Sample records for lightships
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ERIC Educational Resources Information Center
Reed, Judith
1973-01-01
Describes activities abroad Liberty Chesapeake,'' a 133-foot-long retired lightship moored off the East Potomac Park, Washington, D.C., and used as a public excursion boat and floating laboratory by the U.S. National Park Service. (DS)
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Optical design of system for a lightship
NASA Astrophysics Data System (ADS)
Chirkov, M. A.; Tsyganok, E. A.
2017-06-01
This article presents the result of the optical design of illuminating optical system for lightship using the freeform surface. It shows an algorithm of optical design of side-emitting lens for point source using Freeform Z function in Zemax non-sequential mode; optimization of calculation results and testing of optical system with real diode
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Elementary Teacher's Resource Manual, Lightship Chesapeake, 1973-1974.
ERIC Educational Resources Information Center
National Park Service (Dept. of Interior), Washington, DC. National Capital Parks.
This resource guide was written to help teachers prepare students for a tour of the Lightship Chesapeake in Washington, D.C. However, much of the information would be useful in any unit on marine biology and water pollution. A glossary of nautical terms is included as well as possible laboratory assignments and related activities in such areas as…
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VIEW OF FOREDECK FROM ATOP PILOT HOUSE, SIGNAL BELL SEEN ...
VIEW OF FOREDECK FROM ATOP PILOT HOUSE, SIGNAL BELL SEEN IN FOREGROUND WITH AUXILIARY MUSHROOM ANCHOR AND LIFTING TACKLE ON STARBOARD (RIGHT) SIDE. - Lightship 116, Pier 3, Inner Harbor, Baltimore, Independent City, MD
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50 CFR 648.203 - Gear restrictions.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Gear restrictions. 648.203 Section 648.203... Herring Fishery § 648.203 Gear restrictions. (a) Midwater trawl gear may only be used by a vessel issued a... Lightship Area as described in § 648.81(c)(1), provided it complies with the midwater trawl gear exemption...
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DETAIL SHOWING THE STERN TUBE, PROPELLOR SHAFT AND RELATED EQUIPMENT ...
DETAIL SHOWING THE STERN TUBE, PROPELLOR SHAFT AND RELATED EQUIPMENT IN THE LOWER MOTOR ROOM. NOTE THE WORM-WHEEL TURNING GEAR AT CENTER, AND THE KINGBURY THRUST BEARING IN THE FOREGROUND IMMEDIATELY FOREWORD OF THE WORM-WHEEL GEAR. NOTE ALSO THE 50-POUND IRON BALLAST BLOCKS STACKED BETWEEN FRAMES. - Lightship 116, Pier 3, Inner Harbor, Baltimore, Independent City, MD
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Davies, Kimberley T A; Gentleman, W C; DiBacco, C; Johnson, C L
2015-09-01
This study examined whether a measured increase in average body size of adult sea scallops inside three fishery closed areas on Georges Bank (GB), United States (US), was sufficient to increase larval supply to closed areas and open fishing areas in both US and Canadian areas of the Bank. The effects of adult scallop density-at-size and fecundity-at-size on egg production were compared among open and closed fishery areas, countries, and time periods before and after the closed areas were established. Estimated egg production was then used to define spawning conditions in a coupled biological-physical larval tracking model that simulated larval development, mortality, and dispersal. Results showed that order of magnitude increases in larval settlement after closure were facilitated by increases in size-dependant egg production inside and dispersal from Closed Areas I and II, but not Nantucket Lightship Closed Area. The distributions of both egg production and larval settlement became more uniform across the Bank, causing the relative contribution of Canadian larvae to US scallop aggregations to decrease after establishment of Closed Areas I and II. Decreases in small and medium-sized scallop density in Canada and decreases in large scallops over the US-Southern Flank after closure caused local declines in egg production but were not sufficient to negatively affect larval settlement at the regional scale. Our model suggests that the establishment of fishery closed areas on GB considerably strengthened larval supply and settlement within and among several adult scallop aggregations.
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NASA Astrophysics Data System (ADS)
Davies, Kimberley T. A.; Gentleman, W. C.; DiBacco, C.; Johnson, C. L.
2015-09-01
This study examined whether a measured increase in average body size of adult sea scallops inside three fishery closed areas on Georges Bank (GB), United States (US), was sufficient to increase larval supply to closed areas and open fishing areas in both US and Canadian areas of the Bank. The effects of adult scallop density-at-size and fecundity-at-size on egg production were compared among open and closed fishery areas, countries, and time periods before and after the closed areas were established. Estimated egg production was then used to define spawning conditions in a coupled biological-physical larval tracking model that simulated larval development, mortality, and dispersal. Results showed that order of magnitude increases in larval settlement after closure were facilitated by increases in size-dependant egg production inside and dispersal from Closed Areas I and II, but not Nantucket Lightship Closed Area. The distributions of both egg production and larval settlement became more uniform across the Bank, causing the relative contribution of Canadian larvae to US scallop aggregations to decrease after establishment of Closed Areas I and II. Decreases in small and medium-sized scallop density in Canada and decreases in large scallops over the US-Southern Flank after closure caused local declines in egg production but were not sufficient to negatively affect larval settlement at the regional scale. Our model suggests that the establishment of fishery closed areas on GB considerably strengthened larval supply and settlement within and among several adult scallop aggregations.