Physiological responses of estuarine animals to cadmium pollution

Abstract

Toxic effects of cadmium contamination may be observed at all levels of organismic organization. In estuarine areas the sensitivity of euryhaline species to acute Cd toxicity is strongly modified by various abiotic factors, whereas long-term threshold values are less dependent on environmental parameters. Experiments with larval stages of the mollusc Mytilus edulis reveal that Cd effects on life functions such as development and growth are differentially modified by temperature and salinity. High Cd concentrations can be accumulated by adult bivaives of coastal areas without signs of physiological damage. Mechanisms of heavy-metal detoxication in these molluscs seem to be quite different from those known to exist in vertebrates. Among decapod crustaceans, stenoecous species tend to exhibit higher rates of Cd uptake than euryoecous ones.Rates of Cd uptake and of accumulation depend on external and internal factors. In adult Nereis succinea individuals sublethal Cd effects have been recorded on growth and food conversion (in terms of energy content).

Chronic effects of cadmium on two species of mysid shrimp:Mysidopsis bahia andMysidopsis bigelowi

“…Theede et al (1979) and Jones (1975) found less tolerance to cadmium at low salinities and high temperatures and concluded that species living near their distributional limits are sensitive to lower pollution levels than those living at optimum environmental conditions. Theede (1980) later observed that sensitivity to chronic exposure to cadmium is less dependent on environmental salinity and temperature than are the results of acute tests which use high cadmium concentrations.…”

Toxicity and toxicokinetics of cadmium in Capitella sp. I:relative importance of water and sediment as routes of cadmium uptake

“…Since benthic fauna both influence and are influenced by conta- tight coupling between the geochemical fate and biological effects of sediment-associated contaminants (Rhoads 1974, Reynoldson 1987. Like many anthropogenically derived metals, cadmium accumulates in aquatic sediments and reaches its highest concentrations mainly in coastal and estuarine areas (Theede 1980, Ankley et al 1994, Campbell & Tessier 1996. Benthic organisms are able to accumulate cadmium via overlying water, porewater and ingested particles, and the determination of the relative importance of these different routes of uptake and subsequent toxicity to bottom-dwelling organisms is critical for assessing the risks associated with contaminated sediments.…”

“…I was chosen for the present study, because its feeding strategy includes processing large quantities of fine-grained sediment and because the environments containing organically enriched sediments, which are ideal habitats for thls species, often are sites of high heavy metal contamination (Pearson & Rosenberg 1978). Cadmium was chosen because it is characterized as one of the most toxic heavy metals (Theede 1980, Baudo & Muntau 1990) and is known to have an important influence on the energetics of benthic invertebrates (e.g. Theede 1980, Forbes 1991, Forbes & Depledge 1992.…”

“…Cadmium was chosen because it is characterized as one of the most toxic heavy metals (Theede 1980, Baudo & Muntau 1990) and is known to have an important influence on the energetics of benthic invertebrates (e.g. Theede 1980, Forbes 1991, Forbes & Depledge 1992.…”

Effect of temperature and salinity on the toxicity of chromium to three estuarine invertebrates (Corophium volutator, Macoma balthica, Nereis diversicolor)

“…However, data on the effects of variations in salinity and temperature, which are comparable to those encountered in estuaries, in relation to chromium toxicity are not available for animals. Where such studies have been conducted with other metals (Theede, 1980;Coglianese, 1982;Cotter et al, 1982;Denton and Burdon-Jones, 1982), they have generally shown that the acute toxicity of heavy metals increases as temperature increases and as salinity decreases. Frey et al (1983) have reported that hexavalent chromium is very inhibitory to the growth of estuarine phytoplankton in fresh-water, but less inhibitory as salinity increases.…”