THE EFFECTS OF SELECTED HEAVY METAL ELEMENTS (ARSENIC, CADMIUM, NICKEL, ZINC) ON EXPERIMENTALLY GROWN FORAMINIFERAL ASSEMBLAGES FROM SAPELO ISLAND, GEORGIA AND LITTLE DUCK KEY, FLORIDA, USA

摘要

Benthic foraminifera are valuable environmental indicators of heavy metal contaminants in marine environments. To broaden their effectiveness as bioindicators, this study compares individually the effects of selected heavy metal contaminants, including both metabolically essential and non-essential elements, on temperate rotalids and subtropical miliolids, as well as associated monothalamid foraminifera. To accomplish these aims, assemblages of foraminifera were grown experimentally from propagules (small juveniles) collected from two coastal sites: Sapelo Island, Georgia, and Little Duck Key, Florida, that provide an effective comparison between environments and types of foraminifera. Surface sediment was collected from both locations and sieved immediately after collection. Using the propagule method, assemblages of foraminifera were grown in the laboratory from propagules in the sediment samples. Two metabolically essential trace elements, nickel, and zinc, and two non-essential elements, arsenic and cadmium were used to represent both types of heavy metal. Experimental conditions were held constant while varying only the metal concentrations.