Diablo Canyon power plant site ecological study Quarterly Report No. 13; July 1 - September 30, 1976

Abstract

Surveys of 39 random 30-m2 subtidal stations and 56 random1/4-m2 subtidal stations in Diablo Cove and the North Control were completed.The mean density of red abalones, Haliotis rufescens, inDiablo Cove was greater this year (0.02/m2) than last year(0.005/m2). This difference probably reflects sampling variation rather than density change.A total of 29 sportfish catch-per-unit-of-effort stations was sampled in Diablo Cove and 12 in the North Control.Foam observations in Diablo Cove were continued. The coolingwater pumps were not in operation. The amounts of foamappeared to be about the same during certain weather conditions as those when the pumps are in operation, although not as thick.The number of sea otters, Enhydra lutris, decreased substantially between Pt. Buchon and Pecho Rock. This was due to their annual migration (or "pulling back") into the more central parts of their range.Random surveys of the intertidal areas during the upwellingperiod were completed. (11pp.)