FISHERY BULLETIN: VOL. 86, NO. 4 



Figure 7.— Sections through surface region of sori (stained with hematoxylin) from gut of Sebastes mystinus. Upper section is from 

 the stomach, lower is from the intestine. Granular objects in upper section but largely absent in lower section are zoospores in zoosporangia. 



mystinus. But, whereas the predominant of such 

 forms during spring and summer usually were thali- 

 aceans, during the fall they were usually cteno- 

 phores (Fig. 10), pelagic hydrozoans— mostly sipho- 

 nophores (Fig. 11), and hydromedusae. The pelagic 

 hydrozoan Velella velella, which had been prominent 

 during the upwelling season, was not seen. Pelagic 

 gastropods (Fig. 12), pteropods at least, also were 

 more abundant during fall downwelling. On the 

 other hand, these waters were poor in the pelagic 

 diatoms that had bloomed periodically during spring 

 and summer. Furthermore, the nearshore habitat 

 had by this time lost much of its benthos. Many of 

 the more insecurely anchored Nereocystis plants, for 

 example, had been carried away by strong wave 

 surge that frequently swept through the nearshore 

 habitat even during relatively tranquil periods. Al- 



though the loss of these plants greatly increased 

 interplant distances, Nereocystis beds remained 

 dominant features. This was because the plants still 

 in place continued to grow, to produce sori, and to 

 thicken the surface canopy. Probably at least partly 

 because the canopy's increased thickness blocked 

 sunlight from the seafloor below, the algal under- 

 story, Desmarestia lingulata in particular, was 

 greatly reduced. Similarly, many benthic animals 

 that proliferated during the previous upwelling 

 season had become scarce, including the amphipods 

 and mysids noted above to be declining during late 

 summer. 



As the downwelling season progressed through 

 fall toward winter, there were major transforma- 

 tions of the nearshore habitat that, to at least some 

 extent, resulted from southwesterly storms. The 



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