Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8848982 | Journal of Experimental Marine Biology and Ecology | 2018 | 9 Pages |
Abstract
Identifying the natal origin of marine fish is important to understand connectivity and productivity among populations residing in different habitats. Capelin, Mallotus villosus, is a key marine forage fish species that spawns at both beach (warmer, less saline) and deep-water (15-40â¯m; cooler, more saline) habitats along the northeast Newfoundland coast. Currently, the contribution from each habitat to the spawning population is unknown. Previous research, where capelin eggs from known families were lab-reared, identified family-based otolith chemical signatures in the pre-hatch (embryonic) region of larvae. In this study, we investigated whether temperature and salinity influenced embryonic otolith chemistry to determine whether variation in environmental conditions would result in habitat-specific signatures, thereby overwhelming family-based signatures and allowing the identification of natal origin. Capelin eggs from many families were incubated together under controlled temperature (4, 8, 10â¯Â°C) and salinity (10, 20, 30â¯psu) treatments in the lab and uncontrolled conditions within each habitat in the field. Elemental concentrations (i.e., Sr, Ba, Mg, Mn) in the pre-hatch region of 1-day old larvae were quantified via LA ICP-MS. Elemental concentrations varied among individuals reared under identical conditions, likely due to family-based chemical signatures. Despite this variation, mean elemental concentrations differed when mean temperatures varied by â¥4â¯Â°C between treatments (lab) and rearing habitats (field), resulting in high treatment- and habitat-specific classification success (~73-88%) of individuals. In contrast, embryonic otolith chemistry did not vary consistently with salinity. Temperature differs consistently between rearing habitats and, thus, these findings suggest that when capelin rearing habitats differ by â¥4â¯Â°C within a year, chemical signatures in the embryonic otolith may be used to determine the natal origin of individuals.
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Authors
Alison R. Loeppky, Gail K. Davoren,