November 3, 2014 — Managing wild capture fisheries requires large amounts of information to accurately estimate fish population size. Most models of fish population dynamics are based on fisheries-independent surveys, fixed over a particular area during a specific season, and rarely cover the entire range of habitat that fish use.
Many fish are highly mobile ectotherms – an animal that cannot regulate its own body temperature, so its body temperature fluctuates according to its surroundings. They often shift their distributions in response to dynamic properties of the ocean such as changing water temperature. When surveys do not sample the entire range of habitat fish use, systematic shifts in species distribution into, or out of, survey areas can be misinterpreted as increases or decreases in population size.
An important short-lived pelagic forage fish, in the Northwest Atlantic, the Atlantic Butterfish (Peprilus traicanthus) is an example of a fish population characterized by federal fishery regulators as a “data poor” stock. No directed fishery has been permitted since the early 2000’s based on a stock status of “unknown” by the National Marine Fisheries Service. In addition, the fishing industry had been constrained by butterfish incidental catches which served as a “choke” species on the economically important squid fishery.
To better account for shifting habitat distributions in butterfish population assessments, the Integrated Ocean Observing System’s (IOOS®) Mid-Atlantic Regional Association Coastal Ocean Observing System (MARACOOS) formed a multidisciplinary study group of experts in marine ecology, physical oceanography, and stock assessment from the fishing industry, government, and academia.