Nereus Program’s Becca Selden (Wellesley College) and Malin Pinsky (Rutgers University) are co-authors on a new study published in Global Change Biology, that investigated range shifts for marine fish species during a time period of rapid warming on the Northeast U.S. shelf. The authors analyzed annual cold and warm range edge dynamics, finding the cold edge to be a better indicator of climate tracking than the warm. You can read the full abstract below, as well as access the article here.
Abstract: Species around the world are shifting their ranges in response to climate change. To make robust predictions about climate‐related colonizations and extinctions, it is vital to understand the dynamics of range edges. This study is among the first to examine annual dynamics of cold and warm range edges, as most global change studies average observational data over space or over time. We analyzed annual range edge dynamics of marine fishes—both at the individual species level and pooled into cold‐ and warm‐edge assemblages—in a multi‐decade time‐series of trawl surveys conducted on the Northeast U.S. Shelf during a period of rapid warming. We tested whether cold edges show stronger evidence of climate tracking than warm edges (due to non‐climate processes or time lags at the warm edge; the biogeography hypothesis or extinction debt hypothesis), or whether they tracked temperature change equally (due to the influence of habitat suitability; the ecophysiology hypothesis). In addition to exploring correlations with regional temperature change, we calculated species‐ and assemblage‐specific sea bottom and sea surface temperature isotherms and used them to predict range edge position. Cold edges shifted further and tracked sea surface and bottom temperature isotherms to a greater degree than warm edges. Mixed‐effects models revealed that for a one‐degree latitude shift in isotherm position, cold edges shifted 0.47 degrees of latitude, and warm edges shifted only 0.28 degrees. Our results suggest that cold range edges are tracking climate change better than warm range edges, invalidating the ecophysiology hypothesis. We also found that even among highly mobile marine ectotherms in a global warming hotspot, few species are fully keeping pace with climate.
Fredston-Hermann, A., Selden, B., Pinsky, M., Gaines, S.D., & Halpern, B.S. (2020). Cold range edges of marine fishes track climate change better than warm edges. Global Change Biology. doi:10.1111/gcb.15035 link