Irvine, Calif., June 29, 2026 — As oceans warm, marine life is on the move. Fish, corals, crabs, seaweeds and countless other species are shifting into new waters as they search for conditions that allow them to survive. These movements can help species persist in a changing climate, but they can also create unexpected ripple effects for the ecosystems, fisheries and coastal communities that depend on a healthy ocean.
A new study led by Ryan Beshai from the lab of Professor Cascade Sorte at the UC Irvine Charlie Dunlop School of Biological Sciences offers a hopeful step forward: a way to better anticipate which species movements are likely to matter most.
Published in Proceedings of the National Academy of Sciences, the paper, “A general framework for predicting the ecological effects of range expansions in marine systems,” provides a broad framework for understanding how marine species may affect the new communities they enter. Rather than looking only at where species are moving, the study asks a more practical question: What happens when they arrive?
To answer that, Beshai and Sorte drew from lessons in invasion biology, a field that studies how species introduced by people can affect new environments. They then applied those ideas to climate-driven range expansions, analyzing more than 1,200 documented effects from 360 marine species across global regions and major groups of ocean life.
Beshai said the work helps fill an important gap in climate change research. “While there’s growing evidence that range shifts can simultaneously be a response to change and a driver of further change, there was no general framework for anticipating when range shifts might drive large effects,” he said. “Species can persevere by moving into cooler habitats, but they may also create new interactions that drive changes in the recipient community.”
The study found that a species’ role in its original home range can help predict its effects in newly expanded areas. Species higher up the food chain, such as predators, were more likely to have stronger impacts, both positive and negative. The research also found that plants and algae in recipient communities may be especially vulnerable to these changes.
Importantly, the findings do not suggest that moving species should automatically be treated as threats. In many cases, range shifts may help species survive climate change. Some newcomers may even provide food, habitat or other benefits. The framework is designed to help managers identify where attention is most needed, so limited resources can be used wisely and proactively.
Beshai emphasized that the study’s strength came from bringing together an unusually large body of evidence. “Our literature synthesis spans a wide range of taxa, including 360 species from 14 phyla, as well as diverse marine systems and geographic regions. The conceptual framework also has relevance beyond climate-driven range expansions because it links two traditionally separate bodies of ecological theory,” he said.
The work also points to a need for more research, especially on species whose impacts remain unknown. Sorte noted that “Fully one-third of the species that we identified as range shifting did not have any published studies on their impacts, in the region they have expanded into and even where they have historically lived.”
That knowledge gap creates an opportunity for scientists, policymakers and the public to work together. Sorte added that public observations can make a meaningful difference: “Since researchers can only cover a relatively small area with their studies, observations by members of the public are extremely helpful. iNaturalist is the best app for recording species observations and is regularly used by researchers studying range shifts.”
As climate change continues to reshape the oceans, this research offers a path toward smarter, earlier action. By supporting long-term monitoring, public participation and science-based policy, society can better protect marine ecosystems while helping coastal communities prepare for the changes already underway.
About the University of California, Irvine Charlie Dunlop School of Biological Sciences:
Recognized for its pioneering research and academic excellence, the Charlie Dunlop School of Biological Sciences plays a crucial role in the university’s status among the nation’s top 10 public universities, as ranked by U.S. News & World Report. It offers a broad spectrum of degree programs in the biological sciences, fostering innovation and preparing students for leadership in research, education, medicine and industry. Nestled in a globally acclaimed and economically vibrant community, the school contributes to the university’s impact as Orange County’s largest employer and a significant economic contributor. Through its commitment to exploring life’s complexities, the Dunlop School embodies the UC Irvine legacy of innovation and societal impact. For more on the Charlie Dunlop School of Biological Sciences, visit https://www.bio.uci.edu/.