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Mortality, Growth, and Transport of Larval Atlantic Herring Clupea harengus in Maine Coastal Waters
Author(s) -
Graham Joseph J.,
Townsend David W.
Publication year - 1985
Publication title -
transactions of the american fisheries society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.696
H-Index - 86
eISSN - 1548-8659
pISSN - 0002-8487
DOI - 10.1577/1548-8659(1985)114<490:mgatol>2.0.co;2
Subject(s) - clupea , herring , fishery , atlantic herring , larva , ichthyoplankton , oceanography , biology , fish <actinopterygii> , ecology , geology
Microstructural growth increments in otoliths of autumn‐spawned, larval Atlantic herring from the Sheepscot River estuary of western Maine and Sullivan Harbor of eastern Maine provided estimates of mortality, growth, or transport times (or combinations of these) for 19 cohorts in 1980–1982. Mortality within seven cohorts averaged 2%/d (range, 0.7–3.1%/d). Growth (12 cohorts) averaged 0.199 mm/d (0.123–0.270). Transport times of larvae hatched on the spawning ground of eastern Maine and captured in the harbor and estuary (8 cohorts) averaged 16.5 d (5–35 d). Estimates of mortalities agreed (P > 0.05) with those from multicohorts obtained in the 1960s and 1970s (0.4–3.2%/d). Among the cohorts, extremes of larval growth differed significantly (P < 0.05), but most were similar and showed a weak trend toward slower growth in 1980–1982. No difference in growth (P > 0.05) was noted between larvae of cohorts spawned relatively early and those of a cohort spawned late. Larval mortality and growth appeared inversely correlated (P < 0.05) for seven cohorts. Variability in transport times was seven‐fold, suggesting a wide dispersal of larval cohorts throughout the coastal water while in transit from the spawning grounds to inshore areas of retention. Possibly, different members of the same cohort from the eastern coastal spawning ground moved 95 km (straight‐line distance) in 8 d to Sullivan Harbor and also 273 km to the Sheepscot estuary in 35 d. Although larval recruitment mechanisms are manifested inshore, it is suggested that such mechanisms are anticipated through cohort development in the coastal water.