Effects of water-body characteristics other than temperature and salinity on respiration in Euphausia pacifica

Ample evidence exists that many planktonic species are limited in their distribution to a given water mass. It has been suggested that the temperature-salinity values which define a given water mass are in themselves limiting these species' distribution. Other workers have suggested that other unique properties of a water mass may be involved. Euphausia pacifica is distributed throughout the Pacific subarctic water mass; its distribution also extends into British Columbia coastal waters. Experiments have shown that E. pacifica can withstand temperature changes of up to 15 C°; it can also withstand salinity changes of up to 10. Coastal E. pacifica appear to be able to better withstand stress from changes in temperature and salinity in water from some sources than in water from others. These differences are thought to result from differences in the past history of the water in question.Contribution No. 75008 from the Bigelow Laboratory for Ocean Sciences.