The natural distribution of fish populations is heavily dependent on thermal or temperature range limits in the ocean. Sockeye salmon are a good example of this. As the Earth warms, the distribution of salmon in the North Pacific can be expected to change.

Map 5 larger image [GIF, 57.7 kb, 748 X 560, notice]

Scientists from Fisheries and Oceans Canada and Environment Canada simulated the changes expected with a doubling of CO2 in the atmosphere. Map 5 shows the current, normal thermal limits for sockeye salmon in December (upper panel) and July (lower panel). The thermal limits predicted with doubled CO2 are the boundary labeled 2 x CO2. The results indicate that the climate change associated with a doubled atmospheric concentration of CO2 may virtually eliminate salmon habitat from the Pacific Ocean.

Contact:

David W. Welch
Fisheries and Oceans Canada
Pacific Biological Station
Nanaimo, BC
V9R 5K6
250-756-7218
Email: WelchD@dfo-mpo.gc.ca