FORAMINIFERA, LOS ANGELES COUNTY OUTFALL AREA, CALIFORNIA1

Abstract

Foraminifera are sparse beneath the sewage field of the Los Angeles County outfall; segments of an abundance aureole are peripheral to the field and contain from 50 to 500 times as many tests as beneath the field. A zone without live specimens occurs beneath part of the sewage field; excepting for the dead zone, hyaline species are more than 8 times as abundant as arenaceous and porcelaneous species in living populations of the entire outfall area. Planktonic/benthic ratios are singularly high in the outfall area; planktonic foraminifera increase in numbers abruptly from very low values on the shelf to about 100/g in the upper bathyal zone; somewhat higher values occur near the outfall. Species thriving within the outfall area include Bulimina marginata denudata, Buliminella elegantissima, and Discorbis columbiensis.