Climate change and Atlantic croaker fishery – Fishfarmer Magazine

Climate change and Atlantic croaker fishery 29 March, 2010 –

A NEW climate-population model developed by scientists at the US National Oceanographic and Atmospheric Administration (NOAA) to study rising ocean temperatures and fishing rates on one east coast fish population could also forecast the impact of climate change and fishing on other fisheries. The model is one of the first to directly link a specific stock with future impacts of climate change.

In a paper in the March issue of the journal Ecological Applications published online last week by the Ecological Society of America, NOAA researchers forecast the future of the Atlantic croaker fishery in the mid-Atlantic under various climate and fishing scenarios. Atlantic croaker (Micropogonias undulatus) is a coastal marine fish inhabiting the east coast of the United States with an $8 million (£5.4m) annual commercial fishery. Previous studies have shown a strong link between croaker abundance and winter temperature.

“Some fish populations will increase and others decrease as a result of climate change,” said lead author Jon Hare of the Northeast Fisheries Science Center (NEFSC) laboratory in Narragansett, Rhode Island. “Our results demonstrate that climate effects on fisheries must be identified and understood, included in the scientific advice to managers, and factored into fishery management plans if sustainable exploitation is to be achieved.”

For various temperature and fish population scenarios over the next 90 years to 2100, the researchers forecast that at current levels of fishing, the spawning population of Atlantic croaker would increase between 60 and 100%, the centre of the population would shift 30-65 miles northwards, and the maximum sustainable yield from the resource would increase between 30 and 100%.

With ocean temperatures expected to increase through the 21st century, the researchers developed the population model for Atlantic croaker based on the hypothesis that recruitment, or survival of juveniles to adulthood, is determined by winter water temperature.

Atlantic croaker spawn in the coastal ocean and larvae enter estuaries in Delaware Bay, Chesapeake Bay, and Pamlico Sound 30-60 days after hatching. Juveniles spend their first winter in these estuarine nursery habitats. Temperature during this winter period is very important to juvenile survival.

Temperature forecasts were obtained from 14 general circulation models (GCMs) used by the Intergovernmental Panel on Climate Change (IPCC) to simulate three carbon dioxide emission scenarios through 2100: atmospheric carbon dioxide fixed at 350, 550, and 720 parts per million (ppm). By comparison, the atmospheric concentration of carbon dioxide in February 2010 was 389.91 ppm.

Mr Hare and colleagues from NOAA’s Northeast and Southeast Fisheries Science Centers, in collaboration with climate modellers from NOAA’s Earth System Research Laboratory in Boulder, Colorado, linked the Atlantic croaker population model with forecasts of minimum winter temperature in the 14 GCMs. These linked modelling efforts provided estimates of the abundance, distribution and yield of the Atlantic croaker population under different climate-change scenarios and different fishing rates.