A survey of marinas from Virginia to New Jersey found what's described as a 'disturbing' amount of non-native species.
The survey looked for biofouling organisms — creatures like barnacles, that attach to boats or docks.
At nine of the 10 surveyed locations, more non-native biofouling species were found than native ones.
East Carolina University biologist April Blakeslee helped lead the survey. She says this trend is largely due to climate change.
"There's a lot of species that are moving from, like, the tropics and the subtropics up into more temperate region," Blakeslee said, "And so the Mid-Atlantic is receiving a lot of those organisms just because it's a lot warmer in the both the summers and the winters. And so it's allowing species to actually move and establish in those new locations."
Blakeslee says the abundance of these non-native species can not only hurt the general ecology of an area, but they can also cause economic harm by hurting commercially valuable species.