The distribution of heavy metals in the red abalone,Haliotis rufescens, on the California coast

Abstract

The gills, mantle, digestive gland and foot muscle of 74 specimens of the red abalone, Haliotis rufescens, from five localities on the California coast were analyzed for eight heavy metals: Ag, Cd, Cr, Cu, Pb, Hg, Ni, and Zn. The distribution of these elements in the abalones appeared to be non-normal and the non-parametric Wilcoxon U statistic was used to compare sample concentrations. No correlation of metal concentration with size was found. High concentrations of Cd (up to 1400 ppm) were found in the digestive glands of all samples and are assumed to represent natural levels. Cu and Ag concentrations appear to be inversely correlated, with Cu decreasing and silver increasing from north to south. High Hg concentrations in the La Jolla-Long Beach area appear to reflect pollutant inputs; elsewhere Hg levels appeared to derive from natural sources.The results of the baseline program of the International Decade of Ocean Exploration indicate that, with the possible exception of Pb, the current levels of heavy metals in marine ecosystems derive primarily from natural rather than technological sources (IDOE 1972). A considerable amount of evidence accumulated during the program suggested, however, that local inputs of several of the heavy metals, principally Cd, Pb, and Hg, into estuarine and coastal environments might significantly increase environmental levels above background. The present study reports on the distribution of eight heavy metals in the red abalone, Haliotis rufescens (Swainson), obtained from five sites of coastal California, representing both industrial areas and areas relatively undisturbed by man.

Heavy metals in the gastropod mollusc Haliotis tuberculata (L.)

“…This agrees with Marks (1938) who found no effect of size on levels of copper in H.fulgens. Anderlini (1974) was unable to find any relationship for copper or other metals, although this conclusion was based on the analyses of individual tissues in H. rufescens.…”

“…However, nickel which is concentrated in the mantle and copper which is concentrated in the blood are notable exceptions (see Discussion). Concentrations in the digestive gland of//, tuberculata are compared in Table 2 with values given by Anderlini (1974) for H. rufescens from California. His ranges of mean values from five sites, some of which were contaminated, are given and show that concentrations in H. tuberculata are generally at the low end of the range or lower than those for the American species.…”

“…During this century various workers have analysed species of Haliotis for copper, zinc, manganese and iron, the more abundant of the essential heavy metals (Dubois, 1900;Wang Tai Si, 1928;Marks, 1938), but it is only recently that analyses of some of the non-essential metals such as mercury, cadmium and lead have been carried out. Anderlini (1974) published analyses of eight metals (Ag, Cd, Cr, Cu, Hg, Ni, Pb, Zn) in tissues from the red abalone H. rufescens. Samples collected near large urban areas of California contained higher levels of some metals and this was particularly obvious for silver which contaminated both the viscera and the edible foot.…”

Indicators of heavy-metal contamination in the Looe Estuary (Cornwall) with particular regard to silver and lead

“…Standard additions were used to check the recoveries of metals. This enabled corrections to be made for the effect of iron on chromium analyses of sediments and showed that analyses of silver in tissues were not seriously affected by lipids which are difficult to digest with nitric acid (Anderlini, 1974). Thornton, Watling & Darracott (1975) have advocated the analysis of freshwater sediment as a means of recognizing areas of mineralization or metal contamination.…”

Osmoregulation and Excretion in Prosobranch Gastropods Part I: Physiology and Biochemistry

“…In the terrestrial prosobranch Pomatias, concretions in the digestive gland contain iron as well as zinc, and in other species they may be rich in silica and aluminium (Martoja & Martoja, 1973). In Haliotis, the mantle tissue concentrates nickel (Bryan, Potts & Forster, 1977), and it has been suggested by Anderlini (1974) that some adsorption by mucus may be involved in nickel accumulation. The understanding of the mechanisms of uptake, storage and excretion of these heavy metals requires a great deal of further work.…”