In the Pacific Northwest, beach grass communities often create sand dunes that mitigate coastal erosion and flooding risks stemming from rising sea levels caused by climate change.

But Tarik Gouhier, a newly appointed assistant professor in the Department of Earth and Environmental Sciences in the College of Science, says this vital ecosystem service provided to coastal communities may be in jeopardy. The reason, he says? An invasive beach grass species native to the East Coast of North America that builds inferior dune structures owing to its shorter stature and lower density.

Gouhier, in collaboration with colleagues at Oregon State University and Yale, has developed mathematical models that highlight the potential impact of this invasive species on the ecosystem services provided by resident beach grass communities in the Pacific Northwest.

“Whether this invasive species propagates and impacts coastal communities is a big concern,” said Gouhier, a quantitative ecologist. “These beach grass communities provide an alternative to building artificial structures such as sea walls to deal with rising sea levels.”

Studying this invasive beach grass species in its native habitat on the East Coast is among the projects Gouhier will focus on at Northeastern’s Marine Science Center in Nahant, Mass. His overall research will focus on integrating elements from the fields of nonlinear dynamics, spatial ecology and food-web network theory to understand the assembly, stability and functioning of coastal ecosystems experiencing environmental change.

This research, he explains, is broad in scope: from studying the factors that explain the spatiotemporal distribution of mussels — a foundational member of intertidal ecosystems that settles on rocks and provides a home for other organisms — to building mathematical models that help manage fisheries and other invaluable marine resources via networks of reserves.

Gouhier counts ecology and computer science as two of his longtime passions. Nature, the self-described “geek” said, is “complex and beautiful.” He realized that he could combine his interests after his doctoral adviser at McGill University pointed out that ecology is a highly quantitative field.

“There was lots of math everywhere,” Gouhier recalls his advisor explaining. “You can build mechanistic models to understand the patterns that you see in nature. For me, that was absolutely the ‘eureka’ moment.”

Gouhier noted that the MSC was a major factor in attracting him to Northeastern. The research facility, he said, is well positioned to succeed owing to its close proximity to a major urban city (Boston) and boasts a strong interdisciplinary team of researchers assembled and supported by College of Science dean Murray Gibson and MSC director Geoff Trussell.

Gouhier is eager to build new interdisciplinary collaborations with researchers at Northeastern and beyond. “These problems require a cross-disciplinary approach. You need policy, you need to involve management, you need to involve the public and you need fundamental science,” he said. “Most research tends to focus on a single facet of environmental change, but there’s precious little work done to link key results across traditional disciplinary boundaries and communicate them to the public at large.”

He added, “By combining expertise from different fields, interdisciplinary research programs can address such complex problems by allowing the science to directly inform policy decisions and outreach activities.”