Filter-feeding bivalves

In aquatic environments, waterborne lead was the most toxic form. Adverse effects were noted on daphnid reproduction at 1.0 pg Pb+2/L, on rainbow trout survival at 3.5 pg tetraethyllead/L, and on growth of marine algae at 5.1 pg Pb+2/L. High bioconcentration factors were recorded for filter-feeding bivalve molluscs and freshwater algae at 5.0 pg Pb+2/L. 

The neurotoxins may be transmitted to man through bioaccumulation in an intermediate marine host. Toxic bivalves result from the filter-feeding of jP. brevis cells during red tides, and if consumed result in neurotoxic shellfish poisoning, or NSP. Human oral intoxication is rarely fatal. 

Mackenzie, L., V. Beuzenberg, P. Holland, P. McNabb, and A. Selwood. 2004. Solid phase adsorption toxin tracking (Spatt) A new monitoring tool that simulates the biotoxin contamination of filter feeding bivalves. Toxicon 44 901-918. 

MacKenzie, L., Holland, P, McNabb, R, Beuzenberg, V, Selwood, A., and Suzuki, T. 2002. Complex toxin profiles in phytoplankton and Greenshell mussels (Rerna canaliculus), revealed by LC-MS/MS analysis. Toxicon 40, 1321-1330. MacKenzie, A.L., Beuzenberg, Y, Holland, R.T., McNabb, R, and Selwood, A.R. 2004. Solid-phase adsorption toxin tracking (SPATT) a new monitoring tool that simulates the biotoxin contamination of filter-feeding bivalves. Toxicon 44 901-918. 

Forster, S., Zettler, M. L., 2004. The capacity of the filter-feeding bivalve My a arenaria L. to affect water transport in sandy beds. Marine Biology, 144, 1183-1189. 

Clams, oysters, and mussels accumulate chromium from the medium or from contaminated sediments at comparatively low concentrations. For example, oysters subjected to 5.0 (xg Cr+ /L for 12 weeks contained 3.1 mg Cr/kg DW in soft parts and retained 52% of the accumulated chromium after they were transferred to chromium-free seawater for 28 weeks. Mussels (Mytilus edulis) subjected to the same dose-time regimen contained 4.8 mg/kg, but retained only 39% after 28 weeks of depuration. Both oysters and mussels contained higher residues after exposure to 10.0 jig Cr /L for 12 weeks 5.6 and 9.4 mg Cr/kg DW in soft parts, respectively, and both contained substantial (30-58%) residues after 28 weeks in a chromium-free environment. In studies with mussels and softshell clams (Mya arenaria), it was demonstrated that chromium in New Hampshire sediments (contaminated with Cr+ from tannery wastes) was bioavailable to clams by diffusion from seawater, and that both diffusion and particulate uptake were important pathways for mussels. Accumulation was observed at sediment chromium concentrations as low as 150.0 mg/kg. Kaolinite sediments containing up to 1200.0 mg Cr+ /kg produced the most pronounced adverse effects on filtration rates and ciliary activity of bivalve mollusks, leading the authors to conclude that chromium that has accumulated in areas affected by industrial wastes might have serious consequences to filter feeding bivalves. 

Monitoring of PAHs in a diet is important because of the hypothesis that a correlation exists between a high incidence of gastrointestinal cancers in some populations and levels of PAHs in their diet. PAHs have been found in river and sea sediment, seaweed, and phytoplankton that serve as food for fish and marine filter-feeding bivalves. Values for BuP levels reported in nori, a Japanese seaweed, range from 7.4 to 31.3 pg per kg and benzo(fl)anth-racene in clams purchased from Rhode Island stores (USA) range from 0.1 to 0.8 pg per kg wet mass. 

Microplastics of [this size] can be ingested by filter-feeding p>olychaetes, echinoderms, bryozoans, bivalves and barnacles, deposit feeding lug-worms and sea cucumbers, and by detritovores such as amphipods. 

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