ICES report: Cod and future climate change

This 2010 report from the International Council for the Exploration of the Sea (ICES) on cod and climate change, supports the findings of previous work on cod and climate change in the NE Atlantic region in concluding that both temperature and fishing pressure are key to cod stocks. The summary of the report has some important findings:

The results of a non-spatial model that includes temperature, zooplankton, prey, and predators indicate that a 1 to 4°C increase in temperature in the Barents Sea will cause increased cod growth, increased cod production, and decreased maturation rates. However, the positive effects on cod production are offset by cannibalism. (Note that in warmer water fish, as poikiotherms, have a higher metabolic rate, requiring increased oxygen and food. Paradoxically, in warmer water, oxygen is less soluble and less available to the fish and food sources can become reduced, such as in the case of Callanus and cod.)

The report also finds that another study exploring the effect of temperature on all North Atlantic cod stocks
found that a 3 °C rise in temperature would lead to a 30% reduction in the carrying capacity of warm-water stocks. Other likely impacts of warming include a general northward shift in distribution, increased growth and productivity in northern regions, and a decline in southern regions. Fishing pressure will play an
important role in determining the rates of change of the cod populations. On the other hand, fishery management must consider climate effects and develop models that include the combined effects of climate and fishing.

Edited by K. Drinkwater, C. Schrum and K. Brander, the full report and a summary can be read attached below.