Population Statistics And Commercial Catch Rate Of American Lobster Homarus Americanus In The Charlestown Matunuck Rhode Island Region Of Block Island Sound

Author : Joseph R. Uzmann
Publisher :
ISBN 13 :
Total Pages : 102 pages
Book Rating : 4.3/5 (121 download)

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Download or read book Migration and Dispersion of Tagged American Lobsters, Homarus Americanus, on the Southern New England Continental Shelf written by Joseph R. Uzmann and published by . This book was released on 1977 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt: An apparently contiguous stock of American lobsters, Homarus americanus, is concentrated along the outer continental shelf margin and slope from Corsair Canyon westward and southward to the region of Baltimore Canyon. Between April 1968 and May 1971 we captured, tagged, and released a total of 7, 326 lobsters at 52 localities between Corsair Canyon and Baltimore Canyon. As of December 1972, 945 recaptures (12.9% recovery) had been reported, providing a basis for interpretation of seasonal and long-term movements, as well as measurements of growth rate and moult frequency. A classification scheme is developed and applied to distinguish between apparently directed seasonal movements (migrations), localized movements of less than 10 nautical miles (18.5 km), and long-period (>120 days) dispersions of 10 miles or more. This last category includes point to point tracks that cannot be objectively resolved in terms of directionality and may represent random dispersal, a summation of seasonally directed tracks, or both. We conclude from the track analyses that at least 20% of the offshore lobsters annually engage in directed shoalward migrations in spring and summer with return to the shelf margin and slope in fall and winter. This conclusion is reinforced by independent analysis of the time/depth/temperature associations of tagged lobsters at recapture which, of itself, suggests that an even larger proportion of the offshore lobsters annually effect directed migrations in response to seasonal temperature variations.