Contributed by Rudy Molinek, GSA Science Communication Fellow
Boulder, Colo., USA: The consequences of a warming climate are known to be dangerous for marine ecosystems, with environmental changes like ocean acidification and warming, disrupted nutrient supplies, and rising sea levels. For mollusks, important members of marine ecosystems, these changes might spell doom.
According to research presented last week at GSA Connects 2025 in San Antonio, Texas, modelling of environmental change under scenarios of warming climate indicates that mollusks in the western Atlantic Ocean along the coast of North America could face greater than 60% reductions in their range. Surprisingly, the projected losses apply across mollusk species, independent of their physical characteristics or ecological adaptations.
“We’re trying to see if species with specific functional traits might survive or do better than others,” says Dr. Claudia Nuñez-Penichet, a postdoctoral researcher at Virginia Tech’s Department of Fish and Wildlife Conservation. “It didn't matter at all. Everything was very bad for all the species that we looked at in the future, especially under more extreme climatic projections with higher carbon emissions.”
Mollusks, like clams, oysters, and snails, are critical to marine ecosystems. Filter-feeding mollusks like clams and oysters help maintain water quality and control algal blooms. In addition to their biological roles, mollusk shells help shore up the substrate, and features like oyster reefs can provide habitats for many other species. The impacts of a mass loss of mollusks in a region would ripple up and down the food web.
Nuñez-Penichet’s model identifies factors like surface water temperature, acidity, and current velocity in a mollusk species’ modern range, and locates where similar conditions are expected to occur in the future. Then, the researchers explore possible changes of species’ distributions under environmental conditions in different carbon emission scenarios to forecast what might happen to the mollusks in the future.
These types of models don’t capture all the possible factors contributing to species’ survival, like migration, biotic interactions, or sea-level rise, and so the real-world impact of a changing environment might be different than predicted. But this work will help conservationists determine where to direct efforts to promote resilience in coastal marine communities.
“In the case of marine mollusk species, we are showing which areas might be more susceptible” to risk of extinction, says Nuñez-Penichet.
Going forward, Nuñez-Penichet and her collaborators hope to expand their study from 57 mollusk species to more than 200. Additionally, they aim to apply their model to paleontological data to see how past environmental changes shaped current marine ecosystems.
Despite the dire outlook they see in their model, Nuñez-Penichet sees signs of hope. The rates of mollusk loss predicted for the year 2050 in a more extreme carbon emission scenario are similar to those predicted in 2100 under a more moderate scenario. This means that human actions to limit the burning of fossil fuels could prevent the worst impacts on mollusks and the marine ecosystems they support.
“We can make a difference,” Nuñez-Penichet says, “if we actually care.”
Integrating Functional Traits and Ecological Niche Modeling to Assess the Vulnerability of Mollusk Species to Climate Change
Corresponding Author: Claudia Nuñez-Penichet, Virginia Tech, claudianunez@vt.edu
98: T151, Linking Biodiversity Loss to Environmental Stressors Through Integrated Approaches
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