Winter growth and lipid accumulation in juvenile Black sea bass exposed to varying food and temperature conditions during lab experiments conducted from September 2021 to April 2022 at UConn Avery Point

The northern stock of Black sea bass (BSB, Centropristis striata) has greatly expanded over the past decade, potentially due to warming Northwest Atlantic shelf waters affecting overwintering especially in juveniles. To gather better empirical data we quantified winter growth and lipid accumulation in BSB juveniles from Long Island Sound using two complementing experiments. The data from Experiment 1 are presented here.

Experiment 1 measured individual length growth (GR), weight-specific growth (SGR), growth efficiency, and lipid content at constant food and three static temperatures: 6°, 12°, and 19° Celsius (C). Average GR (SGR) decreased from 0.24 millimeters per day (mm d-1) at 19°C (0.89% d-1) to 0.15 mm d-1 at 12°C (0.54% d-1) to 0.04 mm d-1 at 6°C (0.17% d-1). Even at the coldest temperature, most juveniles sustained positive GRs and SGRs; hence, the species’ true thermal growth minimum may be below 6°C. However, lipid accumulation was greatest at 12°C, which is close to what overwintering juveniles likely encounter offshore.

The data from Experiment 2 are presented in a related dataset (https://www.bco-dmo.org/dataset/898012). In both experiments, juveniles disproportionally accumulated lipid over lean mass, with lipid proportions tripling in Exp2 from 4% at 65 mm to 12% at 120 mm.