ENVIRONMENTAL VARIABLES, INCLUDING POLLUTANTS, AFFECTING LIVING BENTHONIC FORAMINIFERIDA

Abstract

Studies of living benthonic foraminiferal assemblages carried out by marine biologists are comparatively rare. This study of the changes in foraminiferal assemblages from three subtidal sites near Plymouth, U.K., has been carried out with the intention of determining the importance of various abiotic and biotic variables to the foraminiferal communities studied using statistical correlation. Temperature and salinity at depth and particle size characteristics together with organic content, bacterial abundance and type, and other meiofauna present were assessed monthly with samples taken for foraminiferal content, and for seasonal diatom analysis. Deformed specimens were very rare in the examined samples of natural assemblages. Three different systems were used in an attempt to culture Elphidium crispiim (Linne) for ecotoxicological studies, which failed. Ecotoxicological studies were carried out upon Roialieila elaticam Pawlowski & Lee and adult Ammonia batavits (Hofker). The types of deformation produced by laboratory-maintained Foraminiferida were found not to be specific to the stressor used and, therefore, the use of this group of Protozoa as indicators of specific pollution is not possible. The methods which Elphidium crispiim utilises to remain epifaunal were investigated and found to be primarily controlled by phototaxis, together with geotaxis.