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At least 955 records · Page 53Linked to original sources
USGS1979

Parathion causes secondary poisoning in a laughing gull breeding colony

Use of organophosphate insecticides as replacements for the more persistent organochlorine compounds has increased dramatically in recent years. Organophosphates are desirable for field application because they break down rapidly in the environment and do not persist in animal tissues (Stickel 1974). Nevertheless, certain organophosphates are extremely toxic to wildlife for short periods after application and have caused widespread mortality among exposed animals (Mills 1973, Stickel 1974, 1975, Mendelssohn 1977, and Zinkl et al. 1978).

Texas↗
USGS1979

Uptake of methoxychlor from food and water by the American toad (Bufo americanus)

Various studies (Mulla et al. 1963; Ferguson and Gilbert 1967; Cooke 1973) have examined the effects of pesticides on anuran amphibians, but the routes of contaminant uptake by transformed amphibians have not been evaluated. The need of frogs and toads to imbibe water from natural surface water would seem to make them vulnerable to uptake from this source. Fish are known to accumulate pesticides from both food and water (Jarvinen et al. 1977). Toads are more terrestrial and tend to lose water less readily than most other amphibians (Thorson and Svihla 1943); hence they should he a conservative estimator of the potential for uptake of pesticides from water. Methoxychlor is an analogue of DDT and has been widely used to replace it. It is a good model of many pesticides in current use in its low persistence in animal tissues (Gardner and Bailey 1975), and its long half life in water (Wolfe et al. 1977). It is also suitable for study because of its relatively low toxicity to amphibians (Kaplan and Overpeck 1964) and its easily detected residues. In the present study we measured the accumulation of methoxychlor from food and water in a preliminary evaluation of the two routes of exposure.

Bulletin of Environmental Contamination and Toxico↗
USGS1979

Tolerance of developing salmonid eggs and fry to nitrate exposure

This paper reports on tests which show significant effects on early salmonid life stages of nitrates at levels commonly found in groundwaters in geographical areas that are influenced by fertilizer application. It has long been known, from fish cultural experience, that in certain site specific locations, chronic problems can be expected with salmonid egg development and early fry mortality. However, fingerlings which survive usually grow normally. A complete explanation is lacking although several environmental factors have been proposed to account for this phenomenon. One, which has so far received little attention, is that nitrate levels in the ground and surface waters of many areas have been increasing significantly over historical background levels. Ammonia, urea, and other potential sources of nitrate can enter natural waters from a variety of sources, such as domestic or industrial sewage, animal feedlots, or seepage and return flows from agricultural lands. The latter may be the largest contributor, since billions of tons of nitrate fertilizers are applied to agricultural crops on a worldwide basis each year. In addition, intensive forest management techniques include the aerial application of nitrate fertilizer to increase the yield of wood products, while range management practices call for use of nitrates to increase forage production. The nitrate that is not taken up by plants ultimately appears in ground or surface waters.

Bulletin of Environmental Contamination and Toxico↗
USGS1971

DDE thins eggshells and lowers reproductive success of captive black ducks

Eggs of captive black ducks fed diets containing DDE at 10 and 30 ppm (dry weight) experienced significant shell thinning and an increase in shell cracking when compared to eggs of untreated black ducks. Eggshells from dosed ducks were: 18-24 percent thinner at the equator than shells from undosed ducks; 28-31 percent thinner at the cap; and 29-38 percent thinner at the apex. Shell cracking averaged 21 percent among eggs fram the 30 ppm DDE dosage and 10 percent among eggs from the 10 ppm dosage. Only 2 percent of the eggs from untreated black ducks were cracked. Survival of ducklings fram dosed parents in terms of 'percentage of 21-day ducklings of embryonated eggs' was 40-76 percent lower than survival of ducklings from undosed parents. Average DDE residues (wet weight) in eggs from hens fed 10 and 30 ppm DDE were 46 ppm and 144 ppm, respectively.

Bulletin of Environmental Contamination and Toxico↗
USGS1972

DDE at low dietary levels kills captive American kestrels

Two of 14 male American kestrels died after 14 and 16 months on a diet containing 2.8 p.p.m., wet weight, p, p'-DDE. The brains of the two birds contained DDE residues of 213 and 301 p.p.m. compared with 14.9 p.p.m. (range, 4.47-26.6 p.p.m.) (wet weights) for 11 of the adult males which were sacrificed after 12 to 16 months on dosage. Autopsies of the two birds compared with autopsies of the sacrificed birds, revealed other characteristics typical of DDE poisoning. Neither bird, when autopsied, displayed characteristics which would suggest that they died of causes other than DDE poisoning.

Bulletin of Environmental Contamination and Toxico↗
USGS1973

DDE: Interference with extra-renal salt excretion in the mallard

The effects of DDE on the function of the salt gland, the main route of sodium chloride excretion in marine birds, were investigated in mature mallards, Anas platyrhynchos, maintained on either fresh water or 1 percent salt water and given 0, 10, 100, or 1000 ppm DDE in the diet (12 birds per level). The rate of sodium chloride excretion by the salt gland following injections of concentrated salt solutions was not reduced (from that of controls) in DDE -treated birds maintained on salt water, but was significantly reduced in DDE -treated birds not previously given salt.

Bulletin of Environmental Contamination and Toxico↗
USGS1980

Toxicity of five forest insecticides to cutthroat trout and two species of aquatic invertebrates

The Northern Rocky Mountain region has had scattered infestation of the western spruce budworm Christoneura occidentalis since the early 1900's (U.S. DEPARTMENT OF AGRICULTURE (USDA) 1976b). On the basis of aerial surveys in 1975, TUNNOCK et al. (1976), estimated that budworm defoliation occurred on 2,278,804 acres of six National Forests in Montana. Since the use of DDT was banned in 1972, there has been a need to develop alternative insecticides with the efficacy of DDT but without its environmental risk. These insecticides must be effective in controlling the budworm, but should not persist in the environment or be toxic to other organisms. The organophosphate and carbamate insecticides are relatively nonpersistent and generally present only a moderate hazard to fish when applied according to label recommendations. The USDA Forest Service has been investigating the effectiveness of these two classes of insecticides against the budworm, and the Columbia National Fisheries Research Laboratory of the U.S. Fish and Wildlife Service has been cooperating with the Forest Service conducted pilot control projects in eastern Montana in 1975 and 1976 to determine the efficacy and environmental impact of acephate, carbaryl, and trichlorfon in controlling the western budworm (USDA 1976 b). In 1975, a similar type project was carried out in Maine with aminocarb, fenitrothion, and trichlorfon (USDA 1976 a). Acephate, fenitrothion, and trichlorfon (organophosphate insecticides) and aminocarb and carbaryl (carbamate insecticides) were selected for toxicity tests against cutthroat trout ( Salmo clarki ), a stonefly ( Pteronarcella badia ), and a freshwater amphipod ( Gammarus pseudolimnaeus ) edemic in streams of the northern Rocky Mountains. Populations of cutthroat trout inhabit lakes and streams in the Rocky Mountains which include some of the most pristine habitat and fisheries in North America. Pteronarcella and Gammarus provide forage for cutthroat trout and feed on decaying vegetation in riffle areas in streams and rivers. Stonefly naiads and amphipods were selected as test organisms because of their importance as trout food and their wide distribution in mountain stream communities. We determined the effect of various water types representing different biogeographical areas in the Intermountain West on the toxicity of these five forest insecticides.

Bulletin of Environmental Contamination and Toxico↗
USGS1988

Toxicity of six heterocyclic nitrogen compounds to Daphnia pulex

We determined the relative toxicities to the aquatic crustacean Daphniz pulex of six heterocyclic nitrogen compunds. These compounds were selected because they were detected in lake trout or walleyes and were commercially available. Stress to the daphnid populations may affect forage fish populations that depend either directly or indirectly on zooplankton as a food source in the Great Lakes.

Bulletin of Environmental Contamination and Toxico↗