Biology and Population Changes of Northern Sand Lance (Ammodytes dubius) from the Gulf of Maine to the Middle Atlantic Bight
Trends in temporal and spatial abundance, and population size structure of the sand lance, Ammodytes dubius, were examined based on trawl survey data from 1963 to 1988. Reproduction, age structure and growth were evaluated in 1986-88 from the Gulf of Maine to Middle Atlantic Bight region off eastern...
| Main Authors: | , , , , |
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.614.2128 http://journal.nafo.int/j11/nelson.pdf |
| Summary: | Trends in temporal and spatial abundance, and population size structure of the sand lance, Ammodytes dubius, were examined based on trawl survey data from 1963 to 1988. Reproduction, age structure and growth were evaluated in 1986-88 from the Gulf of Maine to Middle Atlantic Bight region off eastern USA. Relative abundance indices which were near zero prior to 1976, increased dramatically (5-10 fold) from 1976 to 1981 in all regions studied. Subsequently, abun-dance dropped from 1982 to 1987. Gonadal recrudescence of A. dubius begins in late July and males appeared to mature earlier in a reproductive season than females. Estimates of fecundity ranged from 1,169 to 22,904 ova per female for sand lance 137 to 213 mm total length. Maximum age estimated from otoliths and vertebrae was 5 years. Age at 50 % maturity was age II for all regions in spring. Comparison of Von Bertalanffy growth curves derived for A. dubius from the study regions to published values from Newfoundland and Nova Scotia suggests a decline in length and age with declining latitude. |
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