Warming Atlantic Waters May Cause Invasive Species to Spread

As temperatures warm, invasive species may be getting a leg up. Scientists have found that increased temperatures in the Atlantic could, in turn, increased the range of invasive species, such as lionfish.

In this case, the researchers examined North Carolina reefs, which lie within the temperate-tropical transition zone. Historically, both temperate and tropical species live in this region at their respective range limits. Now, though, it seems as if the waters in this area are becoming more tropical.

"Globally, fish communities are becoming more tropical as a result of warming temperatures, as fish move to follow their optimal temperature range," said Paula Whitfield, lead author of the new study, in a news release. "Along the North Carolina coast, warming water temperatures may allow the expansion of tropical fish species, such as lionfish, into areas that were previously uninhabitable due to cold winter temperatures. The temperature thresholds collected in this study will allow us to detect and to estimate fish community changes related to water temperature."

The researchers combined year-round bottom water temperature data with fish community surveys from 2006 to 2010. In the end, they found that the fish communities were primarily tropical in the deeper areas that were surveyed, from 122 to 150 feet. This, in particular, seemed to show that the fish were limited to warmer, deeper water, which indicated that temperature was the main factor in their range.

"The results will allow us to better understand how the fish communities might shift under different climate change scenarios and provide the type of environmental data to inform future decisions relating to the management and siting of protected areas," said Whitfield.

This is particularly important as invasive species spread. Lionfish in particular are voracious predators, but are largely held in check by being unable to journey further north. If sea temperatures continue to warm, though, these invasive species could potentially spread and cause havoc for local environments.