The difference between farmed and wild salmon sounds pretty clear, but in fact it's an example of how blurry the origin of seafood can be. The farms depend on wild-caught forage fish to feed the salmon; meanwhile, wild salmon runs are often supplemented with young salmon raised in hatcheries. Now a team of researchers is proposing a new label—hybrid seafood—to better categorize the source of seafood and its impacts. "To tell if seafood is environmentally sustainable, you need to know more than whether it's fished or farmed," says Dane Klinger, a doctoral student at Stanford University in Palo Alto, California.
Seafood production encompasses a spectrum of techniques, stretching from wild-caught fisheries such as anchoveta to straight-up aquaculture of mussels and other creatures. In the middle is a gray zone where you find aquaculture-enhanced fisheries and fishery-enhanced aquaculture. A group of scientists, led by Klinger and Mary Turnipseed, now a fellow with the Gordon and Betty Moore Foundation's Marine Conservation Initiative, investigated this issue as part of a project on sustainable seafood at the National Center for Ecological Analysis and Synthesis in Santa Barbara.
Fisheries organizations categorize seafood as coming from either fisheries or aquaculture. Sorting out the origins more accurately would have several advantages, the team argues in an article in press at Marine Policy. First, the new classification would help researchers better understand the potential for growth in fisheries. Yields from wild-fisheries that are stocked, such as Chesapeake oysters, can have the potential to grow faster than ones that aren't. Better terminology could also reduce the risk of double-counting seafood catches and underestimating the environmental impact; for example, the authors note that roughly 70% of Atlantic herring caught in the Gulf of Maine is used for lobster bait.