Research about Lake Coeur d'Alene

USGS2000

Benthic flux of metals and nutrients into the water column of Lake Coeur d'Alene, Idaho: Report of an August, 1999, pilot study

A field study was conducted between August 16-27, 1999, to provide the first direct measurements of the benthic flux of dissolved (0.2-micron filtered) solutes between the bottom sediment and water column at two sites in Lake Coeur d'Alene, Idaho. Trace metals (namely, cadmium, copper, manganese, mercury species, and zinc) and nutrients (namely, ammonia, nitrate plus nitrite, oxygen, orthophosphate and silica) were solutes of primary interest. Benthic flux (sometimes referred to as internal recycling) represents the transport of dissolved chemical species between the water column and the underlying sediment.

Idaho↗

USGS1995

Accumulation in and effects of lead and cadmium on waterfowl and passerines in northern Idaho

Waterfowl and passerines in northern Idaho in 1987 had high levels of lead in their blood and tissues that originated primarily from mining and smelting activities. Four Canada geese ( Branta canadensis ) and one common goldeneye ( Bucephala clangula ) found dead contained 8 to 38 μg/g (wet mass) of lead in their livers. These levels exceed the lower lethal limit of 5 μg/g in experimental birds. Two of the Canada geese (one each from the contaminated and reference areas) died with ingested lead shotgun pellets (shot) in their gizzards, whereas the other three birds from the contaminated area contained no ingested shot and evidently died from ingesting environmental lead in sediment or biota. Lead burdens in most American robins ( Turdus migratorius ) and mallards ( Anas platyrhynchos ) were high, whereas those in tree swallows ( Tachycineta bicolor ) were slightly elevated. Lead accumulated to potentially hazardous levels in blood and tissues of some nestling robins (maxima of 0·87 μg/g in blood and 5·6 μg/g in liver) and mallards (maxima of 10·2 μg/g in blood and 2·8 μg/g in liver). In mallards, lead levels and associated physiological characteristics of blood were significantly different in juveniles (HY) versus adults (AHY). Activity of δ-aminolevulinic acid dehydratase (ALAD) was about 87 to 95% lower than values for control birds in experimental studies. Activity of ALAD was significantly inversely correlated with blood lead levels. Cadmium was detected in kidneys of most birds, but even the maximum concentration of 7·5 μg/g in an AHY mallard was below known harmful levels.

Idaho↗