Observations on the interaction of zinc and cadmium uptake rates in crustaceans (amphipods and crabs) from coastalsites in UK and France differentially enriched with trace metals

摘要

This paper presents results on the possible interaction of zinc and cadmium uptake rates in crustaceans. Zn and Cd uptake rates were measured in amphipods (Orchestia gammarellus) and crabs (Carcinus maenas and Pachygyapsus marmoratus) from five coastal sites in Britain and France subjected to different degrees of trace metal enrichment. The presence or absence of 100 #mu#g 1~(-1) of one metal (1.53 #mu#M 1~(-1) Zn,0.89 #mu#M 1~(-1) Cd) had an inconsistent effect on the rate of uptake of the other metal by O.gammarellus. The presence or absence of 50 #mu#g 1~(-1) of either zinc (0.76 #mu#M 1~(-1)) or cadmium (0.45 #mu#M 1~(-1)) had no effect on the rate of uptake of the other metal by C.maenas (from Millport, Scotland). Zinc and cadmium uptake rates were correlated in individual amphipods and crabs of both species from the five sites. These correlations indicate that zinc and cadmium might share common routes of uptake from solution by crustaceans, but the metals do not consistently interact competitively or synergistically at the exposure concentrations investigated. Regression coefficients of the relationship between zinc and cadmium uptake rates in amphipods and crabs showed occasional, but inconsistent, differences between sites and over time. All three crustaceans take up zinc from solution at a higher rate than cadmium for the same total dissolved metal molar concentration, but at a lower rate than cadmium per free metal ion molar concentration.