Macrozooplankton and Small Nekton in the Coastal Waters 

 Off Vancouver Island (Canada) and Washington , 

 Spring and Fall of 1963 



By 



DONALDS. DAY, Oceanographer 



National Marine Fisheries Service Biological Laboratory 

 Seattle, Washington 98102 



ABSTRACT 



Eight species of euphausiids, 5 species of mysids, and 14 spe- 

 cies of fish were identified. Euphausiids composed about 90 percent by 

 number of the organisms caught, and fluctuations in their abundance were 

 concomitant with changes in the biomass of the samples. The bulk of the 

 organisms collected at night were in the upper 30 m. All species were 

 taken by a 0.9-m. Isaacs-Kidd midwater trawl. 



The concentration of organisms was lowest near shore, reached 

 a maximum at or near the outer edge of the continental shelf, and de- 

 creased again farther offshore. The concentration of organisms was 

 greater in the southern part of the region than in the northern part. This 

 distribution was apparently related to the general surface circulation. 

 Seasonal fluctuations were indicated by a decrease in biomass from spring 

 to fall. 



INTRODUCTION 



Predictions of the location and abundance 

 of commercial fishes that depend on plankton 

 for food can be improved by a knowledge of the 

 distribution and numbers of plankton within 

 large regions of the sea. The waters over the 

 continental shelf and slope along the west coast 

 of the United States and Canada appear to be 

 one of the world's highly productive marine 

 environments (Reid, 1962). Little is known, 

 however, about the distribution and composi- 

 tion of the macrozooplankton and small nekton 

 inhabiting the region off the coasts of Vancouver 

 Island, British Columbia, and the State of 

 Washington. Aron (1959, 1962) reported on the 

 abundance and distribution of oceanic macro- 

 zooplankton and small nekton in the north- 

 eastern Pacific Ocean during the summer of 

 1957 and the summer and early fall of 1958, 

 but he obtained only a few samples in the 

 coastal region. Pearcy (1964) and Pearcy and 



Laurs (1966) studied the seasonal composition, 

 distribution, and migration of the mesopelagic 

 fishes over the continental terrace off the 

 Oregon coast. The taxonomy and distribution 

 of euphausiids in the Pacific Ocean has been 

 studied by Banner (1949); Boden, Johnson, 

 and Brinton (1955); Brinton (1962a); and 

 Hebard (1966). Banner (1947, 1948) investi- 

 gated the taxonomy and distribution of the 

 mysids in the northeastern Pacific Ocean. 



In spring and fall 1963 during oceanographic 

 cruises of the RV George B. Kelez (Ingraham, 

 1967), macrozooplankton and small nekton were 

 collected within 185 km. of shore from Cape 

 Cook on Vancouver Island to Willapa Bay, 

 Wash. The purpose of my report is to show 

 the abundance, distribution, and composition of 

 these organisms over the continental shelf 

 and slope. 



