Inhibition of brain cholinesterase activity in forest birds and squirrels exposed to aerially applied acephate
No abstract available.
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No abstract available.
In April 1980, a Cooper's hawk ( Accipiter cooperii ) was found on the ground in Lakewood, Colorado, unable to fly and in convulsion. The bird died shortly thereafter. The hawk was packed in dry ice and shipped air express to the Fish and Wildlife Service, U. S. Department of the Interior, National Wildlife Health Laboratory, Madison, Wisconsin, for necropsy. Following necropsy, the brain, gastrointestinal tract, and remaining carcass except skin, feet, wings, liver, and kidney were packed in dry ice and shipped air express to the Patuxent Wildlife Research Center, Laurel, Maryland, for chemical residue analysis. Because the bird's behavior before death suggested some form of poisoning, the kidney was assayed for thallium, the liver for lead, and the gastrointestinal tract for strychnine, sodium fluoroacetate, and arsenic. When these assays proved negative, the bird was analyzed for organochlorine pesticides. Necropsy findings and pesticide residue analyses are reported here.
No abstract available.
One member of each pair of incubating laughing gulls at 9 nests was trapped, orally dosed with either 6 mg/kg parathion in corn oil or corn oil alone, and marked about the neck with red dye. Each nest was marked with a numbered stake and the treatment was recorded. A pilot study with captive laughing gulls had determined the proper dosage of parathion that would significantly inhibit their brain AChE activity (about 50% of normal) without overt signs of poisoning. After dosing, birds were released and the nests were observed for 21/2 days from a blind on the nesting island. The activities of the birds at each marked nest were recorded at 10-minute intervals. Results indicated that on the day of treatment there was no difference (P>0.05, Chi-square test) in the proportion of time spent on the nest between treated and control birds. However, birds dosed with 6 mg/kg parathion spent significantly less time incubating on days 2 and 3 than did birds receiving only corn oil. By noon on the third day, sharing of nest duties between pair members in the treated group had approached normal, indicating recovery from parathion intoxication. These findings suggest that sublethal exposure of nesting birds to an organophosphate (OP) insecticide, such as parathion, may result in decreased nest attentiveness, thereby making the clutch more susceptible to predation or egg failure. Behavioral changes caused by sublethal OP exposure could be especially detrimental in avian species where only one pair member incubates or where both members are exposed in species sharing nest duties.
No abstract available.
No abstract available.
Since 1978, a large proportion of the black skimmers (Rynchops niger) nesting along the Texas coast have had high concentrations of DDE in their eggs. Of 284 eggs collected from 5 sites during 1978-81, 99.5% contained detectable (> 0.i0 ppm) w levels of DDE, ranging up to 86 ppm wet-weight; 36% of the eggs contained > i0 ppm DDE (White et al., 1984). During the 4-year period, geometric mean concentrations of DDE remained strikingly similar, with no significant decline in egg contaminant levels. The sources of DDE contamination in skimmers are unknown. Recoveries of juvenile skimmers banded in Texas, Louisiana, and Mississippi indicate that a large proportion of the birds (60%) spend the winter on the east and west coasts of Mexico. Therefore, it is possible that the DDE exposure to Texas skimmers occurs in Mexico during the winter, although some birds remain along the Gulf Coast year-round.\ This study was conducted to determine the degree of DDE and other organochlorine contamination in black skimmers and their food items from sites in Mexico and Texas, and to statistically compare residue concentrations and body condition in individuals from the 2 areas.
No abstract available.
In the event of the development of the large oil shale reserves of Colorado, Utah, and Wyoming, one of the main environmental concerns will be disposal of retorted-oil shale which will be generated in greater volume than the original volume oI the mined oil shale. Investigators have found that leachates of retorted-oil shale are alkaline and have large concentrations of dissolved solids, molybdenum, boron, and fluoride (STOLLENWERK & RUNNELS 1981). STOLLENWERK & RUNNELS (1981) concluded that drainage from waste shale piles could have deleterious effects on the water quality of streams in northwestern Colorado.
Effects on egg quality of mallards fed low concentrations of South Louisiana crude oil and DDE alone or in combination.
No abstract available.
Aquatic birds may serve as indicators of regional metal contamination. Because the food of prefledgling herons (Nycticorax nycticorax ) comes only from areas near the colony, their tissues should reflect local metal contamination. The authors' hypothesis was that prefledgling herons from the Rhode Island colony should have higher concentrations of metals than do those from either the North Carolina or Massachusetts colonies.
No abstract available.
No abstract available.
No abstract available.
There is evidence that fish in Canadian wilderness areas exhibit elevated mercury levels because of the oligotrophic nature of the lakes they inhabit (BROUZES et al. 1977). D'ITRI et al. (1971) reported higher levels of mercury in trout from oligotrophic waters than in trout from eutrophic waters in unpolluted areas. They attributed part of the difference to differences in the food of the fish in the two types of waters. Position on the trophic scale is an important factor determining the degree of bioaccumulation of mercury by aquatic organisms, especially fish. Elevated mercury levels have been reported in fish from three wilderness lakes in northern Maine (NORMANDEAU ASSOCIATES 1978). Concentrations exceeding 0.50 ~g/g were detected in the muscle tissue of many of the fish. We report the levels of mercury in the muscle tissue of brook trout (Salvelinus fontinalis) and lake trout (S. namaycush) from three northern Maine lakes. Mercury levels in fish from two wilderness lakes in the same drainage basin were compared with each other, and in turn with those in fish from a lake in a separate drainage basin. The fish species composition in one of the wilderness lakes, Cliff Lake, is different from that in the other two lakes, enabling us to analyze the effects of trophic structure on mercury concentration in top carnivores. It is unlikely that mercury from agricultural, geological, or local industrial sources occurs in these lakes.
No abstract available.
No abstract available.