Multifactor Models Expose the Impact of Climate Change on Marine Life

For a long time, rising ocean temperatures have been associated with negative effects on marine life, but researchers from Florida State University have discovered that the long-term outlook for numerous marine species is a lot more complex—and perhaps bleaker — than researchers formerly believed.

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FSU doctoral student Jennifer McHenry, Assistant Professor of Geography Sarah Lester and collaborators with the National Oceanic and Atmospheric Administration (NOAA) explored how the habitats of marine species are likely to be impacted by numerous factors linked to climate change like salinity, ocean temperature, and sea surface levels.

Their research is detailed in Global Change Biology.

Most models have only considered the changing temperature of the ocean to make projections for sea life. However, considering factors beyond temperature provide a more complete picture of how marine life will fare as the Earth warms and these factors change accordingly.

Jennifer McHenry, Doctoral Student, Florida State University

Using data on marine species from NOAA’s National Marine Fisheries Service and a high-resolution universal climate model projection from the NOAA Geophysical Fluid Dynamics Laboratory, McHenry and her team analyzed the expected habitat variations of over 100 species living in the U.S Northeast Shelf — an extremely productive and economically significant region that ranges from Cape Hatteras, North Carolina to Nova Scotia, Canada.

Scientists learned that when using a multifactor model, over 50% of marine species in that region would undergo a waning in habitat space.

“That spells serious trouble for certain species,” McHenry said.

Scientists found a blatant contrast after comparing temperature-based models with multifactor models. The latter exposed a more substantial habitat deterioration for certain species.

For instance, the Atlantic cod had reduced habitat space when studying temperature models, but the multifactor habitat suitability models rendered Atlantic cod basically absent in the future.

Atlantic cod was once an important fishery in the Northeast. There are ongoing efforts to rebuild it, but these models indicate a less hopeful future for this species than originally suspected.

Jennifer McHenry, Doctoral Student, Florida State University

The forecast models covered a total of 80 years into the future. Scientists said that gives fishery managers and ecologists time to plan and counter.

We need to have responsive management approaches. A species that is going to have a much smaller range in the future and that’s commercially harvested for seafood might need to have more conservative catch limits to account for the fact that it may be more vulnerable under future climate.

Sarah Lester, Assistant Professor of Geography, Florida State University

Scientists said their study could be replicated in other geographic areas, such as off the western coast of the United States and the Gulf of Mexico.

“Climate change is not just about temperature,” Lester stated, “Unfortunately, it’s going to affect a range of factors. When we try to predict what’s going to happen in the future for marine species, we need to account for the full suite of factors that are going to change and be prepared for the fact that the impact on those species might be worse than what we’d predict just based on temperature.”

Co-authors of the research are Vincent Saba of the NOAA NMFS Northeast Fisheries Science Center and Heather Welch of the NOAA NMFS Southwest Fisheries Science Center in Monterey, California.