SPATIAL PATTERNS OF ZOOPLANKTON BIOMASS IN THE NORTHEAST PACIFIC-OCEAN

We used Mantel's tests and correlograms to statistically detect and de scribe large-scale spatial patterns during spring and summer in zoopla nkton biomass in the northeast Pacific Ocean following winters of vary ing degrees of wind stress. During the spring of 1963, a sampling peri od following a winter of moderate wind stress, we found that sites sep arated by 1 to 100, 201 to 400 and 1101 to 1200 km had similar biomass levels, and that areas of high biomass occurred around the periphery of the Gulf of Alaska. We found similar results for spring data from o ther years following winters of high wind stress. During summers follo wing winters of low wind stress, biomass levels were similar among sit es within 1 to 100 km of each other, but they were generally lower tha n the spring values. We did not detect spatial patterns in biomass dur ing springs following winters of low wind stress, or during summers fo llowing winters of high wind stress. Elevated winter wind stress appea red to favor the formation of discernable spatial patterns in zooplank ton biomass during the subsequent spring, but the pattern did not pers ist into the summer. It appears that spatial patterns ('zooplankton pa tches' at <400 km scales) may be formed b psi meso-scale eddies, while the similarities over larger distance intervals may be attributed to gyre currents and spring bloom dynamics.