Migration of juvenile American eels Anguilla rostrata between freshwater and estuary, as revealed by otolith microchemistry
Journal
Marine Ecology Progress Series
Journal Volume
310
Pages
219-233
Date Issued
2006
Author(s)
Abstract
The temporal patterns in the otolith Sr:Ca ratios of yellow-phase American eels Anguilla rostrata from the East River, Chester, on the Atlantic coast of Nova Scotia, Canada, indicated variable patterns of migration between river and estuarine/marine waters. About 29 % of yellow eels (n = 107) had a history of migration between river and estuary other than their initial entry. Male and sexually undifferentiated eels, potentially mostly male, comprised 96 % of the sample and females comprised 4 %, but the proportions of migratory and non-migratory eels did not vary by sex or development stage. Most migrants (81 %) made only 1 round trip, while 19 % made 2 round trips. Yellow eels with a migratory history were patchily distributed, with most (84 %) concentrated 9.4 km upriver. About 36 % of yellow eels showed a check (false annulus) corresponding with a habitat transition from estuary to river, while for 16 % of yellow eels the check occurred during the initial freshwater entry as an elver. Otolith checks not associated with a habitat transition occurred for 22 % of yellow eels, primarily at intermediate ages. Mean lengths-at-age were higher for eels with a history of primarily estuarine growth than for eels of primarily freshwater growth, as were annual growth rates (26.6 versus 21.7 mm yr-1). © Inter-Research 2006.
Subjects
American eel; Anguilla rostrata; Growth rate; Migratory history; Otolith check; Strontium:calcium ratios
SDGs
Other Subjects
developmental stage; eel; estuarine environment; freshwater environment; juvenile; migration; otolith; Atlantic Coast [North America]; Canada; Cheshire; Chester [Cheshire]; England; Eurasia; Europe; North America; Nova Scotia; United Kingdom; Western Europe; Anguilla rostrata
Type
journal article