Development of a total dissolved solids (TDS) chronic effects benchmark for a northern Canadian lake.

Laboratory chronic toxicity tests with plankton, benthos, and fish early life stages were conducted with total dissolved solids (TDS) at an ionic composition specific to Snap Lake (Northwest Territories, Canada), which receives treated effluent from the Snap Lake Diamond Mine. Snap Lake TDS composition has remained consistent from 2007 to 2014 and is expected to remain unchanged through the life of the mine: Cl (45%-47%), Ca (20%-21%), Na (10%-11%), sulfate (9%); carbonate (5%-7%), nitrate (4%), Mg (2%-3%), and minor contributions from K and fluoride. The TDS concentrations that resulted in negligible effects (i.

Effect of Total Dissolved Solids on Fertilization and Development of Two Salmonid Species.

Some studies have shown that the early life stages of salmonids are particularly sensitive to elevated concentrations of total dissolved solids (TDS). We evaluated the effect of TDS released in treated effluent into Snap Lake (Northwest Territories, Canada) by the Snap Lake Diamond Mine on two salmonids native to Snap Lake: Salvenius namaycush (lake trout) and Thymallus arcticus (Arctic grayling). Exposures encompassed the embryo-alevin-fry early life stages and extended to 142 days for lake trout and 69 days for Arctic grayling.

Development of a strontium chronic effects benchmark for aquatic life in freshwater.

There are no national water-quality guidelines for strontium for the protection of freshwater aquatic life in North America or elsewhere. Available data on the acute and chronic toxicity of strontium to freshwater aquatic life were compiled and reviewed. Acute toxicity was reported to occur at concentrations ranging from 75 mg/L to 15 000 mg/L.

Incorporation of 28-d Leptocheirus plumulosus toxicity data in a sediment weight-of-evidence framework.

A series of side-by-side trials were conducted to evaluate the variability of 28-d Leptocheirus plumulosus amphipod toxicity test data using existing and modified test protocols. One modification included examination of the influence of press-sieving on the sediment chemistry and the toxicity data. Press-sieving sediment did not reduce the variability in the toxicity data and also contributed uncertainty to the chemistry data.

The importance of benthos in weight of evidence sediment assessments--a case study.

Sediment quality in a Texas reservoir subject to point and non-point sources of contaminants was assessed using the Sediment Quality Triad weight of evidence approach. Fifteen stations were sampled plus a reference station which, unfortunately, comprised a different habitat type than the other 15 stations. Accordingly, standard comparisons between reference and exposed stations were inappropriate.

Toxicity of 1,4-dichlorobenzene in sediments to juvenile polychaete worms.

Investigation of sediment contamination associated with a marine sewage outfall in Victoria (BC, Canada) found elevated concentrations of 1,4-dichlorobenzene (1,4-DCB). Juvenile polychaete worm (Neanthes) growth was significantly reduced at or near the outfall, roughly corresponding to elevated 1,4-DCB concentrations. There are few data on 1,4-DCB toxicity to marine organisms and no published literature on its toxicity to benthic marine organisms.