LONG-TERM CHANGES IN LARVAL GREY ROCKCOD: A POTENTIAL CLIMATE CHANGE “WINNER” IN THE WESTERN ANTARCTIC PENINSULA

The western Antarctic Peninsula (WAP) is one of the fastest warming regions globally, leading to decreased sea ice coverage and increased ocean temperature. Many Antarctic fishes have specialized adaptations to survive freezing waters, and thus assumed to have low potential for adapting to a warmer ocean. However, species with physiological and environmental plasticity may experience improved survival and expanded livable ranges, making them climate change “winners” in the Southern Ocean. We used a 27-year time series from the Palmer Antarctica Long-Term Ecological Research (PAL LTER) program of length, abundance, and distributional data for the larvae of the Notothenioid Lepidonotothen squamifrons (grey rockcod) to examine their potential for adaptation and range expansion along the WAP. Information on the early life of grey rockcod is very limited, but physiological plasticity has been documented in adults. We show that since 1993, larval grey rockcod have shifted slightly poleward in mean latitude along the WAP. Our model results also show higher larval abundance and growth rate at higher temperatures. These findings suggest that grey rockcod have the potential for range expansion along the WAP. An adult diet analysis shows that one of their most important food sources are gelatinous salps, which have shown a similar ability to tolerate warmer conditions. These results are some of the first to document a potentially favorable response of fishes endemic to the Southern Ocean to continued warming, helping us envisage the future of this marine pelagic ecosystem.

Presentation Preference: Oral

Primary Presenter: Meredith Nolan, Virginia Institute of Marine Science (mnolan@vims.edu)

Authors:

Meredith Nolan, Virginia Institute of Marine Science, William & Mary  (mnolan@vims.edu)

Kiera Sears, University College Cork  (mskiera23@gmail.com)

Adena Schofeld, University of California, Santa Cruz  (adena.schonfeld@noaa.gov)

Andrew Corso, Coonamessett Farm Foundation  (acorso@cfarm.org)

Deborah Steinberg, Virginia Institute of Marine Science  (debbies@vims.edu)

Eric Hilton, Virginia Institute of Marine Science  (ehilton@vims.edu)