FORAMINIFERAL TRENDS, LAGUNA BEACH OUTFALL AREA, CALIFORNIA1

Abstract

Foraminiferal trends in the area of the Laguna Beach sewer outfall include the following: total populations are five times as abundant at the outfall as elsewhere on the mainland shelf; total live populations are about twice as abundant at the outfall as elsewhere; planktonic specimens are about 50 times as abundant in sediments near the outfall as at similar depths along the mainland shelf; and a Buliminella elegantissima—Bolivina vaughani population describes an abundance aureole within 500 m of the outfall. Negative effects include a marked decline in species diversity at the outfall and a depression aureole formed by a decline of the Buccella frigida group in the living assemblage.