resulting in wave height changes. The influence of tidal currents on the wave height proved to be very small in this context. The tidal fluctuations also influence the instantaneous near-bed currents induced by simultaneous action of non-breaking waves and the tides. During stormy conditions, wave-induced gravity orbital motions dominate the steady flows in the mid-tidal zone, outside the surf zone. At this location, the shallow water friction effect results in weak steady longshore currents, and low water depths explain strong orbital motions. The opposite conditions prevail in the low-tidal zone, where the steady tidal currents are stronger than gravity orbital velocities during a few hours around high tide. Outside this period, with the decrease in water depth and in steady current intensity due to friction effects, the tidal and gravity wave-induced currents have comparable intensities. In both the low- and mid-tidal zones, infragravity motions are weak outside the surf zone. The foregoing results show that outside the surf zone, these megatidal beaches are characterised by wave-dominated mid-tidal zones and tide-dominated low-tidal zones during spring tides. We suggest the term "mixed wave-tide-dominated" for these beaches with very large tidal ranges.
Levoy, Franck; Monfort, Olivier; Larsonneur, Claude
In field surveys, laboratory observations and field-based assays of behavior, I examined the effects of size-dependent predation\\u000a risk on the interaction between size at reproductive maturity and maternal care behavior in the stream-dwelling isopod, Lirceus fontinalis. L. fontinalis exhibit population-specific sizes at reproductive maturity which result in population differences in predation risk during\\u000a the adult phase. Females from streams containing
Beach closures due to high bacterial concentrations deprive the public and disrupt the tourist industry. Almost half the Lake Michigan beaches are closed more than 10% of the time. In 1999 the six-mile long beach in Huntington Beach, California was closed in July and August. Due ...
Caretta caretta (loggerhead sea turtle) nesting activity was recorded daily during three seasons prior to and two seasons immediately following a beach nourish- ment (replenishment) project in Palm Beach County, Florida. Surveys were done at the nourished beach (Jupiter\\/Carlin) and at two natural beaches (Juno and Tequesta). The size of the nourishment effect on nest- ing activity was estimated using
...performing aerobatic maneuvers over the Atlantic Ocean off of Jones Beach State Park...Show at Jones Beach State Park, Atlantic Ocean off of Jones Beach, Wantagh...aircraft over a specified area of the Atlantic Ocean off of Jones Beach State...
It is predicted that the coastal zone will be among the environments worst affected by projected climate change. Projected losses in beach area will negatively impact on coastal infrastructure and continued recreational use of beaches. Beach nourishment practices such as artificial nourishment, replenishment and scraping are increasingly used to combat beach erosion but the extent and scale of projects is poorly documented in large areas of the world. Through a survey of beach managers of Local Government Areas and a comprehensive search of peer reviewed and grey literature, we assessed the extent of nourishment practices in Australia. The study identified 130 beaches in Australia that were subject to nourishment practices between 2001 and 2011. Compared to projects elsewhere, most Australian projects were small in scale but frequent. Exceptions were nine bypass projects which utilised large volumes of sediment. Most artificial nourishment, replenishment and beach scraping occurred in highly urbanised areas and were most frequently initiated in spring during periods favourable to accretion and outside of the summer season of peak beach use. Projects were generally a response to extreme weather events, and utilised sand from the same coastal compartment as the site of erosion. Management was planned on a regional scale by Local Government Authorities, with little monitoring of efficacy or biological impact. As rising sea levels and growing coastal populations continue to put pressure on beaches a more integrated approach to management is required, that documents the extent of projects in a central repository, and mandates physical and biological monitoring to help ensure the engineering is sustainable and effective at meeting goals. PMID:23103149
Cooke, Belinda C; Jones, Alan R; Goodwin, Ian D; Bishop, Melanie J
Field observations of swash flow patterns and morphology change are consistent with the hypothesis that beach cusps form by self-organization, wherein positive feedback between swash flow and developing morphology causes initial development of the pattern and negative feedback owing to circulation of flow within beach cusp bays causes pattern stabilization. The self-organization hypothesis is tested using measurements from three experiments on a barrier island beach in North Carolina. Beach cusps developed after the beach was smoothed by a storm and after existing beach cusps were smoothed by a bulldozer. Swash front motions were recorded on video during daylight hours, and morphology was measured by surveying at 3-4 hour intervals. Three signatures of self-organization were observed in all experiments. First, time lags between swash front motions in beach cusp bays and horns increase with increasing relief, representing the effect of morphology on flow. Second, differential erosion between bays and horns initially increases with increasing time lag, representing the effect of flow on morphology change because positive feedback causes growth of beach cusps. Third, after initial growth, differential erosion decreases with increasing time lag, representing the onset of negative feedback that stabilizes beach cusps. A numerical model based on self-organization, initialized with measured morphology and alongshore-uniform distributions of initial velocities and positions of the swash front at the beginning of a swash cycle, reproduces the measurements, except for parts of one experiment, where limited surveys and a significant low-frequency component to swash motions might have caused errors in model initialization.
Coco, Giovanni; Burnet, T. K.; Werner, B. T.; Elgar, Steve
Dune barrier erosion and possible breakthrough due to storm and hurricane wave activity is studied near Mosquito Lagoon, in Kennedy Space Center property. The results of a geological as well as hydrodynamic appraisal of the problem area indicate that no inlet has existed across the dune barrier since 500 A.D., and that there is little likelihood of a possible breakthrough inlet remaining open permanently, primarily because the relatively shallow lagoon does not contain enough volume of water to maintain an inlet between the ocean and the lagoon. It is therefore recommended that only minimal measures, such as closing up the man-made passes across the dunes, be carried out to ensure continuation of the action of natural beach maintaining processes.
A beach umbrella intercepts all direct UV irradiance, but only part of the diffuse component. Using a simple sky view factor model, we have determined the fraction of the hemispheric diffuse irradiance that is not intercepted by the umbrella. Assuming a sensor at the surface and close to the center of the umbrella, isotropic diffuse irradiance and for an umbrella of 80 cm radius and 100 cm high, our results show that approximately 34% of the incident horizontal irradiance is not intercepted by the umbrella. These results agree with irradiance measurements conducted with and without the umbrella. The model is next extended to examine receipt of UV radiation by a human figure in a vertical position, either standing or sitting. PMID:20059729
Utrillas, María P; Martínez-Lozano, José A; Nuñez, Manuel
Beach grooming and beach award status are both shown to be associated with low macroinvertebrate taxon richness in Scotland. Previous studies in California have revealed that mechanical raking to remove wrack from sandy beaches has negative ecological consequences for coastal ecosystems. In the current study the presence and absence of eight common taxa that inhabit beached wrack on sandy beaches in Scotland was assessed at 60 sites, 24 of which were groomed and 29 of which were in receipt of a beach award. On average 4.86 of the eight taxa were found to be present on ungroomed beaches, whereas only 1.13 taxa were present on groomed beaches. Thus, beach grooming seems to be having a major effect on the biodiversity of beach macroinvertebrates in Scotland. Fewer macroinvertebrate taxa were also found on award (1.5) compared to non-award (4.38) beaches. It was also revealed that award beaches were much more likely to be groomed than non-award beaches, with 69% of award beaches surveyed being groomed compared to only 6% of non-award beaches. This pattern is surprising as the awarding bodies discourage the removal of seaweed and regulations state that beached wrack should only be removed if it constitutes a nuisance. It is concluded that award status, not nuisance level, has the main factor driving most beach grooming and that this has resulted in the substantial loss of macroinvertebrate biodiversity from award beaches in Scotland. In conclusion it is shown that beach grooming has a substantial negative impact upon strandline macroinvertebrate biodiversity in Scotland and that grooming is much more likely to occur on award beaches.
Benthic communities adjacent to a restored beach at Hallandale (Broward County), Florida were analyzed and compared to similar communities at nearby Golden Beach (Dade County). Five sand stations and four reef stations were sampled at each locality along ...
G. A. Marsh, P. R. Bowen, D. R. Deis, D. B. Turbeville, W. R. Courtenay
...coastal recreation waters, including the Great Lakes. EPA encourages coastal and Great Lakes states and tribes that have received BEACH...defined in CWA section 502(21) to mean the Great Lakes and marine coastal waters (including...
More than 150 tests have been analyzed in order to describe the dynamically stable profiles of rock slopes and gravel beaches under wave attack. Relationships between profile parameters and boundary conditions have been established. These relationships ha...
Muir Beach experiences relatively steady northwest coastal winds. Recordings at anemometer stations have indicated wind speeds averaging 10 to 12 mph over the year. This compares favorably with the minimum of 8 to 9 mph generally considered necessary for ...
11. BEACH TOILET BUILDING, OFFICE AND FIRST AID BUILDING, PLANS, ELEVATIONS AND SECTIONS Drawing No. 103-07 - Glen Echo Park, Crystal Swimming Pool, 7300 McArthur Boulevard, Glen Echo, Montgomery County, MD
18. SAND BEACH WITH SUNBATHERS AND UMBRELLAS. VIEW FROM SOUTHEAST. NORTHWEST ELEVATION OF REFRESHMENT STAND Photocopy of 1930-1940 photograph - Glen Echo Park, Crystal Swimming Pool, 7300 McArthur Boulevard, Glen Echo, Montgomery County, MD
We hypothesize that floating debris leaving polluted coastal bays accumulate on nearby pristine beaches. We examined composition,\\u000a quantities and distribution of marine debris along ?150 km of relatively undeveloped, tropical beaches in Costa do Dendê (Bahia,\\u000a Brazil). The study site is located south of Salvador City, the largest urban settlement from NE Brazil. Strong spatial variations\\u000a were observed. Plastics accounted for
Isaac R. Santos; Ana Cláudia Friedrich; Juliana Assunção Ivar do Sul
We hypothesize that floating debris leaving polluted coastal bays accumulate on nearby pristine beaches. We examined composition, quantities and distribution of marine debris along approximately 150 km of relatively undeveloped, tropical beaches in Costa do Dendê (Bahia, Brazil). The study site is located south of Salvador City, the largest urban settlement from NE Brazil. Strong spatial variations were observed. Plastics accounted for 76% of the sampled items, followed by styrofoam (14%). Small plastic fragments resultant from the breakdown of larger items are ubiquitous all over the area. Because the dominant littoral drift in Bahia is southward, average beach debris densities (9.1 items/m) along Costa do Dendê were threefold higher than densities previously observed north of Salvador City. River-dominated and stable beaches had higher debris quantities than unstable, erosional beaches. Areas immediately south of the major regional embayments (Camamu and Todos os Santos) were the preferential accumulation sites, indicating that rivers draining populous areas are the major source of debris to the study site. Our results provide baseline information for future assessments. Management actions should focus on input prevention at the hydrographic basin level rather than on cleaning services on beaches. PMID:18256899
Santos, Isaac R; Friedrich, Ana Cláudia; Ivar do Sul, Juliana Assunção
In a series of studies along the Great Lakes, U.S. Geological Survey scientists are examining the physical processes that influence concentrations of fecal indicator bacteria and related pathogens at recreational beaches. These studies aim to estimate human health risk, improve management strategies, and understand the fate and transport of microbes in the nearshore area. It was determined that embayed beaches act as traps, accumulating Escherichia coli (E. coli) and other bacteria in the basin and even in beach sand. Further, shear stress and wave run-up could resuspend accumulated bacteria, leading to water-contamination events. These findings are being used to target beach design and circulation projects. In previous research, it was determined that E. coli followed a diurnal pattern, with concentrations decreasing throughout the day, largely owing to solar inactivation, but rebounding overnight. Studies at a Chicago beach identified the impact of wave-induced mass transport on this phenomenon, a finding that will extend our understanding of bacterial fate in the natural environment. In another series of studies, scientists examined the impact of river outfalls on bacteria concentrations, using mechanistic and empirical modeling. Through these studies, the models can indicate range and extent of impact, given E. coli concentration in the source water. These findings have been extended to extended lengths of coastlines and have been applied in beach management using empirical predictive modeling. Together, these studies are helping scientists identify and eliminate threats to human and coastal health.
Abstract Ecosystems comprising coastal lakes and ponds are important areas for preserving biodiversity. The natural reserve “Saline di Trapani e Paceco” is an interesting natural area in Sicily, formed by the remaining strips of land among salt pans near the coastline. From January 2008 to January 2010, pitfall trapping was conducted in five sampling sites inside the study area. The community of terrestrial isopods was assessed using the main diversity indices. Twenty-four species were collected, only one of them endemic to western Sicily: Porcellio siculoccidentalis Viglianisi, Lombardo & Caruso, 1992. Two species are new to Sicily: Armadilloniscus candidus Budde-Lund, 1885 and Armadilloniscus ellipticus (Harger, 1878). This is high species richness for a single reserve in Sicily. The extended sampling period also allowed us to study species phenology. Most of the species exhibited higher activity in spring than in autumn while some species also exhibited lower activity in the summer. The species richness revealed that the study area is in an acceptable conservation status; Shannon and Pielou indices also confirmed a more or less even distribution of individuals belonging to different species.
Abstract Nanoparticles of titanium dioxide are one of most widely used nanomaterials in different products in everyday use and in industry, but very little is known about their effects on non- target cells and tissues. Terrestrial isopods were exposed to food dosed with nano-TiO2 to give final nominal concentration 1000 and 2000 µg TiO2/g dry weight of food. The effects of ingested nano-TiO2 on the model invertebrate Porcellio scaber (Isopoda, Crustacea) after short-term (3 and 7 days) and prolonged (14 and 28 days) dietary exposure was assessed by conventional toxicity measures such as feeding rate, weight change and mortality. Cell membrane destabilization was also investigated. No severe toxicity effects were observed after 3, 7, 14 or 28 days of dietary exposure to nano-TiO2, but some animals, particularly those exposed to lower concentrations of nanoparticles, had severely destabilized digestive cell membranes. It was concluded that strong destabilization of the cell membrane was sporadic, and neither concentration- nor time-related. Further research is needed to confirm this sporadic toxic effect of nanoparticles.
The low salinity of the Baltic Sea presents a physiological challenge to marine species. The marine isopod Idotea baltica is notably dominant among the shallow sublittoral of the Baltic Sea in association with Fucus vesiculosus, with permanent populations documented in salinities as low as 3 psu. To investigate the role of physiological plasticity in the successful colonisation of the Baltic by I. baltica three populations from the Swedish coast were here studied, one from the Kattegat (Malmö) and two from the Baltic Sea (Kalmar and Öregrund). These three sites cover the geographic range of this species within the Baltic Sea on the Swedish coast, and also the salinity range of this species within the Baltic Sea (10-5 psu). Individuals from these populations were exposed in the laboratory to a fully crossed experiment with the factors salinity and food source, to test for differences in the physiology of these populations under different conditions that may indicate local adaptation, or no differences that indicate physiological plasticity to differing salinity and food source. Metabolic rate, growth and thermal tolerance responses did not differ between the three populations across salinity treatments after a 12 week exposure. The results of this study indicate that the physiology of adult I. baltica is highly plastic with regard to salinity; this plasticity is likely to have facilitated their colonisation of the Baltic Sea.
Wood, Hannah L.; Nylund, Göran; Eriksson, Susanne P.
Background: Very little is known about the injury characteristics of beach volleyball.Purpose: To describe the incidence and pattern of injuries among professional male and female beach volleyball players.Study Design: Cohort study—retrospective injury recall and prospective registration.Methods: Injuries occurring over a 7.5-week interval of the summer season were retrospectively registered by interviewing 178 of the 188 participating players (95%) in the
Coastal squeeze, or foreshore narrowing, is a result of marine encroachment, such as sea-level rise in the presence of a back-beach barrier, terrestrial encroachment, such as coastal development, or both. In California, the permanent coastal population increased by almost 10 million people between 1980 and 2003, and an additional 130 million beachgoers visit Southern California beaches each year. Beaches in California are an important component of the state and federal economy and provide hundreds of thousands of jobs. Approximately 14% of the California coast from Marin County to the Mexican border is artificially armored with seawalls, rip rap, or revetment, more than half of which protects back-beach developments or lower-lying dynamic regions like harbors and dunes. Many sandy beaches that do not have back-beach armoring are still restricted by commercial and residential infrastructure, parking lots, and roadways. Although these types of coastal infrastructure are not back-beach barriers by intentional design like seawalls and rip rap, they still restrict beaches from landward migration and can cause significant placement loss of the beach. Nearly 67 km, or 44% of the total length of sandy coastline from Long Beach to the U.S.-Mexico border is backed by such infrastructure. This study is part of a broader effort to catalog the extent to which California’s beaches are restricted in the back beach, to describe the effects of back-beach barriers on sandy beach morphology, and to predict how these different beaches might behave with future sea-level rise. Beach morphology, shoreface characteristics, and historical rates of shoreline change were compared between select beaches with back-beach barriers and unrestricted beaches using 1997 LiDAR data and shoreline rates of change published in the U.S. Geological Survey’s National Assessment of Shoreline Change report. Although preliminary results of the morphological analysis show that there is no statistically significant difference in foreshore characteristics such as seasonal berm height and foreshore slope between the two types of beaches, beaches without back-beach barriers have more developed back dune systems and are significantly wider than adjacent restricted beaches, given that no extensive artificial beach nourishment has occurred. In regions such as Ventura and Imperial Beach, unrestricted beaches are 50-100% wider than adjacent beaches with back-beach barriers even with no significant differences in historical rates of shoreline change. Taking into account the nature of the back beach is just as crucial in predicting impacts of sea-level rise on beaches in California as considering inundation and retreat in the foreshore, and will be an important consideration for coastal managers in designing sea-level rise adaptation plans.
A field study was conducted on a dissipative beach at Perranporth, United Kingdom to quantify inner surf and swash-zone bed level change from time scales of individual swash/wave events to tidal cycles. Elevations were measured at millimeter resolution using a new conductivity concentration profiler that allowed quantification of the bed level throughout the duration of the wave/swash cycle and also during periods of bed exposure. Bed level changes were low-frequency-dominated. But individual event-scale net bed level changes exceeding the low frequency and tidal-scale net bed level change were also observed. Net bed level change for individual events was nearly normally distributed with most individual events displaying little or no net bed level change. 'Large' erosion and accretion events with bed level elevation magnitudes that exceeded net tidal elevation change occurred with similar frequency. The similarity between the frequency of 'large' erosion and accretion events suggests that a few events may be ultimately responsible for the observed net elevation change over the tidal cycle. The 'large' events displayed different hydrodynamic characteristics. Erosion events have longer duration onshore-directed flow and higher maximum onshore-directed velocity magnitude than offshore-directed velocity magnitude. The opposite was found for accretion events.
The activity and life history of the cirolanid isopod Natatolana borealisLilljeborg has been studied using (primarily) fish-baited traps deployed at a deep-water station (190 m) in Loch Fyne, Scotland. A voracious scavenger, it burrows into soft mud, emerging to feed when suitable food odours are detected in the water. Isopods were attracted significantly to baited vs. non-baited traps. Underwater video observations revealed that most animals were active in the vicinity of traps, that capture efficiency was low, but retention complete. Only traps on the sea-bed captured mancas or juveniles in any numbers. Any seasonal pattern in catch rate through the year was confounded by high variability. Only one (manca-)brooding female was ever caught in a trap (in April). It is assumed that brooding females desist from feeding. The sex ratio of isopods in most trap collections was thus significantly male dominated. Mancas were trapped during February to August. Growth rate was slowest in adults and was similar for males and females. The maximum growth rate occurred during autumn associated with the seasonal cycle in bottom water temperatures. Longevity was estimated (by following peaks in the size-frequency distributions with time) to be c. 2·5 years, with sexual maturity (based on oostegites/spurred appendix masculinae) achieved after c. 19 months. Semelparity is suggested. A low incidence of an unnamed epicaridean parasite is reported from the Clyde population. Natatolana borealisalso carried peritrich ciliate epizoites on their antennae. Possible predators are swimming crabs and gadid fish, e.g. whiting and cod.
In amphipods and other small-sized crustaceans, allometric relationships are conventionally analysed by fitting the standard model Y = a·Xb (X and Y are, e.g., body length and weight, respectively) whose scaling exponent b is assumed to be constant. However, breakpoints in allometric relationships have long been documented in large-sized crustaceans, ultimately determined by ontogenetic, abrupt variations in the value of b. Here, the existence of breakpoints in length-weight relationships was investigated in four amphipod (i.e., Gammarus aequicauda, Gammarus insensibilis, Microdeutopus gryllotalpa, and Dexamine spinosa) and three isopod species (i.e., Lekanesphaera hookeri, Sphaeroma serratum, and Cymodoce truncata) from three Mediterranean lagoons. The power of two candidate linear models fitted to log10-transformed data - a simple model assuming a constant exponent b and a segmented model assuming b to vary after a breakpoint - was compared using a parsimonious selection strategy based on the Akaike information criterion. The segmented model with a breakpoint provided the most accurate fitting of length-weight data in the majority of the species analysed; non-conclusive results were obtained only for D. spinosa and C. truncata, of which a limited number of specimens was examined. Model parameters were consistent for amphipod and isopod species collected across the three different habitats; the generality of the results was further supported by a literature search confirming that the identified breakpoints corresponded with ontogenetic discontinuities related with sexual maturation in all the species investigated. In this study, segmented regression models were revealed to provide a statistically accurate and biologically meaningful description of length-weight relationships of common amphipod and isopod species. The methodological limitations of the approach are considered, while the practical implications for secondary production estimates are discussed.
...licensee) for operation of the Point Beach Nuclear Plant, Units...and owner from ``FPL Energy Point Beach, LLC'' to ``NextEra Energy Point Beach, LLC.'' On January...i.e., fuel cladding, reactor coolant system pressure...
...Regulatory Commission [Project No. 14345-001] Rock River Beach, Inc.; Notice of Application...filed: November 23, 2012. d. Applicant: Rock River Beach, Inc. e. Name of Project: Rock River Beach Hydroelectric Project. f....
...Regulatory Commission [Project No. 14345-001] Rock River Beach, Inc.; Notice of Application...filed: November 23, 2012. d. Applicant: Rock River Beach, Inc. e. Name of Project: Rock River Beach Hydroelectric Project f....
In this paper, we review and synthesize field measurements of suspended sediment transport on the shoreface of dissipative, intermediate and reflective beach states. The morphodynamic beach state continuum was originally established in the 1970s but at the time, only hydrodynamic processes and morphologies in these various states were described. Since the early 1980s when sensors capable of resolving suspended sediment concentration at intra-wave time scale became available, many studies have examined suspended sediment transport by waves and currents on the shoreface. The synthesis of this work shows that the two end states in the morphodynamic continuum, which are the dissipative and reflective states, exhibit relatively small rates of cross-shore sediment transport and weak gradients in that transport which both ensure that the nearshore morphology is relatively stable. The intervening intermediate beach states typically exhibit prominent bar topographies and in these states, strong morphodynamic feedbacks between hydrodynamic processes and morphology create locally large transport rates and sharp transport gradients which is the reason for the dynamic nature of these beach states. Transport processes driving sediment onshore and offshore within beach states are discussed as well as the transport processes responsible for state transitions.
Aagaard, Troels; Greenwood, Brian; Hughes, Michael
Cyathura carinata, an infaunal, fossorial, isopod is a dominant member of a brackish, shallow water macrobenthic community on the south coast of Sweden. It has a bi-annual life-cycle. Breeding occurs in June-July, and a single brood of between 18-63 eggs per female is produced. The eggs take about 3-4 weeks to develop, the juveniles emerge in mid-late July. Initial recruitment in the study area was estimated to be 1480-1850 juveniles m -2 for 1981-1983 year classes. About 5% of the recruits survive to reproductive age two years later. Growth was characterized by fast growth during summer-autumn, stagnation in winter, and a slow start in spring. Females and males were not separated until just prior to reproduction (i.e. in June of the second year). At this stage males were larger than females and sex ratio was 1:1. During the breeding season, the abundance of males decreased rapidly due to post-reproductive death. Females continued to live, carrying the developing eggs in their brood pouches. Adult females die shortly after the young are released. The entire generation of reproductive adults (two years of age) has died by mid August. No evidence of the stated protogynous hermaphroditism was found in our study. Cohort production was 1·83 g wet wt m -2 for the 1980 cohort and 1·33 for the 1981 cohort. P/B-ratios were 2·12 for the 1980 cohort and 2·48 for the 1981 cohort. The P/B-ratios found were closest to those calculated by the method of Waters when an accurate estimate of mortality was available.
The three-way catalytic converters introduced to oxidize and reduce gaseous automobile emissions represent a source of platinum group elements (PGEs), in particular platinum, palladium and rhodium, to the urban environment. Abrasion of automobile exhausts leads to an increase of the concentration of PGEs in environmental matrices such as vegetation, soil and water bodies. The bioaccumulation of Pd, Pt and Rh by the freshwater isopod Asellus aquaticus was studied in natural ecosystems and under laboratory conditions. Owing to the low concentration level (ng g(-1)) of PGEs in the animals studied. analyses were performed with a quadrupole inductively coupled plasma mass spectrometry (ICP-MS) and hafnium, copper, yttrium, rubidium, strontium and lead were monitored for spectral interference correction. Asellus aquaticus collected in an urban river showed a content (mean +/- s) of 155.4 +/- 73.4, 38.0 +/- 34.6, and 17.9 +/- 12.2 ng g(-1) (dry weight) for Pd, Pt and Rh, respectively. The exposure of Asellus aquaticus to PGE standard solutions for a period of 24h give bioaccumulation factors of Bf: 150, 85, and 7 for Pd, Pt and Rh, respectively. Exposure of Asellus aquaticus to environmental samples for different exposure periods demonstrated that PGE bioaccumulation is time dependent. and shows a higher accumulation for the materials with a higher PGE content. While all three elements have the same uptake rate for exposure to catalyst materials, for exposure to environmental materials they havc a different uptake rate which can be attributed to transformations of the PGE species in the environment. PMID:11791847
Moldovan, M; Rauch, S; Gómez, M; Palacios, M A; Morrison, G M
... Beach's Health Dos and Dont's for Protecting Your Health and Your Beach's Health You can do several things to keep yourself ... closed. Learn more about the risks to your health . Be sun safe Check the UV Index Use ...
...1625-AA08 Special Local Regulations; Miami Super Boat Grand Prix, Miami Beach, FL AGENCY: Coast Guard...Miami Beach, Florida during the Miami Super Boat Grand Prix. The Miami Super Boat Grand Prix will consist of a series of...
This study evaluates sampling procedures and statistical methos for analysis of the fauna assoicated with high-energy sandy beaches. A intensive, one-season sampling of selected physical attributes and fauna of a relatively undistrubed beach site in centr...
In the paper simultaneous samplings of both sediment and beach profiles in a continuously changing ocean beach are reported. Acquisition of these data was coordinated with observations of wind, wave, tide, longshore current, and swash. The site was locate...
Leptotrombidium (Leptotrombidium) arenicola Traub, a vector of scrub typhus, had previously been found to occur in the coastal vegetation behind the edge of open sand along the beaches of Peninsular Malaysia. Surveys of the west coast beaches of Sabah and...
... false Security Zone; Diablo Canyon Nuclear Power Plant, Avila Beach, California...1155 Security Zone; Diablo Canyon Nuclear Power Plant, Avila Beach, California...a 2,000 yard radius of Diablo Canyon Nuclear Power Plant centered at position...
The goal of this study was to quantify the microbial load (enterococci) contributed by the different animals that frequent a beach site. The highest enterococci concentrations were observed in dog feces with average levels of 7.4 × 106 CFU/g; the next highest enterococci levels were observed in birds averaging 3.3 × 105 CFU/g. The lowest measured levels of enterococci were observed in material collected from shrimp fecal mounds (2.0 CFU/g). A comparison of the microbial loads showed that 1 dog fecal event was equivalent to 6,940 bird fecal events or 3.2 × 108 shrimp fecal mounds. Comparing animal contributions to previously published numbers for human bather shedding indicates that one adult human swimmer contributes approximately the same microbial load as one bird fecal event. Given the abundance of animals observed on the beach, this study suggests that dogs are the largest contributing animal source of enterococci to the beach site.
Wright, Mary E.; Solo-Gabriele, Helena M.; Elmir, Samir; Fleming, Lora E.
A technique for inputing a monetary value to the loss in beach recreational services that would result from a hypothetical oil spill in the Georges Bank area combines an oil-spill risk analysis model with a hedonic pricing model of the market for tourist accommodations on Cape Cod and Martha's Vineyard. The estimate of beach pollution costs associated with offshore oil development allows a rational judgment of whether the benefits of developing offshore oil outweigh the costs. The method is an effort to improve the economic efficiency of coastal zone management. The report concludes with a discussion of the many sources of uncertainty and suggestions for overcoming them. Five appendices present information on the models, variables, questionnaire responses, beaches, and factor patterns. 7 figures, 27 tables.
The species composition, densities, biomass and zonation patterns of the macrobenthos of sandy beaches are greatly influenced by the morphodynamics and morphology of the beaches. Macrobenthic zonation patterns along a small-scale morphodynamic gradient, comprising eight Belgian beach sites, were investigated. By taking into account the dimensionless fall velocity ( ?) and the relative tidal range, the beach sites were ordered along the gradient from the ultra-dissipative beach type (UD) to the low tide bar/rip beach type (LTBR). The resulting beach state index varied between 1.8 and 4.2 and the beach profiles were related with the beaches' morphodynamic state. In total 35 macrobenthic species, mainly polychaetes and crustaceans, were encountered, varying between 19 and 23 species per beach site. The species composition was quite similar among beach sites, with Scolelepis squamata being abundant at all eight sites. Furthermore, the macrobenthic distribution patterns were mainly related to elevation at all beach sites. Some remarkable difference in metrics, largely related to the beach morphodynamics and the consequent hydrodynamics, were found. At the hydrodynamically benign and consequently macrobenthos-rich UD beaches, the highest macrobenthic densities and biomass occurred on the upper beach, while at the hydrodynamically harsh and thus macrobenthos-poor LTBR beaches, the maximum densities and biomass occurred lower on the beach. Species, typically occurring on the upper UD beaches, such as Eurydice pulchra, S. squamata, and Bathyporeia sarsi, were restricted to the sub-optimal middle and lower beach zone at LTBR beaches. Only Bathyporeia pilosa was found on the upper beach of both UD and LTBR beaches. The more robust polychaete Ophelia rathkei and the interstitial polychaete Hesionides arenaria were exclusively found in the hydrodynamically harsh conditions of the middle LTBR beach zone.
Four years of beach elevation surveys at Ocean Beach, San Francisco, California, are used to extend an existing equilibrium shoreline change model, previously calibrated with fine sand and moderate energy waves, to medium sand and higher-energy waves. The shoreline, characterized as the cross-shore location of the mean high water contour, varied seasonally by between 30 and 60 m, depending on the alongshore location. The equilibrium shoreline change model relates the rate of horizontal shoreline displacement to the hourly wave energy E and the wave energy disequilibrium, the difference between E and the equilibrium wave energy that would cause no change in the present shoreline location. Values for the model shoreline response coefficients are tuned to fit the observations in 500 m alongshore segments and averaged over segments where the model has good skill and the estimated effects of neglected alongshore sediment transport are relatively small. Using these representative response coefficients for 0.3 mm sand from Ocean Beach and driving the model with much lower-energy winter waves observed at San Onofre Beach (also 0.3 mm sand) in southern California, qualitatively reproduces the small seasonal shoreline fluctuations at San Onofre. This consistency suggests that the shoreline model response coefficients depend on grain size and may be constant, and thus transportable, between sites with similar grain size and different wave climates. The calibrated model response coefficients predict that for equal fluctuations in wave energy, changes in shoreline location on a medium-grained (0.3 mm) beach are much smaller than on a previously studied fine-grained (0.2 mm) beach. Copyright ?? 2011 by the American Geophysical Union.
Yates, M. L.; Guza, R. T.; O'Reilly, W. C.; Hansen, J. E.; Barnard, P. L.
Four years of beach elevation surveys at Ocean Beach, San Francisco, California, are used to extend an existing equilibrium shoreline change model, previously calibrated with fine sand and moderate energy waves, to medium sand and higher-energy waves. The shoreline, characterized as the cross-shore location of the mean high water contour, varied seasonally by between 30 and 60 m, depending on the alongshore location. The equilibrium shoreline change model relates the rate of horizontal shoreline displacement to the hourly wave energy E and the wave energy disequilibrium, the difference between E and the equilibrium wave energy that would cause no change in the present shoreline location. Values for the model shoreline response coefficients are tuned to fit the observations in 500 m alongshore segments and averaged over segments where the model has good skill and the estimated effects of neglected alongshore sediment transport are relatively small. Using these representative response coefficients for 0.3 mm sand from Ocean Beach and driving the model with much lower-energy winter waves observed at San Onofre Beach (also 0.3 mm sand) in southern California, qualitatively reproduces the small seasonal shoreline fluctuations at San Onofre. This consistency suggests that the shoreline model response coefficients depend on grain size and may be constant, and thus transportable, between sites with similar grain size and different wave climates. The calibrated model response coefficients predict that for equal fluctuations in wave energy, changes in shoreline location on a medium-grained (0.3 mm) beach are much smaller than on a previously studied fine-grained (0.2 mm) beach.
Yates, M. L.; Guza, R. T.; O'Reilly, W. C.; Hansen, J. E.; Barnard, P. L.
Even if coastal floods are quite rare events in Sardinia (Italy) at present, they have had dramatic consequences for coastal communities, particularly in conjunction with river flooding. However, flood risk (defined as the product of event probability, vulnerability and value of assets) is expected to increase significantly in the future, due to climate change, defence degradation and sea level rise. Sardinia island has a costal length of approximately 1.900 km including minor neighbouring islands (25% of the entire Italian coasts) and the estimation of the potential exposure of coastal communities to flooding is therefore a critical task. To date methods for achieving this have been based on modelling of coastal inundation using hydrodynamic or GIS-based models of varying complexity. The Dept of Civil and Environmental Engineering and Architecture at the University of Cagliari is carrying out a comprehensive activity of coastal flooding risk mapping at the regional scale within the framework of a scientific collaboration with the Sardinian Regional Authority for the Hydrographic District, that includes monitoring and scientific activities along the entire Sardinian coast. Bathymetry and topographical surveys, sediment characterization, waves and currents measurements, hydrodynamic and morphodynamic modelling are planned, focusing on critical extended areas. In this paper we present an overview of the entire activity programme and give an in-depth account of the ongoing monitoring survey of the dunal system of the Su Giudeu beach (Southern Sardinia, 50 km far from the city of Cagliari). Su Giudeu is a sandy, bay-shaped beach, extending for about 1200 m between two headlands, evolving under waves with a predominant direction of 220-240°N (Scirocco wind). The survey is expected to provide evidence of the response of the remarkable dunal system to wave runup occurring during storm events, to be used in the verification of existing numerical models of dune erosion.
...Establishment of Class C Airspace for Long Beach, CA; Public Meetings AGENCY: Federal Aviation...establish Class C airspace at Long Beach, CA. The purpose of these meetings is to provide...2640 N. Lakewood Blvd., Long Beach, CA 90815, 562-597-4401. Comments:...
The beach and the naked body are a casualty of the idealism that dominates social sciences. Despite the resurgence of work on embodiment, very few accounts have actually explored the centrality of the body on the beach. Drawing on ethnographic research on the island of Menorca (Spain), this article focuses on practices of nudity on the beach. Instead of giving
...Thunder on the Gulf, Gulf of Mexico, Orange Beach, AL AGENCY: Coast Guard, DHS...the Gulf of Mexico for the waters off Orange Beach, Alabama. This action is necessary...race on the Gulf of Mexico, south of Orange Beach, Alabama to occur from...
Sandy beaches are the prime sites for human recreation and underpin many coastal economies and developments. In many coastal areas worldwide, beach recreation relies on the use of off-road vehicles (ORVs) driven on the shore. Yet, the use of ORVs is not universally embraced due to social conflicts with other beach user groups and putative environmental consequences of vehicle traffic
Thomas A. Schlacher; Darren Richardson; Ian McLean
Regional sand resource investigations along the west coast of Florida (from Pinellas County to Collier County) identify types of primary depositional settings that are commonly explored for beach nourishment projects and indicate future availability of sand for beach restoration. Because the nature of sedimentary deposits determines sand quality and its potential use for beach nourishment, it is necessary to understand
Charles W. Finkl; Jeffrey L. Andrews; Lindino Benedet
Are people getting sick from swimming at Great Lakes beaches? Some are. According to the Centers for Disease Control and Prevention, swimmers are experiencing an increase in bacterial borne illnesses from swimming at many popular Great Lakes beaches. The beaches in the Great Lak...
Seasonal change in beach morphology is traditionally ascribed to a variation in the incident wave energy level with calm conditions in summer resulting in wide beaches with pronounced subaerial berms and energetic conditions in winter causing narrow beaches with nearshore bar morphology. The coastline of Perth, Western Australia, is characterised by a large seasonal variation in the incident wave height
...Quintiles Wrightsville Beach Full and Half Marathon. This deviation allows the bridge to...Quintiles Wrightsville Beach Full and Half Marathon committee on behalf of the North Carolina...Quintiles Wrightsville Beach Full and Half Marathon scheduled for Sunday, March 16,...
...Quintiles Wrightsville Beach Full and Half Marathon. This deviation allows the bridge to...Quintiles Wrightsville Beach Full and Half Marathon committee on behalf of the North Carolina...Quintiles Wrightsville Beach Full and Half Marathon scheduled for Sunday, March 17,...
...Quintiles Wrightsville Beach Full and Half Marathon. This deviation allows the bridge to...Quintiles Wrightsville Beach Full and Half Marathon committee on behalf of the North Carolina...Quintiles Wrightsville Beach Full and Half Marathon scheduled for Sunday, March 18,...
Beach sediments collected from the tidal flat and beach slope at the Msasani Beach, about 15 km north of the Dar es Salaam Harbour, are used to (1) establish the grain size distribution pattern, (2) assess the effect of man-made and natural structures (rivers, creeks, sea wall and groynes) on the grain size distribution, and (3) assess whether sediments are
...Lake Worth Inlet; West Palm Beach, FL AGENCY: Coast...Lake Worth Inlet, West Palm Beach, Florida, to provide...designated representative. DATES: This rule is effective...delay in the effective date of this rule would be...Lake Worth Inlet in West Palm Beach, Florida....
...Class E Airspace in the West Palm Beach, FL area, as new Standard...SIAPs) have been developed at Palm Beach County Park Airport...operations within the West Palm Beach, FL airspace area. This...coordinates of the airport. DATES: Effective 0901 UTC,...
...Embry-Riddle Wings and Waves, Atlantic Ocean; Daytona Beach, FL AGENCY...safety zone on the waters of the Atlantic Ocean east of Daytona Beach, Florida...host an air show event over the Atlantic Ocean in Daytona Beach, FL. In...
...a temporary safety zone in the Atlantic Ocean east of Sunny Isles Beach, Florida...boat races will be held in the Atlantic Ocean offshore of Sunny Isles Beach...safety zone. All waters of the Atlantic Ocean east of Sunny Isles Beach,...
To determine more accurately the real-time concentration of fecal indicator bacteria (FIB) in beach water, predictive modeling has been applied in several locations around the Great Lakes to individual or small groups of similar beaches. Using 24 beaches in Door County, Wisconsin, we attempted to expand predictive models to multiple beaches of complex geography. We examined the importance of geographic location and independent variables and the consequential limitations for potential beach or beach group models. An analysis of Escherichia coli populations over 4 yr revealed a geographic gradient to the beaches, with mean E. coli concentrations decreasing with increasing distance from the city of Sturgeon Bay. Beaches grouped strongly by water type (lake, bay, Sturgeon Bay) and proximity to one another, followed by presence of a storm or creek outfall or amount of shoreline enclosure. Predictive models developed for beach groups commonly included wave height and cumulative 48-h rainfall but generally explained little E. coli variation (adj. R2=0.19-0.36). Generally low concentrations of E. coli at the beaches influenced the effectiveness of model results presumably because of low signal-to-noise ratios and the rarity of elevated concentrations. Our results highlight the importance of the sensitivity of regressors and the need for careful methods evaluation. Despite the attractiveness of predictive models as an alternative beach monitoring approach, it is likely that FIB fluctuations at some beaches defy simple prediction approaches. Regional, multi-beach, and individual beach predictive models should be explored alongside other techniques for improving monitoring reliability at Great Lakes beaches. PMID:19875791
Nevers, Meredith B; Shively, Dawn A; Kleinheinz, Gregory T; McDermott, Colleen M; Schuster, William; Chomeau, Vinni; Whitman, Richard L
Sardinera beach in Mona Island, Puerto Rico, has a great recreational and ecological value and is an important research place to gather information on shoreline processes in an area far from the main land and with only scarce man made influences. Beach rock exposures present along the shoreline in Sardinera Beach have increased considerably during the last decade. A new management plan is being developed for Mona Island and the Department of Natural Resources (DNRA) of Puerto Rico wants to better understand the beach sand dynamics on this and other Mona Island beaches. This research includes field and laboratory work that characterize coastal sedimentary processes and helps to better understand the shoreline changes as well as seasonal variations in sand movement and composition. This work also establish the logistics and methodology basis for further studies that will expand to other Mona Island beaches. Benchmarks, GPS coordinates, and landmarks were used to establish ten permanent beach profiles along Sardinera Beach. Beach profiles were (and will be) measured monthly. Sardinera Beach sands are composed mostly of carbonate (CaCO3) components, products of the combination of biological, chemical and diagenetic processes, high grade of micritization, and of lithic limestone fragments. Sand composition differences between Sardinera Beach, the Mona Shelf and adjacent beach, reef crest and reef lagoon systems suggest Sardinera sands are not replenished by the modern marine components produced in these environments. The input of "fresh bioclasts" in this beach seems to be limited by natural (beach rock) and mane made (dock) barriers along the shore and by alteration in the current patterns produced by the man made aperture of the reef. Sardinera's micritized and recrystalized sand deposits seem to have been re-transported between the reefal lagoon and the beach. Sand volume analysis indicates a total sand loss of 1,322 m3 between the months of September to April. Aerial images from the years 1977, 1992 and 2003 show 14 to 27 meters of recession along the coast line.
This report looks beyond waves and explores the probability that waves, currents, sediments and tides self-organize into a rip current-beach cusp coupled system to create a beach condition which endangers the lives of beach bathers. The coastal geography of Baker Beach is described, and information given on how, why, and where the greatest dangers occur.
Public concerns about water quality at beaches have prompted the development of multiple linear regression and other models that can be used to "nowcast" levels of bacterial indicators. Hydrometeorological and biogeochemical data from summer, 2009 were used to develop empirical m...
In South Carolina, the beaches can be a natural laboratory for scientific inquiry. By middle school most students have visited one of the state's beaches through field trips or family vacations. These fun experiences can be a platform for scientific inquiry and investigation. Many students can describe a beach where the sand was perfect for building sand castles, too sharp to walk on, or just right on a hot summer day. With a dissecting microscope and some weak acid, these observations can be turned into an engaging activity for students to explore the chemical and/or mineralogical make-up of the sand. This presentation will describe an experiment where students use a microscope to draw sand samples and identify some common grains. The students form hypotheses about the amount of carbonate in the samples and test these hypotheses using the weak acid. By the end of the lab students should be able to identify several indications that a chemical reaction has occurred and be able to form and test a hypothesis. They should also understand that sand from different beaches may have different mineralogical compositions. This activity incorporates the following National Science Content Standards: Abilities necessary to do scientific inquiry; understandings about scientific inquiry; properties and changes of properties in matter; chemical reactions; and populations, resources, and environments. The activity was developed with the support of the National Science Foundation's Graduate Teaching Fellows in K-12 Education Program, Award # 0440568.
In 1993, the teachers in Virginia Beach City (Virginia) Public Schools surveyed parents' views concerning classroom practices as part of a client satisfaction project. Intended to increase parent involvement, gauge customer satisfaction, and guarantee continuous improvement, the survey found that comments about teacher efforts were overwhelmingly…
For centuries, beach sand has been mined for use as aggregate in concrete, for heavy minerals, and for construction fill. The global extent and impact of this phenomenon has gone relatively unnoticed by academics, NGOs, and major news sources. Most reports of sand mining activities are found at the very local scale (if the mining is ever documented at all).
It is proposed to deepen areas in the Los Angeles part of the Los Angeles-Long Beach Harbors and use the fill to create new lands for terminals. The federal part of the proposed project involves the deepening of existing Federal project channels and turni...
A user-friendly, rule-based expert system has been designed for interpretation of lithofacies characteristics of beach and nearshore depositional environments. Recently, similar expert systems have been widely applied in medicine, business, and mineral exploration. The expert system runs on a VAX 780 (trade name). By incorporating knowledge and understanding of an expert, the system can interact with a user the way
20. 8" PIPELINE ON BEACH AND ALONG PALI, VIEW WEST TOWARD KALAWAO. NOTE GATE VALVE (LARGER) AND BLOW-OFF VALVE (SMALLER). PIPELINE GENERALLY AT 20' ABOVE SEA LEVEL. - Kalaupapa Water Supply System, Waikolu Valley to Kalaupapa Settlement, Island of Molokai, Kalaupapa, Kalawao County, HI
The results of Beached Bird Surveys in Shetland during the period March 1986 to February 1987 are reported. A greater distance was surveyed than in any of the previous 8 annual periods. The 240 corpses found oiled during the period was the highest proport...
files and wave statistics from southern California constituted the data base for this two-faceted statistical study. First, daily beach profile changes were predicted using four different spectral representations of the wave field. These profile changes were predictable using spectral representations of wave energy, radiation stress, energy flux, and wave steepness. Because of constraints on statistical reliability, a longer data set
David G. Aubrey; Douglas L. Inman; Clinton D. Winant
Geophysical studies at Beach Point Peninsula, in the Edgewood area of Aberdeen Proving Ground, Maryland, provide diagnostic signatures of the hydrogeologic framework and possible contaminant pathways. These studies permit construction of the most reasonable scenario linking dense, nonaqueous-phase liquid contaminants introduced at the surface with their pathway through the surficial aquifer. Subsurface geology and contaminant presence were identified by drilling,
L. D. McGinnis; C. R. Daudt; M. D. Thompson; S. F. Miller; W. A. Mandell; J. Wrobel
The Palm Beach County Library System is evaluated for its program to date and for its existing public library resources in the County. Population trends are examined and a realistic program for the development of library services over a six-year period is recommended. The estimated costs for implementation of these recommendations are outlined in…
This report documents a conceptual design effort for the Amphibious Cargo Beaching (ACB) Lighter, a modular barge system which is being developed to replace the Navy Lighter (NL) pontoon causeway system. The ACB Lighter will be rapidly deployed from an au...
Geochemical analyses of beach-stranded tars from Seychelles can be correlated to comparable analyses of an oil sample from a well in the Seychelles offshore. The analyses also enable the precursor source rock to be characterized. Such a source rock was encountered in the three offshore wells and is extensively developed to the west and south of the granitic islands. The
Carbonate beaches are a unique example of the interaction between biological processes, creating the sediments, and physical processes, moving and often removing the sediments. On the sediment supply side, carbonate sediments are born, not made. They exist in dynamic equilibrium between production and destruction. Following the creation of carbonate sediment in coral reef and lagoon environments, the sediments are moved shoreward to the beach, transport along the shore and sometimes, eventually lost offshore, often as the result of tropical storms. Comprehensive studies of the balance between the supply and loss of carbonate sediments and beach dynamics have been completed for the islands of Mauritius and Barbados. Field studies and remote sensing (Compact Airborne Spectrometry Imaging) have been applied to develop carbonate sediment production rates for a range of reef and lagoon conditions. Using GIS, these production rates have been integrated to determine sediment supply rates for different segments of the coastline. 1-D and 2-D models of waves, hydrodynamics, sediment transport and morphodynamics were set-up and tested against observed beach response to storm events or a sequence of storm events. These complex deterministic models are not suitable for application over periods of decades. However, it was possible to characterize storm events by the extent of sand loss, and relate this to key descriptive factors for groups of storm events, thereby encapsulating the erosion response. A long-term predictive tool for evaluating beach erosion and accretion response, over a period of several decades, was developed by combining the supply rates for carbonate sediment and the encapsulated representation of the loss rates through physical processes. The ability of this predictive tool was successfully tested against observed long term beach evolution along sections of the coast in Barbados and Mauritius using air photo analysis in GIS for shoreline change over periods of 40 years. The long-term predictive tool for carbonate beach evolution provided valuable support to developing coastal zone management policy and actions to preserve the beaches in their natural form, minimizing the need for artificial nourishment of the beaches. Many models of sediment movement on shorelines are derived from clastic examples, and fit carbonate coastlines only with difficulty. We have combined field surveys of benthic biota, estimates of sediment production from skeletal growth and bioerosion, and sediment destruction by comminution and dissolution with dynamic models of sediment movement in the littoral zone, achieving improved understanding of coastal processes of erosion and deposition. Mauritius is fringed by shallow lagoons, often with luxuriant stands of Acropora. The offshore region is exhumed Pleistocene-all the sediment on the beaches comes from the lagoons. From surveys of coral cover, and estimates of sediment production from reef, sand and hardground areas, we produced dynamic models that faithfully hindcast shoreline dynamics for decades, and allowed identification of regions especially vulnerable to erosion. On the south coast of Barbados, one of the main issues in stabilising and rehabilitation the coastline is the balance between sediment from longshore drift and local sources. By identifying localised areas of characteristic sediment-producers (e.g., the foraminiferan Homotrema rubrum, the green alga Halimeda), we were able to determine the balance between proximal and distal sediment sources. The resulting model hindcasts the coastline through all the major hurricanes of the past 30 years.
The Gochang Beach, located on the southwestern coast of Korea, was studied in terms of four season variations of surface sediment and sedimentary environment. The Gochang Beach consists of the Dongho, Kwangseungri, Myeongsasipri beaches from north to south. During the four seasons of spring (May), summer (August), and fall (November), and winter (February), surface sediments of 135 sites were sampled across nine survey lines (15 sites in each survey line), respectively. The pocket-type Dongho Beach is mainly composed of fine to coarse sands, and the ratio of fine sand is the largest. The average of grain size is the coarsest in the summer. The spatial distribution of surface sediments shows a coast-parallel band of fine and medium sands during three seasons of spring, fall, and winter, whereas medium sands dominated in the northern part of the study area during the summer. These results suggest that a tide is more effective than a wave in the surface sediments of the Dongho Beach during the summer. The surface sediments of the Kwangseungri Beach are mainly composed of fine-grained sands, and the mean grain size is the coarsest in winter. Mud facies partly exists in summer, whereas it is nearly absent in winter. The spatial distribution of surface sediments shows a coast-parallel band of fine and medium sands during spring, fall, and winter. In the northern part, the study area is dominated by fine sands during summer, whereas by coarse sands during winter. These results are interpreted that tide is more effective than wave on the surface sediment distribution of the Kwangseungri Beach during summer season. The open-coast Myeongsasipri Beach is mainly composed of fine to medium sand, the distribution of which shows a coast-parallel trend. Grain-size distribution shows a bi-modal trend in the summer and winter and a uni-mode in the spring and fall. Grain size of the winter is the coarsest among those of four seasons. During the winter, the upper tidal flat was dominated by medium sand, while the lower tidal flat was dominated by find sand. Such a feature is attributed to wave-dominated sedimentation in the winter. The dominant finer-grain size of the summer rather than that of the winter is interpreted that tidal energy played an important role in the tidal flat sedimentation during the summer. Sedimentary environments of the Myeongsasipri Beach are suggestive of a seasonal change from wave-dominated conditions in the winter to tide-dominated conditions in the summer as a result of seasonal variations of the intensity of onshore-directed winds and waves. Keywords: seasonal variation, surface sediment, macro-tide, beach, Gochang Acknowledgements: This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (2010-0025733) and by the Korea Institute of Marine Science and Technology Promotion (KIMST) through the project grant of Tracking and Prediction on Impacts of Ancient Extreme Climatic Events in the West and South Coastal Zone of Korea.
Beaches dissipate wave energy and regulate the frequency that the cliff foot is subject to wave attack. The relationship between beach levels and cliff recession rates has been established for Pleistocene soft rock cliffs along the North Norfolk and Suffolk coasts, UK. The results suggest that over a decadal timescale, there is a non-linear increase in the average recession rate as the beach profile area above High Water Mark (HWM) decreases. Small changes in beach level can result in significant differences in the recession rates. The impact of a unit change in beach level on the recession rate depends on the initial beach level. On a year-by-year basis, it is possible to divide the beach level and recession relationship into a series of zones with characteristic types of behaviour. At low beach levels there is high to extremely high recession with considerable variability, whereas at high beach levels there is almost zero recession with limited variability. It is concluded that historical recession rates are the product of both the past forcing events and changes in cliff-beach state. Extrapolation of historical rates can be extremely unreliable unless it is supported by an understanding of the dynamic behaviour of the cliff-beach system and the energy inputs over the observation period.
Species richness in sandy beaches is strongly affected by concurrent variations in morphodynamics and salinity. However, as in other ecosystems, different groups of species may exhibit contrasting patterns in response to these environmental variables, which would be obscured if only aggregate richness is considered. Deconstructing biodiversity, i.e. considering richness patterns separately for different groups of species according to their taxonomic affiliation, dispersal mode or mobility, could provide a more complete understanding about factors that drive species richness patterns. This study analyzed macroscale variations in species richness at 16 Uruguayan sandy beaches with different morphodynamics, distributed along the estuarine gradient generated by the Rio de la Plata over a 2 year period. Species richness estimates were deconstructed to discriminate among taxonomic groups, supralittoral and intertidal forms, and groups with different feeding habits and development modes. Species richness was lowest at intermediate salinities, increasing towards oceanic and inner estuarine conditions, mainly following the patterns shown for intertidal forms. Moreover, there was a differential tolerance to salinity changes according to the habitat occupied and development mode, which determines the degree of sensitivity of faunal groups to osmotic stress. Generalized (additive and linear) mixed models showed a clear increase of species richness towards dissipative beaches. All taxonomic categories exhibited the same trend, even though responses to grain size and beach slope were less marked for crustaceans and insects than for molluscs or polychaetes. However, supralittoral crustaceans exhibited the opposite trend. Feeding groups decreased from dissipative to reflective systems, deposit feeders being virtually absent in the latter. This deconstructive approach highlights the relevance of life history strategies in structuring communities, highlighting the relative importance that salinity and morphodynamic gradients have on macroscale diversity patterns in sandy beaches.
Barboza, Francisco R.; Gomez, Julio; Lercari, Diego; Defeo, Omar
Bacterial pathogens in coastal sediments may pose a health risk to users of beaches. Although recent work shows that beach sands harbor both indicator bacteria and potential pathogens, it is not known how deep within beach sands the organisms may persist nor if they may be exposed during natural physical processes. In this study, sand cores of approximately 1 m depth were collected at three sites across the beach face in Kitty Hawk, North Carolina before, during and after large waves from an offshore hurricane. The presence of DNA from the fecal indicator bacterium Enterococci was detected in subsamples at different depths within the cores by PCR amplification. Erosion and accretion of beach sand at the three sites also was determined for each sampling day. The results indicate that ocean beach sands with persisting enterococci signals could be exposed and redistributed when wind, waves, and currents cause beach erosion or accretion. PMID:21984862
Gast, Rebecca J; Gorrell, Levi; Raubenheimer, Britt; Elgar, Steve
Vehicles on beaches cause numerous deleterious effects to coastal wildlife. These impacts may, hypothetically, be lessened if drivers act to reduce disturbance. Since it is unknown to what extent such behavior occurs, and whether it can reduce disturbance, we quantified the behavior of drivers who encountered birds on open-coast, sandy beaches in eastern Australia and the consequent bird responses. Drivers of commercial tourist buses never slowed or altered course ("evaded birds") to avoid disturbing birds; conversely, 34 % of drivers of private cars did evade birds. Drivers of vehicles with fishing rod holders tended ( P = 0.09) to evade birds more frequently than non-fishing vehicles. Evasion, when it occurred, was modest, and did not significantly decrease the intensity of bird response or the probability of escapes on the wing. Voluntary behavioral adjustments to alleviate impacts on wildlife may be unworkable, suggesting that other solutions (e.g., beach closures) might be the only effective and feasible way to reduce disturbance to birds on ocean beaches.
Weston, Michael A.; Schlacher, Thomas A.; Lynn, David
Vehicles on beaches cause numerous deleterious effects to coastal wildlife. These impacts may, hypothetically, be lessened if drivers act to reduce disturbance. Since it is unknown to what extent such behavior occurs, and whether it can reduce disturbance, we quantified the behavior of drivers who encountered birds on open-coast, sandy beaches in eastern Australia and the consequent bird responses. Drivers of commercial tourist buses never slowed or altered course ("evaded birds") to avoid disturbing birds; conversely, 34 % of drivers of private cars did evade birds. Drivers of vehicles with fishing rod holders tended (P = 0.09) to evade birds more frequently than non-fishing vehicles. Evasion, when it occurred, was modest, and did not significantly decrease the intensity of bird response or the probability of escapes on the wing. Voluntary behavioral adjustments to alleviate impacts on wildlife may be unworkable, suggesting that other solutions (e.g., beach closures) might be the only effective and feasible way to reduce disturbance to birds on ocean beaches. PMID:24599507
Weston, Michael A; Schlacher, Thomas A; Lynn, David
Three expeditions were performed in the framework of ANDEEP (ANtarctic benthic DEEP-sea biodiversity, colonisation history and recent community patterns) in order to understand the Southern Ocean (SO) biodiversity of the Isopoda and to investigate faunal connections with other deep-sea areas in the world oceans. We sampled mainly in the Atlantic sector of the SO (Drake Passage along the Shackleton Fracture Zone, off Elephant Island, in the South Shetland Islands area, in the northwestern Weddell Sea, and at the South Sandwich Islands), but also took two stations in each Bellingshausen Sea and Cape Basin. In total, three expeditions yielded 13,046 specimens of Isopoda. During ANDEEP I-II 5525 specimens and 317 species of Isopoda were sampled, and 7521 specimens and 496 species were discriminated from the ANDEEP III material. Overall, Isopoda comprised 35% of all Peracarida sampled, and we identified 674 isopod species from the 40 deep SO stations. Eighty-nine of these species (13%) were known, the others (585 species) were new to the area, and most of these were new to science, 43 genera being recorded for the first time. Asellota comprised 97% of all ANDEEP Isopoda, and Munnopsidae were the most dominant family, followed by the Desmosomatidae, Haploniscidae, and Ischnomesidae. To our present knowledge 87% of the SO deep-sea Isopoda are apparently "endemic". Most species did not occur frequently in the samples. Abundance was higher at the shallower ANDEEP stations and highest in the Powell Basin at station 133, and generally decreased with increasing depth. Species richness was highest with 92 species at the bathyal station 80-9 in 3100 m off Kapp Norvegia, in general, species richness was highest at around 3000 m depth with 216 species found at all ANDEEP stations, and 92 species sampled at a single station in 3100 m depth. The cluster analysis of the isopod composition from ANDEEP revealed in general terms that the abyssal Weddell-Sea stations build one cluster. Depth turned out to be the most important abiotic factor for the species composition reported. Most of the species frequently occurring at the abyssal stations are Munnopsidae, which can swim. The SO deep sea differs in faunal composition from the shelf, and few isopod species occur at many stations, while most species only occur at few. The reasons for these findings are unknown. Future studies should focus on the functional role of the frequent species of the SO deep-sea ecosystem and food-web.
In tide-dominated systems, fine-grained deposits occur in intertidal areas of inner estuaries as loci of convergence of fluvial and marine material. Even in the vicinity of estuaries, mud deposits are rare on open sandy beaches. This study focuses on temporary occurrences of muddy sediments on marine beaches along the Calvados coastline in Normandy, adjacent to the macrotidal Seine estuary (France). Clay mineralogy, major-minor-trace elements and radionuclides were used as particulate markers to determine the provenance of the mud deposits. The fine fraction, defined here as particles <50 ?m, was analysed, in surficial muddy sediments on seven beaches between the Seine estuary and the Orne river mouth, sampled between February 2002 and June 2003. The deposits were compared to earlier Holocene relict deposits, which crop out on some beaches and on the shoreface, and to Mesozoic marls and limestones, which have detached from the coastal cliffs. The use of the three types of particulate markers revealed no significant seasonal or geographical variations between the beaches. The muddy deposits were made up of the same sedimentary pool of particles. The clay mineralogical and geochemical characteristics of these mud deposits enabled modern (i.e. present-day and earlier Holocene fine silts and clays) to be distinguished from ancient (i.e. Mesozoic) sediments. The use of radionuclides ( 60Co and 137Cs) confirmed the marine influence in the modern deposits, with a decreasing gradient along the Calvados beaches towards the east. The presence of several specific major-minor-trace elements (e.g. Ti, P) revealed that some of the fine material originated in the Seine estuary. Despite the occurrence of easily erodable rocks (i.e. clays, marls and limestones) in the coastal cliffs, this source represented a limited supply, which is only of local significance. Small rivers, such as the Orne, Dives and Touques which discharge in the study area act as secondary suppliers of fine-grained material to this system. In spite of the exposed coastal setting where strong tidal currents and waves occur, the beaches have become a distal part of the Seine estuarine system and form a temporary sink for strongly mixed fine material mainly of riverine (Seine River) and open marine (Bay of the Seine and the Central English Channel) origins. This is consistent with the infilling of the estuary, the reduction in accommodation space in its inner part, and the offshore shifting of the depocentre of the mud.
Hydrodynamic forces over the beach sediments are the main driving factors affecting the frequency and magnitude of morphological changes in beach systems. In most of the time, this driving factors act in a foreseeable way and don't represent any danger to the coastal systems nor to its populations. However, hydrodynamic forces are also capable of induce high morphodynamic behavior on the beach profiles and very often in a short period of time which endangers people and property and leads to system retreat. The most common consequences of the occurrence of this type of phenomena over the coastal landforms are costal inundation and erosion. Still, many coastal systems, and specially beach systems, have recovery mechanisms and resilience levels have a very important role in the beach morphodynamic state and exposure to potential damaging events assessments. The wave dominated Portuguese West coast is an high energetic environment during winter, with 2.5m mean offshore significant wave height. Waves with 5 year recurrence period can reach 9.2m and storms are frequent. Beach systems are frequently associated with rocky coasts. In these cases, the subsystems present are beach-dune, beach-cliff and beach-estuary subsystems exposed to NW Atlantic wave climate. This research aim is to access beach hazard and susceptibility to inundation and erosion. Three beach systems were selected and monitored applying sequential profiling methodology over a three year period (2004-2007). Sta. Rita, Azul and Foz do Lizandro beaches are representative systems of the coastal stretch between Peniche and Cascais, which is a cliff dominate coast. Results from the monitoring campaigns are presented, including volume budgets, beach face slope changes, berm occurrence and heights and planimetric coastline dynamics. A hazard and susceptibility assessment schema and zonation are proposed, including the parameterization of local flood (i.e. mean sea, maximum spring tide, and storm surge and run-up levels) and erosion potentials (i.e. volume budget and beach planimetric dynamics).
Beach ridge landforms have been observed in different environments and in settings that range from polar to tropical. Their stratigraphy and sedimentology has received a limited amount of discussion in the literature (Tamura, 2012). In coastal geomorphology a beach ridge can be seen as a transitional deposit between onshore and offshore environments. They are regarded as representing high level wave action along a coastline. In the Caribbean the origin of beach ridges has been variously attributed to one of three extreme wave events: extreme swell, extreme storm or tsunami waves. Beach ridges are arranged in beach ridge plains where there is succession of the landforms and can be several kilometres long. Beach ridge accumulation is not continuous and the coast shows alternating accretion and erosion periods. The use of beach ridges as palaeostorm archives is therefore not straightforward. The temporal continuity of beach ridge formation is being assessed on the beach ridge plains of Anegada, British Virgin Islands (Lesser Antilles). This carbonate platform surrounded by a fringing reef contains two beach ridge plains. There are more than 30 ridges in the Atlantic facing- coast and around 10 in the south, Caribbean- facing coast. The sediments of the modern beaches are dominated by the sand fraction and are 100% biogenic origin due to the isolation of Anegada from terrestrial sediment sources. The beach ridge sections have been studied in different area of Anegada beach ridge plains and present low angle seaward-dipping bedding. The sand fraction is dominant in the stratigraphy with a few intact shells. At only one site were coral pebbles deposited in association with the sand fraction. Aeolian deposits represent the upper part of the beach ridges and reflect the stabilization of the beach ridges with ongoing accretion. The sedimentology of the contemporary beach and dunes will be discussed in terms of their implications for understanding beach ridge genesis and its relationship to extreme wave events. Tamura, T., 2012. Beach ridges and prograded beach deposits as palaeoenvironment records. Earth-Science Reviews, 114, pp. 279-297.
Cescon, Anna Lisa; Cooper, J. Andrew G.; Jackson, Derek W. T.
High energy events emphasize beach erosion processes, sometimes leading to huge volume deficits not balanced by recovery under fair-weather conditions. In this scenario, artificial replenishments are frequently used as a form of coastal protection with large volumes of sediments re-injected in the system without strongly altering the environment as it happens with hard structures. Since climate change is expected to accentuate in the near future erosion effects, the need to artificially feed beaches is likely to increase. Gravel and pebbles are more and more often used as beach fill, on some occasions replacing sandy sediments. That was the case for two beaches located at either sides of the Italian Peninsula (Portonovo, Adriatic Sea; Marina di Pisa, Ligurian Sea), which constitute the study area of the present research. Portonovo is a 500 m-long mixed sand and gravel beach with a significant pebble-sized content (about 40%), unloaded on the beach during multiple replenishments. Marina di Pisa is an artificial, 180 m-long beach, mainly composed of 40-to-90 mm pebbles; it was built in 2008 as a part of a larger protection scheme. Groins or headlands that prevent any sediment exchange with adjacent areas bound both beaches. Periodic topographic surveys were carried out to evaluate the response of these human-altered beaches to high-energy events. The topographic surveys, undertaken with a DGPS-RTK instrument along cross-shore transects (from the landward end of the backshore to about 1.5 m depth seaward), were done following intense storm events occurred during the time period of the research. Transects were done out every 10 m along the entire length of the beaches. Prior to the first topographic survey, a sediment tracing experiment was set up as a form of control of the results provided by the geomorphologic analysis. Pebbles directly sampled from the beaches were marked by means of the RFID technology and injected back all along the beachface. As expected, considerable beach profile changes after the storms were identified, in particular at Portonovo (mixed beach), where huge sediment volumes were displaced longshore according to the incident wave direction as opposed to Marina di Pisa (gravel dominated), where the main beach changes developed along the cross-shore direction. In terms of resilience, results showed a better response of the Portonovo beach rather than the Marina di Pisa beach. The different response might be ascribed to the grain-size that constitutes the beaches: no physical process can rework the pebbles at Marina di Pisa once they are moved during the storms towards the back-end of the backshore or seaward of the step, thus preventing any beach recovery process to take place. Since the awareness on storm impacts is more critical than in the past, the understanding of beach recovery to extreme events needs new insights to combine the preservation of natural beach evolution as well as maintenance for end-users. That is particularly pressing on coarse-grained beaches, where the need to predict storm impact and recovery is much more vital considering that finding suitable sediment to refill the beach is never an easy task.
Beach waste and litter composition and evolution on popular urban (located in the main nucleus of the municipality) and urbanized (located in residential areas outside the main nucleus) beaches of the Costa Brava (Catalan coast) were assessed during the bathing season. Waste and litter production (amount and composition) were affected by urbanization and varied during the summer. Urban beaches had higher densities of waste deposition and lower percentages of organic, domestic and other miscellaneous waste than urbanized beaches. Litter characteristics were also influenced by type of beach, and varied during the season as a consequence of beach use and cleaning practices, but not environmental factors. Urbanized beaches obtained higher scores for aesthetic quality of sand than urban beaches, and small-sized litter tended to accumulate during the season in the beach of Lloret Centre. The most important problems are management of recyclable materials, litter left by users on the sand, and separation of sand from litter. In addition, current efficiency of mechanical cleaning is low, especially in the withdrawal of cigarette butts. These analyses highlight problems that should be addressed in future management of area beaches. PMID:18243682
Global patterns in species richness in sandy beach ecosystems have been poorly understood until comparatively recently, because of the difficulty of compiling high-resolution databases at continental scales. We analyze information from more than 200 sandy beaches around the world, which harbor hundreds of macrofauna species, and explore latitudinal trends in species richness, abundance and biomass. Species richness increases from temperate to tropical sites. Abundance follows contrasting trends depending on the slope of the beach: in gentle slope beaches, it is higher at temperate sites, whereas in steep-slope beaches it is higher at the tropics. Biomass follows identical negative trends for both climatic regions at the whole range of beach slopes, suggesting decreasing rates in carrying capacity of the environment towards reflective beaches. Various morphodynamic variables determine global trends in beach macrofauna. Species richness, abundance and biomass are higher at dissipative than at reflective beaches, whereas a body size follows the reverse pattern. A generalized linear model showed that large tidal range (which determines the vertical dimension of the intertidal habitat), small size of sand particles and flat beach slope (a product of the interaction among wave energy, tidal range and grain size) are correlated with high species richness, suggesting that these parameters represent the most parsimonious variables for modelling patterns in sandy beach macrofauna. Large-scale patterns indicate a scaling of abundance to a body size, suggesting that dissipative beaches harbor communities with highest abundance and species with the smallest body sizes. Additional information for tropical and northern hemisphere sandy beaches (underrepresented in our compilation) is required to decipher more conclusive trends, particularly in abundance, biomass and body size. Further research should integrate meaningful oceanographic variables, such as temperature and primary production, in deciphering latitudinal trends.
The coast of California is comprised of both sandy shorelines and cliffed coastline, and in many areas these features spatially coincide. In order to better understand the regional trends of change along the California coast, the U.S. Geological Survey is quantifying both sandy shoreline change and coastal cliff retreat for the state. The resulting database was used to examine the dynamics of the beach/cliff system. We found inconsistent evidence of a relationship between rates of cliff retreat and shoreline change on the spatial scale of 100-km cells. However, when the data are correlated within individual regions, a strong relationship exists between the geomorphology of the coast and the behavior of the beach/cliff system. Areas of high-relief coast show negative correlations, indicating that higher rates of cliff retreat correlate with lower rates of shoreline erosion. In contrast, low- to moderate-relief coasts show strong positive correlations.
Frequent morning surveys of birds were conducted on 1 km of beach in southern California to investigate shorebird use of an exposed sandy beach. The overall mean abundance (98.6 individuals km -1), estimated biomass (9.6 kg km -1), and species richness (5.5 species km -1) of shorebirds observed were very high for a sandy beach in the temperate zone. Eight species, sanderling ( Calidris alba), semipalmated plover ( Charadrius semipalmatus), marbled godwit ( Limosa fedoa), black-bellied plover ( Pluvialis squatarola), western sandpiper ( Calidris mauri), willet ( Catoptrophorus semipalmatus), surfbird ( Aphriza virgata), and whimbrel ( Numenius phaeopus), occurred in overall mean abundances >1 bird km -1 and accounted for 97% of the abundance and biomass of shorebirds. Sanderlings were the most abundant shorebird every year (64% of individuals and 35% of the biomass). Different species of abundant shorebirds exhibited distinct patterns of use of beach habitat, including fall, spring, and winter peaks in abundance. Temporal variation in shorebird use on seasonal and interannual scales was associated with migration patterns, and also with habitat availability and condition. Seasonal variation in monthly mean abundance and estimated biomass of shorebirds varied over more than an order of magnitude and followed a similar pattern in each year, reaching maxima in the fall or winter (161-280 individuals km -1 and 15.4-23.9 kg km -1) and minima in May or June (3-11 individuals km -1 and 0.8-2.2 kg km -1). A minor peak in shorebird abundance and biomass coinciding with spring migration was observed in April of most years. The number of species of shorebirds observed in individual surveys ranged from 0 to 11 species km -1 and was positively and significantly correlated with abundance. Monthly mean species richness and the total species observed monthly followed similar seasonal patterns, ranging from annual maxima of 7.4-9.1 and 12-17 species km -1 between August and October to minima of 0.8-2.1 and 2-8 species km -1, respectively, during June. In contrast, species turnover was lowest (1.1-1.7) in October and November, and generally highest (2-4) during early summer (June). The amount of sandy intertidal habitat available to shorebirds on the transect was estimated using sand elevations and predicted tide heights. In the fall and winter, the abundance of shorebirds was significantly and positively correlated with tide height, possibly reflecting feeding opportunities and high tide refuge effects during the highest tides. In the spring when sand levels were low, the abundance of shorebirds was negatively correlated with tide height. Prey availability, beach condition and the local availability, and condition of alternative foraging habitats may influence those relationships. Interannual variations in shorebird use and beach condition were observed in the course of the study. During an El Nino Southern Oscillation (ENSO) event (1997-1998), the extent of sandy habitat was greatly reduced and intertidal habitat was mostly converted to rocky substrate. The overall abundance of shorebirds and the mean abundance of some common species (e.g. sanderling) were depressed, and an uncommon species (surfbird, A. virgata) was unusually abundant during the ENSO event. In summary, the results suggest that sandy beaches are important habitat for many species of shorebirds, particularly in areas where alternative coastal foraging habitats, such as coastal wetlands, have become scarce. Understanding the dynamics of and threats to exposed sandy beaches may be increasingly important for shorebird conservation in many coastal regions.
For centuries, beach sand has been mined for use as aggregate in concrete, for heavy minerals, and for construction fill. The global extent and impact of this phenomenon has gone relatively unnoticed by academics, NGOs, and major news sources. Most reports of sand mining activities are found at the very local scale (if the mining is ever documented at all). Yet, sand mining in many localities has resulted in the complete destruction of beach (and related) ecosystems along with severe impacts to coastal protection and tourism. The Program for the Study of Developed Shorelines at Western Carolina University and Beachcare.org have initiated the construction of a global database of beach sand mining activities. The database is being built through a combination of site visits and through the data mining of media resources, peer reviewed papers, and reports from private and governmental entities. Currently, we have documented sand mining in 35 countries on 6 continents representing the removal of millions of cubic meters of sand. Problems extend from Asia where critical infrastructure has been disrupted by sand mining to the Caribbean where policy reform has swiftly followed a highly publicized theft of sand. The Program for the Study of Developed Shorelines recently observed extensive sand mining in Morocco at the regional scale. Tens of kilometers of beach have been stripped of sand and the mining continues southward reducing hope of a thriving tourism-based economy. Problems caused by beach sand mining include: destruction of natural beaches and the ecosystems they protect (e.g. dunes, wetlands), habitat loss for globally important species (e.g. turtles, shorebirds), destruction of nearshore marine ecosystems, increased shoreline erosion rates, reduced protection from storms, tsunamis, and wave events, and economic losses through tourist abandonment and loss of coastal aesthetics. The threats posed by sand mining are made even more critical given the prospect of a significant rise in global sea level over the coming decades. Most governments recognize the local impacts of sand mining and mining activities are illegal in many localities. However, enforcement of these protections has been problematic and there has been little pressure to stop the practice from local or international environmental groups. In many cases, addressing the issue of sand mining requires addressing the local issues that allow it to persist. This includes poverty, corruption, and unregulated development. In areas where beach sand mining significantly supports the local economy, care needs to be given that local workers are given alternative means of income, and builders are provided an affordable substitute for the sand (e.g. crushed rock). Regardless, it is time for both academics and NGOs to address the cumulative environmental impacts of the direct destruction of the world's beaches through mining activities.
A new type of permeable groin (called System of Groins Maltec-Savard - SGMS) has been installed at three eroded sites located in the coastal area on the north shore of the St. Lawrence, Quebec, Canada. In this area, the narrow sandy beaches with sandy or sand-silty cliff of variable height (10-15~m) are exposed to obliquely incident waves arriving from both
Carl Graham Fisher, an Indiana native, was the man who—among other accomplishments—conceived and built Miami Beach, Montauk Manor (on Long Island), the Indianapolis Speedway, and the country-crossing Lincoln and Dixie highways (which foreshadowed today's interstate highway system). Born into poverty, Fisher left home at age 12 to support his family. He made a name for himself in bicycle endurance racing
It is shown how the solution for velocity potential may be determined when the effect of surface tension is included in the linearized theory of Ursell-type edge waves over a plane-sloping beach. The problem is examined without making a hydrostatic assumption. Explicit solutions for edge capillary-gravity waves are given and the dispersion equation is obtained. The influence of capillarity on gravity waves is discussed.
Michigan water quality standards for public bathing beaches require local health departments to collect and analyze a minimum\\u000a of three water samples for Escherichia coli during each sampling event. The geometric mean number of E. coli colonies is then compared to the 300 colonies per 100 ml standard to determine compliance. This article compares the results\\u000a of the currently mandated procedure
Beaches are constantly moving and changing. The dynamic transformations of beaches are mostly the result of the erosion of sand, which can occur through movements alongshore caused by waves, movements off-shore due to storms, or submersion due to sea-level rise. Predicted climate change impacts include potential changes in storminess and accelerated sea-level rise, which will lead to increased coastal erosion. At the same time, the number of people residing in coastal communities is increasing. The risks from eroding beaches (increased coastal flooding, damage to infrastructure, and displaced residents) are therefore increasing in number and scale; and coastal residents are taking actions to protect their homes. One such action is beach nourishment, where sand is added to a resident's property in order to widen the beach. We have developed an economic model of beach nourishment decision-making to investigate the relationship between the optimal volume and timing of beach nourishment and factors such as property value, erosion rate, and initial beach width. In this model, waterfront property owners nourish a beach when the losses in net rental income exceed the costs incurred from nourishing the beach. (Rental income is a function of property value, which in turn depends upon the width of the beach.) It is assumed that erosion and sea-level rise are related. We examine different nourishment scenarios, including one-time nourishment in the first year; constant annual nourishment; and a myopic decision process in which the homeowner nourishes the beach if property losses from erosion over the next five years are expected to exceed the cost of nourishment. One-time nourishment delays property flooding for both constant and accelerating sea level rise; however, this delay is more substantial under constant sea level rise. With continual nourishment, the beach can be maintained under constant sea-level rise, provided that the erosion rate is comparable to the additional width from nourishment each year. In contrast, for practical nourishment volumes, erosion from accelerating sea-level rise eventually out-competes beach nourishment and inundation occurs. Under the myopic decision-making model, with both constant and accelerating sea-level rise, nourishment does not take place until a property is critically endangered. The beach slope, nourishment volume, property value, and initial beach width all are found to be important factors in determining when nourishment should start and how frequently it should occur thereafter. These models can be used by policy-makers to formulate better coastal management policies, by coastal geologists to understand human impacts on beach dynamics, and by the insurance industry to realistically anticipate human risk-taking and decision-making.
Ware, M.; Ashton, A. D.; Hoagland, P.; Jin, D.; Kite-Powell, H.; Lorenzo-Trueba, J.
Hurricanes are a major source for erosion and damage along the southeastern US coastline. This study uses airborne LIDAR data to quantify shoreline change due to Hurricane Ivan. Hurricane Ivan made landfall on the Alabama gulf coast in September, 2004 with maximum sustained winds of 58 m/s. Five separate LIDAR data sets of barrier beaches situated in the front right quadrant of the hurricane were collected during a six month period before and after landfall allowing an excellent timeline for analyzing change in shoreline position. Shorelines were extracted and incremental shoreline position differences were quantified for a 30 km portion of Panama City Beach, Florida. Preliminary results show alternating trends in shoreline change. The hurricane caused an initial average shoreline retreat of more than 16 m relative to pre-storm positions. Within three weeks this shoreline position recovered or moved seaward by 10 m. However, during the 2 month interval between October and December, 2004, the shoreline again retreated 5 m. This 5 m of shoreline retreat in the two months following the initial recovery could be attributed to the beach profile transition from summer to winter, and will have to be researched further.
Robertson, W.; Zhang, K.; Whitman, D.; Leatherman, S. P.
Gulls are often cited as important contributors of fecal contamination to surface waters, and some recreational beaches have used gull control measures to improve microbial water quality. In this study, gulls were chased from a Lake Michigan beach using specially trained dogs, and water quality improvements were quantified. Fecal indicator bacteria and potentially pathogenic bacteria were measured before and during gull control using culture methods and quantitative polymerase chain reaction (qPCR). Harassment by dogs was an effective method of gull control: average daily gull populations fell from 665 before to 17 during intervention; and a significant reduction in the density of a gull-associated marker was observed (p < 0.001). Enterococcus spp. and Escherichia coli densities were also significantly reduced during gull control (p < 0.001 and p = 0.012, respectively for culture methods; p = 0.012 and p = 0.034, respectively for qPCR). Linear regression results indicate that a 50% reduction in gulls was associated with a 38% and 29% decrease in Enterococcus spp. and E. coli densities, respectively. Potentially human pathogenic bacteria were detected on 64% of days prior to gull control and absent during gull intervention, a significant reduction (p = 0.005). This study demonstrates that gull removal can be a highly successful beach remedial action to improve microbial water quality. PMID:22913457
Converse, Reagan R; Kinzelman, Julie L; Sams, Elizabeth A; Hudgens, Edward; Dufour, Alfred P; Ryu, Hodon; Santo-Domingo, Jorge W; Kelty, Catherine A; Shanks, Orin C; Siefring, Shawn D; Haugland, Richard A; Wade, Timothy J
The goal of this study was to quantify the microbial load (enterococci) contributed by the different animals that frequent a beach site. The highest enterococci concentrations were observed in dog feces with average levels of 3.9 x 10(7) CFU/g; the next highest enterococci levels were observed in birds averaging 3.3 x 10(5)CFU/g. The lowest measured levels of enterococci were observed in material collected from shrimp fecal mounds (2.0 CFU/g). A comparison of the microbial loads showed that 1 dog fecal event was equivalent to 6940 bird fecal events or 3.2 x 10(8) shrimp fecal mounds. Comparing animal contributions to previously published numbers for human bather shedding indicates that one adult human swimmer contributes approximately the same microbial load as one bird fecal event. Given the abundance of animals observed on the beach, this study suggests that dogs are the largest contributing animal source of enterococci to the beach site. PMID:19664785
Wright, Mary E; Solo-Gabriele, Helena M; Elmir, Samir; Fleming, Lora E
A total of 357 water samples were collected from a public beach in northern Taiwan during beach season, and the densities of enterococci were analyzed by Enterolert methods. The mean enterococci level was 356 MPN/100 ml and ranged from <10 to 2,005 MPN/100 ml, which was classified as high contamination level according to the WHO water quality guideline (95 percentile >1,000 MPN/100 ml). Most of the deteriorated water quality conditions occurred during rainfall. By excluding data from the rain days, the overall beach water quality would be considered in the moderate contamination level (95 percentile 200-1,000 MPN/100 ml). Among the selected microbiological parameters tested, the densities of total coliforms and enterococci exhibited the highest correlation (r = 0.449, p = 0.009), followed by the concentrations of total coliforms and fecal coliforms (r = 0.403, p = 0.02). Nonetheless, no significant correlation was found between enterococci and fecal coliform levels (r = 0.197, p = 0.271). PMID:17972152
The beetle Phaleria maculata is a common inhabitant of the upper intertidal fringe of Chilean beaches. Anthropogenic intervention in coastal areas has increased intensely, leading to changes in the flora and fauna of sandy beaches. To examine the impact of human activities on P. maculata, we studied several beaches along the northern Chilean coast. Beaches were characterized based on morphodynamics and the level of intervention, leading to the estimation of an "Urbanization Index" based on various indicators. The analysis showed a significant inverse correlation between the rate of urbanization and night sky quality. Larval and adult beetles were almost absent on beaches with high levels of urbanization. The results of simple and multiple correlations based on nMDS ordination showed an inverse relationship between increases in urbanization and the abundance of beetles. Because darkling beetles are very sensitive to human interventions on sandy beaches, we suggest that they are ideal indicator organisms for the health of these environments. PMID:24768173
The shallow aquifer near Riviera Beach, Palm Beach County, Fla., contains a cavity-riddled zone extending north and south about 5 miles inland from the Atlantic Ocean. The zone lies at approximately 60 feet below land surface and varies from 15 to 50 feet in thickness. It is approximately 3 miles in width. Aquifer material is calcareous quartz sand-stone in the cavity zone, whereas the remainder of the consolidated aquifer material is primarily limestone. The zone is overlain by several thin clay beds which provide varying degrees of confinement. The transmissivity of the cavity-riddled zone of the aquifer in the area of investigation is approximately 11,000 square feet per day. Preliminary evaluation indicates that large volumes of water of suitable quality for public supply can be developed from the zone, except in an area adjacent to a landfill where leachate has adversely affected water quality. (USGS)
Identifying key drivers of extreme erosion can be relatively straight forward. Severe flooding, large storms and even human interaction have all been responsible for drastically altering the coastline over short time periods. However when events such as barrier breaching occur with no obvious contributory factors, a deeper understanding of the underlying coastal processes is required. Ideally conclusions on morphological drivers should be drawn from field data collection and remote sensing over a long period of time, i.e. decades. Unfortunately when the barrier beach at Rossbeigh, County Kerry, Ireland, started to erode rapidly in the early 2000's there was no such data collection conducted. By 2008 approximately 1.5million m3 of sand had been eroded and during the winter period of that year the dune breached, resulting in the formation of a barrier island and a new tidal inlet. The initial breach length was 500m but it continued to expand to 750m and then stabilised. A research project has been ongoing at the Hydraulics and Maritime Research Centre of University College Cork since the breaching event. Assessing the threat breaching presents to local infrastructure, housing and industry is part of this research brief. Topographical surveys, sediment sampling, satellite imagery analysis and numerical modelling have previously been conducted to gain an insight into the morphodynamics of Rossbeigh. An initial analysis of the breaching suggested that erosion had slowed and regeneration of the dune was occurring; however further monitoring indicated that as the breach was stabilising other areas of the barrier beach were experiencing increased erosion. As a result of this a field monitoring campaign consisting of wave and tidal data collection was undertaken in the summer of 2011 to gain a clearer understanding of the hydrodynamic processes influencing the erosion patterns. Wave gauges were deployed along the beach at low water and also 4km offshore. Tidal currents were also measured in the breach area, alongshore of Rossbeigh beach and in the vicinity of the newly formed island. The findings provide a new insight into the active processes. The magnitude of tidal currents, directionality of incident waves at high tide and presence of low frequency infragravity waves along Rossbeigh are significant findings that influence the morphology. As a result of this work existing numerical and predictive models require updating to accurately model the morphology of the barrier beach and identify future threats to the local coastline.
The Buenos Aires aggradation plain has a good record of Quaternary sea-level fluctuations. To the east of the Tandilia Range, the elevations of the Pleistocene beaches respond to the tectonic behaviour of the Salado Basin. Holocene beaches indicate a maximum transgression higher than 2 m. The low relief permitted an extended horizontal record of beach/chenier plains interfingered with estuarine environments (coastal lagoons, marshes) covered by a sandy (Eastern) barrier. Between the Tandilia and Ventania ranges, the location of Pleistocene and Holocene beaches are related to a former higher relief; i.e. they are attached to low-altitude cliffs and underneath cliff-top dunes composing the Southern Barrier. At Claromecó, Pleistocene gravel beaches, mostly composed of caliche pebbles, occur at heights between 4 and 7 m, and are overlying estuarine Pleistocene environments. Beaches of the same age are at a level of 10 m at Mar del Plata Harbour and Arroyo Sotelo (west of Mar Chiquita Lagoon). Holocene beaches found at Punta Mogotes and Costa Bonita are at higher altitudes than on the Eastern Barrier (ca. 2-4 m). The Holocene estuarine sequences are related laterally to present operating inlets (Las Brusquitas, La Ballenera, Quequén Grande, Claromecó, Quequén Salado). They are seldon thicker than 2.4 m, and comprise basal layers of black muds; towards the top, the layers are thinner, of coarser grain size and white colours. Grain-size analyses were performed comparatively on Pleistocene, mid-Holocene and present beaches. Sangamonian beaches aregravelly or coarser than medium sand (mean). Holocene beaches are usually coarser than medium sand, but dominantly shelly to the north of Mar del Plata, and composed of volcanic clasts to the south of this city. Modern beaches are dominated by fine sand, except at some erosive beaches between the Mar del Plata capes. They have a lesser content of shells than those of mid-Holocene.
Isla, Federico I.; Cortizo, Luis C.; Schnack, Enrique J.
STS-95 Payload Specialist John H. Glenn Jr. waves to spectators from the back of a silver 1999 C-5 Corvette convertible during a parade down State Road A1A in nearby Cocoa Beach. Organizers of the parade include the Cocoa Beach Area Chamber of Commerce, the Brevard County Tourist Development Council, and the cities of Cape Canaveral and Cocoa Beach. The parade is reminiscent of those held after missions during the Mercury Program.
STS-95 Payload Specialist Chiaki Mukai is perched on the back of a red 1999 C-5 Corvette convertible during a parade down State Road A1A in nearby Cocoa Beach. Organizers of the parade include the Cocoa Beach Area Chamber of Commerce, the Brevard County Tourist Development Council, and the cities of Cape Canaveral and Cocoa Beach. The parade is reminiscent of those held after missions during the Mercury Program.
STS-95 Payload Specialist John H. Glenn Jr. waves to a dense crowd of well-wishers from the back of a silver 1999 C-5 Corvette convertible during a parade down State Road A1A in nearby Cocoa Beach. Organizers of the parade include the Cocoa Beach Area Chamber of Commerce, the Brevard County Tourist Development Council, and the cities of Cape Canaveral and Cocoa Beach. The parade is reminiscent of those held after missions during the Mercury Program.
STS-95 Commander Curtis L. Brown Jr. (in front), along with the other crew members behind him, waves to the crowd as he leads a parade of 1999 C-5 Corvette convertibles down State Road A1A in nearby Cocoa Beach. Organizers of the parade include the Cocoa Beach Area Chamber of Commerce, the Brevard County Tourist Development Council, and the cities of Cape Canaveral and Cocoa Beach. The parade is reminiscent of those held after missions during the Mercury Program.
Two major parameters that determine the beach type are sediment grain size and beach slope. Intermediate beaches normally have steep slopes and are associated with coarse-grained sands and narrow surf zones, while dissipative beaches generally have mild slopes and are related to fine sands and wider surf zones. In the numerical experiments, the Delft3D and Xbeach models were combined and used to resolve the 3D Navier-Stokes equations for incompressible flow and the beach morphology. The sediment transport module supports both bed-load and suspended load transport of non-cohesive sediments. Numerical simulations were run for different hydrodynamic conditions, but with a focus on different beach slopes and grain sizes, and considering hydrodynamic processes, sediment transport in cross- and alongshore directions, as well as foreshore bathymetry changes. Coarsening of the grain size tends to generate a more complex nearshore hydrodynamic pattern. The transformation of incoming waves as they reach shallow water occurs closer the shoreline for steeper profiles. Consistently, the peaks in eddy viscosity, turbulence dissipation rate (TDR), turbulent kinetic energy (TKE) and wave set-up are shifted onshore for steeper slopes. High values of eddy viscosity, TKE and wave set-up are spread offshore for coarser grain sizes. The TDR is an order of magnitude smaller for the coarsest grains compared with other cases. The numerical results showed that TKE, sediment concentrations and sediment transport rate are greater on steep beach than on mild slope beaches. The beach morphology exhibits different erosive characteristics depending on grain size (e.g., foreshore profile evolutions are erosive and accretionary on the fine and coarse sand beaches; respectively). The results confirmed that wave energy, beach grain size and bed slope are the main factors influencing sediment transport and beach morphodynamics.
Bakhtyar, R.; Dastgheib, A.; Barry, D. A.; Roelvink, J.
Waterborne enteric viruses may pose disease risks to bather health but occurrence of these viruses has been difficult to characterize at recreational beaches. The aim of this study was to evaluate water for human virus occurrence at two Southern California recreational beaches with a history of beach closures. Human enteric viruses (adenovirus and norovirus) and viral indicators (F+ and somatic coliphages) were measured in water samples over a 4-month period from Avalon Beach, Catalina Island (n = 324) and Doheny Beach, Orange County (n = 112). Human viruses were concentrated from 40 L samples and detected by nested reverse transcriptase polymerase chain reaction (PCR). Detection frequencies at Doheny Beach were 25.5% (adenovirus) and 22.3% (norovirus), and at Avalon Beach were 9.3% (adenovirus) and 0.7% (norovirus). Positive associations between adenoviruses and fecal coliforms were observed at Doheny (p = 0.02) and Avalon (p = 0.01) Beaches. Human viruses were present at both beaches at higher frequencies than previously detected in the region, suggesting that the virus detection methods presented here may better measure potential health risks to bathers. These virus recovery, concentration, and molecular detection methods are advancing practices so that analysis of enteric viruses can become more effective and routine for recreational water quality monitoring. PMID:24642440
Love, David C; Rodriguez, Roberto A; Gibbons, Christopher D; Griffith, John F; Yu, Qilu; Stewart, Jill R; Sobsey, Mark D
The El Nino conditions of 1982 and 1983 produced unusually frequent and intense storms along the central California coast. These storms produced much greater than normal beach erosion in Monterey Bay, causing extensive damage to coastal structures, erosion of coastal cliffs, and loss of sand from coastal dunes. The beaches accreted during the summer of 1983 and eroded again the next winter. Every beach, however, showed its own pattern of rebuilding; the eigenfunction analysis showed that the beaches did not all reach either their maximum or minimum volumes at the same time.
Dingler, John, R.; Anima, Roberto, J.; Clifton, H. Edward
A consortium of agencies have conducted an extensive investigation of the coastal ocean circulation and transport pathways off Huntington Beach, with the aim of identifying any causal links that may exist between the offshore discharge of wastewater by OCSD and the significant bacterial contamination observed along the Huntington Beach shoreline. This is the third study supported by OCSD to determine possible land-based and coa Although the study identifies several possible coastal ocean pathways by which diluted wastewater may be transported to the beach, including internal tide, sea-breeze and subtidal flow features, there were no direct observations of either the high bacteria concentrations seen in the OCSD plume at the shelf break reaching the shoreline in significant levels or of an association between the existence of a coastal ocean process and beach contamination at or above AB411 levels. It is concluded that the OCSD plume is not a major cause of beach contamination; no causal links could be demonstrated. This conclusion is based on the absence of direct observation of plume-beach links, on analysis of the spatial and temporal patterns of shoreline contamination and coastal ocean processes, and on the observation of higher levels of contamination at the beach than in the plume.
Fecal Indicator Bacteria(FIB) are found in high concentrations in sewage water, and thus are used to indicate whether there is fecal material related pathogen present and to determine whether a beach is safe for recreational use. Studies have shown, however, in subtropical regions, FIB concentrations above EPA standards may be present in the absence of known point sources of human or animal waste, thus reducing the efficacy of FIB beach monitoring programs. An interdisciplinary study is being conducted in Miami, Florida , the goal is to understand the sources and behavior of FIB on a beach without point source loads and also to improve beach health hazard warnings in subtropical regions. This study, examines relationship between enterococci (EPA recommended FIB for use in marine water) and physical environmental parameters such as rain, tide and wind. FIB data employed include Florida Department of Health weekly beach monitoring enterococci (ENT) data during a five year period and a two-day experiment with hourly sampling at Hobie Cat Beach on Virginia Key in the Miami metropolitan area. The environmental data consist of wind from a nearby CMAN tower, and local rain and tide. The analysis also includes data from nearby beaches monitored by the Health Department. Results show the correlation coefficient between ENT and tide at Hobie Cat Beach is positive but not significant(r=0.17). Rain events have a significant influence on ENT at Hobie Cat Beach, with a correlation coefficient of up to 0.7 while at other beaches the correlation is less than 0.2. Reasons for this aberration are being investigated. Although this is the only beach allowing dogs there are other factors of possible importance, such as tidal flats frequented by birds and weaker water circulation and exchange at this beach facing a bay rather than the ocean. Higher ENT levels (> 300CFU/100ml water) are more likely (67% of the time) to be associated with periods of onshore winds, which may affect the circulation of water at the beach or cause waves and wave breaking that stir and resuspend the beach sediment. To help interpret FIB observations and to improve the use of future monitoring results, a coastal circulation model and a bacteria fate model is being constructed to simulate and predict the FIB transport and distribution at Hobie Cat Beach.
Zhu, X.; Wang, J. D.; Elmir, S.; Solo-Gabriele, H. M.; Wright, M. E.; Abdelzaher, A.
Beaches worldwide provide recreational opportunities to hundreds of millions of people and serve as important components of coastal economies. Beach water is often monitored for microbiological quality to detect the presence of indicators of human sewage contamination so as to prevent public health outbreaks associated with water contact. However, growing evidence suggests that beach sand can harbor microbes harmful to human health, often in concentrations greater than the beach water. Currently, there are no standards for monitoring, sampling, analyzing, or managing beach sand quality. In addition to indicator microbes, growing evidence has identified pathogenic bacteria, viruses, and fungi in a variety of beach sands worldwide. The public health threat associated with these populations through direct and indirect contact is unknown because so little research has been conducted relating to health outcomes associated with sand quality. In this manuscript, we present the consensus findings of a workshop of experts convened in Lisbon, Portugal to discuss the current state of knowledge on beach sand microbiological quality and to develop suggestions for standardizing the evaluation of sand at coastal beaches. The expert group at the "Microareias 2012" workshop recommends that 1) beach sand should be screened for a variety of pathogens harmful to human health, and sand monitoring should then be initiated alongside regular water monitoring; 2) sampling and analysis protocols should be standardized to allow proper comparisons among beach locations; and 3) further studies are needed to estimate human health risk with exposure to contaminated beach sand. Much of the manuscript is focused on research specific to Portugal, but similar results have been found elsewhere, and the findings have worldwide implications. PMID:24355396
Sabino, R; Rodrigues, R; Costa, I; Carneiro, C; Cunha, M; Duarte, A; Faria, N; Ferreira, F C; Gargaté, M J; Júlio, C; Martins, M L; Nevers, M B; Oleastro, M; Solo-Gabriele, H; Veríssimo, C; Viegas, C; Whitman, R L; Brandão, J
Beaches worldwide provide recreational opportunities to hundreds of millions of people and serve as important components of coastal economies. Beach water is often monitored for microbiological quality to detect the presence of indicators of human sewage contamination so as to prevent public health outbreaks associated with water contact. However, growing evidence suggests that beach sand can harbor microbes harmful to human health, often in concentrations greater than the beach water. Currently, there are no standards for monitoring, sampling, analyzing, or managing beach sand quality. In addition to indicator microbes, growing evidence has identified pathogenic bacteria, viruses, and fungi in a variety of beach sands worldwide. The public health threat associated with these populations through direct and indirect contact is unknown because so little research has been conducted relating to health outcomes associated with sand quality. In this manuscript, we present the consensus findings of a workshop of experts convened in Lisbon, Portugal to discuss the current state of knowledge on beach sand microbiological quality and to develop suggestions for standardizing the evaluation of sand at coastal beaches. The expert group at the “Microareias 2012” workshop recommends that 1) beach sand should be screened for a variety of pathogens harmful to human health, and sand monitoring should then be initiated alongside regular water monitoring; 2) sampling and analysis protocols should be standardized to allow proper comparisons among beach locations; and 3) further studies are needed to estimate human health risk with exposure to contaminated beach sand. Much of the manuscript is focused on research specific to Portugal, but similar results have been found elsewhere, and the findings have worldwide implications.
Sabino, Raquel; Rodrigues, R.; Costa, I.; Carneiro, Carlos; Cunha, M.; Duarte, A.; Faria, N.; Ferriera, F.C.; Gargate, M.J.; Julio, C.; Martins, M.L.; Nevers, Meredith; Oleastro, M.; Solo-Gabriele, H.; Verissimo, C.; Viegas, C.; Whitman, Richard L.; Brandao, J.
Daily microbiological water quality and precipitation data spanning 6 years were collected from monitoring stations at southern California beaches. Daily precipitation projected for the twenty-first century was derived from downscaled CNRM CM3 global climate model. A time series model of Enterococcus concentrations that was driven by precipitation, matched the general trend of empirical water quality data; there was a positive association between precipitation and microbiological water contamination (P < 0.001). Future projections of precipitation result in a decrease in predicted Enterococcus levels through the majority of the twenty-first century. Nevertheless, variability of storminess due to climate change calls for innovative adaptation and surveillance strategies. PMID:22805768
Semenza, Jan C; Caplan, Joshua S; Buescher, Guido; Das, Tapash; Brinks, Mitchell V; Gershunov, Alexander
...Bay Harbor, California; U.S. Naval Weapons Station, Seal Beach, California; Naval...Bay Harbor, California; U.S. Naval Weapons Station, Seal Beach, California; Naval...permission from the Commanding Officer, Naval Weapons Station, Seal...
Background The Falkland Islands and Patagonia are traditionally assigned to the Magellan Biogeographic Province. Most marine species in Falkland waters are also reported from southern Patagonia. It remains unclear if relatively immobile, marine benthic, shallow-water species maintain gene flow, and by what mechanism. Recurrent fluctuations in sea level during glacial cycles are regarded as a possible mechanism that might have allowed genetic exchange between the regions. However, the realized genetic exchange between the Falkland Islands and Patagonia has never been estimated. Results This study analyses the genetic structure of three populations of the marine shallow-water isopod Serolis paradoxa (Fabricius, 1775) from the Falkland Islands and southern Patagonia (central Strait of Magellan and the Atlantic opening) applying seven nuclear microsatellites and a fragment of the mitochondrial 16S rRNA gene. Both marker systems report highest genetic diversity for the population from the central Strait of Magellan and lowest for the Falkland Islands. The estimated effective population sizes were large for all populations studied. Significant differentiation was observed among all three populations. The magnitude of differentiation between Patagonia and the Falkland Islands (16S: uncorrected p-distance 2.1%; microsatellites: standardized F'ST > 0.86) was an order of magnitude higher than between populations from within Patagonia. This indicates that there is currently no effective gene flow for nominal S. paradoxa between these two regions and it has been absent for time exceeding the last glacial maximum. We argue that specimens from the Strait of Magellan and the Falkland Islands very likely represent two distinct species that separated in the mid-Pleistocene (about 1 MY BP). Conclusion The results of this study indicate limited gene flow between distant populations of the brooding isopod Serolis paradoxa. The patterns of genetic diversity suggest that the only recently inundated Strait of Magellan was colonized by different source populations, most likely from Atlantic and Pacific coastal waters. Our results demonstrate that more systematic testing of shared faunal inventory and realized genetic exchange between Patagonia and the Falkland Islands is needed before a consensus concerning the position of the Falkland Islands relative to the Magellan zoogeographic province can be reached.
Leese, Florian; Kop, Anna; Wagele, Johann-Wolfgang; Held, Christoph
Beach mice, endangered subspecies of oldfield mice (Peromyscus polionotus), occur in a few, isolated populations along the Gulf Coast of Alabama and Florida, USA. To provide information needed for the management of these species, we conducted population viability analyses (PVA) using a stochastic differential equation (Wiener-drift) model applied to long-term demographic data for four populations of beach mice. In the
Madan K. Oli; Nicholas R. Holler; Michael C. Wooten
Recent ; increases in hurricane activity along the Gulf of Mexico lend urgency to understanding storm impacts on beach mice (Peromyscus polionotus) that occupy dune systems along this coast in Florida and Alabama. We documented changes in occupancy patterns of the Santa Rosa beach mouse (P. p. leucocephalus) from Hurricane Ivan and examined predictors of habitat use before and after
Alexander J. Pries; Lyn C. Branch; Deborah L. Miller
...USCG-2012-0314] RIN 1625-AA00 Safety Zone; Carnival Fireworks Display, Nantasket Beach...Beach in the vicinity of Hull, MA for a Carnival fireworks display. This temporary safety...Rule Hull Youth Football is sponsoring a Carnival fireworks display on the waters off...
...Independence Day Fireworks, Kings Beach, CA AGENCY: Coast Guard, DHS. ACTION: Notice...Independence Day Fireworks, Kings Beach, CA in the Captain of the Port, San Francisco...Tahoe Keys Marina in South Lake Tahoe, CA in approximate position 38[deg]...
The Virtual Beach Model Builder (VBMB) is a software tool that can be used to develop predictive models at beaches based on microbial data and observations (explanatory variables) that describe hydrometeorological and biogeochemical conditions. During the summer of 2008, a study...
During the dry season in California, when storm action is limited and river flow is weak, the mouths of many estuaries close, creating barrier beaches and ponding water in the backing lagoons. If these barrier beaches do not breach naturally or are not ma...
Ferry Beach is part of a barrier system that borders the southern end of the Saco Embayment. This portion of the coast is characterized by mesotidal conditions and low wave energy. The beaches in this area are fronted by a low gradient sandy offshore and backed by a continuous foredune ridge. The backbarrier consists of fresh water ponds at Ferry
This report takes a hard look at the day-to-day workings of Palm Beach County (Florida) schools to explain why the systemic change model of Florida's current reform legislation is likely to fail the students in greatest need of improved schooling. The Palm Beach County School District is the 4th largest district in Florida, and the 15th largest in…
Recent studies found high levels ofE. coli in sand, causing concern and media reports about risks of illness from contact with sand during beach recreation. We summarized associations between beach sand exposure and gastrointestinal (GI), respiratory, eye, ear, cut and urinary tr...
Predictive modeling for Escherichia coli concentrations at effluent-dominated beaches may be a favorable alternative to current, routinely criticized monitoring standards. The ability to model numerous beaches simultaneously and provide real-time data decreases cost and effort associated with beach monitoring. In 2004, five Lake Michigan beaches and the nearby Little Calumet River outfall were monitored for E. coli 7 days a week; on nine occasions, samples were analyzed for coliphage to indicate a sewage source. Ambient lake, river, and weather conditions were measured or obtained from independent monitoring sources. Positive tests for coliphage analysis indicated sewage was present in the river and on bathing beaches following heavy rainfall. Models were developed separately for days with prevailing onshore and offshore winds due to the strong influence of wind direction in determining the river's impact on the beaches. Using regression modeling, it was determined that during onshore winds, E. coli could be adequately predicted using wave height, lake chlorophyll and turbidity, and river turbidity (RA?=0.635, N=94); model performance decreased for offshore winds using wave height, wave period, and precipitation (RA?=0.320, N=124). Variation was better explained at individual beaches. Overall, the models only failed to predict E. coli levels above the EPA closure limit (235 CFU/100 ml) on five of eleven occasions, indicating that the model is a more reliable alternative to the monitoring approach employed at most recreational beaches.
Martini, I.P, 1975. Sedimentology of a lacustrine barrier system at Wasaga Beach, Onta- rm, Canada. Sediment. Geol., 14. 169--190 In an area of 4 by 15 miles (6.5 x 24 km) at Wasaga Beach, Ontario, a Holocene system is exposed that can be considered sedimentologically to be a lacustrine \\
This paper examines morphologic response to storms at northern Assateague Island MD. Time series of hindcast waves and water level were input to drive the SBEACH beach erosion and overwash numerical model to estimate beach response, ground-truthed by docu...
On the basis of taxometric analyses of data sets that they created to pose interpretive challenges, S. R. H. Beach, N. Amir, and J. J. Bau (2005) cautioned that using comparison data simulated by J. Ruscio's programs can lead to inaccurate conclusions. Careful examination of S. R. H. Beach et al.'s methods and results plus reanalysis of their data…
Sandhoppers orient towards the shoreline using a sun compass when they are subject to dry conditions. In this study we analysed the orientation of populations from two sandy beaches with wide tidal excursions (Brittany, France): at Damgan (sea to the South) and at Le Verger (sea to the North). At Le Verger beach Talitrus saltator was found together with Deshayesorchestia
S. Gambineri; C. Rossano; V. Durier; L. Fanini; C. Rivault; F. Scapini
THE 25-foot raised beach is well marked all round the northern and eastern coast of Ireland, and is also recognisable on the opposite coast of England and in the Isle of Man. This post-Tertiary beach is contemporaneous with the Upper Estuarine Clays of the Belfast sections,1 and is certainly not later than early Neolithic. At different times worked flints have
The purpose was to provide basic data relative to the utilization of the 26-mile, man-made beach in Harrison County, Mississippi, and to determine factors related to beach use. More specifically, the project was purposed with quantifying the level of beac...
This study presents: (1) basic data on the benthic fauna and surface sediments of the nearshore zone of Panama City Beach, Fla., before restoration of the beach, and (2) the results of a study on the effect of Hurricane Eloise on the benthic fauna in the ...
We studied the beach fidelity of Olive Ridley Turtles (Lepidochelys olivacea) for three seasons at the Rushikulya rookery on the coast of Orissa in India between December and May (2003-2005). We monitored sporadic nesting and arribadas for tagged turtles. Multiple nesting by individual turtles and recapture of tagged turtles confirmed beach fidelity in Olive Ridley Turtles. The inter-nesting intervals ranged
A spectacular submarine spring is located about 4 km east of Crescent Beach, FL, in the Atlantic Ocean. The single vent feature of Crescent Beach Spring provides a unique opportunity to examine onshore–offshore hydrogeologic processes, as well as point source submarine ground water discharge. The Floridan aquifer system in northeastern Florida consists of Tertiary interspersed limestone and dolomite strata. Impermeable
P. W Swarzenski; C. D Reich; R. M Spechler; J. L Kindinger; W. S Moore
This study presents a theoretical model for predictions of nearshore hydrodynamic characteristics and the local sediment transport rate along long, straight beaches. The wave may be periodic or random, the beach may be plane or barred, and the bed may be ...
As Americans head for the beach, the Natural Resource Defense Council (NRDC) issues its twelfth annual report on the status of beach and recreational water quality. Entitled Testing the Waters, the report offers readers a fifty-fifty appraisal of the nation's lake and ocean recreational beach sites. That is, while water quality overall is indeed improving in the United States, beach water quality is suffering notable setbacks, with increasing reports of beach closings and harmful bacteria or contaminant postings. With more than one third of all Americans visiting or vacationing at beach areas, water quality is no small issue, as it impacts both health and economic vitality of areas branded by closings or warnings. In public interest, therefore, the NRDC urges that more be done to ensure that water quality is carefully monitored, reported, and addressed at governmental, corporate, and local levels. Toward that end, the NRDC lists both the good and the bad, groups they identify as "Beach Buddies" and "Beach Bums," respectively those areas that monitor and disclose findings and those that don't. With state-by-state listings of water quality reports and links to many other environmentally dedicated resources, the report should interest all who use America's recreational water sites.
This study evaluated monthly accumulation rates and types of marine debris washed ashore at a recreational beach in Point Pleasant Park, Halifax Harbour, between April and September 2005. Black Rock Beach is 70 m long and a total of 2129 marine debris items were collected and sorted, representing a mean accumulation rate of 355 (±68 SE) items month-1. The total
Tony R. Walker; Jon Grant; Marie-Claude Archambault
Many sandy beaches worldwide receive large amounts of drift seaweed, known as wrack, from offshore algal beds and closer rocky intertidal shores. Despite the important influence of algal wrack on macrofaunal assemblages from different coastal systems, relatively little attention has been paid to the macrofaunal responses in sandy beaches to macrophyte wrack supplies. Algal wrack is a key resource, i.e.
Iván F. Rodil; Celia Olabarria; Mariano Lastra; Jesús López
Nearshore sandbars, an important natural defense mechanism of the beaches, can be monitored using shore-based video systems. Before studying bar dynamics with video images, we must establish the relationship between the real bar positions and the videoed bar positions (detected by the preferential wave breaking on the shallows). This analysis becomes essential in the two studied tideless beaches of Barcelona
Francesca Ribas; Elena Ojeda; Timothy D. Price; Jorge Guillen
...a temporary safety zone in the Atlantic Ocean east of Sunny Isles Beach, Florida...Challenge has been held in the Atlantic Ocean offshore of Sunny Isles Beach...zone around a race area in the Atlantic Ocean offshore of Sunny Isles...
...2013-07-01 2013-07-01 false Atlantic Ocean, off the Port of Palm Beach...Anchorage Grounds Â§ 110.185 Atlantic Ocean, off the Port of Palm Beach...regulations. (1) Vessels in the Atlantic Ocean near Lake Worth...
...1625-AA00 Safety Zone, North Atlantic Ocean; Virginia Beach, VA AGENCY...navigable waters of the North Atlantic Ocean in Virginia Beach, VA to support...over the navigable waters of the Atlantic Ocean. Due to the need to protect...
...establishing a temporary safety zone on the waters of the Atlantic Ocean in the vicinity of Apache Pier in Myrtle Beach, SC...protect life and property on the navigable waters of the Atlantic Ocean off the coast of Myrtle Beach, SC. Persons and...
...2013-07-01 2013-07-01 false Atlantic Ocean off Miami and Miami Beach, Fla...Anchorage Grounds Â§ 110.188 Atlantic Ocean off Miami and Miami Beach, Fla...vessel shall be anchored in the Atlantic Ocean in the vicinity of the...
The sitting beach-chair position is regularly used for shoulder surgery and anesthesia may be induced in that position. We tested the hypothesis that the cardiovascular challenge induced by induction of anesthesia is attenuated if the patient is placed in a reclining beach-chair position. Anesthesia was induced with propofol in the sitting beach-chair (n = 15) or with the beach-chair tilted backwards to a reclining beach-chair position (n = 15). The last group was stepwise tilted to the sitting beach-chair position prior to surgery. Hypotension was treated with ephedrine. Continuous hemodynamic variables were recorded by photoplethysmography and frontal cerebral oxygenation (ScO2) by near infrared spectroscopy. Significant differences were only observed immediately after the induction when patients induced in a reclining beach-chair position had higher mean arterial pressure (MAP) (35 ± 12 vs. 45 ± 15 % reduction from baseline, p = 0.04) and ScO2 (7 ± 6 vs. 1 ± 8% increase from baseline, p = 0.02) and received less ephedrine (mean: 4 vs. 13 mg, p = 0.048). The higher blood pressure and lower need of vasopressor following induction of anesthesia in the reclining compared to the sitting beach-chair position indicate more stable hemodynamics with the clinical implication that anesthesia should not be induced with the patient in the sitting position.
Larsen, S?ren L.; Lyngeraa, Tobias S.; Maschmann, Christian P.; Van Lieshout, Johannes J.; Pott, Frank C.
Numerous beaches around Antarctica are composed of coarse - gravel to boulder - deposits derived from local but limited sediment supplies and buffered wave energy by sea ice. Antarctic coarse-clastic beaches are built and reworked by high-magnitude storm waves. Despite the ambiguous relationship between sea-level and beach height, raised beaches are commonly used to reconstruct relative sea-levels assuming the elevation and age of the beaches reflect post-glacial adjustment. However, as Antarctic beaches are influenced by storm waves as well as vertical land motion, the ages of raised beaches may provide a proxy for past storminess. We assess the temporal distribution of raised beaches for four regions around Antarctica including the South Shetland Islands, Antarctic Peninsula, Ross Sea, and East Antarctica. From previously published dated raised beaches, the age distribution (n = 334) suggests distinct periods of enhanced beach formation around 1, 2, 3.5, and 5-6 thousand years ago. We compare the temporal distribution of raised beaches with Southern Hemisphere climate proxies to determine links between climate conditions that may have an influence on storminess around Antarctica. Current investigation of granulometry observations from raised beaches at several sites along the Antarctic Peninsula is underway to provide additional insight on wave-energy conditions.
...Zone; Labor Day at the Landing Santa Rosa Sound, Fort Walton Beach, FL AGENCY: Coast...safety zone for a portion of the Santa Rosa Sound in Fort Walton Beach, Florida extending...conduct a fireworks display on the Santa Rosa Sound, in Fort Walton Beach, Florida from...
...Coast Super Boat Grand Prix, Atlantic Ocean, Cocoa Beach, FL AGENCY: Coast...safety zone on the waters of the Atlantic Ocean east of Cocoa Beach, Florida...will be held on the waters of the Atlantic Ocean east of Cocoa Beach,...
Field experiments have been conducted on arctic beaches to asses the effectiveness of dispersants for the cleanup of stranded oil. The application of two commercially available chemical dispersants to aged and emulsified oil plots, in the intertidal zone on a semi-sheltered beach, resulted in a significant reduction of oil loadings immediately following the experiment as compared to loadings on adjacent intertidal control plots. The use of dispersants may, therefore, be of some value in mitigation of the potential adverse effects of oil immediately following stranding. In the semi-sheltered arctic environment in which the 1981 experiments were conducted (fetch up to 100 km; two-month open-water season), natural reworking of the oiled intertidal control plots over a 40-day period was effective in removing approximately 85 to 95% of the original oil loading. Further experiments in 1982 replicated the 1981 study in a more sheltered location, with a fetch area of less than 2 km, and indicate that the use of dispersants was not effective in this very low-energy environment. The conclusions drawn from this arctic experiment have a direct relevance to other coastal environments in lower latitudes.
A user-friendly, rule-based expert system has been designed for interpretation of lithofacies characteristics of beach and nearshore depositional environments. Recently, similar expert systems have been widely applied in medicine, business, and mineral exploration. The expert system runs on a VAX 780 (trade name). By incorporating knowledge and understanding of an expert, the system can interact with a user the way an expert consultant would. Interaction consists of a series of questions about lithology, sedimentary structures, and bioturbation of the lithofacies observed in outcrop or core. Uncertain responses are allowed and incorporated into the reasoning. Dialogue varies in different consultations because questions asked by the system depend on users' responses to previous questions. The result is an evaluation of the likelihood that the deposit under consideration is actually a beach or nearshore deposit. Significant lithofacies characteristics, the reasoning used in reaching the conclusion, and pertinent references are provided. Expert systems for other depositional environments are being designed. As their availability increases, geologists without easy access to experts on a particular depositional environment will have expert consultants as close as a computer terminal. Also the ability of the system to explain its reasoning and provide references lends the system to instructional uses.
An instrumented field study of the cross-shore evolution of incident waves was conducted on the shoreface of a gentle sloping microtidal barred-beach (Sète, France). A spectral analysis of typical hydrodynamic conditions (storm, waning storm and fair-weather) was performed from a series of pressure sensor data and synchronized horizontal velocities and pressure data. Results highlight the role of sedimentary bars in the dissipation and the spectral redistribution of incident energy. At the approach to the coast, the bars act like regulators of energy arriving at the shore and non-linear energy transfers are observed from the gravity to infragravity domain, during breaking or non-breaking situations. Consequently, the ratio of infragravity to gravity wave spectral energy density increases shoreward as significant wave height decreases. The study of incident wave reflection shows that during storm conditions, no significant wave reflection is observed and the beach can be classified as dissipative. During fair-weather conditions, a significant reflection from the beachface is observed but the bars do not play any role in this reflection.
Beach nourishment is increasingly used to protect public beach amenity and coastal property from erosion and storm damage. Where beach nourishment uses fill sediments that differ in sedimentology from native beach sands, press disturbances to sandy beach invertebrates and their ecosystem services can occur. How long impacts persist is, however, unclear because monitoring after nourishment typically only extends for several months. Here, monitoring was extended for 3-4 years following each of two spatially separated, replicate nourishment projects using unnaturally coarse sediments. Following both fill events, the contribution to beach sediments of gravel-sized particles and shell fragments was enhanced, and although diminishing through time, remained elevated as compared to control sites at the end of 3-4 years of monitoring, including in the low intertidal and swash zones, where benthic macroinvertebrates concentrate. Consequently, two infaunal invertebrates, haustoriid amphipods and Donax spp., exhibited suppressed densities over the entire post-nourishment period of 3-4 years. Emerita talpoida, by contrast, exhibited lower densities on nourished than control beaches only in the early summer of the first and second years and polychaetes exhibited little response to nourishment. The overall impact to invertebrates of nourishment was matched by multi-year reductions in abundances of their predators. Ghost crab abundances were suppressed on nourished beaches with impacts disappearing only by the fourth summer. Counts of foraging shorebirds were depressed for 4 years after the first project and 2 years after the second project. Our results challenge the view that beach nourishment is environmentally benign by demonstrating that application of unnaturally coarse and shelly sediments can serve as a press disturbance to degrade the beach habitat and its trophic services to shorebirds for 2-4 years. Recognizing that recovery following nourishment can be slow, studies that monitor impacts for only several months are inadequate. PMID:24802271
Peterson, Charles H; Bishop, Melanie J; D'Anna, Linda M; Johnson, Galen A
This paper examines the role of coastline orientation on foredune and dunefield development at Moçambique Beach, Southern Brazil. The beach displays significant alongshore variations in exposure to the prevailing winds and waves, grain size, beach/surfzone morphodynamic type, foredune volume, and type and dimensions of the Holocene dune systems. Two wind analyses and calculation of aeolian drift potentials were carried out, one based on 1 year of wind record and another based on a record of 34 years. Monthly topographic surveys of beach and foredunes on 5 profiles along Moçambique beach were conducted over one year to obtain data on beach mobility and width, aeolian sediment transport and foredune development. Southerly winds dominate, and aeolian sediment supply is minimal in the south, moderate in the central portion and high in the northern portion of the embayment. The relationship between actual sediment supply, foredune building and potential sediment supply is relatively poor over one year due to factors such as beach type and mobility, beach moisture levels, rainfall, storm surge and wave scarping. The intermediate term (34 year) record indicates a strong relationship between foredune size and volume, winds and shoreline orientation: foredune volume is minimum in the southern part of the beach and greatest in the northern part of the beach. The Holocene barrier and dunefield development also reflects the long term control of shoreline orientation and increasing longshore gradient in exposure to southerly winds: for the last 6000-7000 years a small foredune developed in the southern portion, parabolics and small transgressive dunes in the central portion, and a large-scale transgressive dunefield in the northern portion.
The peracarid isopod, Stenosoma nadejda (Rezig 1989), until recently considered to be endemic of the Mediterranean region, was first reported in the Atlantic coast of southern Spain in 2001, and in 2006 abundant populations were discovered throughout the southwestern Portuguese coast. This fast expansion was intriguing because, as a direct brooder, this species has limited mechanisms for dispersal, such as rafting on seaweeds. Did S. nadejda recently extend its range into the Atlantic or was it overlooked in the past? We examined the patterns of genetic diversity and population differentiation accordingly by sequencing the cytochrome c oxidase subunit I mitochondrial gene from 75 individuals collected in five locations in Atlantic Iberia and one in the Mediterranean. Our results indicate that the newly discovered Atlantic populations of S. nadejda appear to be old and have long persisted on Atlantic shores rather than being a recent introduction. High levels of genetic diversity and geographic structure were uncovered in what was initially suspected to be an 'invasive' species. Recent changes in population dynamics may have made S. nadejda more conspicuous in the Atlantic shores, or a more comprehensive survey led to the recognition of this species where it was not expected. PMID:19555413
In the hot debate on arthropod relationships, Crustaceans and the morphology of their appendages play a pivotal role. To gain new insights into how arthropod appendages evolved, developmental biologists recently have begun to examine the expression and function of Drosophila appendage genes in Crustaceans. However, cellular aspects of Crustacean limb development such as myogenesis are poorly understood in Crustaceans so that the interpretative context in which to analyse gene functions is still fragmentary. The goal of the present project was to analyse muscle development in Crustacean appendages, and to that end, monoclonal antibodies against arthropod muscle proteins were generated. One of these antibodies recognises certain isoforms of myosin heavy chain and strongly binds to muscle precursor cells in malacostracan Crustacea. We used this antibody to study myogenesis in two isopods, Porcellio scaber and Idotea balthica (Crustacea, Malacostraca, Peracarida), by immunohistochemistry. In these animals, muscles in the limbs originate from single muscle precursor cells, which subsequently grow to form multinucleated muscle precursors. The pattern of primordial muscles in the thoracic limbs was mapped, and results compared to muscle development in other Crustaceans and in insects. Electronic supplementary material The online version of this article (doi:10.1007/s00427-008-0216-1) contains supplementary material, which is available to authorized users.
The four-lobed hepatopancreas of terrestrial isopods is a highly specialized enzyme secretory, digestive and absorptive region of the midgut. The walls of these blindending tubes are composed of two distinctive epithelial cell types: large, lipid-rich B-cells projecting into the lumen; and small S cells containg (Cu+S)-rich granules. This study investigated the possible stressful effects of accumulated Pb and Zn on the metabolically highly responsive, B-cells. Three major objectives were pursued. First, quantitative electron probe X-ray microanalysis (EPXMA) was employed to determine whether the accumulation of Pb and Zn changes the Fe concentration within individual Fe-granules. Second, simple morphometric techniques were applied to transmission electron micrographs to determine whether competition between essential (Fe) and pollutant (Pb,Zn) metals for binding ligands resulted in an increased granule volume per individual cell. Third, to measure the effect of Pb and Zn accumulation of the amount of stored lipid, in the form of discrete droplets, within the B-cells.
Morgan, A.J.; Gregory, Z.D.E.; Winters, C. (Univ. of Wales College of Cardiff (Wales))
Coastal erosion, storms, sea-level rise, and tsunamis all lead to inundation that puts people and communities at risk. Adapting to these coastal hazards has gained increasing attention with climate change. Instead of promoting one particular strategy such as seawalls or defending against one type of hazard, scholars and practitioners encourage a combination of existing methods and strategies to promote synergistic effects. The recently published Intergovernmental Panel on Climate Change (IPCC) Special Report on climate extremes reflects this trend in the integration of disaster risk management and climate change adaptation. This paper focuses on the roles, compatibilities, and synergies of three coastal adaptation options - engineering, vegetation, and policy - in the case of Ocean Beach in San Francisco. Traditionally engineering approach and ecosystem conservation often have stood in opposition as hard shoreline structures destroy coastal habitats, worsen coastal erosion, divert ocean currents, and prevent the natural migration of shores. A natural migration of shores without structure translates into the abandonment of properties in the coastal zone, and is at odds with property rights and development. For example, policies of relocation, retreat, and insurance may not be popular given the concerns of infrastructure and coastal access. As such, engineering, natural defense, and policy can be more conflictual than complementary. Nonetheless, all these responses are used in combination in many locations. Complementarities and compatibilities, therefore, must be assessed when considering the necessity of engineering responses, natural defense capabilities, and policy options. In this light, the question is how to resolve the problem of mixed responses and short- and long-term interests and values, identify compatibilities, and generate synergies. In the case of Ocean Beach, recent erosions that endangered San Francisco's wastewater treatment system acted as major stimuli in coastal adaptation initiatives and resulted in the Ocean Beach Master Plan. Investigation into the planning processes involving multiple stakeholder engagement such as San Francisco (SF) Public Utilities Commission, California Coastal Commission, National Park Service, SF Department of Public Works, SF Recreation and Park Department, SF Planning Department, and the U.S. Army Corps of Engineers can shed light on trade-offs and synergies of different adaptation responses. The role of the coordinator - SF Planning and Urban Research Commission - as a mediator between different stakeholder interests and priorities, a realistic assessment of current hazard management practices specific to local contexts, and the necessity of combining hazard mitigation policies with coastal management and community management are the key findings of this research. They help inform policy formulation and decision-making in climate change adaptation, and provide a valuable case study that can be transferred to other locations.
A new type of permeable groin (called System of Groins Maltec-Savard - SGMS) has been installed at three eroded sites located in the coastal area on the north shore of the St. Lawrence, Quebec, Canada. In this area, the narrow sandy beaches with sandy or sand-silty cliff of variable height (10-15~m) are exposed to obliquely incident waves arriving from both west (summer) and east (autumn), and to tidal currents (maximum tidal rate is 4.3~m). The periods of summer waves equal 3-5~s, with wave heights of about 0.4-0.7~m. In the autumn, major storm waves reach periods of up to 7-10~s, with wave heights of 1.0-1.2~m. The new groins are sediment traps formed by a central double and permeable groin with several smaller lateral, groins installed on one or both sides of the central groin (Boczar-Karakiewicz et al., 2001). The permeable central and lateral groins are structured by inserting double ranges of wooden piles (diameter of about 10 cm). The space between the ranges of piles (some 0.8~m wide) is filled with tree branches (e.g., the top parts of pine trees, a waste product of the local forest industry). A permeable grid covering the top of the groins forms a cage that holds the branches in place. The lateral groins, are identical but much shorter than the central groin. The whole system dissipates the incident energy of wave- and tidally-generated currents and causes accretion of sand transported by these currents. The GSMS also allows the by-pass of some sediment to adjacent zones without groins. Observations and results of measurements from three experiments field show that: (1) a sandy beach in front of a coastal cliff secures its stability and attenuates the erosion caused by waves and tidal currents; (2) permeability and flexibility of the SGMS causes the accretion of sediment in the protected area without erosion in the neighboring zones; (3) the SGMS does not generate wave reflection and any secondary current; (4) the materials of the groins are easily available, and the cost is low (waste material of the local forest industry); (5) the construction is simple and can be carried out by low-skilled labor force. Boczar-Karakiewicz, B., W. Romanczyk, N. Roy, N. Pelletier, L. Maltec and J.-P. Savard. 2001. New method of beach protection adapted to coastal zones of the estuary of the Saint Lawrence river, Quebec, Canada. Proc. Can. Coast. Conf., Quebec, QC, Canada: 201-214 (in French).
This fact sheet describes utilities created for management of recreational waters to provide efficient data management, data aggregation, and predictive modeling as well as a prototype geographic information system (GIS)-based tool for data visualization and summary. All of these utilities were developed to assist beach managers in making decisions to protect public health. The Environmental Data Discovery and Transformation (EnDDaT) Web service identifies, compiles, and sorts environmental data from a variety of sources that help to define climatic, hydrologic, and hydrodynamic characteristics including multiple data sources within the U.S. Geological Survey and the National Oceanic and Atmospheric Administration. The Great Lakes Beach Health Database (GLBH-DB) and Web application was designed to provide a flexible input, export, and storage platform for beach water quality and sanitary survey monitoring data to compliment beach monitoring programs within the Great Lakes. A real-time predictive modeling strategy was implemented by combining the capabilities of EnDDaT and the GLBH-DB for timely, automated prediction of beach water quality. The GIS-based tool was developed to map beaches based on their physical and biological characteristics, which was shared with multiple partners to provide concepts and information for future Web-accessible beach data outlets.
California's Clean Beach Initiative (CBI) funds projects to reduce loads of fecal indicator bacteria (FIB) impacting beaches, thus providing an opportunity to judge the effectiveness of various CBI water pollution control strategies. Seventeen initial projects were selected for assessment to determine their effectiveness on reducing FIB in the receiving waters along beaches nearest to the projects. Control strategies included low-flow diversions, sterilization facilities, sewer improvements, pier best management practices (BMPs), vegetative swales, and enclosed beach BMPs. Assessments were based on statistical changes in pre- and postproject mean densities of FIB at shoreline monitoring stations targeted by the projects. Most low-flow diversions and the wetland swale project were effective in removing all contaminated runoff from beaches. UV sterilization was effective when coupled with pretreatment filtration and where effluent was released within a few hundred meters of the beach to avoid FIB regrowth. Other BMPs were less effective because they treated only a portion of contaminant sources impacting their target beach. These findings should be useful to other coastal states and agencies faced with similar pollution control problems. PMID:19496001
Coastal squeeze is the largest threat for sandy coastal areas. To mitigate seaward threats, erosion and sea level rise, sand nourishment is commonly applied. However, its long-term consequences for macroinvertebrate fauna, critical to most ecosystem services of sandy coasts, are still unknown. Seventeen sandy beaches - nourished and controls - were sampled along a chronosequence to investigate the abundance of four dominant macrofauna species and their relations with nourishment year and relevant coastal environmental variables. Dean's parameter and latitude significantly explained the abundance of the spionid polychaete Scolelepis squamata, Beach Index (BI), sand skewness, beach slope and latitude explained the abundance of the amphipod Haustorius arenarius and Relative Tide Range (RTR), recreation and sand sorting explained the abundance of Bathyporeia sarsi. For Eurydice pulchra, no environmental variable explained its abundance. For H. arenarius, E. pulchra and B. sarsi, there was no relation with nourishment year, indicating that recovery took place within a year after nourishment. Scolelepis squamata initially profited from the nourishment with "over-recolonisation". This confirms its role as an opportunistic species, thereby altering the initial community structure on a beach after nourishment. We conclude that the responses of the four dominant invertebrates studied in the years following beach nourishment are species specific. This shows the importance of knowing the autecology of the sandy beach macroinvertebrate fauna in order to be able to mitigate the effects of beach nourishment and other environmental impacts.
Leewis, Lies; van Bodegom, Peter M.; Rozema, Jelte; Janssen, Gerard M.
The Parent Supervision Attributes Profile Questionnaire (PSAPQ), developed to measure aspects of caregiver supervision and protectiveness and previously applied within playgrounds and in the home, was modified for implementation in a beach setting. To assess the test-retest reliability of the PSAPQ beach modification (PSAPQ-BEACH), 20 caregivers completed the PSAPQ-BEACH twice, over a mean interval of 18 days (range 10-24). The test-retest reliability and internal consistency of the PSAPQ-BEACH scores were compared to those of the PSAPQ. All scores on the PSAPQ-BEACH were higher than the PSAPQ, providing evidence that the questionnaire remains reliable after its adaptation to beach settings. PMID:21302168
Petrass, Lauren A; Blitvich, Jennifer D; Finch, Caroline F
Human adenoviruses (HAdVs) have been related to several waterborne diseases such as acute gastroenteritis, conjunctivitis, and respiratory illness, and it has been shown that an important human exposure pathway is through recreational waters. However, HAdV occurrence at recreational freshwater beaches has not been previously investigated. In this study, a total of 58 water samples were collected from two recreational beaches on Lake Michigan (i.e., Silver Beach and Washington Park Beach) during the summer of 2004. Occurrences of HAdVs in these lake samples were determined using two hexon-based real-time PCR assays (one for monitoring all 51 serotypes of HAdVs and another for specifically detecting F species HAdVs, i.e., serotypes 40 and 41) and compared to an integrated cell culture (ICC) PCR method. The real-time PCR results showed that 8 of 30 Silver Beach samples and 6 of 28 Washington Park Beach samples contained HAdVs, and F species HAdVs were detected in three of these positive samples. The concentrations of HAdVs ranged from (1.7 ± 0.7) × 101 to (3.4 ± 0.8) × 102 and from (7 ± 2) × 100 to (3.8 ± 0.3) × 103 virus particles/liter for Silver Beach and Washington Park Beach, respectively. F species HAdVs were detected at levels ranging from (4.8 ± 0.8) × 101 to (4.6 ± 1.5) × 102 virus particles/liter. Approximately 60% of the ICC-PCR analyses agreed with the real-time PCR results. This study revealed the occurrence of HAdVs at Lake Michigan recreational beaches. Given the potential health risks, further assessment regarding sources, virus transport, and survival is needed to improve the safety of the region.
Xagoraraki, Irene; Kuo, David H.-W.; Wong, Kelvin; Wong, Mark; Rose, Joan B.
Due to isolation and a period of severe anoxic conditions in geologically recent times, biodiversity is low in the deep Sea of Japan. Among a small group of species inhabiting depths below 2500, only one isopod species, Eurycope spinifrons, was found during the SoJaBio expedition in 2010, but it was the most abundant species of all benthic taxa. E. spinifrons was found with remarkably high numbers of individuals at the sampled stations below 2500 m, providing a rare opportunity to investigate aspects of population structure and reproduction of a deep-sea isopod. The distribution, population structure, fecundity and depth dependent density of E. spinifrons were studied. Brooding females were the longest in body size and least abundant, while mancae were the shortest and most abundant. The mean length of individuals showed little deviation among the stations below 2500 m, ranging from 4.21±0.29 mm in brooding females to 1.20±0.26 mm in free-living mancae. Iteroparity is demonstrated for E. spinifrons. It is argued that females have continuous reproduction which increases in the summer. The length of the brooding females is positively correlated with the number of eggs in the marsupium in our sample (r=0.291; p<0.05). Comparing the mean length of E. spinifrons between different stations revealed that specimens sampled at the upper slope (460 m) were significantly smaller in every developmental stage than those from stations below 2500 m. This finding confirms the existence of a threshold depth below which E. spinifrons was the only isopod species found. Thus, we argue that individuals at deeper stations grow bigger due to reduced competition in the deep Sea of Japan.
Many of the city of Virginia Beach's beach stabilization and sewage disposal problems are the result of an inadequate understanding of the physical and biological systems. Influenced by population and economic pressures, natural systems were artificially stabilized by engineering projects that had to be constantly maintained. These same pressures continue to prevail today in spite of a new environmental awareness; changes are occurring very slowly. Furthermore, the lack of adequate sewage disposal facilities and the continued urbanization of inappropriate areas are threatening Virginia Beach's attractiveness as a resort area.
The 1989 Exxon Valdez oil spill released more than 11 million gallons of oil into Prince William Sound, Alaska, polluting 800 kilometers of beaches. In some areas the spilled oil has persisted on beaches more than 20 years later. To examine the factors affecting the persistence of oil from the spill, Xia et al conducted field studies and numerical modeling of the hydrogeological characteristics of a shallow bedrock beach on Knight Island in western Prince William Sound, the area most heavily polluted by the spill. (Water Resources Research, doi:10.1029/2010WR009179, 2010)
Morphologies of placer platinum group minerals (PGM) are more variable and resistant to modification during transport than placer gold grains. This study documents morphological evolution of PGM placer grains during up to 120 km of transport in beach placers after river transport from inferred sources up to 200 km inland. PGM morphological changes are calibrated with changes in morphology of associated placer gold. Most of the PGM are Pt-Fe alloy and have been fed into the beach placer system from a large river at the western end of the beaches on the south coast of New Zealand. The incoming fluvial PGM suite includes Os, Ir and Ru alloys which may have been derived from distal ophiolitic sources. More proximal sources have Ural-Alaskan affinities and these contributed cooperite and braggite, or sperrylite, locally, as well as Pt-Fe alloy grains. Some PGM may have been recycled through Cretaceous-Quaternary fluvial sediments before entering the modern placer system. Recycled placer PGM grains have also been derived from elevated Quaternary beaches near the coastline. PGM grains entering beach placers have rough surfaces, with remnants of crystal faces, and these evolve to smooth flakes with progressive long-shore transport. PGM flakes have slightly thickened rims caused by impacts by saltating sand on windy beaches, and the most distal beach placers contain flakes with incipient toroidal shapes. These PGM incipient toroids are poorly developed compared to accompanying well-formed toroidal gold that has developed in nearly all beach placers, including those on elevated Quaternary beaches. Typical PGM and gold placer grain size decreases with increasing distance of transport, from fluvial grain size of 400-1,000 to ˜200 microns on the most distal beaches, accompanied by eastward loss of equant PGM grains and associated increase in proportion of flakes. Although net transport distance is ˜120 km in the beach placer complex, frequent aeolian transport of grains from beach to dunes and subsequent recycling by storm surges substantially increased total transport distance in a dynamic windy tectonic environment.
STS-95 Commander Curtis L. Brown Jr. examines the heads up display in the 1999 C-5 Corvette convertible in which he will be riding during a parade down State Road A1A in nearby Cocoa Beach as Dan Adovasio, a parade coordinator, looks on. Organizers of the parade include the Cocoa Beach Area Chamber of Commerce, the Brevard County Tourist Development Council, and the cities of Cape Canaveral and Cocoa Beach. The parade is reminiscent of those held after missions during the Mercury Program.
Placentia Bay currently hosts the highest volume of ship traffic in along the Atlantic Canadian coastline, and is additionally exposed to accidental and deliberate discharges of petroleum products by Trans-Atlantic ship traffic. Placentia Bay has been identified as the region in Canada that is most likely to suffer a petroleum contamination event within the next 10 years. The morphological, sedimentological, energy regime, and marine debris characteristics of 4 beaches at the head of Placentia Bay were investigated in detail. Differing morphological, sedimentological and energy regime conditions alter the sensitivity of each system to oil spill contamination. Differences in the type and amount of marine debris between each system alter the potential risk of exposure to oil spill contamination. Based on differences in sensitivity and exposure, a vulnerability assessment was created for each system. This system was applied to additional beaches and rocky coastlines to demonstrate the applicability of the method and to highlight the actual vulnerability of each study beach relative to the spectrum of beaches actually present throughout eastern Newfoundland. Typical of the majority of beaches throughout Placentia Bay, the 4 study beaches are characterized by gravel dominated, reflective, moderate to high energy systems. Observations of sediment re-working and accretionary features along the beaches of Arnold's Cove and Come by Chance indicate that self-cleaning would not be an effective agent of oil removal in the case of a spill. The absence of sediment re-working and protected nature of Goose Cove beach suggest that oil would persist in this environment for an extended period of time. Evidence of high wave energies at Hollett's Cove indicates that this beach would self-clean effectively. Differing types and quantities of marine debris indicate that each beach, with the exception of Goose Cove, would likely be exposed to oil originating from a Placentia Bay spill. The heaviest quantities would be expected at Hollett's Cove and Arnold's Cove. Based on these factors, Arnold's Cove and Come by Chance are considered the most vulnerable beaches to oil contamination. Hollett's Cove and Goose Cove are considered the least vulnerable respectively. Applying the vulnerability assessment to the additional coastlines revealed that the 4 study beaches rank as moderately to highly vulnerable to oil spill contamination. This ranking, combined with the frequency of vessel traffic, indicates that a significant risk exists.
The amount of seasonal water use is important to the City of Virginia Beach because the primary source of this water is a fragile, shallow aquifer that is the only fresh groundwater source available within the city. Residents in the mostly rural southern half of Virginia Beach rely solely on this aquifer, not only for outdoor water uses but also for indoor domestic uses such as drinking and bathing. Groundwater that is close to the land surface in Virginia Beach is mostly fresh, whereas water 200 feet or more below the land surface is mostly saline and generally too salty to drink or use for irrigating lawns and gardens.
The aim of the present contribution is to compare three numerical models on the grounds of their performance in simulating beach profile response on a monitored storm event in the Praia de Faro, South Portugal. The discussed storm occurred on February 1st, 2009, with duration ~24 hours and WSW waves, with maximum observed significant wave height and peak period, around 5 m and 8.5 s, respectively. The event was the most intense of the year, with a 3 years return period. Three models were run: the open source XBeach, a Bussinesq model (Karambas, T.V. and Koutitas, C., 2002. J. Wat, Port, Coas. & Oc. Eng., 128 (3)) and a linear energetics-approach model (Vousdoukas et al., Cont. Shelf Res., in press). Models were run for five profiles distributed along the whole study site, with circa 500 m spacing between each other; and beachface steepness increasing westwards (ranging from ~6% to 10%). All studied profiles showed signs of berm erosion and off-shore bar formation, with the impacts of the storm becoming less prominent, from the steeper NW profiles to the milder sloped ones, found on the SE boundary. All models overestimated the berm erosion, especially on the steeper profiles for which an unrealistic erosive scarp appeared, coupled with enhanced bar formation. Such behaviour was weaker on the Bousinesq model; which was calibrated for milder avalanching and produced overall improved results (rms errors between 0.2-0.35 m), with the cost of increased computational times. The performance of the energetics approach model was comparable to the other two, despite the significantly reduced computational times (~one order of magnitude). The overall rms errors ranged from 0.2 to 0.5 m, with the higher values corresponding to the western steeper profiles. Apart from a weakness of such profile models to simulate morphological response on reflective beaches, some other factors may account for the differences between predictions and observations: e.g. longshore transport, the presence of structures at the backshore; and even preventive sand supply/rearrangement by the local authorities. The above may explain also that model performance was improved on the more remote and ‘natural’ eastern profile; in which however, unrealistic berm erosion and scarp formation were also shown by the models. The preliminary results presented are part of an on-going effort to develop modelling tools for storm impact prediction/monitoring in the area and model testing/calibration, incorporating results from beach profile monitoring. Model run results comparison for the eastern, milder sloped profile of Praia de Faro
Vousdoukas, M. I.; Almeida, L. M.; Ferreira; Karambas, T. V.
...100.740 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY REGATTAS AND MARINE PARADES SAFETY OF LIFE ON NAVIGABLE WATERS Â§ 100.740 Annual Offshore Super Series Boat Race; Fort Myers Beach, FL....
This report outlines procedures for ship-discharge operations on beaches under wartime conditions by the use of light-amplification equipment. Certain companion projects are incidental to this work and may have widespread applications. These include: Ligh...
Describes a deterministic computer model that incorporates: (1) initial framework composition; (2) abrasion factors for quartz, feldspar, and rock fragments; and (3) a fragmentation ratio for rock fragments to simulate the recycling of coastal sands by rivers and beaches. (TW)
The report describes the biostratigraphy and generalized lithostratigraphy of a subsurface marine facies of the Upper Cretaceous Middendorf Formation encountered in a corehole drilled at Myrtle Beach, South Carolina. Whereas most outcrop and subsurface se...
Describes approximately 15 hours of activities in the Sellicks Beach Area suitable for high school students interested in studying sedimentary and structural geology, geomorphology, and human land use patterns. (CP)
The temporal-spatial distribution of benthic meiofauna was evaluated in four beaches at the north coast of Havana, Cuba, from March 2003 to February 2004. We studied two urban beaches (Santa Fe and La Concha) and two tourist beaches (Mar Azul and Canasi). Monthly meiofauna samplings were taken by scuba-diving using with a syringe (inner diameter 2.5 cm), and physico-chemical parameters (grain size, interstitial salinity and water column salinity were recorded with standard equipment). Statistical analysis (MDS and ANOSIM) were performed. Depth and biotope kind were the same in the four beaches. Highest densities were obtained in Santa Fe (7,133.48 ind/10 cm2) while the lowest mean densities were found in Canasí (892.12 ind/10 cm2). We recorded 13 taxa; the dominant organisms in Santa Fe and Mar Azul were free-living marine nematodes. Copepods were the dominant organisms in La Concha and Canasí. PMID:18491641
Though the lower n-alkanes are considered the most degradable components of crude oil, our experiments with microcosms simulating oiled beaches showed substantial depletion of fluorene, phenanthrene, dibenzothiophene, and other PAH in control treatments consisting of raw seawater...
The Inner Continental Shelf off eastern Florida was surveyed by CERC to obtain information on bottom morphology and sediments, subbottom structure, and sand deposits suitable for restoration of nearby beaches. Primary survey data consists of seismic refle...
Prepared for students who participate in the California State University Long Beach (CSULB) Library Instruction Program (LIP), this document is both a working syllabus for classroom use and an outline of the lecture presentations given by librarian instru...
Stable fly adults were collected from 16 locations within the state of Florida and from locations in six other states in an attempt to determine the source of stable fly populations along Florida beaches on the Gulf of Mexico. Electrophoretic analyses were made of a minimum of 10 enzymes in each of 37 separate populations. Extremely low heterozygosity resulted in an inability to use standard genetic identity and distance procedures for determining the divergence of allopatric populations to establish the source of flies captured from beach areas where reproduction was unlikely. Comparisons of rare alleles in populations grouped geographically, computations of number of possible migrants, and analysis of conditional average frequency of alleles led to the conclusion that flies captured on Florida beaches come from a variety of sites, with locations northwest of the beaches contributing the majority of flies in outbreaks. PMID:1770514
Jones, C J; Hogsette, J A; Patterson, R S; Milne, D E; Propp, G D; Milio, J F; Rickard, L G; Ruff, J P
This paper explores the potential of time-frequency wavelet analysis in resolving beach bacteria concentration and possible explanatory variables across multiple time scales with temporal information still preserved. The wavelet scalograms of E. coli concentrations and the explan...
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...they depart and start their climbs to higher altitudes. Most aircraft departing LNA that are headed...Palm Beach County Park Airport helicopter training activities to take place at higher altitudes. In addition, a minor correction is...
Beaches are among the most dynamic systems in the coastal zone. This is due to the great variability in the main triggering factors that contribute to morphological change. Dramatic coast line retreat can occur in a short period of time due to episodic extreme wave events endangering people and property and therefore defining the local susceptibility to erosion. This research aims to determinate beach recession and volume erosion due to sediment loss during extreme wave events in non artificialized beaches of the Portuguese west coast, for susceptibility analysis. The central west coast of Portugal is a wave dominated high energetic coastal environment. Storm frequency and magnitude are very important features on the definition of the annual local sediment budget and on the anthropogenic elements exposure to the direct action of waves through momentary or permanent coastline retreat. Winter offshore mean significant wave values reach 2.5m and waves with a 5 year recurrence period can be higher than 9m. Results of cross- shore beach profile modeling using storm-induced beach change model (SBEACH) are presented for 3 beach systems, namely Sta. Rita beach, Azul beach and Foz do Lizandro. The calibration tests and the validation process are described and presented. The model run results are based on high definition natural beach profile data of pre- and post-storm measured morphology, on local characteristics of beach sediments and on hydrodynamic variables related to onshore extreme wave data and local tide heights. Results point out the crucial importance of the local calibration process for the model application, with adjusted values of the transport rate coefficient, K, and the coefficient for slope dependent term, ?, differing from the "recommended" values by excess. In most cases validation values show that the locally calibrated SBEACH model explains 90% of the observed volume changes between pre- and post-storm profiles, computing sediment loss by slight excess. Final results of the SBEACH model application using extreme wave conditions associated with a secular recurrence period event are mapped for the 3 beach systems, defining the susceptible areas to extreme erosion.
The morphologic evolution of coastal dunes is inextricably linked to the neighbouring beach through the incessant exchange of sand. Intense storm-wave processes erode the foredune within a few hours and transport its sand sand seaward, while aeolian processes return the eroded sand from the beach into the dune system, although at a much lower pace (months to years, or meso scale). Here we use an 8-year long data set of half-hourly snapshot video images, collected from an ? 50 m high tower on Egmond Beach (The Netherlands), and a concurrent meteorological and water level data set, to examine which factors affect aeolian sand delivery into the dunes. Egmond is a north-south oriented, micro- to meso-tidal, wave-dominated site that faces the North Sea. Its beach is relatively narrow ( ~ 100 m at spring low tide) and mildly sloping (~ 1 : 30), and consists of quartz sand with a median diameter of about 300 ?m. Aeolian activity is clearly visible on the images as sand streamers and, in particular, sand strips, defined as low-amplitude, large-wavelength and slipfaceless deposits that migrate slowly in the wind direction and, depending on wind direction, can have orientations from almost shore-parallel to shore-normal. Beach width in combination with wind direction appeared to be the dominant factors in controlling aeolian activity. Many high wind (>? 13 m/s) events, especially from the west and northwest, were associated with a storm surge that inundated almost the entire beach with, accordingly, no possibility for aeolian transport. In contrast, sand-strip fields covered the entire beach during medium wind (? 12 - 13 m/s) events, especially when the wind was nearly shore-parallel. Many sand-strip events were observed to be regulated by the tide. Prominent sand-strip fields on the intertidal and upper beach were largely limited to low-tide situations with a wide beach, with a rising tide obviously destroying the intertidal sand strips and sometimes also negatively affecting aeolian activity on the upper beach. Rain was seen to shut-down the aeolian system when sand strips were not well developed (low wind speeds, ? 8 - 12 m/s), but not so during substantially stronger winds. Although our assessment of aeolian transport magnitude is qualitative, our work does indicate that there may be a considerable mismatch between the relative importance of potential and actual aeolian transport events on narrow beaches. Future work, in concert with continuous video monitoring, is necessary to actually quantify meso-scale aeolian sand supply.
An evaluation is underway at the Goat Rock State Beach, which is located at the mouth of the Russian River near Jenner, CA. The study focuses on quantifying the influence of a man made jetty on the functioning of a barrier beach and associated implications for estuary fish habitat and flood control. Flow through the beach results from water level differences between the estuary and the ocean. When the estuary is closed or perched, one of the potential major sources of outflow from the lagoon is seepage flow through the barrier beach. The location and design of the jetty could be altering subsurface flow paths through the jetty and possibly impeding or enhancing subsurface flow where the jetty is still intact. This will result in unnatural connectivity between the ocean and the estuary leading to atypical surface water elevations and possibly salinity imbalance. Results of the assessment will enable the Sonoma County Water Agency to understand how the jetty affects formation of the barrier beach and water surface elevations within the estuary. As one aspect of the evaluation, we are using geophysical methods to monitor seepage through the jetty as well as through the beach berm. We are using multiple surface geophysical methods, including: electrical resistivity, seismic refraction, ground penetrating radar, and electromagnetic methods. In general, seismic data are being used to characterize deeper bedrock controls on beach barrier functioning such as, channeling of estuarine water beneath the barrier beach. Electrical and electromagnetic methods are being used to characterize the beach sediment layers that could contribute to preferential flow paths during tide cycles in addition to preferential flow paths created by the jetty structure. Time-lapse electrical and electromagnetic data are being used to monitor moisture changes and mixing of saline and fresh water within the beach berm. Ground penetrating radar data are being used to delineate the geometry of the (often buried) jetty. All data are being integrated with topography, tidal and hydrological information, and electrical conductivity and temperature data from monitoring wells. These results are expected to improve the overall understanding of the jetty's effects on beach permeability and will better improve the understanding of the jetty's influence on estuary habitats and flood risk.
Direct-current resistivity data were collected from 94 vertical electric sounding profiles in northeastern Palm Beach County, Florida. Direct-current resistivity data, which may be used to determine the location and thicknesses of shallow, semipermeable marls or locate zones of high chloride concentration, are presented in this report. The resistivity data consist of field data, smoothed data, layer resistivity from smoothed data, and Cartesian graphs of resistivity in relation to depth for 94 sites located in northeastern Palm Beach County. (USGS)
Natural populations of beach mice exhibit a characteristic color pattern, relative to their mainland conspecifics, driven by natural selection for crypsis. We identified a derived, charge-changing amino acid mutation in the melanocortin-1 receptor (Mc1r) in beach mice, which decreases receptor function. In genetic crosses, allelic variation at Mc1r explains 9.8% to 36.4% of the variation in seven pigmentation traits determining
Hopi E. Hoekstra; Rachel J. Hirschmann; Richard A. Bundey; Paul A. Insel; Janet P. Crossland
Efforts to improve public health protection in recreational swimming waters have focused on obtaining real-time estimates of water quality. Current monitoring techniques rely on the time-intensive culturing of fecal indicator bacteria (FIB) from water samples, but rapidly changing FIB concentrations result in management errors that lead to the public being exposed to high FIB concentrations (type II error) or beaches being closed despite acceptable water quality (type I error). Empirical predictive models may provide a rapid solution, but their effectiveness at improving health protection has not been adequately assessed. We sought to determine if emerging monitoring approaches could effectively reduce risk of illness exposure by minimizing management errors. We examined four monitoring approaches (inactive, current protocol, a single predictive model for all beaches, and individual models for each beach) with increasing refinement at 14 Chicago beaches using historical monitoring and hydrometeorological data and compared management outcomes using different standards for decision-making. Predictability (R2) of FIB concentration improved with model refinement at all beaches but one. Predictive models did not always reduce the number of management errors and therefore the overall illness burden. Use of a Chicago-specific single-sample standard-rather than the default 235 E. coli CFU/100 ml widely used-together with predictive modeling resulted in the greatest number of open beach days without any increase in public health risk. These results emphasize that emerging monitoring approaches such as empirical models are not equally applicable at all beaches, and combining monitoring approaches may expand beach access.
Efforts to improve public health protection in recreational swimming waters have focused on obtaining real-time estimates of water quality. Current monitoring techniques rely on the time-intensive culturing of fecal indicator bacteria (FIB) from water samples, but rapidly changing FIB concentrations result in management errors that lead to the p