Assessment of Macroinvertebrate Communities and Heavy Metal Contamination Along the Intracoastal Waterway in Fort Lauderdale, Florida

摘要

Sediments from four areas adjacent to marinas and a background site in the Intracoastal Waterway were assessed for macroinvertebrate composition and heavy metal contamination. Sediment core samples were collected in 2004 and 2005 for analyses of macroinvertebrate composition and sediment grain size. Additional sediment samples were collected in 2005 for chemical analyses of metals (Al, As, Cd, Cr, Cu, Fe, Pb, Hg, Ni and Zn). MANOVA and dendograms using Bray-Curtis similarity matrices grouped the sites into two clusters: the 3 sites closest to the New River formed one group, and the two end sites formed the other. The sites nearest the New River were dominated by polychaetes, half of which were pollutant-tolerant species (e.g., Capitella capitata). The macroinvertebrate communities of the two end sites were dominated by tanaids, gastropods and sipunculids with fewer annelids than the other 3 sites. The influence of the New River on the study sites appeared to outweigh the sources of metal pollution found in marinas. The 3 sites closest to the New River had higher metal concentrations than the two end sites. The background site, nearest the mouth of the New River, exceeded the Florida sediment quality guideline probable effect level for cadmium and copper while three of the four marina sites exceeded at most one probable effect level and one or more threshold effect levels for cadmium and copper. The furthest site from the New River, which was the closest site to Port Everglades, had the lowest metal concentrations. Additional studies are needed to determine the level of pollutant loading from the New River and its effects on nearby biological communities.