D. W. McLeese

Toxicity of permethrin, decamethrin, and related pyrethroids to salmon and lobster

Conclusions(IR)-cis-permethrin, decamethrin, and NRDC 168S are extremely lethal to salmon and lobster. The increase in lethality relative to that of permethrin follows qualitatively the patterns established in toxicity studies with insects: (IR)-cis isomers are more lethal than (IR)-trans, and the presence of an αcyano group in the phenoxybenzyl moiety increases the lethality. The latter effect is very pronounced for lobsters.The octanol/water partition coefficient alone is not sufficient for predicting the lethality of pyrethroids to salmon or lobster.

Flux of Aroclor 1254 between estuarine sediments and water

ConclusionsComparison of the Freundlich isotherms for adsorption and desorption of Aroclor 1254 indicate that adsorbed PCB does not desorb readily. The Freundlich exponent and K value for desorption, based on the organic carbon content of the sediment, may be of practical use in predicting PCB concentrations in the pore water of settled dredge spoil, provided that the replacement rate of pore water is slow enough to allow establishment of equilibrium conditions. It is assumed that these coefficients may apply to other sediments with different combinations of organic and inorganic components. However, further study to check this and whether the Freundlich isotherms apply at lower concentrations of PCB is required.

Accumulation of copper, zinc, cadmium and lead from two contaminated sediments by three marine invertebrates: a laboratory study

Animals from areas with contaminated sediments have been shown in some cases to contain high levels of trace metals. In other cases, the tissue levels of contaminants were relatively constant regardless of the metal contents of the sediments. The availability of sediment-bound metals to bottom-dwelling organisms has been the subject of a few studies. This study describes the uptake of copper, zinc, cadmium and lead from natural, highly contaminated sediments by three marine invertebrates: Nereis virens, Macoma balthica and Crangon septemspinosa.

Bioaccumulation of chlorobiphenyls and endrin from food by lobsters (Homarus americanus).

The objectives of this paper are to determine the rates of dietary accumulation and clearance of two chlorobiphenyls and endrin in lobsters (Homarus americanus) fed contaminated mussels (Mytilus edulis). The chlorobiphenyls, representing intermediate and high degrees of chlorination, were chosen as model compounds to simulate the accumulation of PCBs. Endrin has been used extensively in eastern Canada and therefore it is of interest to determine its potential for accumulation within the trophic chain.

Toxjcity of CdCl2, CdEDTA, CuCl2, and CuEDTA to marine invertebrates

Trace metals in sea water are mainly associated with chlorides and other inorganic complexes but also may be associated with organic ligands. It is of interest to know if organic complexation affords protection by reducing accumulation and lethality of metals to marine invertebrates. The objective of this paper is to determine if toxicities of Cd and Cu to selected marine invertebrates are altered when the metals are complexed with EDTA. EDTA was chosen as a model for natural chelating agents.

SEDIMENT SORPTION AND TOXICITY OF ORGANOCHLORINE PESTICIDES TO MARINE INVERTEBRATES

ABSTRACT The sorption isotherms of endrin, dieldrin, and endosulfan on several fractions of an estuarine sediment have been determined at several salinities. Organic matter content was the major factor determining the sorption coefficients. Measured values of the adsorption coefficients were in reasonable agreement with those predicted from aqueous solubility data. The importance of pesticide sorption in controlling lethality was confirmed in lethality tests with shrimp ( Crangon septemspinosa ) with constant total concentration of endosulfan and varying concentrations of sediment. The lethality of endosulfan to shrimp decreased when increasing amounts of sediment were added to the seawater.