Biofouling Species on Kelp and Oyster Farms
Mariculture, the cultivation of marine plants and shellfish, is a growing, sustainable industry in Alaska outlined as a high research priority in the Alaska Science and Technology Plan.
Kelp and shellfish mariculture practices require various structures that provide substrate for a diversity of biofouling organisms to settle and grow.
An experimental oyster cage covered in algae.
During community visits and ongoing conversations between Alaska EPSCoR researchers and mariculture farmers, farmers expressed concern that changing environmental conditions could encourage the growth of biofouling species. Biofouling species are organisms that compete with mariculture species for resources, like weeds, and thereby reduce crop quality. Organisms like tunicates can clog up oyster cages, reducing water flow. Kelp adorned with biofouling species is less marketable.
While farmers clean their gear of biofoulers, their growth is still a broad concern. Interface of Change researchers will investigate if reduced salinity and increased turbidity correlate with a reduction of fouling organisms on oyster farms in Kachemak Bay and in the Prince William Sound.
A diver conducts a biofouling species relative abundance survey at an oyster farm. To conduct the survey, PVC quadrats are placed over a side of an oyster cage and the diver takes a photo. Later, the scientists determine the average area each species covers.
To determine sources of variability in salinity and turbidity and to examine how freshwater discharge influences farm water conditions, the researchers will gather environmental data and conduct biofouling species relative abundance surveys. They will share their data and findings with farmers and community members, and they will develop and distribute laminated, graphical keys of biofouling species for farmers to use to identify species and make management decisions.