Dynamics of Ocean Quahog, Arctica isZandica Populations off the Middle Atlantic Coast of the United States
Abundance and size composition estimates of Middle Atlantic ocean quahog. Arctica is~dica ~ populations were derived from seven federal (BCF NMFS) research survey cruises conducted from Cape Cod to Cape Hatteras during 1965-1977. Sampling was performed with a hydraulic shellfish dredge utilizing a t...
Main Authors: | , , , , |
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Format: | Text |
Language: | English |
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Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.423.4653 http://www.nefsc.noaa.gov/publications/series/whlrd/whlrd7916.pdf |
Summary: | Abundance and size composition estimates of Middle Atlantic ocean quahog. Arctica is~dica ~ populations were derived from seven federal (BCF NMFS) research survey cruises conducted from Cape Cod to Cape Hatteras during 1965-1977. Sampling was performed with a hydraulic shellfish dredge utilizing a transect grid-type survey design, post-stratified to area/depth strata. Standardized tows of four minutes duration using a 121.92 cm (48 in) wide dredge sampled approximately 83 m2 of bottom per station. Minimum population size in numbers and biomass (meat weight) was calculated using mean quahog densities (1965-1977) expanded by strata a~eas. Within the surveyed regions, a standing crop of approximately 56.6 x 10 ocean quahogs was estimated. having a biomass of 1.5 x 106 metric tons (mt). The largest proportion of the resource (46%) was located off Long Island, with 44% off New Jersey and 10 % off the Delmarva Peninsula. Estimates of equilibrium yields for the Middle Atlantic quahog resource (Long Island th,'ough Delmarv~) ranged from 3,022 to 45,332 mt. assuming rates of instantaneous natural mortality |
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