Dataset: Adult black sea bass winter survival and lipid dynamics: Wild fish

This dataset contains adult Black Sea Bass (Centropristis striata) winter survival and lipid accumulation in wild-caught fish in Long Island Sound (September 2022 to April 2023). This dataset includes data from fish collected concurrently with those used in a related mesocosm experiment (run Oct 2022 to Apr 2023), with fish collected at the same reef (see 'Related Datasets' section). Study description: We experimentally examined overwintering potential of adult Black Sea Bass (Centropristis striata), an ecologically and economically important fish that seasonally migrates from offshore overwintering grounds to coastal feeding and nursery areas. We collected adults from Long Island Sound in September 2022 and reared them in a laboratory-mesocosm experiment under a contemporary seasonal temperature profile for Long Island Sound (LIS; October 2022 – April 2023) to assess their potential to survive and accumulate lipids throughout the winter. We also fed experimental adults two diet items (blue mussels and Atlantic herring), which are commonly found in Long Island Sound. In addition, we sampled fish from the same reef in LIS at the start (October) and end (April) of the experiment to identify lipid dynamics in wild fish that migrate offshore. Experimental C. striata growth throughout the winter was negligible with high mortality (> 50% observed). While survivors fed herring had higher tissue lipid contents, mortality was 2x higher than for fish fed mussels. In contrast, to the experimental fish, wild-captured fish in the spring had higher gonadosmatic indices than that for survivors across both diet treatments, which was most similar to fall-captured fish. While some fish survived throughout the winter, current winter bottom temperatures still preclude a year-round C. striata presence within Long Island Sound. Overwintering inshore is still disadvantageous compared to seasonally migrating due to surviving experimental fish having lower gonadosomatic indices, suggesting that the offshore overwintering period is a time to build energy reserves. However, as coastal waters continue to warm, changing conditions could lead populations to become year-round residents of Long Island Sound, thus increasing C. striata abundance.