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Sample records for lake roosevelt pelagic

  1. Lake Roosevelt Fisheries Evaluation Program, Part C; Lake Roosevelt Pelagic Fish Study: Washington Department of Fish and Wildlife, 1998 Annual Report.

    SciTech Connect

    Baldwin, Casey; Polacek, Matt; Bonar, Scott

    2002-11-01

    Pelagic fishes, such as kokanee and rainbow trout, provide an important fishery in Lake Roosevelt; however, spawner returns and creel results have been below management goals in recent years. Our objective was to identify factors that potentially limit pelagic fish production in Lake Roosevelt including entrainment, food limitation, piscivory, and other abiotic factors. We estimated the ratio of total fish entrained through Grand Coulee Dam to the pelagic fish abundance for September and October, 1998. If the majority of these fish were pelagic species, then entrainment averaged 10-13% of pelagic fish abundance each month. This rate of entrainment could impose considerable losses to pelagic fish populations on an annual basis. Therefore, estimates of species composition of entrained fish will be important in upcoming years to estimate the proportion of stocked pelagic fish lost through the dam. Food was not limiting for kokanee or rainbow trout populations since growth rates were high and large zooplankton were present in the reservoir. Estimates of survival for kokanee were low (< 0.01 annual) and unknown for rainbow trout. We estimated that the 1997 standing stock biomass of large (>1.1 mm) Daphnia could have supported 0.08 annual survival by kokanee and rainbow trout before fish consumption would have exceeded available biomass during late winter and early spring. Therefore, if recruitment goals are met in the future there may be a bottleneck in food supply for pelagic planktivores. Walleye and northern pikeminnow were the primary piscivores of salmonids in 1996 and 1997. Predation on salmonid prey was rare for rainbow trout and not detected for burbot or smallmouth bass. Northern pikeminnow had the greatest individual potential as a salmonid predator due to their high consumptive demand; however, their overall impact was limited because of their low relative abundance. We modeled the predation impact of 273,524 walleye in 1996, and 39,075 northern pikeminnow in

  2. 36 CFR 7.55 - Lake Roosevelt National Recreation Area.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Lake Roosevelt National... THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.55 Lake Roosevelt National...) Aircraft. Float planes may be operated on Lake Roosevelt on those waters not administered by Indians...

  3. 36 CFR 7.55 - Lake Roosevelt National Recreation Area.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Lake Roosevelt National... THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.55 Lake Roosevelt National...) Aircraft. Float planes may be operated on Lake Roosevelt on those waters not administered by Indians...

  4. Lake Roosevelt Fisheries and Limnological Research : 1996 Annual Report.

    SciTech Connect

    Cichosz, Thomas A.; Underwood, Keith D.; Shields, John; Scholz, Allan; Tilson, Mary Beth

    1997-05-01

    The Lake Roosevelt Monitoring/Data Collection Program resulted from a merger between the Lake Roosevelt Monitoring Program and the Lake Roosevelt Data Collection Project. This project will model biological responses to reservoir operations, evaluate the effects of releasing hatchery origin kokanee salmon and rainbow trout on the fishery, and evaluate the success of various stocking strategies. In 1996, limnological, reservoir operation, zooplankton, and tagging data were collected. Mean reservoir elevation, storage volume and water retention time were reduced in 1996 relative to the last five years. In 1996, Lake Roosevelt reached a yearly low of 1,227 feet above mean sea level in April, a yearly high of 1,289 feet in July, and a mean yearly reservoir elevation of 1,271.4 feet. Mean monthly water retention times in Lake Roosevelt during 1996 ranged from 15.7 days in May to 49.2 days in October. Average zooplankton densities and biomass were lower in 1996 than 1995. Daphnia spp. and total zooplankton densities peaked during the summer, whereas minimum densities occurred during the spring. Approximately 300,000 kokanee salmon and 400,000 rainbow trout were released into Lake Roosevelt in 1996. The authors estimated 195,628 angler trips to Lake Roosevelt during 1996 with an economic value of $7,629,492.

  5. Lake Roosevelt Fisheries Evaluation Program, Part B; Limnology, Primary Production, and Zooplankton in Lake Roosevelt, Washington, 1998 Annual Report.

    SciTech Connect

    Shields, John; Spotts, Jim; Underwood, Keith

    2002-11-01

    The Lake Roosevelt Fisheries Evaluation Program is the result of a merger between two projects, the Lake Roosevelt Monitoring Program (BPA No. 8806300) and the Lake Roosevelt Data Collection Project (BPA No. 9404300). These projects were merged in 1996 to continue work historically completed under the separate projects, and is now referred to as the Lake Roosevelt Fisheries Evaluation Program. The 1998 Annual Report, Part B. Limnology, Primary Production, and Zooplankton in Lake Roosevelt, Washington examined the limnology, primary production, and zooplankton at eleven locations throughout the reservoir. The 1998 research protocol required a continuation of the more complete examination of limnological parameters in Lake Roosevelt that began in 1997. Phytoplankton and periphyton speciation, phytoplankton and periphyton chlorophyll a analysis, complete zooplankton biomass analysis by taxonomic group, and an increased number of limnologic parameters (TDG, TDS, etc.) were examined and compared with 1997 results. Total dissolved gas levels were greatly reduced in 1998, compared with 1997, likely resulting from the relatively normal water year experienced in 1998. Mean water temperatures were similar to what was observed in past years, with a maximum of 22.7 C and a minimum of 2.6 C. Oxygen concentrations were also relatively normal, with a maximum of 16.6 mg/L, and a minimum of 0.9 mg/L. Phytoplankton in Lake Roosevelt was primarily composed of microplankton (29.6%), Cryptophyceae (21.7%), and Bacillriophyceae (17.0 %). Mean total phytoplankton chlorophyll a maximum concentration occurred in May (3.53 mg/m{sup 3}), and the minimum in January (0.39 mg/m{sup 3}). Phytoplankton chlorophyll a concentrations appear to be influenced by hydro-operations and temperature. Trophic status as indicated by phytoplankton chlorophyll a concentrations place Lake Roosevelt in the oligomesotrophic range. Periphyton colonization rates and biovolume were significantly greater at a depth

  6. Measurement of Lake Roosevelt Biota in Relation to Reservoir Operations : Final Report 1993.

    SciTech Connect

    Voeller, Amy C.

    1993-01-01

    The purpose of this study was to collect biological data from Lake Roosevelt to be used in the design of a computer model that will predict biological responses to reservoir operations as part of the System Operation Review Program. This study worked in conjunction with Lake Roosevelt Monitoring Project which investigated the effectiveness of two kokanee salmon hatcheries. This report summarized the data collected from Lake Roosevelt from 1993 and includes limnological, reservoir operation, zooplankton, benthic macroinvertebrate, experimental trawling, and net-pen rainbow trout tagging data. Major components of the Lake Roosevelt model include quantification of impacts to zooplankton, benthic macroinvertebrates, and fish caused by reservoir drawdowns and low water retention times.

  7. Lake Roosevelt Fisheries Evaluation Program, Assessment of the Lake Roosevelt Walleye Population 1998 Annual Report, Part D.

    SciTech Connect

    McLellan, Jason G.; Moffatt, Holly J.; Scholz, Allan T.

    1999-08-01

    A walleye mark-recapture experiment was initiated on Lake Roosevelt in 1997, with the primary objective of estimating the size of the walleye population. The project was continued in 1998 with a revised sampling regime. The primary goals during 1998 were to estimate the size of the walleye population in Lake Roosevelt, estimate the size of the spawning run in the Spokane River Arm, and describe the age structure of the population for use in managing the population and developing a kokanee bioenergetics model. Secondary objectives included: determining walleye movements, back-calculating growth rates, estimating mortality rates, determining walleye condition, and estimating walleye young-of-the-year (YOY) production in the Spokane River Arm. All walleye, {ge} 150 mm TL, were marked with individually numbered Floy{reg_sign} tags, during five passes through the reservoir. The passes occurred between April 1st and September 16th, 1998. The most unbiased estimate of walleye abundance in Lake Roosevelt, 186,482 (40,113 {le} N {le} 943,213), was obtained using the Mtb model of the CAPTURE program. The most unbiased estimate of the size of the walleye spawning run in the Spokane River Arm, 27,345 (1,535 {le} N {le} 57,519), was calculated using the Jolly-Seber model. The abundance estimates appeared reasonable, but they had wide 95 % confidence intervals. Wide confidence intervals were attributed to low capture probabilities. Coefficient of variation (CV) values for both estimates indicated that they were not acceptable for general management, not to mention research. Despite the CV value, we felt that the reservoir estimate was reasonable and that it was the best possible, without a large increase in effort and money. The spawning run estimate could have been improved by a small increase in effort. Ages of walleye in Lake Roosevelt ranged from 0 to 13 years. Growth, mortality, and condition were all average when compared to other walleye producing waters. We recommended

  8. Lake Roosevelt Fisheries Monitoring Program; 1988-1989 Annual Report.

    SciTech Connect

    Peone, Tim L.; Scholz, Allan T.; Griffith, James R.

    1990-10-01

    In the Northwest Power Planning Council's 1987 Columbia River Basin Fish and Wildlife Program (NPPC 1987), the Council directed the Bonneville Power Administration (BPA) to construct two kokanee salmon (Oncorhynchus nerka) hatcheries as partial mitigation for the loss of anadromous salmon and steelhead incurred by construction of Grand Coulee Dam [Section 903 (g)(l)(C)]. The hatcheries will produce kokanee salmon for outplanting into Lake Roosevelt as well as rainbow trout (Oncorhynchus mykiss) for the Lake Roosevelt net-pen program. In section 903 (g)(l)(E), the Council also directed BPA to fund a monitoring program to evaluate the effectiveness of the kokanee hatcheries. The monitoring program included the following components: (1) a year-round, reservoir-wide, creel survey to determine angler use, catch rates and composition, and growth and condition of fish; (2) assessment of kokanee, rainbow, and walleye (Stizostedion vitreum) feeding habits and densities of their preferred prey, and; (3) a mark and recapture study designed to assess the effectiveness of different locations where hatchery-raised kokanee and net pen reared rainbow trout are released. The above measures were adopted by the Council based on a management plan, developed by the Upper Columbia United Tribes Fisheries Center, Spokane Indian Tribe, Colville Confederated Tribes, Washington Department of Wildlife, and National Park Service, that examined the feasibility of restoring and enhancing Lake Roosevelt fisheries (Scholz et al. 1986). In July 1988, BPA entered into a contract with the Spokane Indian Tribe to initiate the monitoring program. The projected duration of the monitoring program is through 1995. This report contains the results of the monitoring program from August 1988 to December 1989.

  9. Lake Roosevelt Fisheries Monitoring Program; 1990 Annual Report.

    SciTech Connect

    Griffith, Janelle R.; Scholz, Allan T.

    1991-09-01

    As partial mitigation for the loss of anadromous salmon and steelhead incurred by construction of Grand Coulee Dam, the Northwest Power Planning Council directed Bonneville Power Administration (BPA) to construct two kokanee salmon (Oncorhynchus nerka) hatcheries on Lake Roosevelt (NPPC 1987 [Section 903 (g)(l)(C)]). The hatcheries are to produce 8 million kokanee salmon fry or 3.2 million adults for outplanting into Lake Roosevelt as well as 500,000 rainbow trout (Oncorhynchus mykiss) for the Lake Roosevelt net-pen programs. In section 903 (g)(l)(E), the Council also directed BPA to fund a monitoring program to evaluate the effectiveness of the kokanee hatcheries. The monitoring program included the following components: (1) conduction of a year-round creel census survey to determine angler pressure, catch rates and composition, growth and condition of fish caught by anglers, and economic value of the fishery. Comparisons will be made before and after hatcheries are on-line to determine hatchery effectiveness; (2) conduct an assessment of kokanee, rainbow trout, and walleye feeding habits, growth rates, and densities of their preferred prey at different locations in the reservoir and how reservoir operations affect population dynamics of preferred prey organisms. This information will be used to determine kokanee and rainbow trout stocking locations, stocking densities and stocking times; (3) conduct a mark-recapture study designed to assess effectiveness of various release times and locations for hatchery-raised kokanee and net-pen raised rainbow so fish-loss over Grand Coulee Dam will be minimized, homing to egg collection sites will be improved and angler harvest will be increased. The above measures were adopted by the Council based on a management plan developed by Upper Columbia United Tribes Fisheries Center, Spokane Indian Tribe, Colville Confederated Tribes, Washington Department of Wildlife, and the National Park Service. This plan examined the

  10. Lake Roosevelt Fisheries Evaluation Program; Meadow Creek vs. Lake Whatcom Stock Kokanee Salmon Investigations in Lake Roosevelt, Annual Report 2002.

    SciTech Connect

    McLellan, Holly

    2003-03-01

    Lake Whatcom, Washington kokanee have been stocked in Lake Roosevelt since 1987 with the primary objective of creating a self-sustaining fishery. Success has been limited by low recruitment to the fishery, low adult returns to hatcheries, and a skewed sex ratio. It was hypothesized that a stock native to the upper Columbia River might perform better than the coastal Lake Whatcom stock. Kokanee from Meadow Creek, a tributary of Kootenay Lake, British Columbia were selected as an alternative stock. Post smolts from each stock were released from Sherman Creek Hatchery in late June 2000 and repeated in 2001. Stock performance was evaluated using three measures; (1) number of returns to Sherman Creek, the primary egg collection facility, (2) the number of returns to 86 tributaries sampled and, (3) the number of returns to the creel. In two repeated experiments, neither Meadow Creek or Lake Whatcom kokanee appeared to be capable of providing a run of three-year old spawners to sustain stocking efforts. Less than 10 three-years olds from either stock were collected during the study period. Chi-square analysis indicated age two Meadow Creek kokanee returned to Sherman Creek and to other tributaries in significantly higher numbers when compared to the Lake Whatcom stock in both 2000 and 2001. However, preliminary data from the Spokane Tribe of Indians indicated that a large number of both stocks were precocial before they were stocked. The small number of hatchery three-year olds collected indicated that the current hatchery rearing and stocking methods will continue to produce a limited jacking run largely composed of precocious males and a small number of three-year olds. No kokanee from the study were collected during standard lake wide creel surveys. Supplemental creel data, including fishing derbies, test fisheries, and angler diaries, indicated anglers harvested two-year-old hatchery kokanee a month after release. The majority of the two-year old kokanee harvested

  11. Lake Roosevelt Fisheries Evaluation Program; Meadow Creek vs. Lake Whatcom Stock Kokanee Salmon Investigations in Lake Roosevelt, 2001 Annual Report.

    SciTech Connect

    McLellan, Holly; Scholz, Allan

    2002-03-01

    Lake Roosevelt has been stocked with Lake Whatcom stock kokanee since 1989 with the primary objective of creating a self-sustaining recreational fishery. Due to low return numbers, it was hypothesized a stock of kokanee, native to the upper Columbia River, might perform better than the coastal Lake Whatcom strain. Kokanee from Meadow Creek, a tributary of Kootenay Lake, British Columbia were selected as an alternative stock. Matched pair releases of Lake Whatcom and Meadow Creek kokanee were made from Sherman Creek Hatchery in late June 2000 and repeated in 2001. Stock performance between Lake Whatcom and Meadow Creek kokanee was evaluated using three performance measures; (1) the number of returns to Sherman Creek, the primary egg collection facility, (2) the number of returns to other tributaries and (3) the number of returns to the creel. Kokanee were collected during five passes through the reservoir via electrofishing, which included 87 tributary mouths during the fall of 2000 and 2001. Chi-square analysis indicated age two Meadow Creek kokanee returned to Sherman Creek in significantly higher numbers when compared to the Whatcom stock in 2000 ({chi}{sup 2} = 736.6; d.f. = 1; P < 0.01) and 2001 ({chi}{sup 2} = 156.2; d.f. = 1; P < 0.01). Reservoir wide recoveries of age two kokanee had similar results in 2000 ({chi}{sup 2} = 735.3; d.f. = 1; P < 0.01) and 2001 ({chi}{sup 2} = 150.1; d.f. = 1; P < 0.01). Six Lake Whatcom and seven Meadow Creek three year olds were collected in 2001. The sample size of three year olds was too small for statistical analysis. No kokanee were collected during creel surveys in 2000, and two (age three kokanee) were collected in 2001. Neither of the hatchery kokanee collected were coded wire tagged, therefore stock could not be distinguished. After two years of monitoring, neither Meadow Creek or Lake Whatcom kokanee appear to be capable of providing a run of three-year-old spawners to sustain stocking efforts. The small number of

  12. Lake Roosevelt Fisheries Evaluation Program; Movements and Growth of Marked Walleye Recaptured in Lake Roosevelt, 2000-2001 Annual Report.

    SciTech Connect

    McLellan, Holly; Scholz, Allan

    2002-03-01

    Walleye (Stizostedion vitreum) have been marked with floy tags in Lake Roosevelt since 1997 to estimate abundance, distribution and movement trends. In 2000, walleye were collected and marked during the spawning run in the Spokane River through electrofishing and angling to supplement movement and growth data collected in previous years. Walleye were also collected and marked during the 2000 and 2001 Kettle Falls Governor's Cup Walleye Tournaments. Seventy-six tag returns were recovered in 2000 and twenty-three in 2001. Walleye migrated into the Spokane River to spawn in mid April and early May. The majority of marked walleye were recovered within 25 km of their original marking location, with a few traveling long distances between recovery locations. Data also verified earlier results that walleye establish summer home ranges. Some walleye remained in the Spokane River, while others moved downstream, or upstream after entering the mainstem of Lake Roosevelt. Those moving upstream moved as far north as Keenlyside Dam in British Columbia (245 km). Growth data indicated similar trends exhibited in the past. Walleye growth and mortality rates were consistent with other walleye producing waters. Walleye condition was slightly below average when compared to other systems.

  13. Lake Roosevelt Volunteer Net Pens, Lake Roosevelt Rainbow Trout Net Pens, 2002-2003 Annual Report.

    SciTech Connect

    Smith, Gene

    2003-11-01

    The completion of Grand Coulee Dam for power production, flood control, and irrigation resulted in the creation of a blocked area above the dam and in the loss of anadromous fish. Because of lake level fluctuations required to meet the demands for water release or storage, native or indigenous fish were often threatened. For many years very little effort was given to stocking the waters above the dam. However, studies by fish biologists showed that there was a good food base capable of supporting rainbow and kokanee (Gangmark and Fulton 1949, Jagielo 1984, Scholz etal 1986, Peone etal 1990). Further studies indicated that artificial production might be a way of restoring or enhancing the fishery. In the 1980's volunteers experimented with net pens. The method involved putting fingerlings in net pens in the fall and rearing them into early summer before release. The result was an excellent harvest of healthy fish. The use of net pens to hold the fingerlings for approximately nine months appears to reduce predation and the possibility of entrainment during draw down and to relieve the hatcheries to open up available raceways for future production. The volunteer net pen program grew for a few years but raising funds to maintain the pens and purchase food became more and more difficult. In 1995 the volunteer net pen project (LRDA) was awarded a grant through the Northwest Power Planning Council's artificial production provisions.

  14. Lake Roosevelt Fisheries Evaluation Program : Lake Whatcom Kokanee Salmon (Oncorhynchus nerka kennerlyi) : Investigations in Lake Roosevelt Annual Report 1999-2000.

    SciTech Connect

    McLellan, Holly J.; Scholz, Allan T.; McLellan, Jason G.; Tilson, Mary Beth

    2001-07-01

    Lake Whatcom stock kokanee have been planted in Lake Roosevelt since 1988 with the primary goal of establishing a self-sustaining fishery. Returns of hatchery kokanee to egg collection facilities and recruitment to the creel have been minimal. Therefore, four experiments were conducted to determine the most appropriate release strategy that would increase kokanee returns. The first experiment compared morpholine and non-morpholine imprinted kokanee return rates, the second experiment compared early and middle run Whatcom kokanee, the third experiment compared early and late release dates, and the fourth experiment compared three net pen release strategies: Sherman Creek hatchery vs. Sherman Creek net pens, Colville River net pens vs. Sherman Creek net pens, and upper vs. lower reservoir net pen releases. Each experiment was tested in three ways: (1) returns to Sherman Creek, (2) returns to other tributaries throughout the reservoir, and (3) returns to the creel. Chi-square analysis of hatchery and tributary returns indicated no significant difference between morpholine imprinted and non-imprinted fish, early run fish outperformed middle run fish, early release date outperformed late release fish, and the hatchery outperformed all net pen releases. Hatchery kokanee harvest was estimated at 3,323 fish, which was 33% of the total harvest. Return rates (1998 = 0.52%) of Whatcom kokanee were low indicating an overall low performance that could be caused by high entrainment, predation, and precocity. A kokanee stock native to the upper Columbia, as opposed to the coastal Whatcom stock, may perform better in Lake Roosevelt.

  15. Lake Roosevelt Fisheries Monitoring Program; Artificial Imprinting and Smoltification in Juvenile Kokanee Salmon Implications for Operating Lake Roosevelt Kokanee Salmon Hatcheries; 1994 Supplement Report.

    SciTech Connect

    Tilson, Mary Beth; Scholz, Allan T.; White, Ronald J.

    1995-02-01

    At the kokanee salmon hatcheries on Lake Roosevelt, constructed as partial mitigation for effects from Grand Coulee Dam, adult returns have been poor. The reason may be in the imprinting or in the smoltification. A study was initiated in 1992 to determine if there was a critical period for thyroxine induced alfactory imprinting in kokanee salmon; experiments were conducted on imprinting to morpholine and phenethyl alcohol. Other results showed that chemical imprinting coincided with elevated thyroxine levels in 1991 kokanee exposed to synthetic chemicals in 1992. In this report, imprinting experiments were repeated; results showed that imprinting occurred concomitant with elevated thyroxine levels in 1991 kokanee exposed to synthetic chemicals in 1992 and tested in 1994 as age 3 spawners. Imprinting also occurred at the same time as thyroxine peaks in 1992 kokanee exposed to synthetic chemicals in 1993 and tested as age 2 spawners. In both groups fish that had the highest whole body thyroxine content (swimup stage) also had the highest percentage of fish that were attracted to their exposure odor in behavioral tests. So, kokanee salmon imprinted to chemical cues during two sensitive periods during development, at the alevin/swimup and smolt stages. A field test was conducted in Lake Roosevelt on coded wire tagged fish. Smoltification experiments were conducted from 1992 to 1994. Recommendations are made for the Lake Roosevelt kokanee hatcheries.

  16. Currents and Undercurrents: An Administrative History of Lake Roosevelt National Recreation Area.

    ERIC Educational Resources Information Center

    McKay, Kathryn L.; Renk, Nancy F.

    The 1,259-mile Columbia River flows out of Canada and across eastern Washington state, forming the border between Washington and Oregon. In 1941 the federal government dammed the Columbia River at the north end of Grand Coulee, creating a man-made reservoir named Lake Roosevelt that inundated homes, farms, and businesses, and disrupted the lives…

  17. Sediment-quality assessment of Franklin D. Roosevelt Lake and the upstream reach of the Columbia River, Washington, 1992

    USGS Publications Warehouse

    Bortleson, Gilbert Carl; Cox, S.E.; Munn, M.D.; Schumaker, R.J.; Block, E.K.

    2001-01-01

    Elevated concentrations of trace elements were found in bed sediment of Lake Roosevelt and the Columbia River, its principal source of inflow. Trace-element concentrations in whole water samples did not exceed criteria for freshwater organisms. Bed sediments of Lake Roosevelt were analyzed for organic compounds associated with wood-pulp waste. Dioxins and furans were found in suspended sediment and water of the Columbia River. Abundance and diversity of benthic invertebrate communities were analyzed.

  18. Measurement of Lake Roosevelt Biota in Relation to Reservoir Operations; 1992 Annual Report.

    SciTech Connect

    Griffith, Janelle R.; McDowell, Amy C.

    1996-01-01

    The purpose of this research project is to collect data to model resident fish requirements for Lake Roosevelt as part of the Bonneville Power Administration (BPA), Bureau of Reclamation (BoR), and U.S. Army Corps of Engineer`s (ACE) System Operation Review. The System Operation Review (SOR) is a tri-agency team functioning to review the use and partitioning of Columbia Basin waters. User groups of the Columbia have been defined as power, irrigation, flood control, anadromous fish, resident fish, wildlife, recreation, water quality, navigation, and cultural resources. Once completed the model will predict biological responses to different reservoir operation strategies. The model being developed for resident fish is based on Montana Department of Fish, Wildlife, and Parks model for resident fish requirements within Hungry Horse and Libby Reservoirs. While the Montana model predicts fish growth based on the impacts of reservoir operation and flow conditions on primary and secondary production levels, the Lake Roosevelt model will also factor in the affects of water retention time on zooplankton production levels and fish entrainment. Major components of the Lake Roosevelt model include: (1) quantification of impacts to zooplankton, benthic invertebrates, and fish caused by reservoir drawdowns and low water retention times; (2) quantification of number, distribution, and use of fish food organisms in the reservoir by season; (3) determination of seasonal growth of fish species as related to reservoir operations, prey abundance and utilization; and (4) quantification of entrainment levels of fish as related to reservoir operations and water retention times. This report contains the results of the resident fish system operation review program for Lake Roosevelt from January through December 1992.

  19. Measurement of Lake Roosevelt Biota in Relation to Reservoir Operations; 1991 Annual Report.

    SciTech Connect

    Griffith, Janelle R.; McDowell, Amy C.; Scholz, Allan T.

    1995-08-01

    The purpose of this study was to collect biological data from Lake Roosevelt to be used in the design of a computer model that would predict biological responses to reservoir operations as part of the System Operation Review program. Major components of the Lake Roosevelt model included: quantification of impacts to phytoplankton, zooplanktons, benthic invertebrates, and fish caused by reservoir drawdowns and low water retention times; quantification of number, distribution, and use of fish food organisms in the reservoir by season; determination of seasonal growth of fish species as related to reservoir operations, prey abundance and utilization; and quantification of entrainment levels of zooplankton and fish as related to reservoir operations and water retention times. This report summarized the data collected on Lake Roosevelt for 1991 and includes limnological, zooplankton, benthic macroinvertebrate, fishery, and reservoir operation data. Discussions cover reservoir operation affect upon zooplankton, benthic macroinvertebrates, and fish. Reservoir operations brought reservoir elevations to a low of 1,221.7 in April, the result of power operations and a flood control shift from Dworshak Dam, in Idaho, to Grand Coulee Dam. Water retention times were correspondingly low reaching a minimum of 14.7 days on April 27th.

  20. Lake Roosevelt Fisheries Evaluation Program : Limnological and Fisheries Monitoring Annual Report 1999.

    SciTech Connect

    McLellan, Holly; Lee, Chuck; Scofield, Ben; Pavlik, Deanne

    1999-08-01

    The Grand Coulee Dam was constructed in 1939 without a fish ladder, which eliminated steelhead (Onchorhynchus mykiss), chinook salmon (O. twshwastica), coho salmon (O. kisutch) and sockeye salmon (O. nerka) from returning to approximately 1,835 km (1,140 miles) of natal streams and tributaries found in the upper Columbia River Drainage in the United States and Canada. The Pacific Northwest Electric Power Planning and Conservation Act of 1980 gave the Bonneville Power Administration (BPA), the authority and responsibility to use its legal and financial resources, 'to protect, mitigate, and enhance fish and wildlife to the extent affected by the development and operation of any hydroelectric project of the Columbia River and its tributaries. This is to be done in a manner consistent with the program adopted by the Northwest Power Planning Council (NWPPC), and the purposes of the Act' (NWPPC, 1987). With the phrase 'protect, mitigate and enhance', Congress signaled its intent that the NWPPC's fish and wildlife program should do more than avoid future hydroelectric damage to the basin's fish and wildlife. The program must also counter past damage, work toward rebuilding those fish and wildlife populations that have been harmed by the hydropower system, protect the Columbia Basin's fish and wildlife resources, and mitigate for harm caused by decades of hydroelectric development and operations. By law, this program is limited to measures that deal with impacts created by the development, operation and management of hydroelectric facilities on the Columbia River and its tributaries. However, off-site enhancement projects are used to address the effects of the hydropower system on fish and wildlife (NWPPC 1987). Resident game fish populations have been established in Franklin D. Roosevelt Lake, the reservoir behind Grand Coulee Dam, since the extirpation of anadromous fish species. The resident game fish populations are now responsible for attracting a large percentage of

  1. Lake Roosevelt Fisheries Evaluation Program; Assessment of the Lake Roosevelt Walleye Population: Compilation of 1997-1999 Data, 1999-2000 Annual Report.

    SciTech Connect

    McLellan, Jason; McLellan, Holly; Scholz, Allan

    2002-03-01

    A walleye mark-recapture study was conducted on Lake Roosevelt between 1997 and 1999. The primary objective of the study was to describe the status and biological characteristics of the walleye population in Lake Roosevelt by determining its abundance, movement patterns, age structure, growth, condition, and mortality. The abundance estimates were also to be used to estimate the consumptive impact of walleye on stocked kokanee and rainbow trout. Walleye were collected by electrofishing and angling. Each walleye was tagged with an individually numbered Floy tag. The Jolly-Seber model was used to estimate the size of the walleye population in 1999, using each year of the study as a mark-recapture occasion. Mark-recapture data collected in 1998 was re-analyzed in 1999 with the data pooled in various combinations, using closed and open population models, in an attempt to provide an estimate of walleye abundance that was unbiased, accurate, and more precise. Minimum distances traveled between mark and recapture location by tagged walleye were determined from tag returns. Over the three study years, a total of 12,343 walleye {ge} 150 mm TL were collected by Eastern Washington University (EWU), Spokane Tribe of Indians, and Washington Department of Fish and Wildlife, and of those, 10,770 were tagged and released. Of the 10,770 walleye marked and released, 775 were recaptured and returned to EWU. The 1999 abundance estimate ({+-} standard error) for walleye {ge} 150 mm TL was 129,183 ({+-} 45,578) and the estimated abundance ({+-} standard error) of walleye {ge} 200 mm TL was 101,508 ({+-} 35,603). A total of 38 population estimates were calculated for 1998. The estimates of the abundance of walleye {ge} 150 mm TL in Lake Roosevelt ranged from 84,335 to 180,568 fish. Estimates of the size of the walleye population {ge} 200 mm TL ranged from 14,971 to 173,702. The 1999 estimate, which used each study year as a mark-recapture occasion, was biased due to unequal capture

  2. Resident Fish Planning: Dworshak Reservoir, Lake Roosevelt and Lake Pend Oreille.

    SciTech Connect

    Fickeisen, Duane H.; Geist, David R.

    1994-01-01

    Research projects are presently being conducted to reduce the amount of uncertainty in how reservoir operations within the Columbia River federal power system affect resident fish. Many of these research projects are being conducted to better define operation strategies being proposed under the Columbia River System Operation Review (SOR). This project provides a basis for understanding the potential effects of different operating strategies being considered under the SOR in reservoir fisheries at Lake Roosevelt, Dworshak Reservoir, and Lake Pend Oreille. The methodological framework used here was adapted from the Regional Assessment of Supplementation Project (RASP), a project framework used for evaluating supplementation strategies for anadromous fish. RASP attempts to diagnose the factors that limit production of fishes and outlines a process that can be followed to systematically reduce uncertainty while achieving the objective. In all three reservoirs concerns exist about protecting sensitive species, particularly bull trout and cutthroat trout. In all three reservoirs a need exists for additional baseline information to provide an adequate understanding of the populations of interest.

  3. Lake Roosevelt Fisheries Evaluation Program : Meadow Creek vs. Lake Whatcom Stock Kokanee Salmon Investigations in Lake Roosevelt Annual Report 2000-2001.

    SciTech Connect

    McLellan, Holly J.; Scholz, Allan T.

    2001-07-01

    Lake Roosevelt has been stocked with Whatcom stock kokanee since 1989 to mitigate for anadromous salmon losses caused by the construction of Grand Coulee Dam. The primary objective of the hatchery plantings was to create a self-sustaining recreational fishery. Due to low return numbers, it was hypothesized a native stock of kokanee might perform better than the coastal Whatcom strain. Therefore, kokanee from Meadow Creek, a tributary of Kootenay Lake, British Columbia were selected as an alternative stock. Matched pair releases of Whatcom stock and Meadow Creek kokanee were made from Sherman Creek in late June 2000. Stock performance between Lake Whatcom and Meadow Creek kokanee was evaluated through three performance measures (1) returns to Sherman Creek, the primary egg collection facility, (2) returns to other tributaries, indicating availability for angler harvest, and (3) returns to the creel. A secondary objective was to evaluate the numbers collected at downstream fish passage facilities. Age 2 kokanee were collected during five passes through the reservoir, which included 89 tributaries between August 17th and November 7th, 2000. Sherman Creek was sampled once a week because it was the primary egg collection location. A total of 2,789 age 2 kokanee were collected, in which 2,658 (95%) were collected at Sherman Creek. Chi-square analysis indicated the Meadow Creek kokanee returned to Sherman Creek in significantly higher numbers compared to the Whatcom stock ({chi}{sup 2} = 734.4; P < 0.01). Reservoir wide recoveries indicated similar results ({chi}{sup 2} = 733.1; P < 0.01). No age 2 kokanee were collected during creel surveys. Age 3 kokanee are expected to recruit to the creel in 2001. No age 2 kokanee were collected at the fish passage facilities due to a 170 mm size restriction at the fish passage centers. Age 3 kokanee are expected to be collected at the fish passage centers during 2001. Stock performance cannot be properly evaluated until 2001, when

  4. Biological and chemical characterization of metal bioavailability in sediments from Lake Roosevelt, Columbia River, Washington, USA

    USGS Publications Warehouse

    Besser, J.M.; Brumbaugh, W.G.; Ivey, C.D.; Ingersoll, C.G.; Moran, P.W.

    2008-01-01

    We studied the bioavailability and toxicity of copper, zinc, arsenic, cadmium, and lead in sediments from Lake Roosevelt (LR), a reservoir on the Columbia River in Washington, USA that receives inputs of metals from an upstream smelter facility. We characterized chronic sediment toxicity, metal bioaccumulation, and metal concentrations in sediment and pore water from eight study sites: one site upstream in the Columbia River, six sites in the reservoir, and a reference site in an uncontaminated tributary. Total recoverable metal concentrations in LR sediments generally decreased from upstream to downstream in the study area, but sediments from two sites in the reservoir had metal concentrations much lower than adjacent reservoir sites and similar to the reference site, apparently due to erosion of uncontaminated bank soils. Concentrations of acid-volatile sulfide in LR sediments were too low to provide strong controls on metal bioavailability, and selective sediment extractions indicated that metals in most LR sediments were primarily associated with iron and manganese oxides. Oligochaetes (Lumbriculus variegatus) accumulated greatest concentrations of copper from the river sediment, and greatest concentrations of arsenic, cadmium, and lead from reservoir sediments. Chronic toxic effects on amphipods (Hyalella azteca; reduced survival) and midge larvae (Chironomus dilutus; reduced growth) in whole-sediment exposures were generally consistent with predictions of metal toxicity based on empirical and equilibrium partitioning-based sediment quality guidelines. Elevated metal concentrations in pore waters of some LR sediments suggested that metals released from iron and manganese oxides under anoxic conditions contributed to metal bioaccumulation and toxicity. Results of both chemical and biological assays indicate that metals in sediments from both riverine and reservoir habitats of Lake Roosevelt are available to benthic invertebrates. These findings will be used as

  5. 36 CFR 7.55 - Lake Roosevelt National Recreation Area.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... persons in the water. (iii) The stretch of the Spokane Arm from 200 feet west of the Two Rivers Marina on the downstream end, to 200 feet east of the Fort Spokane launch ramp on the upstream end, above the... the “narrows” to the confluence of the lake, marked by “flat wake” buoy(s). (ii) Within 200 feet...

  6. Lake Roosevelt Rainbow Trout : Habitat/Passage Improvement Project Annual Report 2000.

    SciTech Connect

    Sear, Sheri

    2001-02-01

    Lake Franklin D. Roosevelt was created with the completion of the Grand Coulee Dam in 1942. The lake stretches 151 miles up-stream to the International border between the United States and Canada at the 49th parallel. Increased recreational use, subsistence and sport fishing has resulted in intense interest and possible exploitation of the resources within the lake. Previous studies of the lake and its fishery have been limited. Early studies indicate that natural reproduction within the lake and tributaries are not sufficient to support a rainbow trout (Onchoryhnchus mykiss) fishery (Scholz et. al., 1988). These studies indicate that the rainbow trout population may be limited by lack of suitable habitat for spawning and rearing (Scholz et. al., 1988). The initial phase of this project (Phase I, baseline data collection- 1990-91) was directed at the assessment of limiting factors such as quality and quantity of available spawning gravel, identification of passage barriers, and assessment of other limiting factors. Population estimates were conducted using the Seber/LeCren removal/depletion method. After the initial assessment of stream parameters, several streams were selected for habitat/passage improvement projects (Phase II, implementation-1992-96). At the completion of project habitat improvements, the final phase (Phase III, monitoring) began. This phase will assess changes and gauge the success achieved through the improvements. The objective of the project is to correct passage barriers and improve habitat conditions of selected tributaries to Lake Roosevelt for adfluvial rainbow trout that utilize tributary streams for spawning and rearing. Streams with restorable habitats were selected for improvements. Completion of improvement efforts should increase the adfluvial rainbow trout contribution to the resident fishery in Lake Roosevelt. Three co-operating agencies, the Confederated Tribes of the Colville Reservation (CCT), the Spokane Tribe of Indians (STI

  7. Lake Roosevelt Rainbow Trout : Habitat/Passage Improvement Project Annual Report 1999.

    SciTech Connect

    Jones, Charles D.

    2000-02-01

    Lake Franklin D. Roosevelt was created with the completion of the Grand Coulee Dam in 1942. The lake stretches 151 miles up-stream to the International border between the United States and Canada at the 49th parallel. Increased recreational use, subsistence and sport fishing has resulted in intense interest and possible exploitation of the resources within the lake. Previous studies of the lake and its fishery have been limited. Early studies indicate that natural reproduction within the lake and tributaries are not sufficient to support a rainbow trout (Onchoryhnchus mykiss) fishery (Scholz et. al., 1988). These studies indicate that the rainbow trout population may be limited by lack of suitable habitat for spawning and rearing (Scholz et. al., 1988). The initial phase of this project (Phase I, baseline data collection- 1990-91) was directed at the assessment of limiting factors such as quality and quantity of available spawning gravel, identification of passage barriers, and assessment of other limiting factors. Population estimates were conducted using the Seber/LeCren removal/depletion method. After the initial assessment of stream parameters, several streams were selected for habitat/passage improvement projects (Phase II, implementation-1992-96). At the completion of project habitat improvements, the final phase (Phase III, monitoring) began. This phase will assess changes and gauge the success achieved through the improvements. The objective of the project is to correct passage barriers and improve habitat conditions of selected tributaries to Lake Roosevelt for adfluvial rainbow trout that utilize tributary streams for spawning and rearing. Streams with restorable habitats were selected for improvements. Completion of improvement efforts should increase the adfluvial rainbow trout contribution to the resident fishery in Lake Roosevelt. Three co-operating agencies, the Confederated Tribes of the Colville Reservation (CCT), the Spokane Tribe of Indians (STI

  8. Lake Roosevelt Rainbow Trout : Habitat/Passage Improvement Project : Annual Report 1998.

    SciTech Connect

    Jones, Charles D.

    1999-02-01

    Lake Franklin D. Roosevelt was created with the completion of the Grand Coulee Dam in 1942. The lake stretches 151 miles up-stream to the International border between the United States and Canada at the 49th parallel. Increased recreational use, subsistence and sport fishing has resulted in intense interest and possible exploitation of the resources within the lake. Previous studies of the lake and its fishery have been limited. Early studies indicate that natural reproduction within the lake and tributaries are not sufficient to support a rainbow trout (Onchoryhnchus mykiss) fishery (Scholz et. al., 1988). These studies indicate that the rainbow trout population may be limited by lack of suitable habitat for spawning and rearing (Scholz et. al., 1988). The initial phase of this project (Phase I, baseline data collection) was directed at the assessment of limiting factors such as quality and quantity of available spawning gravel, identification of passage barriers, and assessment of other limiting factors. Population estimates were conducted using the Seber/LeCren removal/depletion method. After the initial assessment of stream parameters, several streams were selected for habitat/passage improvement projects (Phase II, implementation). At the completion of project habitat improvements, the final phase (Phase III, monitoring) began. This phase will assess changes and gauge the success achieved through the improvements. The objective of the project is to correct passage barriers and improve habitat conditions of selected tributaries to Lake Roosevelt for adfluvial rainbow trout that utilize tributary streams for spawning and rearing. Streams with restorable habitats were selected for improvements. Completion of improvement efforts should increase the adfluvial rainbow trout contribution to the resident fishery in Lake Roosevelt. Personnel of three co-operating agencies, the Confederated Tribes of the Colville Reservation (CCT), the Spokane Tribe of Indians (STI) and

  9. Lake Roosevelt White Sturgeon Recovery Project : Annual Progress Report, January 2003 – March 2004.

    SciTech Connect

    Howell, Matthew D.; McLellan, Jason G.

    2009-07-15

    This report summarizes catch data collected from white sturgeon Acipenser transmontanus in Lake Roosevelt during limited setlining and gill netting activities in the fall of 2003, and documents progress toward development of a U.S. white sturgeon conservation aquaculture program for Lake Roosevelt. From 27-30 October, 42 overnight small mesh gill net sets were made between Marcus and Northport, WA for a total catch of 15 juvenile white sturgeon (275-488 mm FL). All sturgeon captured were of Canadian hatchery origin. These fish had been previously released as sub-yearlings into the Canadian portion (Keenleyside Reach) of the Transboundary Reach of the Columbia River during 2002 and 2003. Most sturgeon (n=14) were caught in the most upstream area sampled (Northport) in low velocity eddy areas. Five fish exhibited pectoral fin deformities (curled or stunted). Growth rates were less than for juvenile sturgeon captured in the Keenleyside Reach but condition factor was similar. Condition factor was also similar to that observed in juvenile sturgeon (ages 1-8) captured in the unimpounded Columbia River below Bonneville Dam between 1987-92. From 10-14 November, 28 overnight setline sets were made in the Roosevelt Reach between the confluence of the Spokane River and Marcus Island for a total catch of 17 white sturgeon (94-213 cm FL). Catch was greatest in the most upstream areas sampled, a distribution similar to that observed during a WDFW setline survey in Lake Roosevelt in 1998. The mean W{sub r} index of 110% for fish captured this year was higher than the mean W{sub r} of 91% for fish captured in 1998. Excellent fish condition hindered surgical examination of gonads as lipid deposits made the ventral body wall very thick and difficult to penetrate with available otoscope specula. Acoustic tags (Vemco model V16 coded pingers, 69 kHz, 48-month life expectancy) were internally applied to 15 fish for subsequent telemetry investigations of seasonal and reproductively

  10. Lake Roosevelt Fisheries Evaluation Program, Part A; Fisheries Creel Survey and Population Status Analysis, 1998 Annual Report.

    SciTech Connect

    Spotts, Jim; Shields, John; Underwood, Keith

    2002-05-01

    The Lake Roosevelt Fisheries Evaluation Program is the result of a merger between two projects, the Lake Roosevelt Monitoring Program (BPA No. 8806300) and the Lake Roosevelt Data Collection Project (BPA No. 9404300). These projects were merged in 1996 to continue work historically completed under the separate projects, and is now referred to as the Lake Roosevelt Fisheries Evaluation Program. Creel and angler surveys estimated that anglers made 196,775 trips to Lake Roosevelt during 1998, with an economic value of $8.0 million dollars, based on the Consumer Price Index (CPI). In 1998 it was estimated that 9,980 kokanee salmon, 226,809 rainbow trout, 119,346 walleye, and over 14,000 smallmouth bass and other species were harvested. Creel data indicates that hatchery reared rainbow trout contribute substantially to the Lake Roosevelt fishery. The contribution of kokanee salmon to the creel has not met the expectations of fishery managers to date, and is limited by entrainment from the reservoir, predation, and possible fish culture obstacles. The 1998 Lake Roosevelt Fisheries Creel and Population Analysis Annual Report includes analyses of the relative abundance of fish species, and reservoir habitat relationships (1990-1998). Fisheries surveys (1990-1998) indicate that walleye and burbot populations appear to be increasing, while yellow perch, a preferred walleye prey species, and other prey species are decreasing in abundance. The long term decreasing abundance of yellow perch and other prey species are suspected to be the result of the lack of suitable multiple reservoir elevation spawning and rearing refugia for spring spawning reservoir prey species, resulting from seasonal spring-early summer reservoir elevation manipulations, and walleye predation. Reservoir water management is both directly, and indirectly influencing the success of mitigation hatchery production of kokanee salmon and rainbow trout. Tag return data suggested excessive entrainment occurred in

  11. Lake Roosevelt Fisheries Evaluation Program; Evaluation of Limiting Factors for Stocked Kokanee and Rainbow Trout in Lake Roosevelt, Washington, 1999 Annual Report.

    SciTech Connect

    Baldwin, Casey; Polacek, Matt

    2009-03-01

    Hatchery supplementation of kokanee Oncorhynchus nerka and rainbow trout O. mykiss has been the primary mitigation provided by Bonneville Power Administration for loss of anadromous fish to the waters above Grand Coulee Dam (GCD). The hatchery program for rainbow trout has consistently met management goals and provided a substantial contribution to the fishery; however, spawner returns and creel survey results for kokanee have been below management goals. Our objective was to identify factors that limit limnetic fish production in Lake Roosevelt by evaluating abiotic conditions, food limitations, piscivory, and entrainment. Dissolved oxygen concentration was adequate throughout most of the year; however, levels dropped to near 6 mg/L in late July. For kokanee, warm water temperatures during mid-late summer limited their nocturnal distribution to 80-100 m in the lower section of the reservoir. Kokanee spawner length was consistently several centimeters longer than in other Pacific Northwest systems, and the relative weights of rainbow trout and large kokanee were comparable to national averages. Large bodied daphnia (> 1.7 mm) were present in the zooplankton community during all seasons indicating that top down effects were not limiting secondary productivity. Walleye Stizostedion vitreum were the primary piscivore of salmonids in 1998 and 1999. Burbot Lota lota smallmouth bass Micropterus dolomieui, and northern pikeminnow Ptychocheilus oregonensis preyed on salmonids to a lesser degree. Age 3 and 4 walleye were responsible for the majority (65%) of the total walleye consumption of salmonids. Bioenergetics modeling indicated that reservoir wide consumption by walleye could account for a 31-39% loss of stocked kokanee but only 6-12% of rainbow trout. Size at release was the primary reason for differential mortality rates due to predation. Entrainment ranged from 2% to 16% of the monthly abundance estimates of limnetic fish, and could account for 30% of total

  12. Measurement of Lake Roosevelt Biota in Relation to Reservoir Operations Appendices; 1991 Annual Report.

    SciTech Connect

    Griffith, Janelle R.; McDowell, Amy C.; Scholz, Allan T.

    1995-08-01

    This report consists of appendices A-F containing the biological data which were collected from Lake Roosevelt, Washington. The data are to be used in the design of a computer model that would predict biological responses of reservoir operations as part of the System Operation Review program. Major components of the model included: Quantification of impacts to phytoplankton, zooplanktons, benthic invertebrates, and fish caused by reservoir drawdowns and low water retention times; quantification of number, distribution, and use of fish food organisms in the reservoir by season; determination of seasonal growth of fish species as related to reservoir operations, prey abundance and utilization; and quantification of entrainment levels of zooplankton and fish as related to reservoir operations and water retention times.

  13. Movements of White Sturgeon in Lake Roosevelt : Final Report 1988-1991.

    SciTech Connect

    Brannon, E.L.; Setter, Ann L.

    1992-06-01

    Historically, white sturgeon moved throughout the Columbia River system, ranging freely from the estuary to the headwaters, with the possible exception of limited passage at Cascades, Celilo and Kettle Falls during spring floods. Construction of Rock Island Dam in 1933, followed by Bonneville in 1938 and Grand Coulee in 1941, completely disrupted sturgeon migratory opportunity, and with the 17 successive Columbia and Snake river dams constructed over the next 32 years an entirely different river system was created for the species. Sturgeon caught between dams were essentially isolated populations with severely limited reproduction potential. Some reservoirs ran from dam to dam with no river habitat remaining, while other reaches had various lengths of free running river, but drastically reduced from historical situations. However, if reservoirs provide habitat for sturgeon use, and therefore compensate to some degree for river loss, the major limiting factors associated with population viability may be reduced spawning success, either from lack of suitable area or poor incubation environments. The most upstream impoundment of the Columbia River in the United States is Lake Roosevelt, behind Grand Coulee Dam. If sturgeon don`t use Lake Roosevelt the capacity of the system to sustain a large sturgeon population would be understandably limited, and much reduced from the pre-dam era. In general this study found that sturgeon spawner aggregations from early spring to mid- summer depend most heavily on the timing of increasing water temperature. In the spring the water temperatures seem to stimulate the fish to start feeding and leave deep pools. The summer provides access to broader and shallower areas for food. The study on sturgeon movement was an attempt to define habitat use in such a reservoir/river system.

  14. Functional convergence among pelagic sculpins of Lake Baikal and deepwater ciscoes of the Great Lakes

    USGS Publications Warehouse

    Eshenroder, Randy L.; Sideleva, Valentina G.; Todd, Thomas N.

    1999-01-01

    The vast, well-oxygenated hypolimnia of Lake Baikal and the Great Lakes were both dominated by endemic planktivorous fishes. These dominants, two species of sculpins (Comephorus, Comephoridae) in Lake Baikal and six species of deepwater ciscoes (Coregonus, Salmonidae) in the Great Lakes, although distant taxonomically, have morphologies suggesting a surprising degree of functional convergence. Here it is proposed that the same two buoyancy-regulation strategies observed in Baikal sculpins also arose in the deepwater ciscoes of the Great Lakes. One strategy favors hydrostatic lift (generated by low specific gravity) and is characterized by fatter, larger-bodied fish with smaller paired fins; the second strategy favors hydrodynamic lift (generated by swimming) and is characterized by leaner, smaller-bodied fish with larger paired fins. Both types likely evolved to feed on a single species of ecologically analogous, vertically migrating macrozooplankter: Macrohectopus branickii in Lake Baikal and Mysis relicta in the Great Lakes. It is suggested that Coregonus did not diversify and proliferate in Lake Baikal as they did in the Great Lakes because by the time Coregonus colonized Lake Baikal, pelagic sculpins were already dominant.

  15. Lake Roosevelt Fisheries Monitoring Progam; Thyroid-Induced Chemical Imprinting in Early Life Stages and Assessment of Smoltification in Kokanee Salmon Implications for Operating Lake Roosevelt Kokanee Salmon Hatcheries; 1993 Supplement Report.

    SciTech Connect

    Tilson, Mary Beth; Galloway, Heather; Scholz, Allan T.

    1994-06-01

    In 1991, two hatcheries were built to provide a kokanee salmon and rainbow trout fishery for Lake Roosevelt as partial mitigation for the loss of anadromous salmon and steelhead caused by construction of Grand Coulee Dam. The Sherman Creek Hatchery, located on a tributary of Lake Roosevelt to provide an egg collection and imprinting site, is small with limited rearing capability. The second hatchery was located on the Spokane Indian Reservation because of a spring water source that supplied cold, pure water for incubating and rearing eggs.`The Spokane Tribal Hatchery thus serves as the production facility. Fish reared there are released into Sherman Creek and other tributary streams as 7-9 month old fry. However, to date, returns of adult fish to release sites has been poor. If hatchery reared kokanee imprint to the hatchery water at egg or swim up stages before 3 months of age, they may not be imprinting as 7-9 month old fry at the time of stocking. In addition, if these fish undergo a smolt phase in the reservoir when they are 1.5 years old, they could migrate below Grand Coulee Dam and out of the Lake Roosevelt system. In the present investigation, which is part of the Lake Roosevelt monitoring program to assess hatchery effectiveness, kokanee salmon were tested to determine if they experienced thyroxine-induced chemical imprinting and smoltification similar to anadromous salmonids. Determination of the critical period for olfactory imprinting was determined by exposing kokanee to different synthetic chemicals (morpholine or phenethyl alcohol) at different life stages, and then measuring the ability to discriminate the chemicals as sexually mature adults. Whole body thyroxine content and blood plasma thyroxine concentration was measured to determine if peak thyroid activity coincided with imprinting or other morphological, physiological or behavioral transitions associated with smoltification.

  16. Big Soda Lake (Nevada). 2. Pelagic sulfate reduction

    USGS Publications Warehouse

    Smith, Richard L.; Oremland, Ronald S.

    1987-01-01

    The epilimnion of hypersaline, alkaline, meromictic Big Soda Lake contains an average 58 mmol sulfate liter−1 and 0.4 µmol dissolved iron liter−1. The monimolimnion, which is permanently anoxic, has a sulfide concentration ranging seasonally from 4 to 7 mmol liter−1. Depth profiles of sulfate reduction in the monimolimnion, assayed with a 35S tracer technique and in situ incubations, demonstrated that sulfate reduction occurs within the water column of this extreme environment. The average rate of reduction in the monimolimnion was 3 µmol sulfate liter−1 d−1in May compared to 0.9 in October. These values are comparable to rates of sulfate reduction reported for anoxic waters of more moderate environments. Sulfate reduction also occurred in the anoxic zone of the mixolimnion, though at significantly lower rates (0.025–0.090 µmol liter−1 d−1 at 25 m). Additions of FeS (1.0 mmol liter−1) doubled the endogenous rate of sulfate reduction in the monimolimnion, while MnS and kaolinite had no effect. These results suggest that sulfate reduction in Big Soda Lake is iron limited and controlled by seasonal variables other than temperature. Estimates of the organic carbon mineralized by sulfate reduction exceed measured fluxes of particulate organic carbon sinking from the mixolimnion. Thus, additional sources of electron donors (other than those derived from the sinking of pelagic autotrophs) may also fuel monimolimnetic sulfate reduction in the lake.

  17. Differential bioaccumulation of potentially toxic elements in benthic and pelagic food chains in Lake Baikal.

    PubMed

    Ciesielski, Tomasz M; Pastukhov, Mikhail V; Leeves, Sara A; Farkas, Julia; Lierhagen, Syverin; Poletaeva, Vera I; Jenssen, Bjørn M

    2016-08-01

    Lake Baikal is located in eastern Siberia in the center of a vast mountain region. Even though the lake is regarded as a unique and pristine ecosystem, there are existing sources of anthropogenic pollution to the lake. In this study, the concentrations of the potentially toxic trace elements As, Cd, Pb, Hg, and Se were analyzed in water, plankton, invertebrates, and fish from riverine and pelagic influenced sites in Lake Baikal. Concentrations of Cd, Hg, Pb and Se in Lake Baikal water and biota were low, while concentrations of As were similar or slightly higher compared to in other freshwater ecosystems. The bioaccumulation potential of the trace elements in both the pelagic and the benthic ecosystems differed between the Selenga Shallows (riverine influence) and the Listvenichnyĭ Bay (pelagic influence). Despite the one order of magnitude higher water concentrations of Pb in the Selenga Shallows, Pb concentrations were significantly higher in both pelagic and benthic fish from the Listvenichnyĭ Bay. A similar trend was observed for Cd, Hg, and Se. The identified enhanced bioavailability of contaminants in the pelagic influenced Listvenichnyĭ Bay may be attributed to a lower abundance of natural ligands for contaminant complexation. Hg was found to biomagnify in both benthic and pelagic Baikal food chains, while As, Cd, and Pb were biodiluted. At both locations, Hg concentrations were around seven times higher in benthic than in pelagic fish, while pelagic fish had two times higher As concentrations compared to benthic fish. The calculated Se/Hg molar ratios revealed that, even though Lake Baikal is located in a Se-deficient region, Se is still present in excess over Hg and therefore the probability of Hg induced toxicity in the endemic fish species of Lake Baikal is assumed to be low. PMID:27130338

  18. Bathymetric and sediment facies maps for China Bend and Marcus Flats, Franklin D. Roosevelt Lake, Washington, 2008 and 2009

    USGS Publications Warehouse

    Weakland, Rhonda J.; Fosness, Ryan L.; Williams, Marshall L.; Barton, Gary J.

    2011-01-01

    The U.S. Geological Survey (USGS) created bathymetric and sediment facies maps for portions of two reaches of Lake Roosevelt in support of an interdisciplinary study of white sturgeon (Acipenser transmontanus) and their habitat areas within Franklin D. Roosevelt Lake, Washington. In October 2008, scientists from the USGS used a boat-mounted multibeam echo sounder (MBES) to describe bathymetric data to characterize surface relief at China Bend and Marcus Flats, between Northport and Kettle Falls, Washington. In March 2009, an underwater video camera was used to view and record sediment facies that were then characterized by sediment type, grain size, and areas of sand deposition. Smelter slag has been identified as having the characteristics of sand-sized black particles; the two non-invasive surveys attempted to identify areas containing black-colored particulate matter that may be elements and minerals, organic material, or slag. The white sturgeon population in Lake Roosevelt is threatened by the failure of natural recruitment, resulting in a native population that consists primarily of aging fish and that is gradually declining as fish die and are not replaced by nonhatchery reared juvenile fish. These fish spawn and rear in the riverine and upper reservoir reaches where smelter slag is present in the sediment of the river lake bed. Effects of slag on the white sturgeon population in Lake Roosevelt are largely unknown. Two recent studies demonstrated that copper and other metals are mobilized from slag in aqueous environments with concentrations of copper and zinc in bed sediments reaching levels of 10,000 and 30,000 mg/kg due to the presence of smelter slag. Copper was found to be highly toxic to 30-day-old white sturgeon with 96-h LC50 concentrations ranging from 3 to 5 (u or mu)g copper per liter. Older juvenile and adult sturgeons commonly ingest substantial amounts of sediment while foraging. Future study efforts in Lake Roosevelt should include sampling of

  19. Persistence of an unusual pelagic zooplankton assemblage in a clear, mountain lake

    USGS Publications Warehouse

    Larson, G.L.; Hoffman, R.L.; David, McIntire C.

    2002-01-01

    The planktonic zooplankton assemblage in Mowich Lake, Mount Rainier National Park (MORA), was composed almost entirely of rotifers in 1966 and 1967. Adult pelagic crustacean taxa were rare. Their paucity was attributed to predation by kokanee salmon (Oncorhynchus nerka), which had been stocked in 1961. During a park-wide survey of 24 lakes in 1988, Mowich Lake was the only one that did not contain at least one planktonic crustacean species. Given the apparent persistence of the unusual pelagic zooplankton assemblage in Mowich Lake, the first objective of this study was to document the interannual variation in the taxonomic structure of the zooplankton assemblages in the lake from 1988 through 1999. A second objective was to determine if it was possible to predict the taxonomic composition of the pelagic crustacean zooplankton assemblage in Mowich Lake prior to the stocking of kokanee salmon. The Mowich Lake zooplankton assemblages in 1988-1999 were consistent with those in 1966 and 1967. Crustacean taxa were extremely rare, but they included most of the primary taxa collected from 23 MORA lakes surveyed in 1988. Nonetheless, the 1988 collections showed that the September rotifer assemblage in Mowich Lake was similar to 10 of the 24 lakes sampled. Seven of the 10 lakes were dominated by cladocerans, primarily Daphnia rosea and Holopedium gibberum. Therefore, it appeared that either one or both of these species may have numerically dominated the crustacean zooplankton assemblage in the lake prior to 1961.

  20. Persistence of an unusual pelagic zooplankton assemblage in a clear mountain lake

    USGS Publications Warehouse

    Larson, Gary L.; Hoffman, Robert L.; McIntire, C.D.

    2002-01-01

    The planktonic zooplankton assemblage in Mowich Lake, Mount Rainier National Park (MORA), was composed almost entirely of rotifers in 1966 and 1967. Adult pelagic crustacean taxa were rare. Their paucity was attributed to predation by kokanee salmon (Oncorhynchus nerka), which had been stocked in 1961. During a park-wide survey of 24 lakes in 1988, Mowich Lake was the only one that did not contain at least one planktonic crustacean species. Given the apparent persistence of the unusual pelagic zooplankton assemblage in Mowich Lake, the first objective of this study was to document the interannual variation in the taxonomic structure of the zooplankton assemblages in the lake from 1988 through 1999. A second objective was to determine if it was possible to predict the taxonomic composition of the pelagic crustacean zooplankton assemblage in Mowich Lake prior to the stocking of kokanee salmon. The Mowich Lake zooplankton assemblages in 1988a??1999 were consistent with those in 1966 and 1967. Crustacean taxa were extremely rare, but they included most of the primary taxa collected from 23 MORA lakes surveyed in 1988. Nonetheless, the 1988 collections showed that the September rotifer assemblage in Mowich Lake was similar to 10 of the 24 lakes sampled. Seven of the 10 lakes were dominated by cladocerans, primarily Daphnia rosea and Holopedium gibberum. Therefore, it appeared that either one or both of these species may have numerically dominated the crustacean zooplankton assemblage in the lake prior to 1961.

  1. Release of elements to natural water from sediments of Lake Roosevelt, Washington, USA

    USGS Publications Warehouse

    Paulson, Anthony J.; Cox, Stephen E.

    2007-01-01

    Reservoir sediments from Lake Roosevelt (WA, USA) that were contaminated with smelter waste discharged into the Columbia River (BC, Canada) were examined using three measures of elemental release reflecting varying degrees of physical mixing and time scales. Aqueous concentrations of Cd, Cu, Pb, and Zn in the interstitial water of reservoir sediments, in the gently stirred overlying waters of incubated sediment cores, and in supernatants of aggressively tumbled slurries of reservoir sediments generally were higher than the concentrations from a reference site. When compared to chronic water-quality criteria, all three measures of release suggest that slag-contaminated sediments near the U.S.-Canadian border are potentially toxic as a result of Cu release and Pb release in two of the three measures. All three measures of Cd release suggest potential toxicity for one site farther down the reservoir, probably contaminated as a result of transport and adsorption of Cd from smelter liquid waste. Releases of Zn and As did not appear to be potentially toxic. Carbonate geochemistry indirectly affects the potential toxicity by increasing water hardness.

  2. Spatial heterogeneity of mercury bioaccumulation by walleye (Stizostedion vitreum) in Lake Roosevelt, Washington

    SciTech Connect

    Short, T.; Munn, M. |

    1995-12-31

    Mercury bioaccumulation was examined in muscle tissue of walleye (Stizostedion vitreum) from Lake Roosevelt, a large (80,000 acres) reservoir receiving metal contaminated wastes from mining and associated processing activities. Walleye were collected from three spatially segregated reaches distributed along the relatively narrow axis of the reservoir to investigate whether regional differences in mercury bioaccumulation could be predicted by spatial patterns of mercury in bed sediment. Mercury concentrations in surficial sediments ranged from < 0.05 to 2.70 mg/kg, and generally decreased from the upper to lower reaches in an incremental fashion. Mercury in bed sediments was positively correlated with sediment organic carbon content; however, differences in organic carbon content accounted for only 15 percent of the variability observed in sediment mercury concentrations among reaches. Overall, mercury concentrations in muscle tissue ranged from 0.11 to 0.44 mg/kg wet weight and was positively correlated with age, weight, and length of walleye. Mercury concentrations of walleye varied spatially within the reservoir, with the highest concentrations occurring in fish from the lower and middle reaches. Condition factor (k) of fish was inversely related to tissue mercury concentration, and was significantly lower in fish collected from the lower and middle reaches compared with fish in the upper reach. Spatial patterns in mercury bioaccumulation could not be predicted by regional differences in sediment concentrations of total mercury. It is suggested that observed spatial patterns of mercury bioaccumulation may be related in part to preferential utilization of specific regions for spawning and foraging, and that these areas likely differ in mercury bioavailability, owing to local differences in edaphic conditions, and in the kinds and availability of food resources.

  3. Lake Roosevelt Rainbow Trout Habitat/Passage Improvement Project, Annual Report 2002-2003.

    SciTech Connect

    Sears, Sheryl

    2004-01-01

    The construction of Chief Joseph and Grand Coulee Dams completely and irrevocably blocked anadromous fish migrations to the Upper Columbia River. Historically this area hosted vast numbers of salmon returning to their natal waters to reproduce and die. For the native peoples of the region, salmon and steelhead were a principle food source, providing physical nourishment and spiritual sustenance, and contributing to the religious practices and the cultural basis of tribal communities. The decaying remains of spawned-out salmon carcasses contributed untold amounts of nutrients into the aquatic, aerial, and terrestrial ecosystems of tributary habitats in the upper basin. Near the present site of Kettle Falls, Washington, the second largest Indian fishery in the state existed for thousands of years. Returning salmon were caught in nets and baskets or speared on their migration to the headwater of the Columbia River in British Columbia. Catch estimates at Kettle Falls range from 600,000 in 1940 to two (2) million around the turn of the century (UCUT, Report No.2). The loss of anadromous fish limited the opportunities for fisheries management and enhancement exclusively to those actions addressed to resident fish. The Lake Roosevelt Rainbow Trout Habitat/Passage Improvement Project is a mitigation project intended to enhance resident fish populations and to partially mitigate for anadromous fish losses caused by hydropower system impacts. This substitution of resident fish for anadromous fish losses is considered in-place and out-of-kind mitigation. Upstream migration and passage barriers limit the amount of spawning and rearing habitat that might otherwise be utilized by rainbow trout. The results of even limited stream surveys and habitat inventories indicated that a potential for increased natural production exists. However, the lack of any comprehensive enhancement measures prompted the Upper Columbia United Tribes Fisheries Center (UCUT), Colville Confederated

  4. Lake Roosevelt Rainbow Trout Habitat/Passage Improvement Project, Annual Report 2001-2002.

    SciTech Connect

    Sears, Sheryl

    2003-01-01

    The construction of Chief Joseph and Grand Coulee Dams completely and irrevocably blocked anadromous fish migrations to the Upper Columbia River. Historically this area hosted vast numbers of salmon returning to their natal waters to reproduce and die. For the native peoples of the region, salmon and steelhead were a principle food source, providing physical nourishment and spiritual sustenance, and contributing to the religious practices and the cultural basis of tribal communities. The decaying remains of spawned-out salmon carcasses contributed untold amounts of nutrients into the aquatic, aerial, and terrestrial ecosystems of tributary habitats in the upper basin. Near the present site of Kettle Falls, Washington, the second largest Indian fishery in the state existed for thousands of years. Returning salmon were caught in nets and baskets or speared on their migration to the headwater of the Columbia River in British Columbia. Catch estimates at Kettle Falls range from 600,000 in 1940 to two (2) million around the turn of the century (UCUT, Report No.2). The loss of anadromous fish limited the opportunities for fisheries management and enhancement exclusively to those actions addressed to resident fish. The Lake Roosevelt Rainbow Trout Habitat/Passage Improvement Project is a mitigation project intended to enhance resident fish populations and to partially mitigate for anadromous fish losses caused by hydropower system impacts. This substitution of resident fish for anadromous fish losses is considered in-place and out-of-kind mitigation. Upstream migration and passage barriers limit the amount of spawning and rearing habitat that might otherwise be utilized by rainbow trout. The results of even limited stream surveys and habitat inventories indicated that a potential for increased natural production exists. However, the lack of any comprehensive enhancement measures prompted the Upper Columbia United Tribes Fisheries Center (UCUT), Colville Confederated

  5. Concentrations and Distribution of Slag-Related Trace Elements and Mercury in Fine-Grained Beach and Bed Sediments of Lake Roosevelt, Washington, April-May 2001

    USGS Publications Warehouse

    Majewski, Michael S.; Kahle, Sue C.; Ebbert, James C.; Josberger, Edward G.

    2003-01-01

    A series of studies have documented elevated concentrations of trace elements such as arsenic, cadmium, copper, lead, mercury, and zinc in the water, bed sediment, or fish of Lake Roosevelt and the upstream reach of the Columbia River. Elevated concentrations of some trace elements in this region are largely attributable to the transport of slag and metallurgical waste discharged into the Columbia River from a smelter in Canada. Although most recent studies have focused on contamination levels in water, bed sediment, and fish, there is growing concern in the region over the potential threat of airborne contaminants to human health. In response to these concerns, the U.S. Geological Survey conducted an assessment of trace-element concentrations in the relatively shallow fine-grained sediment along the shore of Lake Roosevelt that is exposed annually during periods of reservoir drawdown. During each winter and spring, the water level of Lake Roosevelt is lowered as much as about 80 feet to provide space to capture high river flows from spring runoff, exposing vast expanses of lake-bottom sediment for a period of several months. Upon drying, these exposed areas provide an extremely large source for wind-blown dust. This study concluded that trace elements associated with slag and metallurgical waste are present in the fine-grained fraction (less than 63 micrometers) of bed sediments along the length of Lake Roosevelt, and as such, could be components of the airborne dust resulting from exposure, drying, and wind mobilization of the sediments exposed during the annual drawdowns of the reservoir. Trace-element concentrations in the surficial bed sediment varied, but the major components in slag?arsenic, cadmium, copper, lead, and zinc?showed generally pronounced gradients of decreasing concentrations from near the International Border to the Grand Coulee Dam. The results of this study provide base-line information needed to plan and conduct air monitoring of trace

  6. A trophic position model of pelagic food webs: Impact on contaminant bioaccumulation in lake trout

    SciTech Connect

    Zanden, M.J.V.; Rasmussen, J.B.

    1996-11-01

    To test how well use of discrete trophic levels represents pelagic trophic structure, dietary data from > 200 lake trout and pelagic forage fish populations was compiled and calculated a continuous (fractional) measure of trophic position for each population. Lake trout trophic position, which ranged from 3.0 to 4.6, explained 85% of the between-lake variability in mean PCB levels in lake trout muscle tissue, providing a significant improvement over the use of discrete trophic levels as a predictor of contaminant levels. Having demonstrated the utility of trophic position, a generalized {open_quotes}trophic position model{close_quotes} of lake trout food webs was developed. This approach eliminates minor trophic linkages, calculates a fractional measure of each species` trophic position, and aggregates species of similar trophic position into trophic guilds. This {open_quotes}realized{close_quotes} model represents trophic structure in terms of mass transfer and accounts for the complexity and omnivory that characterize aquatic food webs. In our trophic position model, smelt (a species of pelagic forage fish) were designated a trophic guild separate from other pelagic forage fish, due to their elevated trophic position. Separate consideration of smelt was supported by elevated lake trout trophic position, PCB, and Hg levels in lakes containing smelt. Consideration of omnivory caused biomagnification factors (BMFs) to be many times higher than BMFs that ignored omnivory. These omnivory-corrected BMF estimates appeared to be more consistent with values calculated using stable nitrogen isotopes ({delta}{sup 15}N), an alternative continuous measure of trophic position. {delta}{sup 15}N, an alternative continuous measure of trophic position. {delta}{sup 15}N provided trophic position estimates that generally corresponded with our diet-derived estimates. 186 refs., 7 figs., 3 tabs.

  7. Lake Roosevelt Fisheries Evaluation Program; Limnological and Fisheries Monitoring, Annual Report 2000.

    SciTech Connect

    Lee, Chuck; Scofield, Ben; Pavlik, Deanne

    2003-03-01

    A slightly dryer than normal year yielded flows in Lake Roosevelt that were essentially equal to the past ten year average. Annual mean inflow and outflow were 3,160.3 m3/s and 3,063.4 m3/s respectively. Mean reservoir elevation was 387.2 m above sea level at the Grand Coulee Dam forebay. The forebay elevation was below the mean elevation for a total of 168 days. During the first half of the 2000 forebay elevation changed at a rate of 0.121 m/d and during the last half changed at a rate of 0.208 m/d. The higher rate of elevation change earlier in the year is due to the drawdown to accommodate spring runoff. Mean annual water retention time was 40 days. Annual mean total dissolved gas was 108%. Total dissolved gas was greatest at upriver locations (110% = US/Canada Border annual mean) and decreased moving toward Grand Coulee Dam (106% = Grand Coulee Dam Forebay annual mean). Total dissolved gas was greatest in May (122% reservoir wide monthly mean). Gas bubble trauma was observed in 16 fish primarily largescale suckers and was low in severity. Reservoir wide mean temperatures were greatest in August (19.5 C) and lowest in January (5.5 C). The Spokane River and Sanpoil River Arms experienced higher temperatures than the mainstem reservoir. Brief stratification was observed at the Sanpoil River shore location in July. Warm water temperatures in the Spokane Arm contributed to low dissolved oxygen concentrations in August (2.6 mg/L at 33 m). However, decomposition of summer algal biomass was likely the main cause of depressed dissolved oxygen concentrations. Otherwise, dissolved oxygen profiles were relatively uniform throughout the water column across other sampling locations. Annual mean Secchi depth throughout the reservoir was 5.7 m. Nutrient concentrations were generally low, however, annual mean total phosphorus (0.016 mg/L) was in the mesotrophic range. Annual mean total nitrogen was in the meso-oligotrophic range. Total nitrogen to total phosphorus ratios were

  8. Benthic and Pelagic Contributions to Mysis Nutrition across Lake Superior

    EPA Science Inventory

    Quantification of the sources of nutrition to Mysis diluviana is needed to better understand the basis for production in Mysis lakes and to improve models of migration-driven nutrient and contaminant transport. We collected Mysis, plankton, and benthos across Lake Superior using ...

  9. Hydroacoustic estimates of abundance and spatial distribution of pelagic prey fishes in western Lake Superior

    USGS Publications Warehouse

    Mason, Doran M.; Johnson, Timothy B.; Harvey, Chris J.; Kitchell, James F.; Schram, Stephen T.; Bronte, Charles R.; Hoff, MIchael H.; Lozano, Stephen J.; Trebitz, Anett S.; Schreiner, Donald R.; Lamon, E. Conrad; Hrabik, Thomas R.

    2005-01-01

    Lake herring (Coregonus artedi) and rainbow smelt (Osmerus mordax) are a valuable prey resource for the recovering lake trout (Salvelinus namaycush) in Lake Superior. However, prey biomass may be insufficient to support the current predator demand. In August 1997, we assessed the abundance and spatial distribution of pelagic coregonines and rainbow smelt in western Lake Superior by combining a 120 kHz split beam acoustics system with midwater trawls. Coregonines comprised the majority of the midwater trawl catches and the length distributions for trawl caught fish coincided with estimated sizes of acoustic targets. Overall mean pelagic prey fish biomass was 15.56 kg ha−1 with the greatest fish biomass occurring in the Apostle Islands region (27.98 kg ha−1), followed by the Duluth Minnesota region (20.22 kg ha−1), and with the lowest biomass occurring in the open waters of western Lake Superior (9.46 kg ha−1). Biomass estimates from hydroacoustics were typically 2–134 times greater than estimates derived from spring bottom trawl surveys. Prey fish biomass for Lake Superior is about order of magnitude less than acoustic estimates for Lakes Michigan and Ontario. Discrepancies observed between bioenergetics-based estimates of predator consumption of coregonines and earlier coregonine biomass estimates may be accounted for by our hydroacoustic estimates.

  10. Land Use Affects Carbon Sources to the Pelagic Food Web in a Small Boreal Lake

    PubMed Central

    Rinta, Päivi; van Hardenbroek, Maarten; Jones, Roger I.; Kankaala, Paula; Rey, Fabian; Szidat, Sönke; Wooller, Matthew J.; Heiri, Oliver

    2016-01-01

    Small humic forest lakes often have high contributions of methane-derived carbon in their food webs but little is known about the temporal stability of this carbon pathway and how it responds to environmental changes on longer time scales. We reconstructed past variations in the contribution of methanogenic carbon in the pelagic food web of a small boreal lake in Finland by analyzing the stable carbon isotopic composition (δ13C values) of chitinous fossils of planktivorous invertebrates in sediments from the lake. The δ13C values of zooplankton remains show several marked shifts (approx. 10 ‰), consistent with changes in the proportional contribution of carbon from methane-oxidizing bacteria in zooplankton diets. The results indicate that the lake only recently (1950s) obtained its present state with a high contribution of methanogenic carbon to the pelagic food web. A comparison with historical and palaeobotanical evidence indicates that this most recent shift coincided with agricultural land-use changes and forestation of the lake catchment and implies that earlier shifts may also have been related to changes in forest and land use. Our study demonstrates the sensitivity of the carbon cycle in small forest lakes to external forcing and that the effects of past changes in local land use on lacustrine carbon cycling have to be taken into account when defining environmental and ecological reference conditions in boreal headwater lakes. PMID:27487044

  11. Land Use Affects Carbon Sources to the Pelagic Food Web in a Small Boreal Lake.

    PubMed

    Rinta, Päivi; van Hardenbroek, Maarten; Jones, Roger I; Kankaala, Paula; Rey, Fabian; Szidat, Sönke; Wooller, Matthew J; Heiri, Oliver

    2016-01-01

    Small humic forest lakes often have high contributions of methane-derived carbon in their food webs but little is known about the temporal stability of this carbon pathway and how it responds to environmental changes on longer time scales. We reconstructed past variations in the contribution of methanogenic carbon in the pelagic food web of a small boreal lake in Finland by analyzing the stable carbon isotopic composition (δ13C values) of chitinous fossils of planktivorous invertebrates in sediments from the lake. The δ13C values of zooplankton remains show several marked shifts (approx. 10 ‰), consistent with changes in the proportional contribution of carbon from methane-oxidizing bacteria in zooplankton diets. The results indicate that the lake only recently (1950s) obtained its present state with a high contribution of methanogenic carbon to the pelagic food web. A comparison with historical and palaeobotanical evidence indicates that this most recent shift coincided with agricultural land-use changes and forestation of the lake catchment and implies that earlier shifts may also have been related to changes in forest and land use. Our study demonstrates the sensitivity of the carbon cycle in small forest lakes to external forcing and that the effects of past changes in local land use on lacustrine carbon cycling have to be taken into account when defining environmental and ecological reference conditions in boreal headwater lakes. PMID:27487044

  12. Effect of lake-wide planktivory by the pelagic prey fish community in Lakes Michigan and Ontario

    USGS Publications Warehouse

    Rand, Peter S.; Stewart, Donald J.; Lantry, Brian F.; Rudstam, Lars G.; Johannsson, Ora E.; Goyke, Andrew P.; Brandt, Stephen B.; O'Gorman, Robert; Eck, Gary W.

    1995-01-01

    We compared predatory demand by pelagic planktivorous prey fish with invertebrate production in Lake Michigan during 1987 and in Lake Ontario during 1990. Predation by the planktivores in Lake Ontario was nearly fourfold higher than in Lake Michigan (approx. 87 g wet weight∙m−2∙year−1). Predation rates on Mysis were comparable in Lakes Michigan and Ontario (approx. 21 g∙m−2∙year−1), while predation on Diporeia was markedly higher in Lake Michigan than in Lake Ontario (21.3 vs. 8.5 g wet weight∙m−2∙year−1). In Lake Ontario, predatory demand on zooplankton exceeded our best estimate of production by a factor of 1.7. Similarly, predation estimates on Mysis in Lake Ontario were 1.2–2.0 times the estimated rate of production, depending on the production model used. Lake Michigan planktivores consumed approximately 55% of available zooplankton production in 1987, indicating that competition for prey resources, if operating, was not as intense as that in Lake Ontario in 1990. It is unclear how to resolve the paradox that predation could markedly exceed available prey production in some cases. There could be sources of error in the estimates of both the supply and demand sides of these trophic relationships.

  13. Sediment-quality assessment of Franklin D. Roosevelt Lake and the upstream reach of the Columbia River, Washington, 1992

    USGS Publications Warehouse

    Bortleson, Gilbert Carl; Cox, S.E.; Munn, M.D.; Schumaker, R.J.; Block, E.K.; Bucy, L.R.; Cornelius, R.J.

    1994-01-01

    The occurrence and distribution of trace elements and of wood-pulp-related compounds in the sediments of Lake Roosevelt and the upstream reache sampler of the Columbia River were studied in 1992. In addition, an analysis ofbenthic invertebrate community structure and tests of sediment toxicity were conducted. Concentrations of trace elements were elevated, relative to background reference sites, in samples of bed sediment. Copper, lead, and zinc most often exceeded the sediment-quality guidelines for benthic organisms. In whole-water samples, trace-element concentrations did not exceed criteria for freshwater organisms. These concen- trations were relatively small, reflecting the small suspended-sediment concentrations and the large water-diluting capacity of the Columbia River. Elevated concentrations of trace elements in sediments are attributable to the transport of metallurgical waste from a smelter discharging to the Columbia River in Canada. Dioxins and furans were found in Columbia River water, but only a few isomers were detected. A furan isomer common in effluent from pulp and paper mills was found in suspended sediment. Dioxins and furans in the water phase were isolated using solid-phase extraction to concentrate these compounds from large volumes of water. Few of the many other organic compounds associated with wood-pulp waste were detected in the bed sediments of Lake Roosevelt. Benthic invertebrate communities in the Columbia River showed effects from trace elements in bed sediments or from loss of physical habitat. Lethal and sublethal effects were observed in toxicity tests of selected aquatic organisms exposed to bed sediments from the Columbia River near the international boundary.

  14. Lake Roosevelt Fisheries Monitoring Program; Measurement of Thyroxin Concentration as an Indicator of the Critical Period for Imprinting in the Kokanee Salmon (Orcorhynchus Nerka) Implications for Operating Lake Roosevelt Kokanee Hatcheries; 1991 Supplement Report.

    SciTech Connect

    Scholz, Allan T.; White, Ronald J.; Koehler, Valerie A.

    1992-05-01

    Previous investigations have determined that thyroid hormone surges activate olfactory imprinting in anadromous salmonid smolts. The mechanism of action appears to require binding of thyroid hormones to receptors in brain cell nuclei, which stimulates neuron differentiation and wires a pattern of neuron circuitry that allows for the permanent storage of the imprinted olfactory memory. In this study, thyroxine concentrations [T{sub 4}] were measured in 487 Lake Whatcom stock and 70 Lake Roosevelt stock Kokanee salmon to indicate the critical period for imprinting. Eggs, alevins and fry, reared at the Spokane Indian Kokanee Hatchery, were collected from January through August 1991. Sampled fish were flash frozen on dry ice and stored at {minus}80{degrees}C until T{sub 4} was extracted and concentrations determined by radioimmunassay. Mean concentration {+-} SEM of 10--20 individual fish (assayed in duplicate) were determined for each time period. T{sub 4} concentration peaked on the day of hatch at 16.8 ng/g body weight and again at swim-up at 16.0 {+-} 4.7 ng/g body weight. T{sub 4} concentration was 12.5 to 12.9 ng/g body weight in eggs, 7.1 to 15.2 ng/g body weight in. alevins, 4.5 to 11.4 ng/g body weight in 42 to 105 day old fry and 0.1 to 2.9 ng/g body weight in 112 to 185 day old fry. T{sub 4} concentrations were highest in eggs at 13.3 {+-} 2.8 ng/g body weight, then steadily decreased to 0.1 {+-} 0.1 ng/g body weight in older fry. Fry were released in Lake Roosevelt tributaries in July and August 1991, at about 170--180 days post hatching, in order to imprint them to those sites. The results of this study indicate that the time of release was not appropriate for imprinting. If T{sub 4} levels are an accurate guide for imprinting in kokanee, our results suggest that the critical period for imprinting in kokanee is at hatching or swim-up stages.

  15. Big Soda Lake (Nevada). 1. Pelagic bacterial heterotrophy and biomass

    USGS Publications Warehouse

    Zehr, Jon P.; Harvey, Ronald W.; Oremland, Ronald S.; Cloern, James E.; George, Leah H.; Lane, Judith L.

    1987-01-01

    Bacterial activities and abundance were measured seasonally in the water column of meromictic Big Soda Lake which is divided into three chemically distinct zones: aerobic mixolimnion, anaerobic mixolimnion, and anaerobic monimolimnion. Bacterial abundance ranged between 5 and 52 x 106 cells ml−1, with highest biomass at the interfaces between these zones: 2–4 mg C liter−1 in the photosynthetic bacterial layer (oxycline) and 0.8–2.0 mg C liter−1 in the chemocline. Bacterial cell size and morphology also varied with depth: small coccoid cells were dominant in the aerobic mixolimnion, whereas the monimolimnion had a more diverse population that included cocci, rods, and large filaments. Heterotrophic activity was measured by [methyl-3H]thymidine incorporation and [14C]glutamate uptake. Highest uptake rates were at or just below the photosynthetic bacterial layer and were attributable to small (<1 µm) heterotrophs rather than the larger photosynthetic bacteria. These high rates of heterotrophic uptake were apparently linked with fermentation; rates of other mineralization processes (e.g. sulfate reduction, methanogenesis, denitrification) in the anoxic mixolimnion were insignificant. Heterotrophic activity in the highly reduced monimolimnion was generally much lower than elsewhere in the water column. Therefore, although the monimolimnion contained most of the bacterial abundance and biomass (∼60%), most of the cells there were inactive.

  16. Lake size and water-column stability affect the importance of methane for pelagic food webs of boreal lakes

    NASA Astrophysics Data System (ADS)

    Kankaala, Paula; Lopez-Bellido, Jessica; Ojala, Anne; Tulonen, Tiina; Jones, Roger I.

    2013-04-01

    Physical forcing, related to lake size and morphometry, plays an important role in the landscape-scale biogeochemical processing and fluxes of terrestrial carbon in lakes. Boreal lakes are typically dimictic, with mixing of the water column in spring and autumn, but in small, sheltered, humic, forest lakes the spring mixing is often incomplete. This leads to a steep summer stratification and oxygen depletion in the hypolimnion of the lakes. As a result of anaerobic decomposition of organic matter, high concentrations of CH4are typical in these lakes. At the oxic-anoxic interface zone methanotrophic microbes oxidize CH4 to CO2 and partly incorporate CH4-C into microbial biomass, and thus potentially provide a diet source for pelagic consumers. We studied production at the base of the pelagic food web by methane oxidising bacteria (MOB), heterotrophic bacteria (HB) and phytoplankton (PP) in five boreal lakes with a dissolved organic carbon (DOC) concentration varying between 7 and 25 mg C L-1 and an area ranging from 0.004 to 13.4 km2. High MOB activity was detected in the water columns of the three smallest lakes having anoxia in the hypolimnion during summer. The highest MOB activities (ca. 2-12 μmol L-1 d-1) were observed when the CH4:O2 ratio varied between ca. 0.5-12. Seasonally, the highest MOB activities were measured during late-summer mixed layer deepening and autumnal mixing of the whole water column. The proportion of MOB in the total basal production was highest in the two smallest lakes (24-56 and 13-36%), having the steepest summertime stratification. The proportion MOB in the basal production decreased with lake size being 70% of basal production was by PP. In all studied lakes HB contributed only 10-23% of the total basal production, suggesting that a transfer of allochthonous DOC via HB plays only a modest role for the nutrition of the higher trophic levels.

  17. Spatial distribution of pelagic fish larvae in the northern main basin of Lake Huron

    USGS Publications Warehouse

    Roseman, Edward F.; O'Brien, Timothy P.

    2013-01-01

    Larval fish occurrence in inshore and offshore zones in the northern main basin of Lake Huron was assessed during 2007 as part of a larger ecological examination of Lake Huron foodwebs and habitats. Day and night collections using neuston and conical nets at inshore (1.5–15 m depths) and offshore (37 and 91 m depths) locations at De Tour and Hammond Bay to assess the abundance, phenology, and spatial distribution of pelagic ichthyoplankton during spring and early summer were made. In general, densities of larval fishes were higher at De Tour than Hammond Bay during daytime neuston net collections, with the exception of Longnose Sucker, which were only collected at Hammond Bay. Lake Whitefish, Burbot, and Rainbow Smelt dominated inshore catches in early spring with Cisco, Deepwater Sculpin, Emerald Shiner, Bloater, Slimy Sculpin, Ninespine Stickleback, and Yellow Perch larvae also collected. Nighttime nearshore and offshore sampling revealed that Rainbow Smelt and Burbot larvae were present in relatively high abundances compared to inshore densities. Concentrations of larvae of deepwater demersal fishes such as Lake Whitefish and Deepwater Sculpin suggest that inshore zones in northern Lake Huron are important nursery habitats emphasizing a critical production and recruitment linkage between inshore and deepwater zones.

  18. In situ relations of target strength to fish size for Great Lakes pelagic planktivores

    USGS Publications Warehouse

    Fleischer, Guy W.; Argyle, Ray L.; Curtis, Gary L.

    1997-01-01

    We found mean target strength to be a reliable in situ predictor of fish weight, which allows direct estimation of the pelagic planktivore fish biomass from target strength measurements. Fish were collected by midwater trawling concurrent with target strength measurements (120-kHz frequency) in Lake Michigan. The mean weight of fish caught ranged from 2 to 71 g and mean target strength ranged from –54.9 to –38.0 decibels. Changes in mean target strength explained 73% of the variability in mean weight for combinations of various planktivore species, principally rainbow smelt Osrnerus mordax, bloaters Coregonus hovi, and alewives Alosa pseudoharengus. Bloaters were found to be less acoustically reflective than the other pelagic species, and a linear regression model with a classification variable was used to predict weight from target strength for bloaters and for the other species. We demonstrated that variations in the backscattering properties of different fish species must be considered to obtain accurate acoustic-based estimates of fish biomass.

  19. Acoustic measures of the abundance and size of pelagic planktivores in Lake Michigan

    USGS Publications Warehouse

    Brandt, Stephen B.; Mason, Doran M.; Patrick, E. Vincent; Argyle, Ray L.; Wells, L.; Unger, Philip A.; Stewart, Donald J.

    1991-01-01

    Based on acoustic data taken at night and vertically stratified by bottom depth (3–110 m only), the total number (± 95% Cl) of pelagic fishes in Lake Michigan was 43.4 ± 10.1 x 109 or 226.0 ± 55.2 kt in spring (mean density 0.7–3.8 fish·m-2 or 1.6–12.8 ga·m-2) and 115.8 ± 18.3 x 109 or 313.2 ± 74.3 kt in late summer, 1987 (mean density 1.1–7.0 fish·m-2 or 3.0–13.2 g·m-2); approximately 30% of this increase in numbers (35% of biomass) occurred within Green Bay. Abundance estimates from horizontally stratified (by water column depth) data were within 9-11% of vertically stratified estimates during spring but over 20% higher during summer. By extrapolation to all water depths, we estimated total pelagic biomass as 274.6 kt for spring and 410.8 kt for summer. During both seasons, smaller fishes were nearer to the surface and nearer shore than larger individuals, and acoustic measures of size approximated the sizes of fishes caught in trawls. Bioenergetic model simulations suggest that 60% of the available production of alewife (Alosa pseudoharengus) was either consumed by stocked salmonines (52.9%) or commercially harvested (7.1%) in 1987. Underwater acoustics proved a valuable tool for lakewide assessments of fish abundances in the Great Lakes.

  20. Lake Roosevelt Fisheries Monitoring Program; Artificial Imprinting of Lake Roosevelt Kokanee Salmon (Oncorhynchus Nerka) with Synthetic Chemicals: Measurement of Thyroxine Content as an Indicator of the Sensitive Period for Imprinting to Olfactory Cues; 1992 Supplement Report.

    SciTech Connect

    Scholz, Allan T.; White, Ronald J.; Tilson, Mary Beth

    1993-09-01

    {sub 4} peaked a second time during swimup (88-95 days post-fertilization) at 24.3 {+-} 3.8 ng/g body weight. After swimup, T{sub 4} concentration steadily declined to about 0.6 ng/g body weight in 225 day old post-fertilization fry. Thus, results of our 1992 investigations were consistent with our preliminary 1991 study. In all cases: (1) T{sub 4} concentration was relatively high in eggs and alevins as compared to older fry; and (2) T{sub 4} peaks occurred at hatch and swimup. Blood serum T{sub 4} concentration was measured in 9 month to 21 month-old Lake Whatcom stock, 1990 year class, kokanee from July 1991 to August 1992. T{sub 4} concentrations were low in summer, peaked slightly in October, were low in early winter, then peaked several times between January and May 1992. Thus, the 1990 year class Lake Whatcom kokanee evidenced high T{sub 4} activity from egg to swimup stages in their first year and in the winter and spring of their second year of life. The fish appeared to undergo smolt transformation between 16-18 months old. In 1992, Lake Whatcom (1991 cohort) kokanee were exposed to synthetic chemicals--1,072,000 to morpholine and 1,117,000 to phenethyl alcohol--at different life history stages: (1) eye to hatch; (2) hatch; (3) hatch to swimup; (4) swimup; and (5) post-swimup fry (in February, March, April and May-June). Additionally, Lake Whatcom (1990 cohort) kokanee were exposed to synthetic chemicals--36,000 to morpholine and 51,600 to phenethyl alcohol--at age 16-18 months. Most of these fish were marked and released in Lake Roosevelt in July and August 1992 as part of a field test. A portion of the fish from each group was retained at the Spokane Tribal hatchery until August-October 1993, when behavioral tests will be conducted to determine if the fish imprinted to their exposure odor.

  1. Use of classification trees to apportion single echo detections to species: Application to the pelagic fish community of Lake Superior

    USGS Publications Warehouse

    Yule, Daniel L.; Adams, Jean V.; Hrabik, Thomas R.; Vinson, Mark R.; Woiak, Zebadiah; Ahrenstroff, Tyler D.

    2013-01-01

    Acoustic methods are used to estimate the density of pelagic fish in large lakes with results of midwater trawling used to assign species composition. Apportionment in lakes having mixed species can be challenging because only a small fraction of the water sampled acoustically is sampled with trawl gear. Here we describe a new method where single echo detections (SEDs) are assigned to species based on classification tree models developed from catch data that separate species based on fish size and the spatial habitats they occupy. During the summer of 2011, we conducted a spatially-balanced lake-wide acoustic and midwater trawl survey of Lake Superior. A total of 51 sites in four bathymetric depth strata (0–30 m, 30–100 m, 100–200 m, and >200 m) were sampled. We developed classification tree models for each stratum and found fish length was the most important variable for separating species. To apply these trees to the acoustic data, we needed to identify a target strength to length (TS-to-L) relationship appropriate for all abundant Lake Superior pelagic species. We tested performance of 7 general (i.e., multi-species) relationships derived from three published studies. The best-performing relationship was identified by comparing predicted and observed catch compositions using a second independent Lake Superior data set. Once identified, the relationship was used to predict lengths of SEDs from the lake-wide survey, and the classification tree models were used to assign each SED to a species. Exotic rainbow smelt (Osmerus mordax) were the most common species at bathymetric depths 100 m (384 million; 6.0 kt). Cisco (Coregonus artedi) were widely distributed over all strata with their population estimated at 182 million (44 kt). The apportionment method we describe should be transferable to other large lakes provided fish are not tightly aggregated, and an appropriate TS-to-L relationship for abundant pelagic fish species can be determined.

  2. Comparing nearshore benthic and pelagic prey as mercury sources to lake fish: the importance of prey quality and mercury content.

    PubMed

    Karimi, Roxanne; Chen, Celia Y; Folt, Carol L

    2016-09-15

    Mercury (Hg) bioaccumulation in fish poses well-known health risks to wildlife and humans through fish consumption. Yet fish Hg concentrations are highly variable, and key factors driving this variability remain unclear. One little studied source of variation is the influence of habitat-specific feeding on Hg accumulation in lake fish. However, this is likely important because most lake fish feed in multiple habitats during their lives, and the Hg and caloric content of prey from different habitats can differ. This study used a three-pronged approach to investigate the extent to which habitat-specific prey determine differences in Hg bioaccumulation in fish. This study first compared Hg concentrations in common nearshore benthic invertebrates and pelagic zooplankton across five lakes and over the summer season in one lake, and found that pelagic zooplankton generally had higher Hg concentrations than most benthic taxa across lakes, and over a season in one lake. Second, using a bioenergetics model, the effects of prey caloric content from habitat-specific diets on fish growth and Hg accumulation were calculated. This model predicted that the consumption of benthic prey results in lower fish Hg concentrations due to higher prey caloric content and growth dilution (high weight gain relative to Hg from food), in addition to lower prey Hg levels. Third, using data from the literature, links between fish Hg content and the degree of benthivory, were examined, and showed that benthivory was associated with reduced Hg concentrations in lake fish. Taken together, these findings support the hypothesis that higher Hg content and lower caloric content make pelagic zooplankton prey greater sources of Hg for fish than nearshore benthic prey in lakes. Hence, habitat-specific foraging is likely to be a strong driver of variation in Hg levels within and between fish species. PMID:27173839

  3. A review of abiotic and biotic interactions in pelagic communities: Processes relevant to L Lake

    SciTech Connect

    Bowers, J.A.

    1988-01-01

    The purpose of this report is to provide a state-of-the-art review of structural and functional processes in pelagic communities and extrapolate these empirical and theoretical results to L Lake, the once-through cooling reservoir at the Savannah River Plant. Man-made reservoirs differ from natural lakes in their origins, hydrodynamics, sedimentation patterns, and general eutrophication histories. Phosphorus and nitrogen limitation of phytoplankton productivity controls the rate of eutrophication, while also determining algal community structure. Here the Lean and Monod models of nutrient fluxing and uptake kinetics provide useful constructs for predictive purposes. Much of the reduced carbon synthesized by primary production is shunted through the microbial loop where heterotrophic flagellates and protozoans pass this carbon on to the macrozooplankton. This recently discovered pathway is common to eutrophic reservoirs where blue-green species dominate phytoplankton assemblages. Through selective grazing and tactile oriented predation, the crustacean zooplankton partially regulates the relative abundance of algae and microzooplankton species. 194 refs., 10 figs.

  4. Revealing Roosevelt

    NASA Technical Reports Server (NTRS)

    2006-01-01

    This image mosaic from the microscopic imager aboard NASA's Mars Exploration Rover Opportunity shows detailed structure of a small fin-like structure dubbed 'Roosevelt,' which sticks out from the outcrop pavement at the edge of 'Erebus Crater.'

    Roosevelt lines a fracture in the local pavement and scientists hypothesize that it is a fracture fill, formed by water that percolated through the fracture. This would mean the feature is younger than surrounding rocks and, therefore, might provide evidence of water that was present some time after the formation of Meridiani Planum sedimentary rocks.

    The image shows fine laminations (layers about 1 millimeter or .04 inch thick) that run parallel to the axis of the fin. Some of the textures visible in the image likely indicate that minerals precipitated from the outcrop rocks, but sediment grains are also apparent.

    The three frames combined into this mosaic were taken during Opportunity's 727th Martian day, or sol (Feb. 8, 2006). In subsequent days, the rover completed textural and chemical inspection of Roosevelt to help the science team understand this structure's significance for Martian history.

  5. Contaminant trends in sport fish from Lake Roosevelt and the upper Columbia River, Washington, 1994-1998

    USGS Publications Warehouse

    Munn, Mark D.

    2000-01-01

    Fish from Lake Roosevelt were first reported to contain elevated concentrations of contaminants in the early 1980?s, with mercury, dioxins and furans, and polychlorinated biphenyls (PCBs) identified as being of most concern to human health. Over the following years there were a series of studies by United States and Canadian agencies addressing contaminants in fish from both a human and environmental perspective. In the early 1990?s, industrial discharges to the Columbia River above the international boundary decreased. The dominant changes in industrial practices included a reduction in slag and effluent discharges from a lead-zinc smelter, and a reduction in dioxins and furans due to processing changes at a Canadian pulp mill. It is believed that these two alterations in industrial practices may have greatly reduced the loading of selected contaminants to the Columbia River system. In response to these recent changes, the U.S. Geological Survey initiated this present study for the purpose of determining the present concentrations of mercury, dioxins and furans, and PCBs in fish, and, if possible, to determine if concentrations have changed since the 1994 studies. All contaminant analysis was done on fish fillets in order to address human health concerns. Our study concluded that the concentrations of contaminants in fish that were identified as a potential threat to human health have either not changed since the 1994 studies, or have decreased. PCBs, as determined by Aroclor 1254, do not appear to have changed between 1994 and 1998; sources of PCBs are presently unknown. In contrast, dioxins and furans, as indicated by 2,3,7,8-TCDF, did show a significant decrease in rainbow trout fillets from 1994 to 1998. However, there was no apparent change in the average 2,3,7,8-TCDF concentrations in mountain whitefish, with the reason uncertain at this time. Average concentrations of 2,3,7,8-TCDF were higher in mountain whitefish than in rainbow trout. Toxicity equivalence

  6. Seasonality of photochemical dissolved organic carbon mineralization and its relative contribution to pelagic CO2 production in northern lakes

    NASA Astrophysics Data System (ADS)

    Vachon, Dominic; Lapierre, Jean-François; Giorgio, Paul A.

    2016-03-01

    Boreal and northern temperate lakes (hereinafter referred to as northern lakes) are sites of intense processing of dissolved organic carbon (DOC), which is reflected in part in the persistent CO2 supersaturation of their surface waters. These ecosystems are subject to strong seasonal fluctuations in both irradiance and DOC amount and quality, which in turn should result in temporal shifts in the magnitude of DOC photodegradation. Here we explore the temporal patterns in the magnitude of water column DOC photomineralization and its potential contribution to pelagic CO2 production in three northern lakes of different DOC content. We performed laboratory DOC photodegradation incubations and combined the resulting rates with field measurements and modeling to reconstruct the annual cycle in depth-integrated DOC photomineralization. We found that areal rates of DOC photomineralization were driven by both irradiance and intrinsic DOC photoreactivity, both of which showed seasonality. Over an annual cycle, depth-integrated DOC photomineralization rates were remarkably similar across lakes, averaging 4.4 (SD = 0.7) g C m-2 yr-1 and daily rates followed an apparent seasonal pattern. The contribution of DOC photomineralization to total pelagic CO2 production (as the sum of respiration and DOC photomineralization) peaked after ice melt (up to 49%), averaging 14% for the entire open water season. Our study identifies potential hot periods of photochemical activity that result from the interplay between DOC properties and environmental conditions, which should be incorporated into models of lake functioning.

  7. Ecological speciation in postglacial European whitefish: rapid adaptive radiations into the littoral, pelagic, and profundal lake habitats

    PubMed Central

    Præbel, Kim; Knudsen, Rune; Siwertsson, Anna; Karhunen, Markku; Kahilainen, Kimmo K; Ovaskainen, Otso; Østbye, Kjartan; Peruzzi, Stefano; Fevolden, Svein-Erik; Amundsen, Per-Arne

    2013-01-01

    Understanding how a monophyletic lineage of a species diverges into several adaptive forms has received increased attention in recent years, but the underlying mechanisms in this process are still under debate. Postglacial fishes are excellent model organisms for exploring this process, especially the initial stages of ecological speciation, as postglacial lakes represent replicated discrete environments with variation in available niches. Here, we combine data of niche utilization, trophic morphology, and 17 microsatellite loci to investigate the diversification process of three sympatric European whitefish morphs from three northern Fennoscandian lakes. The morphological divergence in the gill raker number among the whitefish morphs was related to the utilization of different trophic niches and was associated with reproductive isolation within and across lakes. The intralacustrine comparison of whitefish morphs showed that these systems represent two levels of adaptive divergence: (1) a consistent littoral–pelagic resource axis; and (2) a more variable littoral–profundal resource axis. The results also indicate that the profundal whitefish morph has diverged repeatedly from the ancestral littoral whitefish morph in sympatry in two different watercourses. In contrast, all the analyses performed revealed clustering of the pelagic whitefish morphs across lakes suggesting parallel postglacial immigration with the littoral whitefish morph into each lake. Finally, the analyses strongly suggested that the trophic adaptive trait, number of gill rakers, was under diversifying selection in the different whitefish morphs. Together, the results support a complex evolutionary scenario where ecological speciation acts, but where both allopatric (colonization history) and sympatric (within watercourse divergence) processes are involved. PMID:24455129

  8. Ecological speciation in postglacial European whitefish: rapid adaptive radiations into the littoral, pelagic, and profundal lake habitats.

    PubMed

    Præbel, Kim; Knudsen, Rune; Siwertsson, Anna; Karhunen, Markku; Kahilainen, Kimmo K; Ovaskainen, Otso; Ostbye, Kjartan; Peruzzi, Stefano; Fevolden, Svein-Erik; Amundsen, Per-Arne

    2013-12-01

    Understanding how a monophyletic lineage of a species diverges into several adaptive forms has received increased attention in recent years, but the underlying mechanisms in this process are still under debate. Postglacial fishes are excellent model organisms for exploring this process, especially the initial stages of ecological speciation, as postglacial lakes represent replicated discrete environments with variation in available niches. Here, we combine data of niche utilization, trophic morphology, and 17 microsatellite loci to investigate the diversification process of three sympatric European whitefish morphs from three northern Fennoscandian lakes. The morphological divergence in the gill raker number among the whitefish morphs was related to the utilization of different trophic niches and was associated with reproductive isolation within and across lakes. The intralacustrine comparison of whitefish morphs showed that these systems represent two levels of adaptive divergence: (1) a consistent littoral-pelagic resource axis; and (2) a more variable littoral-profundal resource axis. The results also indicate that the profundal whitefish morph has diverged repeatedly from the ancestral littoral whitefish morph in sympatry in two different watercourses. In contrast, all the analyses performed revealed clustering of the pelagic whitefish morphs across lakes suggesting parallel postglacial immigration with the littoral whitefish morph into each lake. Finally, the analyses strongly suggested that the trophic adaptive trait, number of gill rakers, was under diversifying selection in the different whitefish morphs. Together, the results support a complex evolutionary scenario where ecological speciation acts, but where both allopatric (colonization history) and sympatric (within watercourse divergence) processes are involved. PMID:24455129

  9. Food web topology and parasites in the pelagic zone of a subarctic lake

    USGS Publications Warehouse

    Amundsen, P.-A.; Lafferty, K.D.; Knudsen, R.; Primicerio, R.; Klemetsen, A.; Kuris, A.M.

    2009-01-01

    Parasites permeate trophic webs with their often complex life cycles, but few studies have included parasitism in food web analyses. Here we provide a highly resolved food web from the pelagic zone of a subarctic lake and explore how the incorporation of parasites alters the topology of the web. 2. Parasites used hosts at all trophic levels and increased both food-chain lengths and the total number of trophic levels. Their inclusion in the network analyses more than doubled the number of links and resulted in an increase in important food-web characteristics such as linkage density and connectance. 3. More than half of the parasite taxa were trophically transmitted, exploiting hosts at multiple trophic levels and thus increasing the degree of omnivory in the trophic web. 4. For trophically transmitted parasites, the number of parasite-host links exhibited a positive correlation with the linkage density of the host species, whereas no such relationship was seen for nontrophically transmitted parasites. Our findings suggest that the linkage density of free-living species affects their exposure to trophically transmitted parasites, which may be more likely to adopt highly connected species as hosts during the evolution of complex life cycles. 5. The study supports a prominent role for parasites in ecological networks and demonstrates that their incorporation may substantially alter considerations of food-web structure and functioning. ?? 2009 British Ecological Society.

  10. Landslide conditions along the Ferry County highway parallelling Lake Roosevelt from Kettle Falls to the mouth of the Spokane River, Washington

    USGS Publications Warehouse

    Jones, Fred O.

    1954-01-01

    As part of the program of the U.S. Geological Survey, landslides are being studied in several localities in the United States. These studies are directed toward assembling criteria for recognition of landslides, classification, and cataloging of remedial or control methods that have been effective.  In the gorge of the Columbia Ricer in Washington, landslides of large magnitude have been active intermittently since the valley was first incised.  Closure of Grand Coulee Dam, with the consequent rise of water forming Franklin D. Roosevelt Lake, has introduced the factor of a rising and fluctuating water table that accentuates the incidence of landsliding.  This area was selected for study because of the magnitude of the landslides and the unknown but significant influence of a fluctuating water table.  Data resulting from the studies will be summarized in a final report.

  11. Concentrations of mercury and other trace elements in walleye, smallmouth bass, and rainbow trout in Franklin D. Roosevelt Lake and the upper Columbia River, Washington, 1994

    USGS Publications Warehouse

    Munn, M.D.; Cox, S.E.; Dean, C.J.

    1995-01-01

    Three species of sportfish--walleye, smallmouth bass, and rainbow trout--were collected from Franklin D. Roosevelt Lake and the upstream reach of the Columbia River within the state of Washington, to determine the concentrations of mercury and other selected trace elements in fish tissue. Concentrations of total mercury in walleye fillets ranged from 0.11 to 0.44 milligram per kilogram, with the higher concentrations in the larger fish. Fillets of smallmouth bass and rainbow trout also contained mercury, but generally at lower concentrations. Other selected trace elements were found in fillet samples, but the concentrations were generally low depending on species and the specific trace element. The trace elements cadmium, copper, lead, and zinc were found in liver tissue of these same species with zinc consistently present in the highest concentration.

  12. Benthic‐pelagic coupling drives non‐seasonal zooplankton blooms and restructures energy flows in shallow tropical lakes

    PubMed Central

    Schagerl, Michael; Yasindi, Andrew; Singer, Gabriel; Kaggwa, Mary Nakabungo; Winder, Monika

    2016-01-01

    Abstract Zooplankton blooms are a frequent phenomenon in tropical systems. However, drivers of bloom formation and the contribution of emerging resting eggs are largely unexplored. We investigated the dynamics and the triggers of rotifer blooms in African soda‐lakes and assessed their impact on other trophic levels. A meta‐analysis of rotifer peak densities including abundances of up to 6 × 105 individuals L−1 demonstrated that rotifer bloom formation was uncoupled from the food environment and the seasonality of climatic conditions. A time series with weekly sampling intervals from Lake Nakuru (Kenya) revealed that intrinsic growth factors (food quality and the physicochemical environment) significantly affected rotifer population fluctuations, but were of minor importance for bloom formation. Instead, rotifer bloom formation was linked to sediment resuspension, a prerequisite for hatching of resting‐eggs. Population growth rates exceed pelagic birth rates and simulations of rotifer dynamics confirmed the quantitative importance of rotifer emergence from the sediment egg‐bank and signifying a decoupling of bloom formation from pelagic reproduction. Rotifer blooms led to a top‐down control of small‐sized algae and facilitated a switch to more grazing‐resistant, filamentous cyanobacteria. This shift in phytoplankton composition cascaded up the food chain and triggered the return of filter‐feeding flamingos. Calculations of consequent changes in the lake's energy budget and export of aquatic primary production to terrestrial ecosystems demonstrated the large potential impact of nonseasonal disturbances on the functioning of shallow tropical lakes. PMID:27587899

  13. Effect of inorganic N enrichment on basal pelagic production in boreal unproductive lakes along a gradient of DOC concentration - results after 1 year of fertilization

    NASA Astrophysics Data System (ADS)

    Deininger, Anne; Bergström, Ann-Kristin

    2013-04-01

    Input of inorganic nitrogen (N) in boreal unproductive lakes is steadily increasing due to anthropogenic deposition and usage of artificial fertilizers. N enrichment is predicted to have a major impact on the ecosystem productivity and food web structure in unproductive clear-water and humic lakes. For a long time, pelagic primary production (PP) has been mainly regarded as being phosphorus (P) limited. However, recent studies have shown that this is not true for unproductive lakes in northern Sweden, where phytoplankton is mainly N limited. Addition of inorganic N should therefore increase phytoplankton growth in these lake ecosystems. Bacterial production (BP) in the pelagic habitat, on the other hand, is usually limited by P. Nevertheless, elevated N could have a stimulating effect on BP through enhanced leakage of dissolved organic carbon (DOC) from phytoplankton following enhanced N availability and higher PP. Further, unproductive lakes vary naturally in their DOC content which affects overall nutrient- (N and P), energy- and carbon availability (light, C) for the basal producers (phytoplankton, bacteria). It is still not clear how higher inorganic N availability affects primary- and bacterial production in the pelagic in lakes with varying DOC content. We subsequently assessed this question by conducting whole-lake fertilization experiments with inorganic N additions in 6 lakes with varying DOC concentrations (2 low DOC; 2 medium DOC; 2 high DOC). For each DOC level one lake functioned as a reference and one was fertilized with N. Year 2011 was a reference year (all lakes) and 2012 was the first year of fertilization (i.e. in 3 lakes). Measurements included basal productivity such as primary production and bacteria production, lake water chemistry and physical parameters (i.e. light, temperature). The results of this study will help to develop a conceptual understanding of how increased inorganic N availability (through land use such as forestry and

  14. Field experiments investigating the Benthic Pelagic coupling over a zebra mussel be in the western basin of Lake Erie

    SciTech Connect

    Loewen, M.R.; Cozzi, P.; Hamblin, P.F.; Ackerman, J.D.

    1995-06-01

    Unlike the relatively well-known unidirectional tidal flows in coastal marine environments, mixing in freshwater lakes is likely to be primarily wind driven and intermittent. Moreover, recent data indicates that flow rate affects zebra mussel filter feeding in a ramp-like manner not predicted by conventional static-flow models. Both of these outcomes indicate that direct measurements of the physical transport processes and the resultant biology of filter feeding must be made in situ to begin to understand the impact of zebra mussels on the pelagic foodwebs. The purpose of the following paper is to report the results of a preliminary study of the biophysical factors that relate to the benthic-pelagic coupling in a zebra mussel bed within the western basin of Lake Erie. Althoug work is still in progress, our preliminary results indicate a complex flow field over the zebra mussel bed. By means of a simple model, we have demonstrated that the extrapolation of individual laboratory-based feeding rates to a field situation leads to a significant overestimation of the actual feeding rates. Further work is in progress to refine the model to allow for vertical variability in organic concentration, a more accurate prescription of the turbulent transport or organic material above the bed and to validate other model assumptions such as the assumption of two-dimensional flow over the bed.

  15. Characterization of the contents and histology of the gastrointestinal tracts of White Sturgeon (Acipenser transmontanus) captured from Upper Lake Roosevelt, Washington, October 2008

    USGS Publications Warehouse

    Parsley, Michael J.; van der Leeuw, Bjorn K.; Elliott, Diane G.

    2010-01-01

    The gastrointestinal tracts of 37 juvenile white sturgeon (Acipenser transmontanus) captured from the upper part of Lake Roosevelt during October 2008, were examined to identify prey taxa and to determine if the fish were consuming smelter slag along with other sediments. Histological examination of the gastrointestinal tract tissues and comparison with similar tissues from hatchery-reared fish also was performed. The contents of the gastro-intestinal tracts (guts) indicated that white sturgeon were actively foraging on various benthic invertebrates and the diet was quite diverse, with more than 50 percent of the fish feeding on five or more different taxa. Slag was present in 76 percent of the guts examined. Although not all guts contained slag particles, larger fish tended to have greater amounts of slag in their guts. Histology of the gut tissues showed the presence of a chronic inflammatory response, and the severity of the response had a significant positive correlation (P = 0.01) with fish length and weight suggesting that the inflammation represented a response to long-term exposure to one or more stressors. However, additional work is needed to determine if the physical or chemical properties of slag contributed to this response.

  16. Energy density and size of pelagic prey fishes in Lake Ontario, 1978-1990: Implications for salmonine energetics

    USGS Publications Warehouse

    Rand, Peter S.; Lantry, Brian F.; O'Gorman, R.; Owens, Randall W.; Stewart, Donald J.

    1994-01-01

    We describe dynamics of energy density and size of Lake Ontario alewife Alosa pseudoharengus and rainbow smelt Osmerus mordax, and we use a bioenergetics model of a common pelagic piscivore, chinook salmon Oncorhynchus tshawytscha, to demonstrate the effect of these factors on piscivore daily ration during 1978–1990. The energy density of alewives varied more than twofold between peaks in September (age 1) or October–November (age ≥2) and the lows in May (age 1) or July–September (age≥2). The previously described seasonal pattern of energy density of Lake Michigan alewives was similar except that energy density of older alewives (age≥3) was markedly higher in Lake Michigan. During 1978–1990, the spring energy density of Lake Ontario alewives peaked in 1979 (6,259 J/g wet weight), declined irregularly until 1985, and then remained stable through 1990 (at approximately 4,600 J/g). The initial decline may have been a density-dependent response to a burgeoning alewife population, but the lack of an increase in alewife condition in the late 1980s, when alewife biomass fell, suggests a decline in lake productivity. Energy density of rainbow smelt increased with age in Lake Ontario and condition was invariant during 1978–1990 despite a threefold change in rainbow smelt biomass. Rainbow smelt energy density was lower and fluctuated less seasonally in Lake Ontario than in Lake Michigan. Mean weight of alewives aged 2 and older dropped from 41 g in 1978 to 19 g in 1989 in Lake Ontario. Rainbow smelt aged 2 and older showed a drop in mean weight from 13–17 g in 1978–1982 to 8 g in 1990. This downward trend in mean size of alewives was correlated with the sizes of alewives consumed by Lake Ontario chinook salmon during 1983–1987. For adult chinook salmon to maintain a constant growth rate during 1978–1990, mean individual daily ration during June–October had to increase from a low of 2.2% body weight/d (or 1.5 prey fish/d) in 1979 to 3.1% body

  17. HYDROACOUSTIC ESTIMATES OF ABUNDANCE AND SPATIAL DISTRIBUTION OF PELAGIC PREY FISHES IN WESTERN LAKE SUPERIOR

    EPA Science Inventory

    Lake herring (Coregonus artedi) and rainbow smelt (Osmerus mordax) are a valuable prey resource for the recovering lake trout (Salvelinus namaycush). However, their respective biomasses may be insufficient to support the current predator demand. In August 1977, we assessed the ...

  18. Terrestrial, benthic, and pelagic resource use in lakes: Results from a three-isotope Bayesian mixing model

    USGS Publications Warehouse

    Solomon, C.T.; Carpenter, S.R.; Clayton, M.K.; Cole, J.J.; Coloso, J.J.; Pace, M.L.; Vander Zanden, M. J.; Weidel, B.C.

    2011-01-01

    Fluxes of organic matter across habitat boundaries are common in food webs. These fluxes may strongly influence community dynamics, depending on the extent to which they are used by consumers. Yet understanding of basal resource use by consumers is limited, because describing trophic pathways in complex food webs is difficult. We quantified resource use for zooplankton, zoobenthos, and fishes in four low-productivity lakes, using a Bayesian mixing model and measurements of hydrogen, carbon, and nitrogen stable isotope ratios. Multiple sources of uncertainty were explicitly incorporated into the model. As a result, posterior estimates of resource use were often broad distributions; nevertheless, clear patterns were evident. Zooplankton relied on terrestrial and pelagic primary production, while zoobenthos and fishes relied on terrestrial and benthic primary production. Across all consumer groups terrestrial reliance tended to be higher, and benthic reliance lower, in lakes where light penetration was low due to inputs of terrestrial dissolved organic carbon. These results support and refine an emerging consensus that terrestrial and benthic support of lake food webs can be substantial, and they imply that changes in the relative availability of basal resources drive the strength of cross-habitat trophic connections. ?? 2011 by the Ecological Society of America.

  19. 52. THE DOWNSTREAM FACE OF ROOSEVELT DAM. THE ROOSEVELT POWER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    52. THE DOWNSTREAM FACE OF ROOSEVELT DAM. THE ROOSEVELT POWER HOUSE IS LOCATED AT THE CENTER OF THE PHOTO WITH THE TRANSFORMER HOUSE LOCATED AT THE RIGHT. THE NORTH SPILLWAY IS AT THE FAR LEFT AND SOUTH SPILLWAY AT THE FAR RIGHT Photographer: Mark Durben, 1984 - Roosevelt Power Canal & Diversion Dam, Parallels Salt River, Roosevelt, Gila County, AZ

  20. SPATIAL PATTERNS IN ASSEMBLAGE STRUCTURES OF PELAGIC FORAGE FISH AND ZOOPLANKTON IN WESTERN LAKE SUPERIOR

    EPA Science Inventory

    This manuscript reports on the spatial distribution of zooplankton and forage fish in western Lake Superior. Fish and zooplankton assemblages are shown to differ substantially in abundance and size structure both between the open lake and nearshore regions and between two differe...

  1. Concentrations of Elements in Sediments and Selective Fractions of Sediments, and in Natural Waters in Contact with Sediments from Lake Roosevelt, Washington, September 2004

    USGS Publications Warehouse

    Paulson, Anthony J.; Wagner, Richard J.; Sanzolone, Richard F.; Cox, Steven E.

    2006-01-01

    Twenty-eight composite and replicate sediment samples from 8 Lake Roosevelt sites were collected and analyzed for 10 alkali and alkaline earth elements, 2 non-metals, 20 metals, and 4 lanthanide and actinide elements. All elements were detected in all sediment samples except for silver (95 percent of the elements detected for 1,008 analyses), which was detected only in 4 samples. Sequential selective extraction procedures were performed on single composite samples from the eight sites. The percentage of detections for the 31 elements analyzed ranged from 76 percent for the first extraction fraction using a weak extractant to 93 percent for the four-acid dissolution of the sediments remaining after the third sequential selective extraction. Water samples in various degrees of contact with the sediment were analyzed for 10 alkali and alkaline earth elements, 5 non-metals, 25 metals, and 16 lanthanide and actinide elements. The filtered water samples included 10 samples from the reservoir water column at 8 sites, 32 samples of porewater, 55 samples from reservoir water overlying sediments in 8 cores from the site incubated in a field laboratory, and 24 water samples that were filtered after being tumbled with sediments from 8 sites. Overall, the concentrations of only 37 percent of the 6,776 analyses of the 121 water samples were greater than the reporting limit. Selenium, bismuth, chromium, niobium, silver, and zirconium were not detected in any water samples. The percentage of concentrations for the water samples that were above the reporting limit ranged from 14 percent for the lanthanide and actinide elements to 77 percent for the alkali and alkaline earth elements. Concentrations were greater than reporting limits in only 23 percent of the analyses of reservoir water and 29 percent of the analyses of reservoir water overlying incubation cores. In contrast, 47 and 48 percent of the concentrations of porewater and water samples tumbled with sediments, respectively

  2. Spatial patterns in assemblage structures of pelagic forage fish and zooplankton in western Lake Superior

    USGS Publications Warehouse

    Johnson, Timothy B.; Hoff, Michael H.; Trebitz, Anett S.; Bronte, Charles R.; Corry, Timothy D.; Kitchell, James F.; Lozano, Stephen J.; Mason, Doran M.; Scharold, Jill V.; Schram, Stephen T.; Schreiner, Donald R.

    2004-01-01

    We assessed abundance, size, and species composition of forage fish and zooplankton communities of western Lake Superior during August 1996 and July 1997. Data were analyzed for three ecoregions (Duluth-Superior, Apostle Islands, and the open lake) differing in bathymetry and limnological and biological patterns. Zooplankton abundance was three times higher in the Duluth-Superior and Apostle Islands regions than in the open lake due to the large numbers of rotifers. Copepods were far more abundant than Cladocera in all ecoregions. Mean zooplankton size was larger in the open lake due to dominance by large calanoid copepods although size of individual taxa was similar among ecoregions. Forage fish abundance and biomass was highest in the Apostle Islands region and lowest in the open lake ecoregion. Lake herring (Coregonus artedi), rainbow smelt (Osmerus mordax) and deepwater ciscoes (Coregonus spp.) comprised over 90% of the abundance and biomass of fishes caught in midwater trawls and recorded with hydroacoustics. Growth and condition of fish was good, suggesting they were not resource limited. Fish and zooplankton assemblages differed among the three ecoregions of western Lake Superior, due to a combination of physical and limnological factors related to bathymetry and landscape position.

  3. Foraging mechanisms of siscowet lake trout (Salvelinus namaycush siscowet) on pelagic prey

    USGS Publications Warehouse

    Keyler, Trevor D.; Hrabik, Thomas R.; Austin, C. Lee; Gorman, Owen T.; Mensinger, Allen F.

    2015-01-01

    The reaction distance, angle of attack, and foraging success were determined for siscowet lake trout (Salvelinus namaycush siscowet) during laboratory trials under lighting conditions that approximated downwelling spectral irradiance and intensity (9.00 × 108–1.06 × 1014 photons m− 2 s− 1) at daytime depths. Siscowet reaction distance in response to golden shiners (Notemigonus crysoleucas) was directly correlated with increasing light intensity until saturation at 1.86 × 1011 photons m− 2 s− 1, above which reaction distance was constant within the range of tested light intensities. At the lowest tested light intensity, sensory detection was sufficient to locate prey at 25 ± 2 cm, while increasing light intensities increased reaction distance up to 59 ± 2 cm at 1.06 × 1014 photons m− 2 s− 1. Larger prey elicited higher reaction distances than smaller prey at all light intensities while moving prey elicited higher reaction distances than stationary prey at the higher light intensities (6.00 × 109 to 1.06 × 1014 photons m− 2 s− 1). The capture and consumption of prey similarly increased with increasing light intensity while time to capture decreased with increasing light intensity. The majority of orientations toward prey occurred within 120° of the longitudinal axis of the siscowet's eyes, although reaction distances among 30° increments along the entire axis were not significantly different. The developed predictive model will help determine reaction distances for siscowet in various photic environments and will help identify the mechanisms and behavior that allow for low light intensity foraging within freshwater systems.

  4. Can pelagic forage fish and spawning cisco (Coregonus artedi) biomass in the western arm of Lake Superior be assessed with a single summer survey?

    USGS Publications Warehouse

    Yule, D.L.; Stockwell, J.D.; Schreiner, D.R.; Evrard, L.M.; Balge, M.; Hrabik, T.R.

    2009-01-01

    Management efforts to rehabilitate lake trout Salvelinus namaycush in Lake Superior have been successful and the recent increase in their numbers has led to interest in measuring biomass of pelagic prey fish species important to these predators. Lake Superior cisco Coregonus artedi currently support roe fisheries and determining the sustainability of these fisheries is an important management issue. We conducted acoustic and midwater trawl surveys of the western arm of Lake Superior during three periods: summer (July-August), October, and November 2006 to determine if a single survey can be timed to estimate biomass of both prey fish and spawning cisco. We evaluated our methods by comparing observed trawl catches of small (<250 mm total length) and large fish to expected trawl catches based on acoustic densities in the trawl path. We found the relationship between observed and expected catches approached unity over a wide range of densities, suggesting that our acoustic method provided reasonable estimates of fish density, and that midwater trawling methods were free of species- and size-selectivity issues. Rainbow smelt Osmerus mordax was by number the most common species captured in the nearshore (<80 m bathymetric depth) stratum during all three surveys, while kiyi Coregonus kiyi was predominant offshore except during November. Total biomass estimates of rainbow smelt in the western arm were similar during all three surveys, while total biomass of kiyi was similar between summer and October, but was lower in November. Total biomass of large cisco increased substantially in November, while small bloater Coregonus hoyi biomass was lower. We compared our summer 2006 estimates of total fish biomass to the results of a summer survey in 1997 and obtained similar results. We conclude that the temporal window for obtaining biomass estimates of pelagic prey species in the western arm of Lake Superior is wide (July through October), but estimating spawning cisco abundance

  5. Incorporation of inorganic mercury (Hg2+) in pelagic food webs of ultraoligotrophic and oligotrophic lakes: the role of different plankton size fractions and species assemblages

    USGS Publications Warehouse

    Soto Cárdenas, Carolina; Diéguez, Maria C.; Ribeiro Guevara, Sergio; Marvin-DiPasquale, Mark; Queimaliños, Claudia P.

    2014-01-01

    In lake food webs, pelagic basal organisms such as bacteria and phytoplankton incorporate mercury (Hg2+) from the dissolved phase and pass the adsorbed and internalized Hg to higher trophic levels. This experimental investigation addresses the incorporation of dissolved Hg2+ by four plankton fractions (picoplankton: 0.2–2.7 μm; pico + nanoplankton: 0.2–20 μm; microplankton: 20–50 μm; and mesoplankton: 50–200 μm) obtained from four Andean Patagonian lakes, using the radioisotope 197Hg2+. Species composition and abundance were determined in each plankton fraction. In addition, morphometric parameters such as surface and biovolume were calculated using standard geometric models. The incorporation of Hg2+ in each plankton fraction was analyzed through three concentration factors: BCF (bioconcentration factor) as a function of cell or individual abundance, SCF (surface concentration factor) and VCF (volume concentration factor) as functions of individual exposed surface and biovolume, respectively. Overall, this investigation showed that through adsorption and internalization, pico + nanoplankton play a central role leading the incorporation of Hg2+ in pelagic food webs of Andean lakes. Larger planktonic organisms included in the micro- and mesoplankton fractions incorporate Hg2+ by surface adsorption, although at a lesser extent. Mixotrophic bacterivorous organisms dominate the different plankton fractions of the lakes connecting trophic levels through microbial loops (e.g., bacteria–nanoflagellates–crustaceans; bacteria–ciliates–crustaceans; endosymbiotic algae–ciliates). These bacterivorous organisms, which incorporate Hg from the dissolved phase and through their prey, appear to explain the high incorporation of Hg2+ observed in all the plankton fractions.

  6. A multispecies statistical age-structured model to assess predator-prey balance: application to an intensively managed Lake Michigan pelagic fish community

    USGS Publications Warehouse

    Tsehaye, Iyob; Jones, Michael L.; Bence, James R.; Brenden, Travis O.; Madenjian, Charles P.; Warner, David M.

    2014-01-01

    Using a Bayesian model fitting approach, we developed a multispecies statistical catch-at-age model to assess trade-offs between predatory demands and prey productivities, focusing on the Lake Michigan pelagic fish community. We assessed these trade-offs in terms of predation mortalities and productivities of alewife (Alosa pseudoharengus) and rainbow smelt (Osmerus mordax) and functional responses of salmonines. Our predation mortality estimates suggest that salmonine consumption has been a major driver of historical fluctuations in prey abundance, with sharp declines in alewife abundance in the 1980s and 2000s coinciding with estimated increases in predation mortalities. While Chinook salmon (Oncorhynchus tshawytscha) were food limited during periods of low alewife abundance, other salmonines appeared to maintain a (near) maximum per-predator consumption across all observed prey densities, suggesting that feedback mechanisms are unlikely to help maintain a balance between predator consumption and prey productivity in Lake Michigan. This study demonstrates that a multispecies modeling approach that combines stock assessment methods with explicit consideration of predator–prey interactions could provide the basis for tactical decision-making from a broader ecosystem perspective.

  7. Recommended Resources about Eleanor Roosevelt.

    ERIC Educational Resources Information Center

    Social Education, 1984

    1984-01-01

    Books, films, and additional resources available from the National Women's History Resource Service are included in this annotated listing of resource materials which can be used to teach about Eleanor Roosevelt in elementary and secondary social studies classrooms. (RM)

  8. The effects of biomanipulation on the biogeochemistry, carbon isotopic composition and pelagic food web relations of a shallow lake

    NASA Astrophysics Data System (ADS)

    Bontes, B. M.; Pel, R.; Ibelings, B. W.; Boschker, H. T. S.; Middelburg, J. J.; Van Donk, E.

    2006-03-01

    In this study we investigated the effects of experimental biomanipulation on community structure, ecosystem metabolism, carbon biogeochemistry and stable isotope composition of a shallow eutrophic lake in the Netherlands. Three different biomanipulation treatments were applied. In two parts of the lake, isolated from the rest, fish was removed and one part was used as a reference treatment in which no biomanipulation was applied. Stable isotopes have proved useful to trace trophic interactions at higher food web levels but until now methodological limitations have restricted species specific isotope analysis in the plankton community. We applied a new approach based on the combination of fluorescence activated cell sorting (FACS) and isotope ratio mass spectrometry (IRMS) to trace carbon flow through the planktonic food web. With this method we aimed at obtaining group specific δ13C signatures of phytoplankton and to trace possible shifts in δ13C resulting from fish removal.

    Biomanipulation led to an increase in transparency and macrophyte biomass and decrease in phytoplankton abundance, but zooplankton numbers did not increase. Fish removal also resulted in high pH, high O2, low CO2 and more negative δ13CDIC values than expected, which is attributed to chemical enhanced diffusion with large negative fractionation. Despite high temporal variation we detected differences between the isotopic signatures of the primary producers and between the different treatments. The fractionation values of green algae (~21) and diatoms (~23) were similar and independent of treatment, while fractionation factors of filamentous cyanobacteria were variable between the treatments that differed in CO2 availability. 13C-labeling of the phytoplankton groups showed that biomanipulation led to increased growth rates of green algae and diatoms at the expense of cyanobacteria. Finally, consumers seemed generalists to the available food sources.

  9. Eleanor Roosevelt's "Education for Citizenship."

    ERIC Educational Resources Information Center

    Patton, Lillian; Patton, Thomas

    1984-01-01

    Eleanor Roosevelt taught history, current events, literature, and drama at the K-12 Todhunter School. Her views concerning social studies are discussed. She believed that the primary purpose of education in a democracy was the development of informed, productive citizens in an atmosphere in which individuals could reach their full potential. (RM)

  10. Eleanor Roosevelt and Civil Rights

    ERIC Educational Resources Information Center

    Kirkwood-Tucker, Toni Fuss

    2011-01-01

    Eleanor Roosevelt's support of African American rights was one of the highlights of her activities as first lady. Her fearless advocacy for justice pulled her into political controversies that were unprecedented for the wife of a president. The first lady's initiatives in support of the rights of African Americans offer students an excellent…

  11. 60. ROOSEVELT POWER CANAL, FLUME AT STA. 973 Courtesy of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    60. ROOSEVELT POWER CANAL, FLUME AT STA. 973 Courtesy of Dept. of the Interior, Bureau of Reclamation, Salt River Project, Arizona - Roosevelt Power Canal & Diversion Dam, Parallels Salt River, Roosevelt, Gila County, AZ

  12. 1. TEMPORARY POWER HOUSE AT ROOSEVELT DAM. TRAMWAY LINES CAN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. TEMPORARY POWER HOUSE AT ROOSEVELT DAM. TRAMWAY LINES CAN BE SEEN AT TOP OF PHOTOGRAPH Photographer: Walter J. Lubken, May 10, 1906 - Roosevelt Power Canal & Diversion Dam, Parallels Salt River, Roosevelt, Gila County, AZ

  13. 79. ROOSEVELT POWER CANAL, REHABILITATION, CROSS DRAINAGE FLUME LONGITUDINAL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    79. ROOSEVELT POWER CANAL, REHABILITATION, CROSS DRAINAGE FLUME - LONGITUDINAL SECTIONS Courtesy of Dept. of the Interior, Bureau of Reclamation, Salt River Project, Arizona - Roosevelt Power Canal & Diversion Dam, Parallels Salt River, Roosevelt, Gila County, AZ

  14. 81. ROOSEVELT POWER CANAL, REHABILITATION, CROSS DRAINAGE FLUMES CENTER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    81. ROOSEVELT POWER CANAL, REHABILITATION, CROSS DRAINAGE FLUMES - CENTER BENT DETAILS Courtesy of Dept. of the Interior, Bureau of Reclamation, Salt River Project, Arizona - Roosevelt Power Canal & Diversion Dam, Parallels Salt River, Roosevelt, Gila County, AZ

  15. 80. ROOSEVELT POWER CANAL, REHABILITATION, CROSS DRAINAGE FLUME FLUME ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    80. ROOSEVELT POWER CANAL, REHABILITATION, CROSS DRAINAGE FLUME - FLUME DETAILS Courtesy of Dept. of the Interior, Bureau of Reclamation, Salt River Project - Roosevelt Power Canal & Diversion Dam, Parallels Salt River, Roosevelt, Gila County, AZ

  16. 76. CONDENSED PROFILE OF ROOSEVELT POWER CANAL Courtesy of Dept. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    76. CONDENSED PROFILE OF ROOSEVELT POWER CANAL Courtesy of Dept. of the Interior, Bureau of Reclamation, Salt River Project, Arizona - Roosevelt Power Canal & Diversion Dam, Parallels Salt River, Roosevelt, Gila County, AZ

  17. 77. ROOSEVELT POWER CANAL LOCATION MAP, WORK TO BE DONE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    77. ROOSEVELT POWER CANAL LOCATION MAP, WORK TO BE DONE BY CONTRACT Courtesy of Dept. of the Interior, Bureau of Reclamation, Salt River Project - Roosevelt Power Canal & Diversion Dam, Parallels Salt River, Roosevelt, Gila County, AZ

  18. The effects of biomanipulation on the biogeochemistry, carbon isotopic composition and pelagic food web relations of a shallow turf lake

    NASA Astrophysics Data System (ADS)

    Bontes, B. M.; Pel, R.; Ibelings, B. W.; Boschker, H. T. S.; Middelburg, J. J.; van Donk, E.

    2005-08-01

    The effects of fish removal on the biogeochemistry and lower-trophic level food web relations were studied in a shallow eutrophied turf lake. Biomanipulation led to an increase in transparency and macrophyte biomass and decrease in phytoplankton abundance, but zooplankton numbers did not increase. Moreover, fish removal resulted in high pH, high O2, low CO2, and more negative δ13CDIC values than expected, which is proposed to be the likely result of chemical enhanced diffusion with large negative fractionation (-13). By combining fluorescence activated cell sorting and isotope ratio mass spectrometry (IRMS) of fatty acids we were able to obtain group specific δ13C signatures and to trace possible shifts in δ13C resulting from fish removal. Fractionation values of green algae (20) and diatoms (22) were uniform and independent of treatment, while fractionation factors of filamentous cyanobacteria were variable between the treatments that differed in CO2 availability. 13C-labeling of the phytoplankton groups showed that biomanipulation led to increased growth rates of green algae and diatoms at the expense of cyanobacteria. Finally, the primary consumer Chydorus appeared to prefer cyanobacteria, whilst Asplanchna grazed predominantly upon eukaryotes.

  19. Franklin D. Roosevelt at Langley 1940

    NASA Technical Reports Server (NTRS)

    1940-01-01

    President Franklin D. Roosevelt visited Langley Field on 29 July 1940. View of President Franklin D. Roosevelt in a car inside a NACA hangar, two unidentified men stand behind the car, and the wing of a plane is visible in the background. Photograph published in Engineer in Charge: A History of the Langley Aeronautical Laboratory, 1917-1958 by James R. Hansen (page 147).

  20. Eleanor Roosevelt: First Lady as Magazine Journalist.

    ERIC Educational Resources Information Center

    Beasley, Maurine H.

    Although Eleanor Roosevelt's career as a magazine journalist has been all but forgotten, it was an important part of her public activity while she was First Lady from 1933 to 1945. In contrast to ideas then current, Mrs. Roosevelt insisted on her right to earn money from her magazine work while in the White House. There is also evidence that her…

  1. The Press Conferences of Eleanor Roosevelt.

    ERIC Educational Resources Information Center

    Beasley, Maurine H.

    Newly discovered transcriptions of 87 of First Lady Eleanor Roosevelt's women-only press conferences held from 1933 to 1945 make possible an examination of the objectives, topics, and value of these conferences. By holding the conferences, Mrs. Roosevelt attributed to women an important function in the political communication process, and at the…

  2. UV - THEODORE ROOSEVELT NATIONAL PARK ND

    EPA Science Inventory

    Brewer 131 is located in Theodore Roosevelt NP (South Section), measuring ultraviolet solar radiation. Irradiance and column ozone are derived from this data. Ultraviolet solar radiation is measured with a Brewer Mark IV, single-monochrometer, spectrophotometer manufactured by SC...

  3. Einstein/Roosevelt Letters: A Unit.

    ERIC Educational Resources Information Center

    Bodle, Walter S.

    1985-01-01

    The letters in this unit of study intended for secondary students are facsimile reproductions of the correspondence between Albert Einstein and President Roosevelt on the possibility of constructing an atomic bomb. Classroom activities are also suggested. (RM)

  4. Eleanor Roosevelt Centennial 1884-1984. Eleanor Roosevelt Curriculum Kit, K-6.

    ERIC Educational Resources Information Center

    Morgan, Bette, Comp.

    This study unit is designed to assist elementary students in discovering Eleanor Roosevelt's contributions to U.S. history and to the world. The unit begins with a brief biography of Eleanor Roosevelt, followed by biography study questions. Learning activities are then suggested. Students are asked to make costumes and portray her at different…

  5. Lorena A. Hickok: Journalistic Influence on Eleanor Roosevelt.

    ERIC Educational Resources Information Center

    Beasley, Maurine

    1980-01-01

    Examines Lorena A. Hickok as a journalist and assesses her influence on Eleanor Roosevelt's relationships with the press, particularly women reporters, in the period immediately before and after Roosevelt's election as president in 1932. (Author/GT)

  6. Eleanor Roosevelt and the Wartime Campaign against Jim Crow.

    ERIC Educational Resources Information Center

    Black, Allida M.

    1996-01-01

    Describes Eleanor Roosevelt's efforts to correct institutional racism. Mrs. Roosevelt worked continually in support of civil rights for African Americans in employment, housing, and the armed services. Her efforts often were met with vehement and venomous opposition. (MJP)

  7. 82. ROOSEVELT POWER CANAL, SUGGESTED ARRANGEMENT FOR ELECTRICAL OPERATION OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    82. ROOSEVELT POWER CANAL, SUGGESTED ARRANGEMENT FOR ELECTRICAL OPERATION OF SLUICE GATES AND CANAL INTAKE GATES AT DIVERSION DAM Courtesy of Dept. of the Interior, Bureau of Reclamation, Salt River Project, Arizona - Roosevelt Power Canal & Diversion Dam, Parallels Salt River, Roosevelt, Gila County, AZ

  8. Roosevelt's First Inaugural: A Study of Technique.

    ERIC Educational Resources Information Center

    Ryan, Halford Ross

    1979-01-01

    Examines three rhetorical techniques that Franklin D. Roosevelt used in his "First Inaugural Address" to announce and implement his New Deal. The various speech drafts examined reveal that he purposefully used military metaphor, the scapegoat, and the carrot-and-stick approach to accomplish certain persuasive goals. (JMF)

  9. Eleanor Roosevelt: First Lady as Radio Pioneer.

    ERIC Educational Resources Information Center

    Beasley, Maurine H.; Belgrade, Paul

    Eleanor Roosevelt's commercial radio broadcasts during her White House years (1933-1945) were significant for three reasons. First, she was one of the few women who performed as a news commentator during this period. Her ability to pursue such a career owed much to her position as First Lady and represented the merging of the roles of celebrity…

  10. Roosevelt/UMass Staff Development Program.

    ERIC Educational Resources Information Center

    Byas, Ulysses

    The Roosevelt School District, with the lowest wealth per pupil of the 56 districts located in Nassau County, Long Island, New York, worked with the Urban Education Department of the University of Massachusetts' Division of Instructional Leadership to design and implement a degree-granting staff development program centered around identifying and…

  11. 36 CFR 7.54 - Theodore Roosevelt National Park.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 1 2012-07-01 2012-07-01 false Theodore Roosevelt National Park. 7.54 Section 7.54 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.54 Theodore Roosevelt National Park....

  12. 36 CFR 7.54 - Theodore Roosevelt National Park.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Theodore Roosevelt National Park. 7.54 Section 7.54 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.54 Theodore Roosevelt National Park....

  13. 36 CFR 7.54 - Theodore Roosevelt National Park.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Theodore Roosevelt National Park. 7.54 Section 7.54 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.54 Theodore Roosevelt National Park....

  14. 36 CFR 7.54 - Theodore Roosevelt National Park.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 1 2013-07-01 2013-07-01 false Theodore Roosevelt National Park. 7.54 Section 7.54 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.54 Theodore Roosevelt National Park....

  15. 36 CFR 7.54 - Theodore Roosevelt National Park.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 1 2014-07-01 2014-07-01 false Theodore Roosevelt National Park. 7.54 Section 7.54 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.54 Theodore Roosevelt National Park....

  16. Mrs. Roosevelt and Mrs. Bethune: Collaborators for Racial Justice.

    ERIC Educational Resources Information Center

    Bickerstaff, Joyce; Rich, Wilbur C.

    1984-01-01

    Eleanor Roosevelt broke the rules of race relations when she became friends with a leading Black woman, Mary McLeod Bethune, founder and president of Bethune-Cookman College. Without the mentorship of Mary Bethune, Mrs. Roosevelt may not have understood the southern mentality, White or Black. (RM)

  17. Lake

    ERIC Educational Resources Information Center

    Wien, Carol Anne

    2008-01-01

    The lake is blue black and deep. It is a glaciated finger lake, clawed out of rock when ice retracted across Nova Scotia in a northerly direction during the last ice age. The lake is narrow, a little over a mile long, and deep, 90 to 190 feet in places according to local lore, off the charts in others. The author loves to swim there, with a sense…

  18. 34. photographer unknown September 1937 ROOSEVELT ARRIVING FOR DEDICATION OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    34. photographer unknown September 1937 ROOSEVELT ARRIVING FOR DEDICATION OF BONNEVILLE DAM. - Bonneville Project, Columbia River, 1 mile Northeast of Exit 40, off Interstate 84, Bonneville, Multnomah County, OR

  19. Reagan as Roosevelt: The Elasticity of Pseudo-Populist Appeals.

    ERIC Educational Resources Information Center

    Woodward, Gary C.

    1983-01-01

    Shows that the presidencies of Franklin Roosevelt and Ronald Reagan have been rhetorical echoes of the original Populists. Demonstrates the durability and elasticity of a style born in nineteenth century grass roots political reform. (PD)

  20. Lake Roosevelt Fisheries Monitoring Program; 1993 Annual Report.

    SciTech Connect

    Underwood, Keith D.; Shields, John

    1996-06-01

    The first three years of this study were used to collect pre-hatchery baseline data on the fishery. The Spokane Tribal Hatchery began stocking kokanee and rainbow trout in 1991 and Sherman Creek Hatchery began stocking by 1992. The estimated number of kokanee (13,986) harvested in 1993 was similar to harvest numbers in the previous years, but the number of rainbow trout (403,277) and walleye (337,413) harvested doubled from estimates made in past years. The stocking of yearling kokanee began in1992, totaling approximately 140,000 yearlings. The yearlings were not expected to begin entering the creel until 1993 with the main harvest in 1994. As a result, it was too early to speculate on the effect of stocking yearlings instead of fry on the creel. The 1993 rainbow trout harvest escalated. The increased number of walleye harvested was believed to be from the increased angler pressure. Kokanee salmon and rainbow trout growth appeared to be similar to previous years. The growth of walleye was less than in year past, but the average size of walleye in the creel increased. The feeding habits of kokanee, rainbow trout and walleye in 1993 were similar to previous years.

  1. Theodore Roosevelt Inaugural Site: Birthplace of the Modern Presidency. Teaching with Historic Places.

    ERIC Educational Resources Information Center

    Brogan-Linnabery, Ann Marie

    In 1901, while vacationing in New York's Adirondack Mountains, Vice President Theodore Roosevelt received news that President McKinley had been shot and was not expected to live. By the time Roosevelt arrived at the home of his friend Ansley Wilcox in Buffalo (New York), the President was dead. Roosevelt was inaugurated in the library of his…

  2. Depicting Disability: The Franklin Delano Roosevelt Memorial in Washington, D.C.

    ERIC Educational Resources Information Center

    Stephenson, C. Todd

    1996-01-01

    Examines the controversy over the representation of President Roosevelt in the Franklin Delano Roosevelt Memorial in Washington, DC. The sculptures in the memorial do not show Roosevelt's cane, braces, or wheelchair. Disability advocates claim that this reinforces shameful stereotypes. Memorial supporters believe it should reflect the public…

  3. Establishing the Rhetorical Presidency through Presidential Rhetoric: Theodore Roosevelt and the Brownsville Raid

    ERIC Educational Resources Information Center

    Stuckey, Mary

    2006-01-01

    Theodore Roosevelt was an important figure in the development of the presidency as a primary and authoritative source for definitions of national identity. Through an analysis of three specific rhetorical moves Roosevelt made in arguments over the "proper" interpretation of the Brownsville Raid, this essay examines how Roosevelt both justified his…

  4. 77 FR 56808 - Arapaho and Roosevelt National Forests and Pawnee National Grassland; Larimer County, CO; Middle...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-14

    ...; ] DEPARTMENT OF AGRICULTURE Forest Service Arapaho and Roosevelt National Forests and Pawnee National Grassland... Roosevelt National Forests and Pawnee National Grassland is preparing an environmental impact statement to... Supervisor for the Arapaho and Roosevelt National Forests and Pawnee National Grassland. Nature of...

  5. Lake Pend Oreille Predation Research, Annual Report 2002-2003.

    SciTech Connect

    Bassista, Thomas

    2004-02-01

    During August 2002 we conducted a hydroacoustic survey to enumerate pelagic fish >406 mm in Lake Pend Oreille, Idaho. The purpose of this survey was to determine a collective lakewide biomass estimate of pelagic bull trout Salvelinus confluentus, rainbow trout Oncorhynchus mykiss, and lake trout S. namaycush and compare it to pelagic prey (kokanee salmon O. nerka) biomass. By developing hydroacoustic techniques to determine the pelagic predator to prey ratio, we can annually monitor their balance. Hydroacoustic surveys were also performed during December 2002 and February 2003 to investigate the effectiveness of autumn and winter surveys for pelagic predators. The inherent problem associated with hydroacoustic sampling is the inability to directly identify fish species. Therefore, we utilized sonic tracking techniques to describe rainbow trout and lake trout habitat use during our winter hydroacoustic survey to help identify fish targets from the hydroacoustic echograms. During August 2002 we estimated there were 39,044 pelagic fish >406 mm in Lake Pend Oreille (1.84 f/ha). Based on temperature and depth utilization, two distinct groups of pelagic fish >406 mm were located during August; one group was located between 10 and 35 m and the other between 40 and 70 m. The biomass for pelagic fish >406 mm during August 2002 was 73 t (metric ton). This would account for a ratio of 1 kg of pelagic predator for every 2.63 kg of kokanee prey, assuming all pelagic fish >406 mm are predators. During our late fall and winter hydroacoustic surveys, pelagic fish >406 mm were observed at lake depths between 20 and 90 m. During late fall and winter, we tracked three rainbow trout (168 habitat observations) and found that they mostly occupied pelagic areas and predominantly stayed within the top 10 m of the water column. During late fall (one lake trout) and winter (four lake trout), we found that lake trout (184 habitat observations) utilized benthic-nearshore areas 65% of the time

  6. Wolf Point Substation, Roosevelt County, Montana

    SciTech Connect

    Not Available

    1991-05-01

    The Western Area Power Administration (Western), an agency of the United States Department of Energy, is proposing to construct the 115-kV Wolf Point Substation near Wolf Point in Roosevelt County, Montana (Figure 1). As part of the construction project, Western's existing Wolf Point Substation would be taken out of service. The existing 115-kV Wolf Point Substation is located approximately 3 miles west of Wolf Point, Montana (Figure 2). The substation was constructed in 1949. The existing Wolf Point Substation serves as a Switching Station'' for the 115-kV transmission in the region. The need for substation improvements is based on operational and reliability issues. For this environmental assessment (EA), the environmental review of the proposed project took into account the removal of the old Wolf Point Substation, rerouting of the five Western lines and four lines from the Cooperatives and Montana-Dakota Utilities Company, and the new road into the proposed substation. Reference to the new proposed Wolf Point Substation in the EA includes these facilities as well as the old substation site. The environmental review looked at the impacts to all resource areas in the Wolf Point area. 7 refs., 6 figs.

  7. Presidential Science Advising from Roosevelt to Reagan

    NASA Astrophysics Data System (ADS)

    Herken, Gregg

    2004-05-01

    The relationship between American presidents and science has always been surprisingly idiosyncratic. Chief executives from Franklin Roosevelt to Ronald Reagan have adopted very different approaches to dealing with the scientific community. The early history of presidential science advising is the story of a few energetic individuals who sought to influence government policy when there was no established method for scientists to approach the White House. President Eisenhower created such a channel in 1957 with the President's Science Advisory Committee [PSAC]. Under Ike, advising the president became for the first time a systematic and formal enterprise for scientists. But the decades after Sputnik witnesses a steady waning of the importance of the president's scientists. This decline was accelerated by the Vietnam war and controversies over anti-ballistic missile defense and the supersonic transport, culminating in the abolition of PSAC by the Nixon administration in 1973. To some observers, science advising reached its nadir a decade later, with President Reagan's announcement of the Strategic Defense Initiative (SDI). The advent of "Star Wars" demonstrated the influence of a small, select group of politically-active scientists: a consultative process reminscient of the ad hoc situation pre-PSAC.

  8. The Misunderstood Asthma of Theodore Roosevelt.

    PubMed

    Camargo, Carlos A; Roosevelt, Tweed

    2015-01-01

    In this special article, we examine the asthma of President Theodore "TR" Roosevelt (1858-1919). Through a comprehensive review of thousands of source documents, and a modern understanding of asthma, we examine several misunderstandings, including the longstanding assertion that TR's illness was "psychosomatic." TR's respiratory problems began in early childhood, and the historical record provides strong evidence for poorly controlled, persistent asthma. Like many patients, his asthma entered a relatively quiescent stage during adolescence, coincident with initiation of a vigorous exercise program when TR was 12 years old. Nevertheless, TR continued to suffer serious asthma exacerbations, both in adolescence and adulthood. Although psychosocial issues affect most chronic diseases, there is little (if any) support for assertions that TR's asthma was psychosomatic. We believe that TR's childhood struggles with asthma, and the misconception that he vanquished his illness through exercise, were experiences that profoundly affected his worldview. TR is known for his appreciation of life's struggles and for a bedrock belief that people can create major change with sufficient motivation and hard work. In different ways, misunderstandings about asthma contributed to the early development of these personal characteristics. Together with later experiences, they contributed to a lifetime of action that changed modern history. PMID:26271837

  9. Carbon dynamics in eutrophic, temperate lakes

    SciTech Connect

    Riemann, B.; Sondergaard

    1986-01-01

    This book contains papers dealing with pools, pathways, fluxes and transformation of organic matter in the pelagic zone of eutrophic, temperate lakes. It is a direct result of the work of a research group during the period 1981-85, whose aim was to summarize current understanding and specify gas in pelagic carbon metabolism.

  10. The Multi-Missionary Eleanor Roosevelt of American Indian Literatures

    ERIC Educational Resources Information Center

    Roemer, Kenneth M.

    2005-01-01

    In this tribute to LaVonne Ruoff, the author describes Ruoff as the "Eleanor Roosevelt of Native American Literature," noting her enormous amount of committee and administrative work done to ensure that the infant American Indian studies discipline was saved and would thrive. In addition to Ruoff's own literary works in the field, she furthered…

  11. Eleanor Roosevelt and "My Day": The White House Years.

    ERIC Educational Resources Information Center

    Beasley, Maurine

    Beginning in 1936, First Lady Eleanor Roosevelt wrote an unprecedented newspaper column that provided readers with a detailed recital of her daily activities. Titled "My Day," the column gave behind-the-scenes glimpses of White House life and served as a platform from which the First Lady could state her personal views. The column was a mixture of…

  12. Eleanor Roosevelt Resigns from the DAR: A Study in Conscience.

    ERIC Educational Resources Information Center

    Freeman, Elsie T.; And Others

    1984-01-01

    Because the Daughters of the American Revolution's (DAR) Black exclusion rule prevented Black singer Marion Anderson from performing in the DAR auditorium in 1939, Eleanor Roosevelt resigned from the organization. Primary source materials regarding this incident and learning activities for secondary level students are presented. (RM)

  13. Dear Mrs. Roosevelt: Cries for Help from Depression Youth.

    ERIC Educational Resources Information Center

    Cohen, Robert

    1996-01-01

    Personalizes the devastating effect of the Great Depression on young people through excerpts of letters sent to Eleanor Roosevelt. Young people across the country responded to the First Lady's efforts on behalf of the poor and dispossessed. Discusses the many relief and work programs created by the New Deal. (MJP)

  14. The strokes that killed Churchill, Roosevelt, and Stalin.

    PubMed

    Ali, Rohaid; Connolly, Ian D; Li, Amy; Choudhri, Omar A; Pendharkar, Arjun V; Steinberg, Gary K

    2016-07-01

    From February 4 to 11, 1945, President Franklin D. Roosevelt of the United States, Soviet Union Premier Joseph Stalin, and British Prime Minister Winston Churchill met near Yalta in Crimea to discuss how post-World War II (WWII) Europe should be organized. Within 2 decades of this conference, all 3 men had died. President Roosevelt died 2 months after the Yalta Conference due to a hemorrhagic stroke. Premier Stalin died 8 years later, also due to a hemorrhagic stroke. Finally, Prime Minister Churchill died 20 years after the conference because of complications due to stroke. At the time of Yalta, these 3 men were the leaders of the most powerful countries in the world. The subsequent deterioration of their health and eventual death had varying degrees of historical significance. Churchill's illness forced him to resign as British prime minister, and the events that unfolded immediately after his resignation included Britain's mismanagement of the Egyptian Suez Crisis and also a period of mistrust with the United States. Furthermore, Roosevelt was still president and Stalin was still premier at their times of passing, so their deaths carried huge political ramifications not only for their respective countries but also for international relations. The early death of Roosevelt, in particular, may have exacerbated post-WWII miscommunication between America and the Soviet Union-miscommunication that may have helped precipitate the Cold War. PMID:27364260

  15. Analysis of summer phosphorus fluxes within the pelagic zone of Eau Galle Reservoir, Wisconsin

    USGS Publications Warehouse

    James, W.F.; Barko, J.W.

    1993-01-01

    Major phosphorus (P) fluxes to and from the pelagic zone (i.e., open water region including epilimnion, metalimnion, and hypolimnion) were estimated from data collected over a 6 year period during the summer in Eau Galle Reservoir, Wisconsin. P inputs to the pelagic zone included profundal sediments, the watershed, groundwater, and transport of P from the littoral zone. P outputs from the pelagic zone included discharge from the reservoir, deposition, and transport of P to the littoral zone. Nighttime convective circulation was assumed to be the dominant mechanism of P exchange between the littoral and pelagic zones. Littoral P inputs, often neglected from budgetary analyses, accounted for 15% of the total measured P input and 25% of the internal P input to the pelagic zone. External P inputs were greatest, accounting for 42% of the total measured P input to the pelagic zone. These results emphasize the need for control of various sources of P inputs in the development of lake and reservoir management strategies.

  16. Area development plan of the geothermal potential in planning region 8, Roosevelt - Custer area

    SciTech Connect

    Not Available

    1980-07-01

    Geothermal resource data, the Roosevelt-Custer Region development plan, and energy, economic, and institutional considerations are presented. Environmental considerations and water availability are discussed. (MHR)

  17. Carbon in weathered ordinary chondrites from Roosevelt County

    NASA Technical Reports Server (NTRS)

    Ash, R. D.; Pillinger, C. T.

    1993-01-01

    A suite of Roosevelt County ordinary chondrites of known terrestrial age have been analyzed for carbon content and isotopic composition. Initial results indicate that significant carbon contamination is evident only in samples with a terrestrial age greater than 40 ka. These samples are of weathering grade D and E and contain three times more carbon than the less weathered samples. The soil in which they were preserved has a carbon content of ca. 1.5 percent. Over 200 meteorites have been recovered from a series of soil depleted areas of New Mexico and West Texas. Most have been recovered from blowouts near Clovis in Roosevelt County (RC) on the high plains of New Mexico. The mineralogical and petrologic Al effects of weathering upon these samples have been studied previously and show that the degree of weathering is largely depend ant upon the terrestrial residence time. The study was undertaken to determine the effects of prolonged exposure to the soil and climate of Roosevelt County upon ordinary chondrites in the hope that this will enable a better understanding of the problems associated with the collection of meteoritic falls. A suite of ten grade 4 to 6 H, L, and LL ordinary chondrites were analyzed for carbon content and isotopic composition.

  18. First Lady of the World: Eleanor Roosevelt at Val-Kill. Teaching with Historic Places.

    ERIC Educational Resources Information Center

    Stoeberl, Todd

    This lesson traces the use of Eleanor Roosevelt's retreat, Val-Kill, a "shack" (actually a stone cottage) built in 1925 on the grounds of the Roosevelt family estate at Hyde Park (New York), and how it nurtured her spirit, personal style, and humanitarian efforts. The lesson explains that Eleanor and her women friends later expanded the retreat by…

  19. Springwood: Birthplace and Home to Franklin D. Roosevelt. Teaching with Historic Places.

    ERIC Educational Resources Information Center

    Scholl, Charlotte Ofca

    Springwood, the birthplace and home of Franklin Delano Roosevelt, is a large, rambling structure faced with stucco and fieldstone, situated in a landscaped clearing on a bluff overlooking the Hudson River. Roosevelt was born there to a family of wealth and position on January 30, 1882. It is the only site in the U.S. where a president was born,…

  20. Eleanor Roosevelt and the Declaration of Human Rights: A Simulation Activity.

    ERIC Educational Resources Information Center

    Gilbert, Sally; Shollenberger, Kathy

    2001-01-01

    Provides a brief background on Eleanor Roosevelt and the Declaration of Human Rights. Presents a lesson wherein students simulate the creation of the Declaration of Human Rights and consider the leadership skills of Eleanor Roosevelt. Explains that the activity requires three class periods and some student preparation before the lesson. (CMK)

  1. Bridge to the Future: Franklin Roosevelt's Speech at the Dedication of the Triborough Bridge

    ERIC Educational Resources Information Center

    Rosenbaum, David L.

    2009-01-01

    When President Franklin D. Roosevelt took office on March 4, 1933, 15 million Americans, or one quarter of the nation's workers, were jobless. Hope faded as despair spread. Three years later, on July 10, 1936, Roosevelt took a special overnight train from Washington, D.C., to New York City for the dedication of the Triborough Bridge. The next day,…

  2. Revisiting the death of Eleanor Roosevelt: was the diagnosis of tuberculosis missed?

    PubMed

    Lerner, B H

    2001-12-01

    Controversy has surrounded the death of Eleanor Roosevelt in 1962. There has been a persistent sense that doctors missed the diagnosis of miliary tuberculosis, thereby jeopardizing her life. This article, using Roosevelt's medical chart and other previously unreviewed documents, revisits her illness and death. What disease actually killed Eleanor Roosevelt? Did her physicians miss the diagnosis? These questions are of particular importance in light of the recent Institute of Medicine report estimating that almost 100,000 Americans die each year from medical mistakes. Why has the possibility of error clouded the care of Roosevelt for almost 40 years? What can Roosevelt's case reveal about ongoing efforts to reduce mistakes in clinical practice? PMID:11769765

  3. Lake whitefish and lake herring population structure and niche in ten south-central Ontario lakes

    USGS Publications Warehouse

    Carl, Leon M.; McGuiness, Fiona

    2006-01-01

    This study compares simple fish communities of ten oligotrophic lakes in south-central Ontario. Species densities and population size structure vary significantly among these lake communities depending on fish species present beyond the littoral zone. Lake whitefish are fewer and larger in the presence of lake herring than in their absence. Diet analysis indicates that lake whitefish shift from feeding on both plankton and benthic prey when lake herring are absent to a primarily benthic feeding niche in the presence of lake herring. When benthic round whitefish are present, lake whitefish size and density decline and they move lower in the lake compared to round whitefish. Burbot are also fewer and larger in lakes with lake herring than in lakes without herring. Burbot, in turn, appear to influence the population structure of benthic coregonine species. Lower densities of benthic lake whitefish and round whitefish are found in lakes containing large benthic burbot than in lakes with either small burbot or where burbot are absent. Predation on the pelagic larvae of burbot and lake whitefish by planktivorous lake herring alters the size and age structure of these populations. As life history theory predicts, those species with poor larval survival appear to adopt a bet-hedging life history strategy of long-lived individuals as a reproductive reserve.

  4. DEEPWATER AND NEARSHORE FOOD WEB CHARACTERIZATIONS IN LAKE SUPERIOR

    EPA Science Inventory

    Due to the difficulty associated with sampling deep aquatic systems, food web relationships among deepwater fauna are often poorly known. We are characterizing nearshore versus offshore habitats in the Great Lakes and investigating food web linkages among profundal, pelagic, and ...

  5. LAKE HERRING (COREGONUS ARTEDI) AND RAINBOW SMELT (OSMERUS MORDAX) DIETS IN LAKE SUPERIOR

    EPA Science Inventory

    This manuscript reports on the diets of lake herring and rainbow smelt, currently the two dominant forage fish species (fish that are food for game fishes) in western Lake Superior. Despite the pelagic nature of both these species, they have substantially different diets and henc...

  6. The Roosevelt years: crucial milieu for Carl Rogers' innovation.

    PubMed

    Barrett-Lennard, Godfrey T

    2012-02-01

    This study explores broad features of political culture and event of the 1930s and World War 2 years, viewed in relation to the emergence and rapid early growth of the new therapy of Carl Rogers. The paper traces Rogers' early professional life and examines distinctive emphases in sociopolitical thought and development during Franklin D. Roosevelt's leadership as President over the prolonged emergency of the Great Depression and the crisis of the War. The study includes a focus on the President's own outlook and style, pertinent New Deal innovations, and wartime needs. Twelve features of this larger context are discriminated as together having vital importance for the new therapy and its founder. The congruent courses of the macrocontext and of Rogers' innovation are followed to the ending of Roosevelt's life. Direct causation is not attributed, but the evidence adduced newly points to particular contours of a larger environment favorable for the expression of Rogers' values and rare ability. In sum, the author concludes that a synergy of highly conducive historical circumstance and individual exceptionality contributed to the philosophical underpinnings, attitudinal values and early momentum of Rogers' client-centered therapy. PMID:22530376

  7. Epiphyton as a Niche for Ammonia-Oxidizing Bacteria: Detailed Comparison with Benthic and Pelagic Compartments in Shallow Freshwater Lakes▿

    PubMed Central

    Coci, M.; Bodelier, P. L. E.; Laanbroek, H. J.

    2008-01-01

    Next to the benthic and pelagic compartments, the epiphyton of submerged macrophytes may offer an additional niche for ammonia-oxidizing bacteria in shallow freshwater lakes. In this study, we explored the potential activities and community compositions of ammonia-oxidizing bacteria of the epiphytic, benthic, and pelagic compartments of seven shallow freshwater lakes which differed in their trophic status, distribution of submerged macrophytes, and restoration history. PCR-denaturing gradient gel electrophoresis analyses demonstrated that the epiphytic compartment was inhabited by species belonging to cluster 3 of the Nitrosospira lineage and to the Nitrosomonas oligotropha lineage. Both the ammonia-oxidizing bacterial community compositions and the potential activities differed significantly between compartments. Interestingly, both the ammonia-oxidizing bacterial community composition and potential activity were influenced by the restoration status of the different lakes investigated. PMID:18263748

  8. 77 FR 73974 - Information Collection: Arapaho-Roosevelt National Forest Visitor Surveys for Recreation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-12

    ...In accordance with the Paperwork Reduction Act of 1995, the Forest Service is seeking comments from all interested individuals and organizations on the new information collection, Arapaho-Roosevelt National Forest Visitor Surveys for Transportation System Alternatives...

  9. Roosevelt Island - a good place for an ice core

    NASA Astrophysics Data System (ADS)

    Conway, H.; Bertler, N.; Dahl-Jensen, D.; Hindmarsh, R. C. A.; Pyne, A.; Brook, E.; Waddington, E.; Kipfstuhl, S.; Hawley, R.; Fitzpatrick, J.

    2012-04-01

    Roosevelt Island, a coastal ice dome in the eastern Ross Sea of West Antarctica, is ideally situated for investigating histories of climate and deglaciation of the region. With ice thickness H=745m, accumulation rate b=0.18m/yr, the characteristic timescale at the divide H/b is ~4kyr. Radar-detected layers (assumed to be isochrones) are arched upward beneath the divide; the pattern of the stack of bumps does not show evidence of divide migration. Matching the depth-profile of bump amplitudes using a 1-D transient ice-flow model indicates that the island has thinned about 300m since the onset of divide-type flow 3-4kyr BP (Conway et al., 1999). A coupled thermo-mechanical model yields similar results for the onset of divide flow and rate of thinning, and also shows that relatively high power rheology (n=4) is necessary to match the observed bump-amplitude distribution (Martin et al., 2006). A depth-age relationship is needed to infer histories of climate and ice dynamics farther back in time (Waddington et al., 2005; Price et al., 2007; Parrenin et al, 2007). RICE (Roosevelt Island Climate Evolution) Project is an international partnership between scientists from New Zealand, USA, Denmark, United Kingdom, Germany, Australia, Italy and China. A primary goal is to drill and date a core from Roosevelt Island. Drilling at the south summit is underway and will be completed during the 2012-13 austral summer. Initial calculations indicate the glacial transition is at about 80% depth; we expect to be able to infer histories of climate and ice dynamics over the past 40kyr. A depth-age relationship will be established from depth profiles of stable isotopes, chemistry, electrical conductivity and gas (methane) chronology. Physical properties (grain size and fabric, dust and volcanic layers) will also be measured. Borehole temperature profiles will be measured after drilling is complete. The spatial pattern of the modern thinning rate is being determined directly from repeat

  10. President Franklin D Roosevelt (1882-1945) and Doctor Frank Howard Lahey's (1880-1953) dilemma: The complexities of medical confidentiality with World Leaders.

    PubMed

    Steinberg, David

    2016-02-01

    In the months before the Presidential Election of November 1944, there were serious concerns about the health of President Franklin D Roosevelt. He had lost considerable weight and his once robust appearance had given way to a tired and haggard look. Despite these worrisome observations, Vice-Admiral Ross T McIntire, who served as Franklin Roosevelt's personal physician from 1933 until Roosevelt's death, lied when he proclaimed Roosevelt to be in 'excellent condition for a man of his age'. The truth about Roosevelt's health was further obscured when Roosevelt's medical records disappeared. PMID:24737195

  11. Patterns in benthic biodiversity link lake trophic status to structure and potential function of three large, deep lakes.

    PubMed

    Hayford, Barbara L; Caires, Andrea M; Chandra, Sudeep; Girdner, Scott F

    2015-01-01

    Relative to their scarcity, large, deep lakes support a large proportion of the world's freshwater species. This biodiversity is threatened by human development and is in need of conservation. Direct comparison of biodiversity is the basis of biological monitoring for conservation but is difficult to conduct between large, insular ecosystems. The objective of our study was to conduct such a comparison of benthic biodiversity between three of the world's largest lakes: Lake Tahoe, USA; Lake Hövsgöl, Mongolia; and Crater Lake, USA. We examined biodiversity of common benthic organism, the non-biting midges (Chironomidae) and determined lake trophic status using chironomid-based lake typology, tested whether community structure was similar between the three lakes despite geographic distance; and tested whether chironomid diversity would show significant variation within and between lakes. Typology analysis indicated that Lake Hövsgöl was ultra-oligotrophic, Crater Lake was oligotrophic, and Lake Tahoe was borderline oligotrophic/mesotrophic. These results were similar to traditional pelagic measures of lake trophic status for Lake Hövsgöl and Crater Lake but differed for Lake Tahoe, which has been designated as ultra-oligotrophic by traditional pelagic measures such as transparency found in the literature. Analysis of similarity showed that Lake Tahoe and Lake Hövsgöl chironomid communities were more similar to each other than either was to Crater Lake communities. Diversity varied between the three lakes and spatially within each lake. This research shows that chironomid communities from these large lakes were sensitive to trophic conditions. Chironomid communities were similar between the deep environments of Lake Hövsgöl and Lake Tahoe, indicating that chironomid communities from these lakes may be useful in comparing trophic state changes in large lakes. Spatial variation in Lake Tahoe's diversity is indicative of differential response of chironomid

  12. Computational visual ecology in the pelagic realm

    PubMed Central

    Nilsson, Dan-E.; Warrant, Eric; Johnsen, Sönke

    2014-01-01

    Visual performance and visual interactions in pelagic animals are notoriously hard to investigate because of our restricted access to the habitat. The pelagic visual world is also dramatically different from benthic or terrestrial habitats, and our intuition is less helpful in understanding vision in unfamiliar environments. Here, we develop a computational approach to investigate visual ecology in the pelagic realm. Using information on eye size, key retinal properties, optical properties of the water and radiance, we develop expressions for calculating the visual range for detection of important types of pelagic targets. We also briefly apply the computations to a number of central questions in pelagic visual ecology, such as the relationship between eye size and visual performance, the maximum depth at which daylight is useful for vision, visual range relations between prey and predators, counter-illumination and the importance of various aspects of retinal physiology. We also argue that our present addition to computational visual ecology can be developed further, and that a computational approach offers plenty of unused potential for investigations of visual ecology in both aquatic and terrestrial habitats. PMID:24395965

  13. Computational visual ecology in the pelagic realm.

    PubMed

    Nilsson, Dan-E; Warrant, Eric; Johnsen, Sönke

    2014-01-01

    Visual performance and visual interactions in pelagic animals are notoriously hard to investigate because of our restricted access to the habitat. The pelagic visual world is also dramatically different from benthic or terrestrial habitats, and our intuition is less helpful in understanding vision in unfamiliar environments. Here, we develop a computational approach to investigate visual ecology in the pelagic realm. Using information on eye size, key retinal properties, optical properties of the water and radiance, we develop expressions for calculating the visual range for detection of important types of pelagic targets. We also briefly apply the computations to a number of central questions in pelagic visual ecology, such as the relationship between eye size and visual performance, the maximum depth at which daylight is useful for vision, visual range relations between prey and predators, counter-illumination and the importance of various aspects of retinal physiology. We also argue that our present addition to computational visual ecology can be developed further, and that a computational approach offers plenty of unused potential for investigations of visual ecology in both aquatic and terrestrial habitats. PMID:24395965

  14. Magnetic properties of pelagic marine carbonates

    NASA Astrophysics Data System (ADS)

    Roberts, A. P.; Florindo, F.; Chang, L.; Jovane, L.; Heslop, D.; Larrasoaña, J.

    2013-05-01

    Pelagic carbonates are deposited far from the continents, usually at water depths of 3,000-6,000 m, at rates slower than 10 cm/kyr. Pelagic carbonates are globally important and have yielded many outstanding paleomagnetic records both from ocean drilling and analysis of outcrops from tectonically uplifted sedimentary sequences. Recent recognition of the widespread preservation of biogenic magnetite has fundamentally changed our understanding of the magnetic properties of pelagic carbonates. We review evidence concerning the range of magnetic minerals typically preserved in these sediments, the effects of magnetic mineral diagenesis on paleomagnetic and environmental magnetic records carried by pelagic carbonates and what they tell us about the environments concerned. Despite recent advances, much remains to be discovered. We are only at early stages of understanding how biogenic magnetite gives rise to paleomagnetic signals and whether it is responsible for a poorly understood biogeochemical remanent magnetization. Recently developed techniques hold much potential for testing how different species of magnetotactic bacteria, which produce different magnetite morphologies, respond to changing nutrient and oxygenation conditions and whether it will be possible to develop proxies for ancient nutrient conditions from well calibrated modern records of such processes. A tantalizing link between giant magnetofossils and Paleogene hyperthermal events needs to be tested and much more needs to be learned about the relationship between climate and the organisms that biomineralized these giant magnetite particles. Despite being studied for over 70 years, the magnetic properties of pelagic carbonates hold many secrets that await discovery.

  15. Myoglobin in pelagic small cetaceans.

    PubMed

    Dolar, M L; Suarez, P; Ponganis, P J; Kooyman, G L

    1999-02-01

    Although myoglobin (Mb) is considered to contribute significantly to the oxygen and diving capacity of marine mammals, few data are available for cetaceans. Cetacean by-catch in the tuna driftnet fisheries in the Sulu Sea, Philippines, afforded the opportunity to examine Mb content and distribution, and to determine muscle mass composition, in Fraser's (Lagenodelphis hosei) and spinner (Stenella longirostris) dolphins and a pygmy killer whale (Feresa attenuata). Age was estimated by body length determination. Stomach contents were analyzed for the presence or absence of milk and solid foods. It was hypothesized (a) that Mb concentration ([Mb]) would be higher in Fraser's and spinner dolphins than in other small cetaceans because of the known mesopelagic distribution of their prey, (b) that [Mb] would vary among different muscles according to function during diving, and (c) that [Mb] would increase with age during development. The results were as follows. (1) Myoglobin concentrations of the longissimus muscle in adult Fraser's (6.8-7.2 g 100 g-1 muscle) and spinner (5-6 g 100 g-1 muscle) dolphins and in an immature pygmy killer whale (5.7 g 100 g-1 muscle) were higher than those reported previously for small cetaceans. (2) [Mb] varied significantly among the different muscle types in adult dolphins but not in calves; in adults, swimming muscles had significantly higher [Mb] than did non-swimming muscles, contained 82-86 % of total Mb, and constituted 75-80 % of total muscle mass. (3) Myoglobin concentrations in Fraser's and spinner dolphins increased with size and age and were 3-4 times greater in adults than in calves. The high Mb concentrations measured in the primary locomotory muscles of these pelagic dolphins are consistent with the known mesopelagic foraging behaviour of Fraser's and spinner dolphins and suggest that the pygmy killer whale is also a deep-diving species. The high Mb concentrations in epaxial, hypaxial and abdominal muscle groups also support

  16. Magnetic properties of pelagic marine carbonates

    NASA Astrophysics Data System (ADS)

    Roberts, Andrew P.; Florindo, Fabio; Chang, Liao; Heslop, David; Jovane, Luigi; Larrasoaña, Juan C.

    2013-12-01

    Pelagic carbonates are deposited far from continents, usually at water depths of 3000-6000 m, at rates below 10 cm/kyr, and are a globally important sediment type. Recent advances, with recognition of widespread preservation of biogenic magnetite (the inorganic remains of magnetotactic bacteria), have fundamentally changed our understanding of the magnetic properties of pelagic carbonates. We review evidence for the magnetic minerals typically preserved in pelagic carbonates, the effects of magnetic mineral diagenesis on paleomagnetic and environmental magnetic records of pelagic carbonates, and what magnetic properties can tell us about the open-ocean environments in which pelagic carbonates are deposited. We also discuss briefly late diagenetic remagnetisations recorded by some carbonates. Despite recent advances in our knowledge of these phenomena, much remains undiscovered. We are only at early stages of understanding how biogenic magnetite gives rise to paleomagnetic signals in sediments and whether it carries a poorly understood biogeochemical remanent magnetisation. Recently developed techniques have potential for testing how different magnetotactic bacterial species, which produce different magnetite morphologies, respond to changing nutrient and oxygenation conditions. Future work needs to test whether it is possible to develop proxies for ancient nutrient conditions from well-calibrated modern magnetotactic bacterial occurrences. A tantalizing link between giant magnetofossils and Paleogene hyperthermal events needs to be tested; much remains to be learned about the relationship between climate and the organisms that biomineralised these large and novel magnetite morphologies. Rather than being a well-worn subject that has been studied for over 60 years, the magnetic properties of pelagic carbonates hold many secrets that await discovery.

  17. Upwellings in Lake Baikal

    NASA Astrophysics Data System (ADS)

    Shimaraev, M. N.; Troitskaya, E. S.; Blinov, V. V.; Ivanov, V. G.; Gnatovskii, R. Yu.

    2012-02-01

    Based on shipboard and satellite observations, the characteristics of upwelling in Lake Baikal in the period of direct temperature stratification have been determined for the first time. Coastal upwellings appear annually under the effect of run-down and alongshore winds and are traced along the coast to a distance of up to 60-100 km and up to 250 km in North Baikal. Analogous to the way it occurs in seas, water rises from the depths of 100-200 m (350 m as a maximum) at the velocity of 0.1 × 10-2-6.5 × 10-2 cm/s. Divergence in the field of intràbasin cyclonic macrovortices produces upwelling in the Baikal pelagic zone and downwelling in the vicinity of shores; this lasts from 7 to 88 days and covers the depth interval of 80-300 m in August and up to 400-800 m in early-mid November. The area of upwellings occupies up to 20-60% of the separate basins of the lake. Vertical circulation of water in the field of pelagic upwellings leads to intensification of coastal currents and to formation of the thermobar with a heat inert zone in the central part of the lake in November, and this thermobar is not observed in other lakes, at that.

  18. Depth gradients in food-web processes linking habitats in large lakes: Lake Superior as an exemplar ecosystem

    USGS Publications Warehouse

    Sierszen, Michael E.; Hrabik, Thomas R.; Stockwell, Jason D.; Cotter, Anne M; Hoffman, Joel C.; Yule, Daniel L.

    2014-01-01

    Support of whole-lake food webs through trophic linkages among pelagic, profundal and littoral habitats appears to be integral to the functioning of large lakes. These linkages can be disrupted though ecosystem disturbance such as eutrophication or the effects of invasive species and should be considered in native species restoration efforts.

  19. Lake-floor sediment texture and composition of a hydrothermally-active, volcanic lake, Lake Rotomahana

    NASA Astrophysics Data System (ADS)

    Pittari, A.; Muir, S. L.; Hendy, C. H.

    2016-03-01

    Young volcanic lakes undergo a transition from rapid, post-eruptive accumulation of volcaniclastic sediment to slower pelagic settling under stable lake conditions, and may also be influenced by sublacustrine hydrothermal systems. Lake Rotomahana is a young (129 year-old), hydrothermally-active, volcanic lake formed after the 1886 Tarawera eruption, and provides a unique insight into the early evolution of volcanic lake systems. Lake-bottom sediment cores, 20-46 cm in length, were taken along a transect across the lake and characterised with respect to stratigraphy, facies characteristics (i.e., grain size, componentry) and pore water silica concentrations. The sediments generally comprise two widespread facies: (i) a lower facies of light grey to grey, very fine lacustrine silt derived from the unconsolidated pyroclastic deposits that mantled the catchment area immediately after the eruption, which were rapidly reworked and redeposited into the lake basin; and (ii) an upper facies of dark, fine-sandy diatomaceous silt, that settled from the pelagic zone of the physically stable lake. Adjacent to sublacustrine hydrothermal vents, the upper dark facies is absent, and the upper part of the light grey to grey silt is replaced by a third localised facies comprised of hydrothermally altered pale yellow to yellowish brown, laminated silt with surface iron-rich encrustations. Microspheres, which are thought to be composed of amorphous silica, although some may be halloysite, have precipitated from pore water onto sediment grains, and are associated with a decrease in pore water silicon concentration. Lake Rotomahana is an example of a recently-stabilised volcanic lake, with respect to sedimentation, that shows signs of early sediment silicification in the presence of hydrothermal activity.

  20. Vegetation changes associated with a population irruption by Roosevelt elk

    USGS Publications Warehouse

    Starns, H D; Weckerly, Floyd W.; Ricca, Mark; Duarte, Adam

    2015-01-01

    Interactions between large herbivores and their food supply are central to the study of population dynamics. We assessed temporal and spatial patterns in meadow plant biomass over a 23-year period for meadow complexes that were spatially linked to three distinct populations of Roosevelt elk (Cervus elaphus roosevelti) in northwestern California. Our objectives were to determine whether the plant community exhibited a tolerant or resistant response when elk population growth became irruptive. Plant biomass for the three meadow complexes inhabited by the elk populations was measured using Normalized Difference Vegetation Index (NDVI), which was derived from Landsat 5 Thematic Mapper imagery. Elk populations exhibited different patterns of growth through the time series, whereby one population underwent a complete four-stage irruptive growth pattern while the other two did not. Temporal changes in NDVI for the meadow complex used by the irruptive population suggested a decline in forage biomass during the end of the dry season and a temporal decline in spatial variation of NDVI at the peak of plant biomass in May. Conversely, no such patterns were detected in the meadow complexes inhabited by the nonirruptive populations. Our findings suggest that the meadow complex used by the irruptive elk population may have undergone changes in plant community composition favoring plants that were resistant to elk grazing.

  1. Vegetation changes associated with a population irruption by Roosevelt elk.

    PubMed

    Starns, Heath D; Weckerly, Floyd W; Ricca, Mark A; Duarte, Adam

    2015-01-01

    Interactions between large herbivores and their food supply are central to the study of population dynamics. We assessed temporal and spatial patterns in meadow plant biomass over a 23-year period for meadow complexes that were spatially linked to three distinct populations of Roosevelt elk (Cervus elaphus roosevelti) in northwestern California. Our objectives were to determine whether the plant community exhibited a tolerant or resistant response when elk population growth became irruptive. Plant biomass for the three meadow complexes inhabited by the elk populations was measured using Normalized Difference Vegetation Index (NDVI), which was derived from Landsat 5 Thematic Mapper imagery. Elk populations exhibited different patterns of growth through the time series, whereby one population underwent a complete four-stage irruptive growth pattern while the other two did not. Temporal changes in NDVI for the meadow complex used by the irruptive population suggested a decline in forage biomass during the end of the dry season and a temporal decline in spatial variation of NDVI at the peak of plant biomass in May. Conversely, no such patterns were detected in the meadow complexes inhabited by the nonirruptive populations. Our findings suggest that the meadow complex used by the irruptive elk population may have undergone changes in plant community composition favoring plants that were resistant to elk grazing. PMID:25628868

  2. Vegetation changes associated with a population irruption by Roosevelt elk

    PubMed Central

    Starns, Heath D; Weckerly, Floyd W; Ricca, Mark A; Duarte, Adam

    2015-01-01

    Interactions between large herbivores and their food supply are central to the study of population dynamics. We assessed temporal and spatial patterns in meadow plant biomass over a 23-year period for meadow complexes that were spatially linked to three distinct populations of Roosevelt elk (Cervus elaphus roosevelti) in northwestern California. Our objectives were to determine whether the plant community exhibited a tolerant or resistant response when elk population growth became irruptive. Plant biomass for the three meadow complexes inhabited by the elk populations was measured using Normalized Difference Vegetation Index (NDVI), which was derived from Landsat 5 Thematic Mapper imagery. Elk populations exhibited different patterns of growth through the time series, whereby one population underwent a complete four-stage irruptive growth pattern while the other two did not. Temporal changes in NDVI for the meadow complex used by the irruptive population suggested a decline in forage biomass during the end of the dry season and a temporal decline in spatial variation of NDVI at the peak of plant biomass in May. Conversely, no such patterns were detected in the meadow complexes inhabited by the nonirruptive populations. Our findings suggest that the meadow complex used by the irruptive elk population may have undergone changes in plant community composition favoring plants that were resistant to elk grazing. PMID:25628868

  3. Magnetotelluric models of the Roosevelt Hot Springs thermal area, Utah

    SciTech Connect

    Wannamaker, P.E.; Ward, S.H.; Hohmann, G.W.; Sill, W.R.

    1980-09-01

    The Roosevelt Hot Springs (RHS) thermal area, which includes a hotwater-dominated fracture zone prospect, near the eastern margin of the Basin-Range tectonic province, conceivably possesses a whole family of resistivity structures that includes the following: deep hot brine reservoirs, deep-seated partially molten heat sources in the crust or upper mantle that drive the convective system, near-surface hydrothermal alteration zones, wet sedimentary fill in valleys, and a regional, apparently one-dimensional resistivity profile of the crust and upper mantle. This complex resistivity makeup, particular to RHS but probably similar to that at other geothermal areas in the Great Basin, must be treated as being fully three-dimensional (3-D). In an attempt to understand these structures, broadband (10/sup -3/ to 10/sup -2/ Hz) tensor magnetotelluric (MT) data were obtained including apparent resistivities (rho/sub a/), impedance phases (phi) and vertical magnetic field transfer functions for 93 sites in the vicinity of this resource area.

  4. Seasonal habitat selection by lake trout (Salvelinus namaycush) in a small Canadian shield lake: Constraints imposed by winter conditions

    USGS Publications Warehouse

    Blanchfield, P.J.; Tate, L.S.; Plumb, J.M.; Acolas, M.-L.; Beaty, K.G.

    2009-01-01

    The need for cold, well-oxygenated waters significantly reduces the habitat available for lake trout (Salvelinus namaycush) during stratification of small temperate lakes. We examined the spatial and pelagic distribution of lake trout over two consecutive summers and winters and tested whether winter increased habitat availability and access to littoral regions in a boreal shield lake in which pelagic prey fish are absent. In winter, lake trout had a narrowly defined pelagic distribution that was skewed to the upper 3 m of the water column and spatially situated in the central region of the lake. Individual core areas of use (50% Kernel utilization distributions) in winter were much reduced (75%) and spatially non-overlapping compared to summer areas, but activity levels were similar between seasons. Winter habitat selection is in contrast to observations from the stratified season, when lake trout were consistently located in much deeper waters (>6 m) and widely distributed throughout the lake. Winter distribution of lake trout appeared to be strongly influenced by ambient light levels; snow depth and day length accounted for up to 69% of the variation in daily median fish depth. More restricted habitat use during winter than summer was in contrast to our original prediction and illustrates that a different suite of factors influence lake trout distribution between these seasons. ?? Springer Science+Business Media B.V. 2009.

  5. Evaluating analytical approaches for estimating pelagic fish biomass using simulated fish communities

    USGS Publications Warehouse

    Yule, Daniel L.; Adams, Jean V.; Warner, David M.; Hrabik, Thomas R.; Kocovsky, Patrick M.; Weidel, Brian C.; Rudstam, Lars G.; Sullivan, Patrick J.

    2013-01-01

    Pelagic fish assessments often combine large amounts of acoustic-based fish density data and limited midwater trawl information to estimate species-specific biomass density. We compared the accuracy of five apportionment methods for estimating pelagic fish biomass density using simulated communities with known fish numbers that mimic Lakes Superior, Michigan, and Ontario, representing a range of fish community complexities. Across all apportionment methods, the error in the estimated biomass generally declined with increasing effort, but methods that accounted for community composition changes with water column depth performed best. Correlations between trawl catch and the true species composition were highest when more fish were caught, highlighting the benefits of targeted trawling in locations of high fish density. Pelagic fish surveys should incorporate geographic and water column depth stratification in the survey design, use apportionment methods that account for species-specific depth differences, target midwater trawling effort in areas of high fish density, and include at least 15 midwater trawls. With relatively basic biological information, simulations of fish communities and sampling programs can optimize effort allocation and reduce error in biomass estimates.

  6. Lake size and fish diversity determine resource use and trophic position of a top predator in high-latitude lakes

    PubMed Central

    Eloranta, Antti P; Kahilainen, Kimmo K; Amundsen, Per-Arne; Knudsen, Rune; Harrod, Chris; Jones, Roger I

    2015-01-01

    Prey preference of top predators and energy flow across habitat boundaries are of fundamental importance for structure and function of aquatic and terrestrial ecosystems, as they may have strong effects on production, species diversity, and food-web stability. In lakes, littoral and pelagic food-web compartments are typically coupled and controlled by generalist fish top predators. However, the extent and determinants of such coupling remains a topical area of ecological research and is largely unknown in oligotrophic high-latitude lakes. We analyzed food-web structure and resource use by a generalist top predator, the Arctic charr Salvelinus alpinus (L.), in 17 oligotrophic subarctic lakes covering a marked gradient in size (0.5–1084 km2) and fish species richness (2–13 species). We expected top predators to shift from littoral to pelagic energy sources with increasing lake size, as the availability of pelagic prey resources and the competition for littoral prey are both likely to be higher in large lakes with multispecies fish communities. We also expected top predators to occupy a higher trophic position in lakes with greater fish species richness due to potential substitution of intermediate consumers (prey fish) and increased piscivory by top predators. Based on stable carbon and nitrogen isotope analyses, the mean reliance of Arctic charr on littoral energy sources showed a significant negative relationship with lake surface area, whereas the mean trophic position of Arctic charr, reflecting the lake food-chain length, increased with fish species richness. These results were supported by stomach contents data demonstrating a shift of Arctic charr from an invertebrate-dominated diet to piscivory on pelagic fish. Our study highlights that, because they determine the main energy source (littoral vs. pelagic) and the trophic position of generalist top predators, ecosystem size and fish diversity are particularly important factors influencing function and

  7. Lake size and fish diversity determine resource use and trophic position of a top predator in high-latitude lakes.

    PubMed

    Eloranta, Antti P; Kahilainen, Kimmo K; Amundsen, Per-Arne; Knudsen, Rune; Harrod, Chris; Jones, Roger I

    2015-04-01

    Prey preference of top predators and energy flow across habitat boundaries are of fundamental importance for structure and function of aquatic and terrestrial ecosystems, as they may have strong effects on production, species diversity, and food-web stability. In lakes, littoral and pelagic food-web compartments are typically coupled and controlled by generalist fish top predators. However, the extent and determinants of such coupling remains a topical area of ecological research and is largely unknown in oligotrophic high-latitude lakes. We analyzed food-web structure and resource use by a generalist top predator, the Arctic charr Salvelinus alpinus (L.), in 17 oligotrophic subarctic lakes covering a marked gradient in size (0.5-1084 km(2)) and fish species richness (2-13 species). We expected top predators to shift from littoral to pelagic energy sources with increasing lake size, as the availability of pelagic prey resources and the competition for littoral prey are both likely to be higher in large lakes with multispecies fish communities. We also expected top predators to occupy a higher trophic position in lakes with greater fish species richness due to potential substitution of intermediate consumers (prey fish) and increased piscivory by top predators. Based on stable carbon and nitrogen isotope analyses, the mean reliance of Arctic charr on littoral energy sources showed a significant negative relationship with lake surface area, whereas the mean trophic position of Arctic charr, reflecting the lake food-chain length, increased with fish species richness. These results were supported by stomach contents data demonstrating a shift of Arctic charr from an invertebrate-dominated diet to piscivory on pelagic fish. Our study highlights that, because they determine the main energy source (littoral vs. pelagic) and the trophic position of generalist top predators, ecosystem size and fish diversity are particularly important factors influencing function and

  8. CONCORDANCE OF TAXONOMIC COMPOSITION PATTERNS ACROSS MULTIPLE LAKE ASSEMBLAGES: EFFECTS OF SCALE, BODY SIZE, AND LAND USE

    EPA Science Inventory

    We assessed environmental gradients and the extent to which they induced concordant patterns of taxonomic composition among benthic macroinvertebrate, riparian bird, sedimentary diatom, fish, and pelagic zooplankton assemblages in 186 northeastern U.S.A. lakes. Human population ...

  9. "Maybe You Could Help?" Letters to Eleanor Roosevelt, 1934-1942

    ERIC Educational Resources Information Center

    Royal, Mary Mason

    2005-01-01

    Eleanor Roosevelt could be called a Superstar First Lady. In the era when women's suffrage was first being exercised, she was "pushing the envelope" of what the President's wife, and women in general, might be expected to do in civic life. She wrote syndicated columns for magazines and newspapers, the most famous of which was entitled "My Day," a…

  10. Roosevelt's World War II Army of Community Service Workers. Children and Their Teachers.

    ERIC Educational Resources Information Center

    Field, Sherry L.

    1996-01-01

    Profiles the extraordinary World War II public support efforts conducted by school children and teachers across the United States. Encouraged by the Roosevelt administration, teachers and pupils mobilized support for war bond sales and salvage collection drives. Many children raised "Victory Gardens" producing food to help the war effort. (MJP)

  11. 77 FR 49021 - Minor Boundary Revision at Theodore Roosevelt Inaugural National Historic Site

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-15

    ... National Park Service Minor Boundary Revision at Theodore Roosevelt Inaugural National Historic Site AGENCY... Historic Site is modified to include Tract 01-102 containing 0.15 of an acre. The tract is located in Erie... Historic Site. The boundary revision is depicted on Map No. 442/107,298 dated October 13, 2011. The map...

  12. TISSUE ASSAYS AND POPULATION CHARACTERISTICS OF ROOSEVELT HOT SPRINGS' ANIMALS (1977-1978)

    EPA Science Inventory

    Geothermal energy exploration is being conducted at several locations in the United States including a site at Roosevelt Hot Springs in southwest Utah. To assess any possible impact and to help design a monitoring strategy for geothermal development, element concentrations in ani...

  13. 78 FR 70414 - Pricing for the 2013 Coin and Chronicles Set-Theodore Roosevelt

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-25

    ... United States Mint Pricing for the 2013 Coin and Chronicles Set--Theodore Roosevelt AGENCY: United States Mint, Department of the Treasury. ACTION: Notice. SUMMARY: The United States Mint is announcing a price...: Marc Landry, Acting Associate Director for Sales and Marketing; United States Mint; 801 9th Street...

  14. 77 FR 39987 - Arapaho and Roosevelt National Forests and Pawnee National Grassland; Boulder and Gilpin County...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-06

    ... Forest Service Arapaho and Roosevelt National Forests and Pawnee National Grassland; Boulder and Gilpin... and Pawnee National Grassland is preparing an Environmental Impact Statement (EIS) to consider and... Pawnee National Grassland, located at 2140 Yarmouth Avenue, Boulder, CO 80301; and one on July 19,...

  15. 78 FR 45953 - Theodore Roosevelt National Wildlife Refuge, Sharkey County, MS; and Holt Collier National...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-30

    ... Fish and Wildlife Service Theodore Roosevelt National Wildlife Refuge, Sharkey County, MS; and Holt Collier National Wildlife Refuge in Washington County, MS AGENCY: Fish and Wildlife Service, Interior..., Refuge Manager, Yazoo National Wildlife Refuge, 595 Yazoo Refuge Road, Hollandale, MS 38748. FOR...

  16. GEOTHERMAL ENVIRONMENTAL ASSESSMENT BASELINE STUDY: VEGETATION AND SOILS OF THE ROOSEVELT HOT SPRINGS GEOTHERMAL RESOURCE AREA

    EPA Science Inventory

    Identification and elemental concentrations of indigenous soil and plant systems found on the Roosevelt Hot Spring KGRA are described. Twenty-three different soils and five separate plant communities are geographically mapped and identified. One hundred forty-seven plant species ...

  17. 77 FR 2975 - Roosevelt Water Conservation District; Notice of Termination of Exemption by Implied Surrender...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-20

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Roosevelt Water Conservation District; Notice of Termination of Exemption by Implied Surrender and Soliciting Comments, Protests, and Motions To Intervene Take notice that the following hydroelectric proceeding has...

  18. 75 FR 44977 - General Management Plan/Abbreviated Final Environmental Impact Statement, Roosevelt-Vanderbilt...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-30

    ... availability of the Abbreviated Final Environmental Impact Statement for the General Management Plan (GMP/EIS) for Roosevelt-Vanderbilt National Historic Sites, Hyde Park, New York. The Abbreviated Final GMP/EIS includes an analysis of agency and public comments received on the Draft GMP/EIS with NPS responses,...

  19. Measurement of Lake Roosevelt Biota in Relation to Reservoir Operations : Appendices 1992.

    SciTech Connect

    Griffith, Janelle R.; McDowell, Amy C.

    1996-01-01

    These appendices include: A RESERVOIR ELEVATION AND WATER RETENTION TIME: Daily reservoir levels and water retention time in 1992, Elevation vs area, Elevation vs gross storage; B ZOOPLANKTON: Zooplankton density, Zooplanktion biomass; C BENTHIC MACROINVERTEBRATE DATA: Benthic sampling record, Benthic sampling depths, Benthic orders identified, Mean weight values obtained for benthics, D WATER COLUMN PROFILE: Monthly water profiles.

  20. Title: Biogenic Magnetite Prevails in Oxic Pelagic Red Clay Core in the South Pacific Gyre

    NASA Astrophysics Data System (ADS)

    Shimono, T.; Yamazaki, T.

    2012-12-01

    Magnetotactic bacteria have been observed in wide variety of environments, including soils, freshwater lakes, and marine sediments, since Blakemore (1975) first described in 1975. Magnetotactic bacteria, which most commonly live within the oxic-anoxic transition zone (OATZ) of aquatic environments, produce intracellular crystals of magnetic minerals, specifically magnetite or greigite. It is considered that the magnetite/greigite crystals facilitate the bacteria's search for optimal conditions within the sharp chemical gradients of the OATZ. Petermann and Bleil (1993) reported living magnetotactic bacteria in pelagic and hemipelagic sediments near OATZ in the eastern South Atlantic at water depths to about 3,000 m, but they couldn't find actively swimming magnetotactic bacteria in sediments of deeper water depths. The South Pacific Gyre (SPG) is far from continents and the lowest productivity region on Earth. IODP site U1365 (water depth ~5,700 m) cored pelagic red clay of 75.5 m thick above ~100 Ma basement (except for the chart layer from ~42 to 63.5 m) in the western edge of the SPG. The core mainly consists of iron rich clay. The color is dark reddish and/or dark brown throughout the core. We conducted a paleomagnetic and environmental rock magnetic study of the pelagic clay core. The magnetostratigraphy revealed the top 5 m sediments cover the last 5 My, and sedimentation rate decreases downward from 1.7 to 0.6 m/m.y. Geochemical measurements of pore water indicate that dissolved oxygen was present throughout the core (>50 μM). Thus oxygen penetrates through the entire sediment column to the sediment/basalt interface, and there is no OATZ. Magnetic mineral assemblage of this core is dominated by biogenic magnetite despite no OATZ. First-order reversal curve (FORC) diagrams of all specimens have a narrow central ridge along the Hc axis with very small vertical spread. This indicates very weak magnetostatic interaction (Roberts et al., 2000), and is the

  1. Viral and grazer regulation of prokaryotic growth efficiency in temperate freshwater pelagic environments.

    PubMed

    Pradeep Ram, A S; Colombet, Jonathan; Perriere, Fanny; Thouvenot, Antoine; Sime-Ngando, Telesphore

    2015-02-01

    In aquatic systems, limited data exists on the impact of mortality forces such as viral lysis and flagellate grazing when seeking to explain factors regulating prokaryotic metabolism. We explored the relative influence of top-down factors (viral lysis and heterotrophic nanoflagellate grazing) on prokaryotic mortality and their subsequent impact on their community metabolism in the euphotic zone of 21 temperate freshwater lakes located in the French Massif Central. Prokaryotic growth efficiency (PGE, index of prokaryotic community metabolism) determined from prokaryotic production and respiration measurements varied from 5 to 74% across the lakes. Viral and potential grazer-induced mortality of prokaryotes had contrasting impact on PGE. Potential flagellate grazing was found to enhance PGE whereas viral lysis had antagonistic impacts on PGE. The average PGE value in the grazing and viral lysis dominated lake water samples was 35.4% (±15.2%) and 17.2% (±8.1%), respectively. Selective viral lysis or flagellate grazing on prokaryotes together with the nature of contrasted substrates released through mortality processes can perhaps explain for the observed variation and differences in PGE among the studied lakes. The influences of such specific top-down processes on PGE can have strong implications on the carbon and nutrient fluxes in freshwater pelagic environments. PMID:25764557

  2. Aggregation of organic matter by pelagic tunicates

    SciTech Connect

    Pomeroy, L.R.; Deibel, D.

    1980-07-01

    Three genera of pelagic tunicates were fed concentrates of natural seston and an axenic diatom culture. Fresh and up to 4-day-old feces resemble flocculent organic aggregates containing populations of microorganisms, as described from highly productive parts of the ocean, and older feces resemble the nearly sterile flocculent aggregates which are ubiquitous in surface waters. Fresh feces consist of partially digested phytoplankton and other inclusions in an amorphous gelatinous matrix. After 18 to 36 h, a population of large bacteria develops in the matrix and in some of the remains of phytoplankton contained in the feces. From 48 to 96 h, protozoan populations arise which consume the bacteria and sometimes the remains of the phytoplankton in the feces. Thereafter only a sparse population of microorganisms remains, and the particles begin to fragment. Water samples taken in or below dense populations of salps and doliolids contained greater numbers of flocculent aggregates than did samples from adjacent stations.

  3. Roosting Ecology and the Evolution of Pelage Markings in Bats

    PubMed Central

    Santana, Sharlene E.; Dial, Thomas O.; Eiting, Thomas P.; Alfaro, Michael E.

    2011-01-01

    Multiple lineages of bats have evolved striking facial and body pelage makings, including spots, stripes and countershading. Although researchers have hypothesized that these markings mainly evolved for crypsis, this idea has never been tested in a quantitative and comparative context. We present the first comparative study integrating data on roosting ecology (roost type and colony size) and pelage coloration patterns across bats, and explore the hypothesis that the evolution of bat pelage markings is associated with roosting ecologies that benefit from crypsis. We find that lineages that roost in the vegetation have evolved pelage markings, especially stripes and neck collars, which may function in crypsis through disruptive coloration and a type of countershading that might be unique to bats. We also demonstrate that lineages that live in larger colonies and are larger in size tend not to have pelage markings, possibly because of reduced predation pressures due to the predator dilution effect and a lower number of potential predators. Although social functions for pelage color patterns are also possible, our work provides strong support for the idea that roosting ecology has driven the evolution of pelage markings in bats. PMID:21991371

  4. Patterns in Benthic Biodiversity Link Lake Trophic Status to Structure and Potential Function of Three Large, Deep Lakes

    PubMed Central

    Hayford, Barbara L.; Caires, Andrea M.; Chandra, Sudeep; Girdner, Scott F.

    2015-01-01

    Relative to their scarcity, large, deep lakes support a large proportion of the world’s freshwater species. This biodiversity is threatened by human development and is in need of conservation. Direct comparison of biodiversity is the basis of biological monitoring for conservation but is difficult to conduct between large, insular ecosystems. The objective of our study was to conduct such a comparison of benthic biodiversity between three of the world’s largest lakes: Lake Tahoe, USA; Lake Hövsgöl, Mongolia; and Crater Lake, USA. We examined biodiversity of common benthic organism, the non-biting midges (Chironomidae) and determined lake trophic status using chironomid-based lake typology, tested whether community structure was similar between the three lakes despite geographic distance; and tested whether chironomid diversity would show significant variation within and between lakes. Typology analysis indicated that Lake Hövsgöl was ultra-oligotrophic, Crater Lake was oligotrophic, and Lake Tahoe was borderline oligotrophic/mesotrophic. These results were similar to traditional pelagic measures of lake trophic status for Lake Hövsgöl and Crater Lake but differed for Lake Tahoe, which has been designated as ultra-oligotrophic by traditional pelagic measures such as transparency found in the literature. Analysis of similarity showed that Lake Tahoe and Lake Hövsgöl chironomid communities were more similar to each other than either was to Crater Lake communities. Diversity varied between the three lakes and spatially within each lake. This research shows that chironomid communities from these large lakes were sensitive to trophic conditions. Chironomid communities were similar between the deep environments of Lake Hövsgöl and Lake Tahoe, indicating that chironomid communities from these lakes may be useful in comparing trophic state changes in large lakes. Spatial variation in Lake Tahoe’s diversity is indicative of differential response of chironomid

  5. Seismic baseline and induction studies: Roosevelt Hot Springs, Utah and Raft River, Idaho

    SciTech Connect

    Zandt, G.; McPherson, L.; Schaff, S.; Olsen, S.

    1982-05-01

    Local seismic networks were established at the Roosevelt Hot Springs geothermal area, utah and at Raft River geothermal area, Idaho to monitor the background seismicity prior to initiation of geothermal power production. The Raft River study area is currently seismically quiet down to the level of approximately magnitude one. The Roosevelt Hot Springs area has low-level seismic activity for M/sub L/ greater than about two; however, microearthquake (M/sub L/ less than or equal to 2) swarms appear to be relatively common. One swarm occurred adjacent to the Roosevelt geothermal area during the summer of 1981. From June 27 to August 28, 1044 microearthquakes (M/sub L/ less than or equal to 1.5) were recorded from which 686 earthquakes were located and analysed. The main cluster of microearthquakes was located about 2 km east of the production field at a depth of about 5 km. A few small events were located in the production field at shallow depths (< 2 km). Three of the four largest earthquakes in the swarm (M/sub L/ 1.5-2.0) were located 4 to 5 km further east along a n-NW trend beneath the flank of the adjacent Mineral Mountains. Focal mechanism solutions indicate primarily normal faulting due to the regional E-W extension which characterizes this portion of the eastern Basin and Range province. Hence, the Mineral Mountain swarm appears to be a natural release of tectonic stress in this area. Nevertheless, the occurrence of natural earthquake swarms indicates a potential for induced seismicity at Roosevelt Hot Springs after major production operations are initiated.

  6. Annual layers in the Roosevelt Island (coastal Antarctica) ice core determined from conductivity and calcium measurements

    NASA Astrophysics Data System (ADS)

    Simonsen, Marius; Vallelonga, Paul; Kjær, Helle; Neff, Peter; Bertler, Nancy; Svensson, Anders; Dahl-Jensen, Dorthe; Riis, Marie

    2015-04-01

    The Roosevelt Island Climate Evolution (RICE) Project aims to determine the stability of the Ross Ice Shelf and thus the West Antarctic Ice Sheet in a warming world. A 764 m ice core (79.36° S, 161.71° W) was drilled in 2011-13 at the summit of the Roosevelt Island ice dome, a location surrounded by the Ross Ice Shelf. The site has high accumulation (0.26 m ice equivalent) and a mean annual temperature of -23 °C. From 2012 to 2014, continuous flow analysis (CFA) of the ice core enabled continuous measurements of conductivity, acidity, calcium and insoluble dust particle concentrations along the core. The RICE ice core features high background levels of sulphate and marine salts, due to the low altitude of the site (550 m asl) and its proximity to open ocean. At Roosevelt Island, calcium is influenced by both dust and marine salt inputs. By investigating the residual offset between conductivity and calcium, it has been possible to calculate non-sea salt conductivity and hence determine impurity layers deriving from volcanic eruptions. We present a preliminary chronology for the last 2000 years of deposition in the RICE ice core, composed of counted impurity layers and constrained by a limited number of large, well-dated volcanic eruptions.

  7. Bathythermal habitat use by strains of Great Lakes- and Finger Lakes-origin lake trout in Lake Huron after a change in prey fish abundance and composition

    USGS Publications Warehouse

    Bergstedt, Roger A.; Argyle, Ray L.; Krueger, Charles C.; Taylor, William W.

    2012-01-01

    A study conducted in Lake Huron during October 1998–June 2001 found that strains of Great Lakes-origin (GLO) lake trout Salvelinus namaycush occupied significantly higher temperatures than did Finger Lakes-origin (FLO; New York) lake trout based on data from archival (or data storage) telemetry tags that recorded only temperature. During 2002 and 2003, we implanted archival tags that recorded depth as well as temperature in GLO and FLO lake trout in Lake Huron. Data subsequently recorded by those tags spanned 2002–2005. Based on those data, we examined whether temperatures and depths occupied by GLO and FLO lake trout differed during 2002–2005. Temperatures occupied during those years were also compared with occupied temperatures reported for 1998–2001, before a substantial decline in prey fish biomass. Temperatures occupied by GLO lake trout were again significantly higher than those occupied by FLO lake trout. This result supports the conclusion of the previous study. The GLO lake trout also occupied significantly shallower depths than FLO lake trout. In 2002–2005, both GLO and FLO lake trout occupied significantly lower temperatures than they did in 1998–2001. Aside from the sharp decline in prey fish biomass between study periods, the formerly abundant pelagic alewife Alosa pseudoharengus virtually disappeared and the demersal round goby Neogobius melanostomus invaded the lake and became locally abundant. The lower temperatures occupied by lake trout in Lake Huron during 2002–2005 may be attributable to changes in the composition of the prey fish community, food scarcity (i.e., a retreat to cooler water could increase conversion efficiency), or both.

  8. A new look at the Lake Superior biomass size spectrum

    EPA Science Inventory

    We synthesized data from multiple sampling programs and years to describe the Lake Superior pelagic biomass size structure for two time periods separated by 5 years. The data consisted of water analyzed on a Coulter counter for algae, in situ measurements with a laser optical pl...

  9. Near shore-wetland fish movements in the Great Lakes

    EPA Science Inventory

    Linkages of Great Lakes coastal wetlands and near shore habitats are under-explored, yet 90 species of fish are known to utilize wetlands for spawning and/or nursery habitat. The duration and frequency of wetland use for pelagic species with mobile adult stages is also poorly un...

  10. Food Web Topology in High Mountain Lakes.

    PubMed

    Sánchez-Hernández, Javier; Cobo, Fernando; Amundsen, Per-Arne

    2015-01-01

    Although diversity and limnology of alpine lake systems are well studied, their food web structure and properties have rarely been addressed. Here, the topological food webs of three high mountain lakes in Central Spain were examined. We first addressed the pelagic networks of the lakes, and then we explored how food web topology changed when benthic biota was included to establish complete trophic networks. We conducted a literature search to compare our alpine lacustrine food webs and their structural metrics with those of 18 published lentic webs using a meta-analytic approach. The comparison revealed that the food webs in alpine lakes are relatively simple, in terms of structural network properties (linkage density and connectance), in comparison with lowland lakes, but no great differences were found among pelagic networks. The studied high mountain food webs were dominated by a high proportion of omnivores and species at intermediate trophic levels. Omnivores can exploit resources at multiple trophic levels, and this characteristic might reduce competition among interacting species. Accordingly, the trophic overlap, measured as trophic similarity, was very low in all three systems. Thus, these alpine networks are characterized by many omnivorous consumers with numerous prey species and few consumers with a single or few prey and with low competitive interactions among species. The present study emphasizes the ecological significance of omnivores in high mountain lakes as promoters of network stability and as central players in energy flow pathways via food partitioning and enabling energy mobility among trophic levels. PMID:26571235

  11. Food Web Topology in High Mountain Lakes

    PubMed Central

    Sánchez-Hernández, Javier; Cobo, Fernando; Amundsen, Per-Arne

    2015-01-01

    Although diversity and limnology of alpine lake systems are well studied, their food web structure and properties have rarely been addressed. Here, the topological food webs of three high mountain lakes in Central Spain were examined. We first addressed the pelagic networks of the lakes, and then we explored how food web topology changed when benthic biota was included to establish complete trophic networks. We conducted a literature search to compare our alpine lacustrine food webs and their structural metrics with those of 18 published lentic webs using a meta-analytic approach. The comparison revealed that the food webs in alpine lakes are relatively simple, in terms of structural network properties (linkage density and connectance), in comparison with lowland lakes, but no great differences were found among pelagic networks. The studied high mountain food webs were dominated by a high proportion of omnivores and species at intermediate trophic levels. Omnivores can exploit resources at multiple trophic levels, and this characteristic might reduce competition among interacting species. Accordingly, the trophic overlap, measured as trophic similarity, was very low in all three systems. Thus, these alpine networks are characterized by many omnivorous consumers with numerous prey species and few consumers with a single or few prey and with low competitive interactions among species. The present study emphasizes the ecological significance of omnivores in high mountain lakes as promoters of network stability and as central players in energy flow pathways via food partitioning and enabling energy mobility among trophic levels. PMID:26571235

  12. 50 CFR 622.274 - Pelagic longline closed areas.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... ATLANTIC Dolphin and Wahoo Fishery Off the Atlantic States § 622.274 Pelagic longline closed areas. (a) If... dolphin or wahoo— (1) In the Northeastern United States closed area from June 1 through June 30 each...

  13. 50 CFR 622.274 - Pelagic longline closed areas.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... ATLANTIC Dolphin and Wahoo Fishery Off the Atlantic States § 622.274 Pelagic longline closed areas. (a) If... dolphin or wahoo— (1) In the Northeastern United States closed area from June 1 through June 30 each...

  14. Percentage of microbeads in pelagic microplastics within Japanese coastal waters.

    PubMed

    Isobe, Atsuhiko

    2016-09-15

    To compare the quantity of microbeads with the quantity of pelagic microplastics potentially degraded in the marine environment, samples were collected in coastal waters of Japan using neuston nets. Pelagic spherical microbeads were collected in the size range below 0.8mm at 9 of the 26 stations surveyed. The number of pelagic microbeads smaller than 0.8mm accounted for 9.7% of all microplastics collected at these 9 stations. This relatively large percentage results from a decrease in the abundance of microplastics smaller than 0.8mm in the upper ocean, as well as the regular loading of new microbeads from land areas, in this size range. In general, microbeads in personal care and cosmetic products are not always spherical, but rather are often a variety of irregular shapes. It is thus likely that this percentage is a conservative estimate, because of the irregular shapes of the remaining pelagic microbeads. PMID:27297592

  15. Lake Life.

    ERIC Educational Resources Information Center

    Ohrn, Deborah Gore, Ed.

    1993-01-01

    This quarterly publication of the State Historical Society of Iowa features articles and activities for elementary school students. This summer issue focuses on the topic of lake life. The issue includes the following features: (1) "Where the Lakes Are Map"; (2) "Letter from the Lake"; (3) "Lake People"; (4) "Spirit Lake"; (5) "Lake Manawa"; (6)…

  16. IN-SITU DUOX™ CHEMICAL OXIDATION TECHNOLOGY TO TREAT CHLORINATED ORGANICS AT THE ROOSEVELT MILLS SITE, VERNON, CT: SITE CHARACTERIZATION AND TREATABILITY STUDY

    EPA Science Inventory

    A study was performed investigating the feasibility of applying the DUOX™ chemical oxidation technology to chlorinated solvent contaminated media at the Roosevelt Mills site in Vernon, Connecticut. The Roosevelt Mills site is a former woolen mill that included dry cleaning operat...

  17. Range contraction in large pelagic predators

    PubMed Central

    Worm, Boris; Tittensor, Derek P.

    2011-01-01

    Large reductions in the abundance of exploited land predators have led to significant range contractions for those species. This pattern can be formalized as the range–abundance relationship, a general macroecological pattern that has important implications for the conservation of threatened species. Here we ask whether similar responses may have occurred in highly mobile pelagic predators, specifically 13 species of tuna and billfish. We analyzed two multidecadal global data sets on the spatial distribution of catches and fishing effort targeting these species and compared these with available abundance time series from stock assessments. We calculated the effort needed to reliably detect the presence of a species and then computed observed range sizes in each decade from 1960 to 2000. Results suggest significant range contractions in 9 of the 13 species considered here (between 2% and 46% loss of observed range) and significant range expansions in two species (11–29% increase). Species that have undergone the largest declines in abundance and are of particular conservation concern tended to show the largest range contractions. These include all three species of bluefin tuna and several marlin species. In contrast, skipjack tuna, which may have increased its abundance in the Pacific, has also expanded its range size. These results mirror patterns described for many land predators, despite considerable differences in habitat, mobility, and dispersal, and imply ecological extirpation of heavily exploited species across parts of their range. PMID:21693644

  18. Evaluation of methods to estimate lake herring spawner abundance in Lake Superior

    USGS Publications Warehouse

    Yule, D.L.; Stockwell, J.D.; Cholwek, G.A.; Evrard, L.M.; Schram, S.; Seider, M.; Symbal, M.

    2006-01-01

    Historically, commercial fishers harvested Lake Superior lake herring Coregonus artedi for their flesh, but recently operators have targeted lake herring for roe. Because no surveys have estimated spawning female abundance, direct estimates of fishing mortality are lacking. The primary objective of this study was to determine the feasibility of using acoustic techniques in combination with midwater trawling to estimate spawning female lake herring densities in a Lake Superior statistical grid (i.e., a 10′ latitude × 10′ longitude area over which annual commercial harvest statistics are compiled). Midwater trawling showed that mature female lake herring were largely pelagic during the night in late November, accounting for 94.5% of all fish caught exceeding 250 mm total length. When calculating acoustic estimates of mature female lake herring, we excluded backscattering from smaller pelagic fishes like immature lake herring and rainbow smelt Osmerus mordax by applying an empirically derived threshold of −35.6 dB. We estimated the average density of mature females in statistical grid 1409 at 13.3 fish/ha and the total number of spawning females at 227,600 (95% confidence interval = 172,500–282,700). Using information on mature female densities, size structure, and fecundity, we estimate that females deposited 3.027 billion (109) eggs in grid 1409 (95% confidence interval = 2.356–3.778 billion). The relative estimation error of the mature female density estimate derived using a geostatistical model—based approach was low (12.3%), suggesting that the employed method was robust. Fishing mortality rates of all mature females and their eggs were estimated at 2.3% and 3.8%, respectively. The techniques described for enumerating spawning female lake herring could be used to develop a more accurate stock–recruitment model for Lake Superior lake herring.

  19. Deglacial and lake level fluctuation history recorded in cores, Beaver Lake, Upper Peninsula, Michigan

    USGS Publications Warehouse

    Fisher, Timothy G.; Whitman, Richard L.

    1999-01-01

    Sediment cores collected from the littoral and pelagic zones of Beaver Lake, Michigan record fluctuations in the water level of Lake Superior. Beaver Lake is a small 300 ha lake in Pictured Rocks National Lakeshore (PRNL) now separated from Lake Superior by a dune-capped barrier bar. Cores were collected using a vibracorer from a lake-ice platform in February 1997. A 2.85 m long core in 10 m of water contains well-sorted sand, rhythmites, peat, interbedded sand and gyttja, and is capped with 1 m of massive gyttja. A 9480 BP AMS age from the basal sand provides a minimum deglacial date for the area. Further analysis indicates a sand-dominated depositional environment from a low lake stand at approximately 8500 BP to present. An approximate 8800 BP red to gray sediment color transition records either the cessation of meltwater input from Lake Agassiz or receding ice, while a younger similarly colored transition, 6600 BP in age, likely records sediment reworking in the coastal zone. Four AMS ages on peat range from 8520 to 7340 BP and are indicative of the Houghton low phase. Burial of the peat by stratified sand and gyttja after 7340 BP indicates a rising lake level. Peat at a higher level in the lake basin, encountered in shallow littoral cores, ranges in age from 6800 to 6420 BP, which estimates a 0.91 m rise/century in lake level to the Nipissing level by 5000 BP.

  20. The Ecological History of Lake Ontario According to Phytoplankton

    NASA Astrophysics Data System (ADS)

    Allinger, L. E.; Reavie, E. D.

    2014-12-01

    Lake Ontario's water quality has fluctuated since European settlement and our understanding of the cause-and-effect linkages between observed ecosystem shifts and stressors are evolving and improving. Changes in the physical and chemical environment of the lake due to non-indigenous species, pollution, sedimentation, turbidity and climate change altered the pelagic primary producers, so algal assessments have been valuable for tracking long-term conditions. We present a chronological account of pelagic algal assessments and some nearshore areas to summarize past and present environmental conditions in Lake Ontario. This review particularly focuses on diatom-based assessments as their fossils in sediments have revealed the combined effects of environmental insults and recovery. This review recaps the long-term trends according to three unique regions: Hamilton Harbor, the main lake basin and the Bay of Quinte. We summarize pre-European settlement, eutrophication throughout most of the 20th century, subsequent water quality improvement due to nutrient reductions and filter-feeding dreissenid colonization and contemporary pelagic, shoreline and embayment impairments. Recent pelagic phytoplankton data suggest that although phytoplankton biovolume remains stable, species composition has shifted to an increase in spring eutrophic diatoms and summer blue-green algae. Continued monitoring and evaluation of historical data will assist in understanding and responding to the natural and anthropogenic drivers of Lake Ontario's environmental conditions. As such we have initiated a new paleolimnological investigation, supported by the Environmental Protection Agency-Great Lakes National Program Office, to reconstruct the long-term environmental history of Lake Ontario and will present preliminary results.

  1. Restoring piscivorous fish populations in the Laurentian Great Lakes causes seabird dietary change

    USGS Publications Warehouse

    Hebert, C.E.; Weseloh, D.V.C.; Idrissi, A.; Arts, M.T.; O'Gorman, R.; Gorman, O.T.; Locke, B.; Madenjian, C.P.; Roseman, E.F.

    2008-01-01

    Ecosystem change often affects the structure of aquatic communities thereby regulating how much and by what pathways energy and critical nutrients flow through food webs. The availability of energy and essential nutrients to top predators such as seabirds that rely on resources near the water's surface will be affected by changes in pelagic prey abundance. Here, we present results from analysis of a 25-year data set documenting dietary change in a predatory seabird from the Laurentian Great Lakes. We reveal significant declines in trophic position and alterations in energy and nutrient flow over time. Temporal changes in seabird diet tracked decreases in pelagic prey fish abundance. As pelagic prey abundance declined, birds consumed less aquatic prey and more terrestrial food. This pattern was consistent across all five large lake ecosystems. Declines in prey fish abundance may have primarily been the result of predation by stocked piscivorous fishes, but other lake-specific factors were likely also important. Natural resource management activities can have unintended consequences for nontarget ecosystem components. Reductions in pelagic prey abundance have reduced the capacity of the Great Lakes to support the energetic requirements of surface-feeding seabirds. In an environment characterized by increasingly limited pelagic fish resources, they are being offered a Hobsonian choice: switch to less nutritious terrestrial prey or go hungry. ?? 2008 by the Ecological Society of America.

  2. Population attributes of lake trout in Tennessee reservoirs

    USGS Publications Warehouse

    Russell, Drew; Bettoli, Phillip William

    2013-01-01

    We sampled stocked Salvelinus namaycush (Lake Trout) in Watauga Lake and South Holston Lake, TN using experimental gill nets in 2009-2010 to describe their growth, longevity, and condition. Annuli in sagittal otoliths formed once a year in early spring in both reservoirs. South Holston Lake (n = 99 Lake Trout) has been stocked since 2006, and the oldest fish was age 4. Watauga Lake has been stocked since the mid-1980s, and we collected 158 Lake Trout up to age 20. Annual mortality for age-3 and older fish in Watauga Lake was 24%. When compared to Lake Trout in northern lakes, Tennessee Lake Trout exhibited average to above-average growth and longevity. Condition of Lake Trout in both reservoirs varied seasonally and tended to be lowest in fall, but rebounded in winter and spring. Lake Trout in both reservoirs appeared to be spatially segregated from pelagic prey fishes during summer stratification, but growth rates and body condition were high enough to suggest that neither system was being overstocked.

  3. Presidents and health reform: from Franklin D. Roosevelt to Barack Obama.

    PubMed

    Morone, James A

    2010-06-01

    The health care reforms that President Barack Obama signed into law in March 2010 were seventy-five years in the making. Since Franklin D. Roosevelt, U.S. presidents have struggled to enact national health care reform; most failed. This article explores the highly charged political landscape in which Obama maneuvered and the skills he brought to bear. It contrasts his accomplishments with the experiences of his Oval Office predecessors. Going forward, implementation poses formidable challenges for Democrats, Republicans, and the political process itself. PMID:20530336

  4. Ecological Insights from Pelagic Habitats Acquired Using Active Acoustic Techniques.

    PubMed

    Benoit-Bird, Kelly J; Lawson, Gareth L

    2016-01-01

    Marine pelagic ecosystems present fascinating opportunities for ecological investigation but pose important methodological challenges for sampling. Active acoustic techniques involve producing sound and receiving signals from organisms and other water column sources, offering the benefit of high spatial and temporal resolution and, via integration into different platforms, the ability to make measurements spanning a range of spatial and temporal scales. As a consequence, a variety of questions concerning the ecology of pelagic systems lend themselves to active acoustics, ranging from organism-level investigations and physiological responses to the environment to ecosystem-level studies and climate. As technologies and data analysis methods have matured, the use of acoustics in ecological studies has grown rapidly. We explore the continued role of active acoustics in addressing questions concerning life in the ocean, highlight creative applications to key ecological themes ranging from physiology and behavior to biogeography and climate, and discuss emerging avenues where acoustics can help determine how pelagic ecosystems function. PMID:26515810

  5. Pelagic crinoids (Roveacrinida, Crinoidea) discovered in the Neogene of Poland

    NASA Astrophysics Data System (ADS)

    Gorzelak, Przemysław; Salamon, Mariusz A.; Ferré, Bruno

    2011-10-01

    Until recently, it has been assumed that pelagic crinoids, the roveacrinids (Roveacrinida, Crinoidea), became extinct during the Cretaceous-Paleogene boundary event. Recent finds of well-preserved roveacrinidal remains (brachials and radials) in the Danian (Early Paleogene) of Poland showed that they survived into the earliest Cenozoic. This group was thus characterized as a "dead clade walking". Here, we present fossil evidence that these pelagic crinoids survived in Poland until at least the Middle Miocene (Badenian, ca. 14 Myr ago)—more than 50 Myr after their supposed extinction. These Miocene roveacrinids constitute the first documented evidence of Roveacrinida in strata of Neogene age, thus prolonging the stratigraphic range of pelagic crinoids. This find characterizes the order as a "Lazarus taxon" rather than a "dead clade walking" group.

  6. Ecological Insights from Pelagic Habitats Acquired Using Active Acoustic Techniques

    NASA Astrophysics Data System (ADS)

    Benoit-Bird, Kelly J.; Lawson, Gareth L.

    2016-01-01

    Marine pelagic ecosystems present fascinating opportunities for ecological investigation but pose important methodological challenges for sampling. Active acoustic techniques involve producing sound and receiving signals from organisms and other water column sources, offering the benefit of high spatial and temporal resolution and, via integration into different platforms, the ability to make measurements spanning a range of spatial and temporal scales. As a consequence, a variety of questions concerning the ecology of pelagic systems lend themselves to active acoustics, ranging from organism-level investigations and physiological responses to the environment to ecosystem-level studies and climate. As technologies and data analysis methods have matured, the use of acoustics in ecological studies has grown rapidly. We explore the continued role of active acoustics in addressing questions concerning life in the ocean, highlight creative applications to key ecological themes ranging from physiology and behavior to biogeography and climate, and discuss emerging avenues where acoustics can help determine how pelagic ecosystems function.

  7. The Pelagics Habitat Analysis Module (PHAM): Decision Support Tools for Pelagic Fisheries

    NASA Astrophysics Data System (ADS)

    Armstrong, E. M.; Harrison, D. P.; Kiefer, D.; O'Brien, F.; Hinton, M.; Kohin, S.; Snyder, S.

    2009-12-01

    PHAM is a project funded by NASA to integrate satellite imagery and circulation models into the management of commercial and threatened pelagic species. Specifically, the project merges data from fishery surveys, and fisheries catch and effort data with satellite imagery and circulation models to define the habitat of each species. This new information on habitat will then be used to inform population distribution and models of population dynamics that are used for management. During the first year of the project, we created two prototype modules. One module, which was developed for the Inter-American Tropical Tuna Commission, is designed to help improve information available to manage the tuna fisheries of the eastern Pacific Ocean. The other module, which was developed for the Coastal Pelagics Division of the Southwest Fishery Science Center, assists management of by-catch of mako, blue, and thresher sharks along the Californian coast. Both modules were built with the EASy marine geographic information system, which provides a 4 dimensional (latitude, longitude, depth, and time) home for integration of the data. The projects currently provide tools for automated downloading and geo-referencing of satellite imagery of sea surface temperature, height, and chlorophyll concentrations; output from JPL’s ECCO2 global circulation model and its ROM California current model; and gridded data from fisheries and fishery surveys. It also provides statistical tools for defining species habitat from these and other types of environmental data. These tools include unbalanced ANOVA, EOF analysis of satellite imagery, and multivariate search routines for fitting fishery data to transforms of the environmental data. Output from the projects consists of dynamic maps of the distribution of the species that are driven by the time series of satellite imagery and output from the circulation models. It also includes relationships between environmental variables and recruitment. During

  8. 78 FR 70015 - Proposed Information Collection; Comment Request; Large Pelagic Fishing Survey

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-22

    ... Pelagic Fishing Survey AGENCY: National Oceanic and Atmospheric Administration (NOAA), Commerce. ACTION... of a current information collection. The Large Pelagic Fishing Survey consists of dockside and... Atlantic Ocean. The survey provides the National Marine Fisheries Service (NMFS) with information...

  9. 76 FR 12340 - Proposed Information Collection; Comment Request; Large Pelagic Fishing Survey

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-07

    ... Pelagic Fishing Survey AGENCY: National Oceanic and Atmospheric Administration (NOAA). ACTION: Notice... SUPPLEMENTARY INFORMATION: I. Abstract The Large Pelagic Fishing Survey consists of dockside and telephone.... The survey provides the National Marine Fisheries Service (NMFS) with information to monitor catch...

  10. RICE ice core: Black Carbon reflects climate variability at Roosevelt Island, West Antarctica

    NASA Astrophysics Data System (ADS)

    Ellis, Aja; Edwards, Ross; Bertler, Nancy; Winton, Holly; Goodwin, Ian; Neff, Peter; Tuohy, Andrea; Proemse, Bernadette; Hogan, Chad; Feiteng, Wang

    2015-04-01

    The Roosevelt Island Climate Evolution (RICE) project successfully drilled a deep ice core from Roosevelt Island during the 2011/2012 and 2012/2013 seasons. Located in the Ross Ice Shelf in West Antarctica, the site is an ideal location for investigating climate variability and the past stability of the Ross Ice Shelf. Black carbon (BC) aerosols are emitted by both biomass burning and fossil fuels, and BC particles emitted in the southern hemisphere are transported in the atmosphere and preserved in Antarctic ice. The past record of BC is expected to be sensitive to climate variability, as it is modulated by both emissions and transport. To investigate BC variability over the past 200 years, we developed a BC record from two overlapping ice cores (~1850-2012) and a high-resolution snow pit spanning 2010-2012 (cal. yr). Consistent results are found between the snow pit profiles and ice core records. Distinct decadal trends are found with respect to BC particle size, and the record indicates a steady rise in BC particle size over the last 100 years. Differences in emission sources and conditions may be a possible explanation for changes in BC size. These records also show a significant increase in BC concentration over the past decade with concentrations rising over 1.5 ppb (1.5*10^-9 ng/g), suggesting a fundamental shift in BC deposition to the site.

  11. Roosevelt elk density and social segregation: Foraging behavior and females avoiding larger groups of males

    USGS Publications Warehouse

    Weckerly, F.; McFarland, K.; Ricca, M.; Meyer, K.

    2004-01-01

    Intersexual social segregation at small spatial scales is prevalent in ruminants that are sexually dimorphic in body size. Explaining social segregation, however, from hypotheses of how intersexual size differences affects the foraging process of males and females has had mixed results. We studied whether body size influences on forage behavior, intersexual social incompatibility or both might influence social segregation in a population of Roosevelt elk (Cervus elaphus roosevelt) that declined 40% over 5 y. Most males and females in the population occurred in the same forage patches, meadows, but occupied different parts of meadows and most groups were overwhelming comprised of one sex. The extent of segregation varied slightly with changing elk density. Cropping rate, our surrogate of forage ingestion, of males in mixed-sex groups differed from males in male-only groups at high, but not low, elk density. In a prior study of intersexual social interactions it was shown that females avoided groups containing ???6 males. Therefore, we predicted that females should avoid parts of meadows where groups of males ???6 were prevalent. Across the 5 y of study this prediction held because ???5% of all females were found in parts of meadows where median aggregation sizes of males were ???6. Social segregation was coupled to body size influences on forage ingestion at high density and social incompatibility was coupled to social segregation regardless of elk density.

  12. Hot dry rock geothermal potential of Roosevelt Hot Springs area: review of data and recommendations

    SciTech Connect

    East, J.

    1981-05-01

    The Roosevelt Hot Springs area in west-central Utah possesses several features indicating potential for hot dry rock (HDR) geothermal development. The area is characterized by extensional tectonics and a high regional heat flow of greater than 105 mW/m/sup 2/. The presence of silicic volcanic rocks as young as 0.5 to 0.8 Myr and totaling 14 km/sup 3/ in volume indicates underlying magma reservoirs may be the heat source for the thermal anomaly. Several hot dry wells have been drilled on the periphery of the geothermal field. Information obtained on three of these deep wells shows that they have thermal gradients of 55 to 60/sup 0/C/km and bottom in impermeable Tertiary granitic and Precambrian gneissic units. The Tertiary granite is the preferred HDR reservoir rock because Precambrian gneissic rocks possess a well-developed banded foliation, making fracture control over the reservoir more difficult. Based on a fairly conservative estimate of 160 km/sup 2/ for the thermal anomaly present at Roosevelt Hot Springs, the area designated favorable for HDR geothermal exploration may be on the order of seven times or more than the hydrogeothermal area currently under development.

  13. Tissue assays and population characteristics of Roosevelt Hot Springs' animals (1977-1978). Project report

    SciTech Connect

    Nelson, Z.C.; Sutton, W.W.

    1981-08-01

    Geothermal energy exploration is being conducted at several locations in the United States including a site at Roosevelt Hot Springs in southwest Utah. To assess any possible impact and to help design a monitoring strategy for geothermal development, element concentrations in animal tissues and selected animal population characteristics were determined at Roosevelt Hot Springs for the 1977-1978 period. The information can be used as baseline data as it was collected before any extensive industrial development had taken place. Concentrations of barium, boron, cadmium, chromium, copper, iron, lead, manganese, strontium and zinc were determined for livestock and wildlife samples. In some cases, concentration values for additional elements (e.g., arsenic, lithium, magnesium, potassium and sodium) were also established. Small mammal populations (primarily rodents and lagamorphs) were also characterized as part of the effort to conduct baseline surveys prior to extensive geothermal development. Objectives of the limited population survey were to present information on habitat associations and species diversity as well as to provide an estimate of animal abundance both adjacent to and distant from the KGRA (Known Geothermal Resource Area).

  14. Acord 1-26 hot, dry well, Roosevelt Hot Springs hot dry rock prospect, Utah

    SciTech Connect

    Shannon, S.S. Jr.; Pettitt, R.; Rowley, J.; Goff, F.; Mathews, M.; Jacobson, J.J.

    1983-08-01

    The Acord 1-26 well is a hot, dry well peripheral to the Roosevelt Hot Springs known geothermal resource area (KGRA) in southwestern Utah. The bottom-hole temperature in this 3854-m-deep well is 230/sup 0/C, and the thermal gradient is 54/sup 0/C/km. The basal 685 m, comprised of biotite monzonite and quartz schist and gneiss, is a likely hot, dry rock (HDR) prospect. The hole was drilled in a structural low within the Milford Valley graben and is separated from the Roosevelt KGRA to the east by the Opal Mound Fault and other basin faults. An interpretation of seismic data approximates the subsurface structure around the well using the lithology in the Acord 1-26 well. The hole was drilled with a minimum of difficulty, and casing was set to 2411 m. From drilling and geophysical logs, it is deduced that the subsurface blocks of crystalline rock in the vicinity of the Acord 1-26 well are tight, dry, shallow, impermeable, and very hot. A hydraulic fracture test of the crystalline rocks below 3170 m is recommended. Various downhole tools and techniques could be tested in promising HDR regimes within the Acord 1-26 well.

  15. Theodore Roosevelt High School, Project C.H.A.S.P. O.E.E. Evaluation Report, 1982-1983.

    ERIC Educational Resources Information Center

    Sjostrom, Barbara R.; Schulman, Robert

    In 1982-83, Project CHASP offered bilingual instruction and support services to 100 Cambodian and 75 Hispanic limited-English-speaking students in the 9th and 10th grades at Theodore Roosevelt High School, Bronx, New York. The goal of the program was to develop student proficiency in the English language skills necessary for full mainstreaming…

  16. Continuous and discrete measurements of atmospheric methane from an ice core from Roosevelt Island, East Ross Sea, Antarctica

    NASA Astrophysics Data System (ADS)

    Blunier, T.; Simonsen, M. F.; Brook, E.; Lee, J.; Vallelonga, P. T.; Bertler, N. A. N.

    2014-12-01

    A new ice core from Roosevelt Island was drilled for the Roosevelt Island Climate Evolution (RICE) project to establish the history of deglaciation of the Ross Sea. Evidence of glacial retreat in the Ross Sea Embayment shows that deglaciation happened in several stages of rapid collapse and persisted well after the melting of the Northern Hemisphere ice sheets was complete. The drill location on a small island surrounded by sea ice makes dating the core a challenge. We present a timescale for Roosevelt Island using mixing ratios of methane in air preserved within the ice core measured continuously with a Picarro laser spectrometer as well as in high-resolution with gas chromatography (GC). Discrete data from GC analysis over the top 400m of core replicate both the magnitude and variations from other high-resolution ice core records from WAIS Divide, Law Dome, GISP2 and NEEM S1. Both the continuous and discrete methane records of the RICE core were matched to these established records and provide an accurate and consistent depth-age relationship for the past 3.6kyr. The deeper part of the core was measured continuously in July 2014. First inspection of the data suggests that the oldest section of the core reaches into the previous interglacial (Eemian). We will present preliminary evaluated continuous methane data for the deeper part of the core together with a first time scale for the Roosevelt Island ice core.

  17. A Comparative Case Study of Self-Actualization in Eleanor Roosevelt and Antoine de Saint-Exupery.

    ERIC Educational Resources Information Center

    Tyska, Cynthia Ann

    Eleanor Roosevelt and Antoine de Saint-Exupery are described as strongly developed self-actualizing people. They were selected as subjects of this study because they are generally believed to possess self-actualizing characteristics and because their positions as public figures made it more likely that data on them would be accessible.…

  18. 77 FR 60981 - TGP Granada, LLC and Roosevelt Wind Ranch, LLC v. Public Service Company of New Mexico, Tortoise...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-05

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket Nos. EL12-42-000, EL12-42-001; EL12-43-000, EL12-43-001 TGP Granada, LLC and Roosevelt Wind Ranch, LLC v. Public Service Company of New Mexico, Tortoise Capital...

  19. Letters from George Washington and Samuel Cabble, and Speeches by Franklin D. Roosevelt and John F. Kennedy

    ERIC Educational Resources Information Center

    Potter, Lee Ann

    2008-01-01

    In this article, the author uses several primary sources to demonstrate that George Washington, Samuel Cabble, Franklin D. Roosevelt, and John F. Kennedy stated their awareness of contemporary challenges, but looked to the future with hope and optimism. When they envisioned the future, their words indicated that they did not just imagine it, but…

  20. Dealing with Disaster through Compassionate Giving: San Francisco Earthquake Survivors Write to President Theodore Roosevelt, January 3, 1909

    ERIC Educational Resources Information Center

    Hussey, Michael

    2011-01-01

    On January 3, 1909, Emily Hamilton and Louis Overstreet wrote to President Theodore Roosevelt begging his "leave to work under your Committee for the relief of the sufferers of Italy." The two were engaged and were willing to rush their marriage plans if the president needed them. Their letter was prompted by the powerful earthquake that struck…

  1. Geochemistry of sericite and chlorite in well 14-2 Roosevelt Hot Springs geothermal system and in mineralized hydrothermal systems

    SciTech Connect

    Ballantyne, J.M.

    1980-06-01

    Chemical compositions of chlorite and sericite from one production well in the Roosevelt geothermal system have been determined by electron probe methods and compared with compositions of chlorite and sericite from porphyry copper deposits. Modern system sericite and chlorite occur over a depth interval of 2 km and a temperature interval of 250/sup 0/C.

  2. Seamounts are hotspots of pelagic biodiversity in the open ocean

    PubMed Central

    Morato, Telmo; Hoyle, Simon D.; Allain, Valerie; Nicol, Simon J.

    2010-01-01

    The identification of biodiversity hotspots and their management for conservation have been hypothesized as effective ways to protect many species. There has been a significant effort to identify and map these areas at a global scale, but the coarse resolution of most datasets masks the small-scale patterns associated with coastal habitats or seamounts. Here we used tuna longline observer data to investigate the role of seamounts in aggregating large pelagic biodiversity and to identify which pelagic species are associated with seamounts. Our analysis indicates that seamounts are hotspots of pelagic biodiversity. Higher species richness was detected in association with seamounts than with coastal or oceanic areas. Seamounts were found to have higher species diversity within 30–40 km of the summit, whereas for sets close to coastal habitat the diversity was lower and fairly constant with distance. Higher probability of capture and higher number of fish caught were detected for some shark, billfish, tuna, and other by-catch species. The study supports hypotheses that seamounts may be areas of special interest for management for marine pelagic predators. PMID:20448197

  3. Olfaction Contributes to Pelagic Navigation in a Coastal Shark

    PubMed Central

    Nosal, Andrew P.; Chao, Yi; Farrara, John D.; Chai, Fei; Hastings, Philip A.

    2016-01-01

    How animals navigate the constantly moving and visually uniform pelagic realm, often along straight paths between distant sites, is an enduring mystery. The mechanisms enabling pelagic navigation in cartilaginous fishes are particularly understudied. We used shoreward navigation by leopard sharks (Triakis semifasciata) as a model system to test whether olfaction contributes to pelagic navigation. Leopard sharks were captured alongshore, transported 9 km offshore, released, and acoustically tracked for approximately 4 h each until the transmitter released. Eleven sharks were rendered anosmic (nares occluded with cotton wool soaked in petroleum jelly); fifteen were sham controls. Mean swimming depth was 28.7 m. On average, tracks of control sharks ended 62.6% closer to shore, following relatively straight paths that were significantly directed over spatial scales exceeding 1600 m. In contrast, tracks of anosmic sharks ended 37.2% closer to shore, following significantly more tortuous paths that approximated correlated random walks. These results held after swimming paths were adjusted for current drift. This is the first study to demonstrate experimentally that olfaction contributes to pelagic navigation in sharks, likely mediated by chemical gradients as has been hypothesized for birds. Given the similarities between the fluid three-dimensional chemical atmosphere and ocean, further research comparing swimming and flying animals may lead to a unifying paradigm explaining their extraordinary navigational abilities. PMID:26735492

  4. Seamounts are hotspots of pelagic biodiversity in the open ocean.

    PubMed

    Morato, Telmo; Hoyle, Simon D; Allain, Valerie; Nicol, Simon J

    2010-05-25

    The identification of biodiversity hotspots and their management for conservation have been hypothesized as effective ways to protect many species. There has been a significant effort to identify and map these areas at a global scale, but the coarse resolution of most datasets masks the small-scale patterns associated with coastal habitats or seamounts. Here we used tuna longline observer data to investigate the role of seamounts in aggregating large pelagic biodiversity and to identify which pelagic species are associated with seamounts. Our analysis indicates that seamounts are hotspots of pelagic biodiversity. Higher species richness was detected in association with seamounts than with coastal or oceanic areas. Seamounts were found to have higher species diversity within 30-40 km of the summit, whereas for sets close to coastal habitat the diversity was lower and fairly constant with distance. Higher probability of capture and higher number of fish caught were detected for some shark, billfish, tuna, and other by-catch species. The study supports hypotheses that seamounts may be areas of special interest for management for marine pelagic predators. PMID:20448197

  5. Olfaction Contributes to Pelagic Navigation in a Coastal Shark.

    PubMed

    Nosal, Andrew P; Chao, Yi; Farrara, John D; Chai, Fei; Hastings, Philip A

    2016-01-01

    How animals navigate the constantly moving and visually uniform pelagic realm, often along straight paths between distant sites, is an enduring mystery. The mechanisms enabling pelagic navigation in cartilaginous fishes are particularly understudied. We used shoreward navigation by leopard sharks (Triakis semifasciata) as a model system to test whether olfaction contributes to pelagic navigation. Leopard sharks were captured alongshore, transported 9 km offshore, released, and acoustically tracked for approximately 4 h each until the transmitter released. Eleven sharks were rendered anosmic (nares occluded with cotton wool soaked in petroleum jelly); fifteen were sham controls. Mean swimming depth was 28.7 m. On average, tracks of control sharks ended 62.6% closer to shore, following relatively straight paths that were significantly directed over spatial scales exceeding 1600 m. In contrast, tracks of anosmic sharks ended 37.2% closer to shore, following significantly more tortuous paths that approximated correlated random walks. These results held after swimming paths were adjusted for current drift. This is the first study to demonstrate experimentally that olfaction contributes to pelagic navigation in sharks, likely mediated by chemical gradients as has been hypothesized for birds. Given the similarities between the fluid three-dimensional chemical atmosphere and ocean, further research comparing swimming and flying animals may lead to a unifying paradigm explaining their extraordinary navigational abilities. PMID:26735492

  6. Lake morphometry and resource polymorphism determine niche segregation between cool- and cold-water-adapted fish.

    PubMed

    Hayden, Brian; Harrod, Chris; Kahilaineni, Kimmo K

    2014-02-01

    Climate change is increasing ambient temperatures in Arctic and subarctic regions, facilitating latitudinal range expansions of freshwater fishes adapted to warmer water temperatures. The relative roles of resource availability and interspecific interactions between resident and invading species in determining the outcomes of such expansions has not been adequately evaluated. Ecological interactions between a cool-water adapted fish, the perch (Perca fluviatilis), and the cold-water adapted European whitefish (Coregonus lavaretus), were studied in both shallow and deep lakes with fish communities dominated by (1) monomorphic whitefish, (2) monomorphic whitefish and perch, and (3) polymorphic whitefish and perch. A combination of stomach content, stable-isotope, and invertebrate prey availability data were used to identify resource use and niche overlap among perch, the trophic generalist large sparsely rakered (LSR) whitefish morph, and the pelagic specialist densely rakered (DR) whitefish morph in 10 subarctic lakes at the contemporary distribution limit of perch in northern Scandinavia. Perch utilized its putative preferred littoral niche in all lakes. LSR whitefish utilized both littoral and pelagic resources in monomorphic whitefish-dominated lakes. When found in sympatry with perch, LSR whitefish exclusively utilized pelagic prey in deep lakes, but displayed niche overlap with perch in shallow littoral lakes. DR whitefish was a specialist zooplanktivore, relegating LSR whitefish from pelagic habitats, leading to an increase in niche overlap between LSR whitefish and perch in deep lakes. Our results highlight how resource availability (lake depth and fish community) governs ecological interactions between native and invading species, leading to different outcomes even at the same latitudes. These findings suggest that lake morphometry and fish community structure data should be included in bioclimate envelope-based models of species distribution shifts

  7. Latitudinal and photic effects on diel foraging and predation risk in freshwater pelagic ecosystems.

    PubMed

    Hansen, Adam G; Beauchamp, David A

    2015-03-01

    . Model results show that diel-seasonal foraging and predation risk in freshwater pelagic ecosystems changes considerably with latitude, turbidity and cloud cover. These changes alter the structure of pelagic predator-prey interactions, and in turn, the broader role of pelagic consumers in habitat coupling in lakes. PMID:25266197

  8. Longer Food Chains in Pelagic Ecosystems: Trophic Energetics of Animal Body Size and Metabolic Efficiency.

    PubMed

    McGarvey, Richard; Dowling, Natalie; Cohen, Joel E

    2016-07-01

    Factors constraining the structure of food webs can be investigated by comparing classes of ecosystems. We find that pelagic ecosystems, those based on one-celled primary producers, have longer food chains than terrestrial ecosystems. Yet pelagic ecosystems have lower primary productivity, contrary to the hypothesis that greater energy flows permit higher trophic levels. We hypothesize that longer food chain length in pelagic ecosystems, compared with terrestrial ecosystems, is associated with smaller pelagic animal body size permitting more rapid trophic energy transfer. Assuming negative allometric dependence of biomass production rate on body mass at each trophic level, the lowest three pelagic animal trophic levels are estimated to add biomass more rapidly than their terrestrial counterparts by factors of 12, 4.8, and 2.6. Pelagic animals consequently transport primary production to a fifth trophic level 50-190 times more rapidly than animals in terrestrial webs. This difference overcomes the approximately fivefold slower pelagic basal productivity, energetically explaining longer pelagic food chains. In addition, ectotherms, dominant at lower pelagic animal trophic levels, have high metabolic efficiency, also favoring higher rates of trophic energy transfer in pelagic ecosystems. These two animal trophic flow mechanisms imply longer pelagic food chains, reestablishing an important role for energetics in food web structure. PMID:27322123

  9. A test for within-lake niche differentiation in the nine-spined sticklebacks (Pungitius pungitius).

    PubMed

    Calboli, Federico C F; Byström, Pär; Merilä, Juha

    2016-07-01

    Specialization for the use of different resources can lead to ecological speciation. Accordingly, there are numerous examples of ecologically specialized pairs of fish "species" in postglacial lakes. Using a polymorphic panel of single nucleotide variants, we tested for genetic footprints of within-lake population stratification in nine-spined sticklebacks (Pungitius pungitius) collected from three habitats (viz. littoral, benthic, and pelagic) within a northern Swedish lake. Analyses of admixture, population structure, and relatedness all supported the conclusion that the fish from this lake form a single interbreeding unit. PMID:27547310

  10. Bioaccumulation of toxaphene congeners in the lake superior food web

    USGS Publications Warehouse

    Muir, D.C.G.; Whittle, D.M.; De Vault, D. S.; Bronte, C.R.; Karlsson, H.; Backus, S.; Teixeira, C.

    2004-01-01

    The bioaccumulation and biotransformation of toxaphene was examined in the food webs of Lake Superior and Siskiwit Lake (Isle Royale) using congener specific analysis as well as stable isotope ratios of carbon and nitrogen to characterize food webs. Toxaphene concentrations (calculated using technical toxaphene) in lake trout (Salvelinus namaycush) from the western basin of Lake Superior (N = 95) averaged (±SD) 889 ± 896 ng/g wet wt and 60 ± 34 ng/g wet wt in Siskiwit Lake. Major congeners in lake trout were B8-789 (P38), B8-2226 (P44), B9-1679 (P50), and B9-1025 (P62). Toxaphene concentrations were found to vary seasonally, especially in lower food web organisms in Lake Superior and to a lesser extent in Siskiwit Lake. Toxaphene concentrations declined significantly in lake herring (Coregonus artedii), rainbow smelt (Omerus mordax), and slimy sculpin (Cottus cognatus) as well as in zooplankton (> 102 &mn;m) and Mysis (Mysis relicta) between May and October. The seasonal variation may reflect seasonal shifts in the species abundance within the zooplankton community. Trophic magnification factors (TMF) derived from regressions of toxaphene congener concentrations versus δ15N were > 1 for most octa- and nonachlorobornanes in Lake Superior except B8-1413 (P26) and B9-715. Log bioaccumulation factors (BAFs) for toxaphene congeners in lake trout (ng/g lipid/ng/L dissolved) ranged from 4.54 to 9.7 and were significantly correlated with log octanol-water partition coefficients. TMFs observed for total toxaphene and congener B9-1679 in Lake Superior were similar to those in Arctic lakes, as well as to previous studies in the Great Lakes, which suggests that the bioaccumulation behavior of toxaphene is similar in pelagic food webs of large, cold water systems. However, toxaphene concentrations were lower in lake trout from Siskiwit Lake and lakes in northwestern Ontario than in Lake Superior possibly because of shorter food chains and greater reliance on zooplankton or

  11. The jellification of north temperate lakes

    PubMed Central

    Jeziorski, Adam; Tanentzap, Andrew J.; Yan, Norman D.; Paterson, Andrew M.; Palmer, Michelle E.; Korosi, Jennifer B.; Rusak, James A.; Arts, Michael T.; Keller, Wendel (Bill); Ingram, Ron; Cairns, Allegra; Smol, John P.

    2015-01-01

    Calcium (Ca) concentrations are decreasing in softwater lakes across eastern North America and western Europe. Using long-term contemporary and palaeo-environmental field data, we show that this is precipitating a dramatic change in Canadian lakes: the replacement of previously dominant pelagic herbivores (Ca-rich Daphnia species) by Holopedium glacialis, a jelly-clad, Ca-poor competitor. In some lakes, this transformation is being facilitated by increases in macro-invertebrate predation, both from native (Chaoborus spp.) and introduced (Bythotrephes longimanus) zooplanktivores, to which Holopedium, with its jelly coat, is relatively invulnerable. Greater representation by Holopedium within cladoceran zooplankton communities will reduce nutrient transfer through food webs, given their lower phosphorus content relative to daphniids, and greater absolute abundances may pose long-term problems to water users. The dominance of jelly-clad zooplankton will likely persist while lakewater Ca levels remain low. PMID:25411451

  12. Partial diel vertical migrations in pelagic fish.

    PubMed

    Mehner, Thomas; Kasprzak, Peter

    2011-07-01

    1. Field studies on diel vertical migration (DVM) usually report uniform behaviour with population-wide ascents and descents during crepuscular periods. This contrasts partial seasonal migrations of many animal populations, where individuals choose either the resident or the migrant strategy depending on population density, feeding opportunity and predation risk in the resident and migrant habitats. 2. We tested whether DVM of freshwater zooplanktivorous fish (Coregonus spp.) resembles partial migrations. Twenty-eight hydroacoustic surveys were performed in the deep Lake Stechlin (Germany) between 2000 and 2010, with samplings encompassing all months between March and December. Zooplankton samples were simultaneously taken in epilimnetic and hypolimnetic layers. Fish obtained from depth-stratified samplings by a midwater trawl were used to test for individual differences between residents and migrants. 3. We show for the first time that DVMs of freshwater fish resemble patterns of partial migrations often found in seasonal environments. Across all samplings, 7-33% of fish did not ascend at dusk, but exhibited the resident strategy. The proportion or residents increased at low zooplankton feeding rates in the daytime habitat and during months when the temperature difference between daytime and night-time habitats was minor. 4. Slightly larger size and higher caloric density of migrants over residents in one of the coexisting Coregonus species suggested that individual differences contributed to the migration strategy performed. However, these results were based on one sample only, and extrapolation to the entire data set is not possible. 5. Our results are indirect evidence that the balance between migrants and residents may primarily depend on the trade-off between feeding gains and metabolic and predation costs of migration. However, the results also suggest that the global fitness consequences for the resident and migrant strategies may not be identical

  13. Nearshore energy subsidies support Lake Michigan fishes and invertebrates following major changes in food web structure

    USGS Publications Warehouse

    Turschak, Benjamin A; Bunnell, David B.; Czesny, Sergiusz J.; Höök, Tomas O.; Janssen, John; Warner, David M.; Bootsma, Harvey A

    2014-01-01

    Aquatic food webs that incorporate multiple energy channels (e.g. nearshore benthic or pelagic) with varying productivity and turnover rates convey stability to biological communities by providing multiple independent energy sources. Within the Lake Michigan food web, invasive dreissenid mussels have caused rapid changes to food web structure and potentially altered the channels through which consumers acquire energy. We used stable C and N isotopes to determine how Lake Michigan food web structure has changed in the past decade, coincident with the expansion of dreissenid mussels, decreased pelagic phytoplankton production and increased nearshore benthic algal production. Fish and invertebrate samples collected from sites around Lake Michigan were analyzed to determine taxa-specific 13C:12C (delta 13C) and 15N:14N (delta 15N) ratios. Sampling took place during two distinct periods, 2002-2003 and 2010-2012, that spanned the period of dreissenid expansion, and included nearshore, pelagic and profundal fish and invertebrate taxa. Magnitude and direction of the 13C shift indicated significantly greater reliance upon nearshore benthic energy sources among nearly all fish taxa as well as profundal invertebrates. Although the mechanisms underlying this 13C shift likely varied among species, possible causes include the transport of benthic algal production to offshore waters and an increased reliance on nearshore prey items. Delta 15N shifts were more variable and of smaller magnitude across taxa although declines in delta 15N among some pelagic fishes may indicate a shift to alternative prey resources. Lake Michigan fishes and invertebrates appear to have responded to dreissenid induced changes in nutrient and energy pathways by switching from pelagic to alternative nearshore energy subsidies. Although large shifts in energy allocation (i.e. pelagic to nearshore benthic) resulting from invasive species appear to have affected total production at upper trophic

  14. Conceptual geologic model and native state model of the Roosevelt Hot Springs hydrothermal system

    SciTech Connect

    Faulder, D.D.

    1991-01-01

    A conceptual geologic model of the Roosevelt Hot Springs hydrothermal system was developed by a review of the available literature. The hydrothermal system consists of a meteoric recharge area in the Mineral Mountains, fluid circulation paths to depth, a heat source, and an outflow plume. A conceptual model based on the available data can be simulated in the native state using parameters that fall within observed ranges. The model temperatures, recharge rates, and fluid travel times are sensitive to the permeability in the Mineral Mountains. The simulation results suggests the presence of a magma chamber at depth as the likely heat source. A two-dimensional study of the hydrothermal system can be used to establish boundary conditions for further study of the geothermal reservoir.

  15. 16-year trends in elements of lichens at Theodore Roosevelt National Park, ND

    USGS Publications Warehouse

    Bennett, J.P.; Wetmore, C.M.

    2000-01-01

    An epiphytic lichen and a soil lichen in two very closely related genera (Parmelia sulcata and Xanthoparmelia chlorochroa, respectively) were sampled 16 years apart at Theodore Roosevelt National Park in North Dakota and measured for their elemental content. Mercury and cadmium decreased approximately 30% over the time period in both species. Sulfur decreased 8% in the epiphytic species, but increased 20% in the soil lichen. Factor analysis revealed that soil elements were higher in the soil lichen, indicating there was some soil contamination in that species. A relationship between iron and titanium was found only in the soil lichen. Sulfur and mercury were highly enriched in both species relative to the soil, which suggests that the atmosphere is a contributing source of these elements. New baseline values were calculated, 22 elements for both species, although it is not recommended that the soil lichen be sampled in the future.

  16. Climatic and density influences on recruitment in an irruptive population of Roosevelt elk

    USGS Publications Warehouse

    Starns, Heath D.; Ricca, Mark A.; Duarte, Adam; Weckerly, Floyd W.

    2014-01-01

    Current paradigms of ungulate population ecology recognize that density-dependent and independent mechanisms are not always mutually exclusive. Long-term data sets are necessary to assess the relative strength of each mechanism, especially when populations display irruptive dynamics. Using an 18-year time series of population abundances of Roosevelt elk (Cervus elaphus roosevelti) inhabiting Redwood National Park in northwestern California we assessed the influence of population size and climatic variation on elk recruitment and whether irruptive dynamics occurred. An information-theoretic model selection analysis indicated that abundance lagged 2 years and neither climatic factors nor a mix of abundance and climatic factors influenced elk recruitment. However, density-dependent recruitment differed between when the population was declining and when the population increased and then stabilized at an abundance lower than at the start of the decline. The population displayed irruptive dynamics.

  17. Bipole-dipole survey at Roosevelt Hot Springs, Thermal Area, Beaver County, Utah

    SciTech Connect

    Frangos, W.; Ward, S.H.

    1980-09-01

    A bipole-dipole electrical resistivity survey at Roosevelt Hot Springs thermal area, Beaver County, Utah was undertaken to evaluate the technique in a well-studied Basin and Range geothermal prospect. The major electrical characteristics of the area are clearly revealed but are not particularly descriptive of the geothermal system. More subtle variations of electrical resistivity accompanying the geothermal activity are detectable, although the influence of near-surface lateral resistivity variations imposes upon the survey design the necessity of a high station density. A useful practical step is to conduct a survey using transmitter locations and orientations which minimize the response of known features such as the resistivity boundary due to a range front fault. Survey results illustrate the effects of transmitter orientation and placement, and of subtle lateral resistivity variations. A known near-surface conductive zone is detected while no evidence is found for a deep conductive region.

  18. A new look at the Lake Superior biomass size-spectrum

    EPA Science Inventory

    We combined data from multiple sampling programs to describe the Lake Superior pelagic biomass size structure. The data represented phytoplankton, zooplankton and prey-fish that spanned over 10 orders of magnitude in size and two time periods separated by five years. The biomas...

  19. Initial Continuous Chemistry Results From The Roosevelt Island Ice Core (RICE)

    NASA Astrophysics Data System (ADS)

    Kjær, H. A.; Vallelonga, P. T.; Simonsen, M. F.; Neff, P. D.; Bertler, N. A. N.; Svensson, A.; Dahl-Jensen, D.

    2014-12-01

    The Roosevelt Island ice core (79.36° S, -161.71° W) was drilled in 2011-13 at the top of the Roosevelt Island ice dome, a location surrounded by the Ross ice shelf. The RICE ice core provides a unique opportunity to look into the past evolution of the West Antarctic Ice sheet. Further the site has high accumulation; 0.26 m of ice equivalent is deposited annually allowing annual layer determination for many chemical parameters. The RICE core was drilled to bedrock and has a total length of 763 metres. Preliminary results derived from water isotopes suggest that the oldest ice reaches back to the Eemian, with the last glacial being compressed in the bottom 60 metres. We present preliminary results from the RICE ice core including continuous measurements of acidity using an optical dye method, insoluble dust particles, conductivity and calcium. The core was analyzed at the New Zealand National Ice Core Research Facility at GNS Science in Wellington. The analytical set up used to determine climate proxies in the ice core was a modified version of the Copenhagen CFA system (Bigler et al., 2011). Key volcanic layers have been matched to those from the WAIS record (Sigl et al., 2013). A significant anti-correlation between acidity and calcium was seen in the Holocene part of the record. Due to the proximity to the ocean a large fraction of the calcium originates from sea salt and is in phase with total conductivity and sodium. In combination with the insoluble dust record, calcium has been apportioned into ocean-related and dust-related sources. Variability over the Holocene is presented and attributed to changing inputs of marine and dust aerosols.

  20. Species succession and sustainability of the Great Lakes fish community

    USGS Publications Warehouse

    Eshenroder, Randy L.; Burnham-Curtis, Mary K.

    1999-01-01

    This article concentrates on the sustainability of the offshore pelagic and deepwater fish communities that were historically dominated by lake trout (Salvelinus namaycush). The causes of alteration in these fish communities (i.e., overfishing, introductions, and cultural eutrophication) were identified by Loftus and Regier (1972). Here we look at the ecology of these altered communities in relation to sustainability and discuss the need for restoration.

  1. Diet and habitat use by age-0 deepwater sculpins in northern Lake Huron, Michigan and the Detroit River

    USGS Publications Warehouse

    Roseman, Edward F.

    2014-01-01

    Deepwater sculpins (Myoxocephalus thompsonii) are an important link in deepwater benthic foodwebs of the Great Lakes. Little information exists about deepwater sculpin spawning habits and early life history ecology due to difficulty in sampling deep offshore habitats. Larval and age-0 deepwater sculpins collected in northern Lake Huron and the Detroit River during 2007 were used to improve our understanding of their habitat use, diet, age, and growth. Peak larval density reached 8.4/1000 m3 in the Detroit River during April and was higher than that in Lake Huron. Offshore bottom trawls at DeTour and Hammond Bay first collected benthic age-0 deepwater sculpins in early September when fish were ≥ 25 mm TL. Otolith analysis revealed that hatch dates for pelagic larvae occurred during late March and larvae remained pelagic for 40 to 60 days. Diet of pelagic larvae (10–21 mm TL) was dominated by calanoid copepods at all sample locations. Diets of benthic age-0 fish varied by location and depth: Mysis and chironomids were prevalent in fish from Hammond Bay and the 91 m site at DeTour, but only chironomids were found in fish from the 37 m DeTour site. This work showed that nearshore epilimnetic sites were important for pelagic larvae and an ontogenetic shift from pelagic planktivore to benthivore occurred at about 25 mm TL in late summer. Age analysis showed that larvae remained pelagic long enough to be transported through the St. Clair–Detroit River system, Lake Erie, and the Niagara River, potentially contributing to populations in Lake Ontario.

  2. Vulnerability of the Oceanic Whitetip Shark to Pelagic Longline Fisheries

    PubMed Central

    Tolotti, Mariana Travassos; Bach, Pascal; Hazin, Fábio; Travassos, Paulo; Dagorn, Laurent

    2015-01-01

    A combination of fisheries dependent and independent data was used to assess the vulnerability of the oceanic whitetip shark to pelagic longline fisheries. The Brazilian tuna longline fleet, operating in the equatorial and southwestern Atlantic, is used as a case study. Fisheries dependent data include information from logbooks (from 1999 to 2011) and on-board observers (2004 to 2010), totaling 65,277 pelagic longline sets. Fisheries independent data were obtained from 8 oceanic whitetip sharks tagged with pop-up satellite archival tags in the area where longline fleet operated. Deployment periods varied from 60 to 178 days between 2010 and 2012. Tagging and pop-up sites were relatively close to each other, although individuals tended to travel long distances before returning to the tagging area. Some degree of site fidelity was observed. High utilization hotspots of tagged sharks fell inside the area under strongest fishing pressure. Despite the small sample size, a positive correlation between tag recorded information and catch data was detected. All sharks exhibited a strong preference for the warm and shallow waters of the mixed layer, spending on average more than 70% of the time above the thermocline and 95% above 120 m. Results indicate that the removal of shallow hooks on longline gear might be an efficient mitigation measure to reduce the bycatch of this pelagic shark species. The work also highlights the potential of tagging experiments to provide essential information for the development of spatio-temporal management measures. PMID:26492091

  3. Developmental defects in pelagic fish embryos from the western Baltic

    NASA Astrophysics Data System (ADS)

    v. Westernhagen, H.; Dethlefsen, V.; Cameron, P.; Berg, J.; Fürstenberg, G.

    1988-03-01

    In February/March 1983 and 1984 a survey of pelagic fish eggs was conducted in the western Baltic (Kiel Bight), employing a horizontally towed plankton net (1 m Ø and 300 μm mesh). Maximum egg numbers in the upper meter of the S=21×10-3 salinity layer were 200·100 m-3. The most abundant eggs were cod (up to 142 eggs·100 m-3), followed by plaice (up to 74 eggs·100 m-3) and flounder (20 eggs·100 m-3). A considerable percentage of embryos of all species displayed aberrant development. In 1983 18% of cod, 22% of flounder and 24% of plaice eggs caught contained defective embryos; in 1984 this number was larger, ranging from 28% in plaice over 32% in cod to 44% in flounder. Early developmental stages showed the highest malformation rates (up to 51% in the case of early flounder embryos). With progressive development, malformations decreased in numbers, being lowest prior to hatching. Highest rates of malformations were recorded in the Mecklenburg Bight in 1983. A second area with high incidence of malformation rates was located south and east of the island of Langeland. Several reasons, including environmental and anthropogenic factors, for the occurrence of malformed embryos in pelagic fish eggs are discussed. The potential of malformation rates in embryos of pelagic fish eggs as a tool for monitoring is considered.

  4. Vulnerability of the Oceanic Whitetip Shark to Pelagic Longline Fisheries.

    PubMed

    Tolotti, Mariana Travassos; Bach, Pascal; Hazin, Fábio; Travassos, Paulo; Dagorn, Laurent

    2015-01-01

    A combination of fisheries dependent and independent data was used to assess the vulnerability of the oceanic whitetip shark to pelagic longline fisheries. The Brazilian tuna longline fleet, operating in the equatorial and southwestern Atlantic, is used as a case study. Fisheries dependent data include information from logbooks (from 1999 to 2011) and on-board observers (2004 to 2010), totaling 65,277 pelagic longline sets. Fisheries independent data were obtained from 8 oceanic whitetip sharks tagged with pop-up satellite archival tags in the area where longline fleet operated. Deployment periods varied from 60 to 178 days between 2010 and 2012. Tagging and pop-up sites were relatively close to each other, although individuals tended to travel long distances before returning to the tagging area. Some degree of site fidelity was observed. High utilization hotspots of tagged sharks fell inside the area under strongest fishing pressure. Despite the small sample size, a positive correlation between tag recorded information and catch data was detected. All sharks exhibited a strong preference for the warm and shallow waters of the mixed layer, spending on average more than 70% of the time above the thermocline and 95% above 120 m. Results indicate that the removal of shallow hooks on longline gear might be an efficient mitigation measure to reduce the bycatch of this pelagic shark species. The work also highlights the potential of tagging experiments to provide essential information for the development of spatio-temporal management measures. PMID:26492091

  5. Distribution and dispersal of the zebra mussel (Dreissena polymorpha) in the Great Lakes region

    USGS Publications Warehouse

    Griffiths, Ronald W.; Schloesser, Donald W.; Leach, Joseph H.; Kovalak, William P.

    1991-01-01

    Dreissena polymorpha (Pallas), a small mussel common throughout most of Europe, was discovered in June of 1988 in the southern part of Lake St. Clair. Length–frequency analyses of populations from the Great Lakes and review of historical benthic studies suggest that the mussel was introduced into Lake St. Clair in late 1986, probably as a result of the discharge of ballast water from an ocean-crossing vessel. Following the 1990 reproductive season, Dreissenapopulations ranged from the head of the St. Clair River, through Lake St. Clair, the Detroit River, Lake Erie, the Welland Canal, and the Niagara River to the western basin and southern shoreline of Lake Ontario. Isolated populations were found in the St. Lawrence River and in harbours in Lakes Huron, Michigan, and Superior. The rapid dispersal of this organism has resulted from its high fecundity, pelagic larval stage, bysso-pelagic drifting ability of juveniles, and human activities associated with commercial shipping, fishing, and boating (research and pleasure). Virtually any waterbody that can be reached by boaters and fisherman within a few days travel of the lower Great Lakes, particularly Lake Erie, seems to be at risk of being invaded by this nuisance species.

  6. Status of rainbow smelt in the U.S. waters of Lake Ontario, 2013: Section 12 of NYSDEC Lake Ontario Unit annual report 2013

    USGS Publications Warehouse

    Weidel, Brian C.; Connerton, Michael J.

    2014-01-01

    Rainbow Smelt Osmerus mordax are the second most abundant pelagic prey fish in Lake Ontario after Alewife Alosa psuedoharengus. The 2013, USGS/NYSDEC bottom trawl assessment indicated the abundance of Lake Ontario age-1 and older Rainbow Smelt decreased by 69% relative to 2012. Length frequency-based age analysis indicated that age-1 Rainbow Smelt constituted approximately 50% of the population, which is similar to recent trends where the proportion of age-1 has ranged from 95% to 42% of the population. While they constituted approximately half of the catch, the overall abundance index for age 1 was one of the lowest observed in the time series, potentially a result of cannibalism from the previous year class. Combined data from all bottom trawl assessments along the southern shore and eastern basin indicate the proportion of the fish community that is Rainbow Smelt has declined over the past 30 years. In 2013 the proportion of the pelagic fish catch (only pelagic species) that was Rainbow Smelt was the second lowest in the time series at 3.1%. Community diversity indices, based on bottom trawl catches, indicate that Lake Ontario fish community diversity, as assessed by bottom trawls, has sharply declined over the past 36 years and in 2013 the index was the lowest value in the time series. Much of this community diversity decline is driven by changes in the pelagic fish community and dominance of Alewife.

  7. Water geochemistry and hydrogeology of the shallow aquifer at Roosevelt Hot Springs, southern Utah: A hot dry rock prospect

    SciTech Connect

    Vuataz, F.D.; Goff, F.

    1987-12-01

    On the western edge of the geothermal field, three deep holes have been drilled that are very hot but mostly dry. Two of them (Phillips 9-1 and Acord 1-26 wells) have been studied by Los Alamos National Laboratory for the Hot Dry Rock (HDR) resources evaluation program. A review of data and recommendations have been formulated to evaluate the HDR geothermal potential at Roosevelt. The present report is directed toward the study of the shallow aquifer of the Milford Valley to determine if the local groundwater would be suitable for use as make-up water in an HDR system. This investigation is the result of a cooperative agreement between Los Alamos and Phillips Petroleum Co., formerly the main operator of the Roosevelt Hot Springs Unit. The presence of these hot dry wells and the similar setting of the Roosevelt area to the prototype HDR site at Fenton Hill, New Mexico, make Roosevelt a very good candidate site for creation of another HDR geothermal system. This investigation has two main objectives: to assess the water geochemistry of the valley aquifer, to determine possible problems in future make-up water use, such as scaling or corrosion in the wells and surface piping, and to assess the hydrogeology of the shallow groundwaters above the HDR zone, to characterize the physical properties of the aquifer. These two objectives are linked by the fact that the valley aquifer is naturally contaminated by geothermal fluids leaking out of the hydrothermal reservoir. In an arid region where good-quality fresh water is needed for public water supply and irrigation, nonpotable waters would be ideal for an industrial use such as injection into an HDR energy extraction system. 50 refs., 10 figs., 10 tabs.

  8. CS2 and COS in soil gases of the Roosevelt Hot Springs Known Geothermal Resource Area, Beaver County, Utah

    USGS Publications Warehouse

    Hinkle, Margaret E.; Harms, Thelma F.

    1978-01-01

    Soil-gas samples were collected in two parallel traverses across the Dome fault zone of the Roosevelt Hot Springs Known Geothermal Resource Area. Gas chromatographic analyses of the samples showed anomalous concentrations of CS3 and COS east of the Dome fault; higher concentrations of CS2 and COS also occurred over an area in which the hydrothermal system is close to the surface. Measurement of these gases may be useful in exploration for new geothermal sources.

  9. CONNECTICUT LAKES

    EPA Science Inventory

    This is a 1:24,000-scale datalayer of named lakes in Connecticut. It is a polygon Shapefile that includes all lakes that are named on the U.S. Geologicial Survey (USGS) 7½ minute topographic quadrangle maps that cover the State of Connecticut, plus other officially named lakes i...

  10. Lake Powell

    Atmospheric Science Data Center

    2014-05-15

    article title:  Lake Powell     View Larger Image ... (14.42 mb)   This true-color image over Lake Powell was acquired by Multi-angle Imaging SpectroRadiometer (MISR) in late March 2000. Lake Powell was formed with the construction of the Glen Canyon Dam in 1963, on the ...