April 2, 2014 — Fisheries researchers from North Carolina State University (NCSU) have found that black sea bass (Centropristis striata) can usually survive the physical trauma that results from being hauled up from deep water then released at the surface.
The finding is part of a larger study of the fish’s mortality rate, which will inform stock assessments designed to help ensure that the black sea bass fishery is sustainable.
Black sea bass are bottom-dwelling fish, and are often caught at depths of greater than 60 feet. When the fish are brought to the surface, the rapid change in pressure causes the fish’s swim bladder to expand. This forces other organs out of the way and can result in visible “barotrauma” – such as the fish’s stomach being forced partially out of its mouth.
Conventional wisdom long held that this sort of visible barotrauma meant that a fish would die when thrown back into the water. But that’s not true, according to the NC State study.
The research team was attempting to develop accurate estimates of “discard mortality” rates for black sea bass, meaning that they wanted to know what percentage of the fish would die if they were caught and thrown back. Discard mortality rates are used to make informed stock assessments for fish species because it helps fisheries officials understand how many fish that are caught and released can be expected to survive. Black sea bass are a valuable species for commercial fishing and are also popular with recreational anglers. Millions of black sea bass are caught and released by recreational anglers off the south Atlantic coast of the US each year.