Invasive Sea Squirts Threaten Shellfish Aquaculture
National Centers for Coastal Ocean Science researchers and their collaborators found that ten invasive tunicate species are fouling shellfish aquaculture operations along much of the U.S. East Coast, causing decreased growth rates, increased mortality, and high maintenance costs. The survey identified the locations of highest fouling, which will be used to develop a plan to for reduce reducing the economic impact of tunicates in shellfish culture operations.
Invasive tunicates–also known as sea squirts–are adversely affecting aquaculture of species such as bay scallop, Eastern oyster, hard clam, and blue mussels along much of the U.S. East Coast. Colonial tunicates such as Didemnum vexillum can form dense mats that overgrow adult scallops, limit space for larval development, and prevent fish from bottom feeding. Masses of invasive Ciona intestinalis and Styela clava latch onto aquaculture cages and lines, adding weight, blocking water and nutrients, and competing with shellfish for food.
This study was conducted with the Woods Hole Oceanographic Institution and state aquaculture collaborators.