Vertical Distribution and Sampling Variability of Larval and Juvenile Sand Lance (Ammodytessp.) on Nantucket Shoals and Georges Bank
| Autor: | D C Potter, R G Lough |
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| Rok vydání: | 1987 |
| Předmět: | |
| Zdroj: | Journal of Northwest Atlantic Fishery Science. 7:107-116 |
| ISSN: | 1811-8224 0250-6408 |
| DOI: | 10.2960/j.v7.a12 |
| Popis: | Vertical distribution and movement of sand lance larvae and juveniles «81 mm SL) are summarized from four cruises during winter and spring seasons in 1978, 1981 and 1983. Opening-closing nets (1-m 2 and 10-m 2 MOCNESS) were used to sample discrete strata for day and night vertical profiles and to make serial double-oblique transects for spatial variability. In December-January, recentlyhatched larvae (5 mm SL) were found throughout the water column in well-mixed shelf water, with highest density usually in the 10-20 m depth range. In February-March, the larger larvae (>10 mm SL) were found throughout the water column during both day and night, but these appeared to be in transition to adult behavior, with many of them living near the bottom during the day and moving up in the water column at night. In April, premetamorphic young (20-30 mm SL) were caught mostly at night, and their abundance increased with depth. In May, postmetamorphic juveniles (50-81 mm SL) were caught mostly at night. Presumably, they were near the bottom or burrowed in the substrate during the day. Avoidance of the samplers by large larvae (>10 mm) and juveniles prevents firm conclusions on their vertical distribution and movement. |
| Databáze: | OpenAIRE |
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