South Atlantic Bight reef fish distributions: lack of poleward shifts amid climate change

Climate change is generally expected to drive species poleward in response to warming temperatures; however, responses can be complex and counterintuitive. This study analyzed the trends of bottom temperature, species distributions, and population size for 16 species of reef fishes in the South Atlantic Bight (SAB) over 2 decades to assess whether these reef fishes are exhibiting climate-driven shifts in distribution and biomass. Results indicated negligible changes in bottom water temperatures. Most species maintained stable distributions, although, unexpectedly, 3 species shifted southward while only one shifted poleward. However, over half of the species experienced declines in biomass over time, despite no significant increase in their temperature of occurrence. These findings suggest that bottom water temperatures are not currently the dominant driver of SAB reef fish distribution and population dynamics, while fishing pressure and recruitment failure may play a role. This study provides a critical baseline for understanding SAB reef fish distributions and highlights the importance of regional variability in a warming world.