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L. J. Blus

Publications and source records attributed to L. J. Blus.

At least 55 records · Page 3Linked to original sources
USGS1984

DDE in birds' eggs: Comparisons of two methods for estimating critical levels

The sample egg technique and eggshell thickness-residue regression analysis were comparatively evaluated as tools in estimating critical levels of DDE in birds? eggs that seriously affect reproductive successa nd population starts....In comparing critical values of DDE that were derived from the two methods, the estimates were lower using the sample egg technique for both the Brown Pelican (3 ?g/g vs 8 ?g/g) and the Black-crowned Night-Heron (12?g/g/ vs 54 ?g/g) assuming a critical value of eggshell thinning at 20%....Extension of the regression line beyond the eggshell thickness-DDE residue data base is likely to result in spurious critical values of DDE. When sufficient thickness and residue data are available for estimating critical values of DDE from the regression equation, the estimates are meaningful but are likely to be inflated because adverse effects unrelated to eggshell thinning such as parental behavior and embryotoxicity unrelated to eggshell deficiencies are not taken into account.....Establishing critical levels of pollutants in eggs and tissues is a necessary procedure in assessing effects of these chemicals on individuals and populations of sensitive species. There are inherent difficulties in quantifying the effects of any pollutant on population trends and declines in productivity. The sample egg technique is apparently a more sensitive method for estimating critical levels of DDE, but some subjective interpretation is required for results obtained by both methods.

The Wilson Bulletin↗
USGS1983

Effects of heptachlor on American kestrels in the Columbia Basin, Oregon

Wheat seeds treated with heptachlor to control wireworms (Ctenicara pruinina) resulted in American kestrels (Falco sparverius) in the Columbia Basin accumulating residues of heptachlor epoxide (HE) that reduced productivity and caused some adult mortality. The kestrel is more sensitive to HE residues in eggs than the Canada goose (Branta canadensis moffitti), i.e., reduced productivity occurs at > 1.5 ppm in kestrel eggs vs. > 10 ppm in Canada goose eggs. Neither kestrel eggshells nor Canada goose eggshells were thinned by HE. The reduced use of heptachlor in 1979, because of a partial ban, resulted in an immediate lowering of HE concentrations in kestrel eggs the following year.

Oregon↗
USGS1982

Further interpretation of the relation of organochlorine residues in brown pelican eggs to reproductive success

This study was conducted to provide additional interpretation of the relation of organochlorine pollutants to reproductive success and population stability of brown pelicans Pelecanus occidentalis in the southeastern United States from 1969 to 1977. The sample egg technique was employed in South Carolina; it involved collecting an egg from each of 156 marked nests, analysing the eggs for residues and relating residue levels to nest success. All of the organochlorines appeared to induce adverse effects on reproductive success of brown pelicans, but the correlative evidence indicated that DDE was responsible for most of the pollutant-related nest failure. Close intercorrelation of each of the organochlorines presented a problem in the separation of the effects of each pollutant. The critical level of DDE in brown pelican eggs was 3 μg g −1 , this level was associated with substantially impaired reproductive success and 4 μg g −1 of DDE was associated with sotal reproductive failure. The critical level for dieldrin was not determined, but it appeared to exceed 1 μg g −1 . Dieldrin, DDT, DDD and the PCBs apparently exerted a minor effect on reproductive success of brown pelicans in South Carolina. Endrin seemed to induce reproductive impairment in brown pelicans in Louisiana in 1975. The critical level in eggs is only roughly estimated at <0·5 μg g −1 because it was not possible to use the sample egg technique in this small population. Significant declines in organochlorine residues in South Carolina during this study were associated with increases in eggshell thickness, reproductive success and the breeding population. Of those avian species studied, the brown pelican remains the most sensitive to organochlorine contaminants, particularly DDE and endrin; factors related to this sensitivity are poorly known.

South Carolina↗
USGS1981

PCBs and organochlorine pesticides in wild mink and river otters from Oregon

Mink (Mustela vison) and river otters (Lutra canadensis) collected during the 1978-1979 trapping season in Oregon were analyzed for organochlorine pesticide and polychlorinated biphenyl (PCB) residues. PCB residues were most frequently encountered in both species from the Lower Columbia River. PCB residues in 6 of 9 Columbia River mink livers were as high as those reported in livers of experimental female mink that experienced total reproductive failure after eating a PCB-contaminated diet of 0.64 ppm for 160 days. Also, some fish from the Columbia River contained PCBs (range 0.24-2.8 ppm) equivalent to or higher than the dietary dosage given in the same laboratory study. River otter livers from the same area contained even higher levels of PCBs [(M) geometric mean 9.3 ppm, (F) geometric mean 3.5 ppm], but the relative sensitivity of the 2 species to these contaminants is unknown. The river otter harvest along the Lower Columbia River has declined in the last 3 decades, whereas the statewide harvest trend is upward. PCBs were generally low or not detected in the remainder of the Oregon locations studied. Lower Columbia River collections also showed the highest organochlorine pesticides (mainly DDE) in both species. We are less concerned about the DDE residues reported, particularly in mink, because mink are less sensitive to DDT than to PCBs. Population declines of both mink and otters resulting from PCB contamination may have occurred, and may still be occurring, along the Lower Columbia River.

Book chapter↗
USGS1980

Pollution ecology of breeding great blue herons in the Columbia Basin, Oregon and Washington

Approximately 40 pairs of Great Blue Herons ( Ardea herodias ) formerly nested in trees on or near Blalock Island about 95 km downstream from Richland, Washington, in the Columbia River (Nehls 1972 ). In conjunction with construction of the John Day Lock and Dam and before creating Lake Umatilla in 1968, large trees along the shoreline, including those in the heronry on Blalock Island, were removed except for about six cottonwood trees ( Populus sp.) that were left standing near the south bank of the river (David Lenhart, pers. comm.). As a mitigation procedure, the Umatilla National Wildlife Refuge (Umatilla) was established in 1967. The herons subsequently established a secondary heronry in the six cottonwoods; 20 pairs were present in 1971 (Nehls 1972). The inundated trees died and deteriorated; only two trees with eight nests remained in 1976 (Henny and Kurtz 1978), and we found just two nests in one tree in 1978. With a decrease in traditional nesting sites, the birds nested on islands in big sagebrush ( Artemisia tridentata ), on channel markers in the Columbia River, and on nesting platforms constructed for Canada Geese ( Branta canadensis ). The purpose of this paper is to describe the breeding biology of Great Blue Herons at Umatilla and the McNary Recreation Area (McNary) in 1978 and the relationship of organochlorine residues in eggs to eggshell thickness and reproductive success. The primary reason for conducting this study was to determine if the heptachlor seed treatment that was severely affecting Canada Geese at Umatilla (Blus et al. 1979) was also a hazard to Great Blue Herons. At the same time we also investigated possible effects of other organochlorines on the herons.

Oregon, Washington↗
USGS1979

Relation of environmental factors to breeding status of royal and sandwich terns in South Carolina, USA

The population ecology of the royal tern Sterna maxima and sandwich tern Sterna sandvicensis was investigated in South Carolina from 1970 through 1977. Royal and sandwich terns nested together in all of the colonies that we located. The peak in egg laying usually occurred in early May; peak hatching occurred from late May to mid-June. Clutch size for both species was one egg. Tidal flooding was the major factor in egg loss. The breeding population was 15,499 pairs in 1974 and 18,096 pairs in 1975; sandvicensis made up about 5% of the breeding population. The average number of young fledged per nest ranged from 0·36 to 0·44. Residues of organochlorine pollutants in most eggs and tissues were low and posed no identifiable threat to the terns. There was a decline in DDE and dieldrin residues in eggs of maxima . The future of royal and sandwich terns in South Carolina seems fairly secure as the population is apparently at or near carrying capacity and most of the major nesting sites are dedicated to protection of nesting birds.

South Carolina↗
USGS1979

Effects of heptachlor-treated cereal grains on Canada geese in the Columbia Basin

In 1976 and 1977, die-offs of birds of several species occurred in Umatilla and Morrow counties, Oregon. Detection of high levels of heptachlor epoxide (HE) in tissues of Canada geese (Branta canadensis) prompted this study to determine the extent and impact of heptachlor contamination on geese on two study areas on the Columbia River--the Umatilla National Wildlife Refuge (Umatilla) in Oregon and Washington and on the McNary Recreation Area (McNary) about 65 km upstream in Washington. Nest success of Great Basin Canada geese (B. c. moffitti) at McNary was 90.2 percent compared to 5I.7 percent at Umatilla. HE in eggs was correlated with nest success--95 percent of the nests from which sample eggs contained <1 ?g/g of HE were successful compared to 20 percent of those with eggs that contained >10 ug/g. Eggs from McNary were essentially clean of organochlorine pollutants, while eggs from Umatilla contained an average of 2.93 ?g/g of HE and a maximum of 24.29 ug/g. Lethal levels of HE were detected in brains of resident Great Basin Canada geese and over-wintering Taverner's geese (B. c. taverneri) that were found dead on or near Umatilla: The source of HE in geese appeared to be ingestion of seeds treated with heptachlor for wireworm control. The small population of moffitti is in danger of extirpation from heptachlor. Recommendations for minimizing the heptachlor problem include: (1) improved handling of treated grain to decrease its availability to wildlife, (2) use of treated seed only in areas requiring wireworm control, and cessation of prophylactic use, particularly on wheat planted in irrigated circles immediately following potatoes, and (3) replacement of heptachlor with a safer chemicaL

Book chapter↗
USGS1979

Organochlorine pollutants and population status of least terns in South Carolina

Least Tern nesting colonies on the Cape Romain National Wildlife Refuge and surrounding areas in South Carolina were studied from 1971 through 1975. We located 10 colonies including 6 on the Refuge and 4 on nearby coastal islands. The number of nests in each colony ranged from several up to 220. Least Terns began reproductive activity in April, and the egg-laying period ranged from May to July. The earliest hatching record was 6 June. Reproductive success in most colonies seemed poor. Tidal flooding of eggs, predation of eggs and young, and disturbance by domestic animals and man were responsible for most failures. Residues of DDE, PCB's, and other organochlorine pollutants in the eggs were low and posed no identifiable threat to the Least Terns. DDE residues in eggs declined from 0.63 μg/g in 1972 to 0.33 μg/g in 1975. In contrast, PCB residue trends were erratic; mean residue values were 0.40 μg/g in 1972, 1.08 μg/g in 1974, and 0.62 μg/g in 1975. Eggshell thickness means for 1972, 1974, and 1975 were 2 to 7% lower than the pre-1947 mean; but the differences between means were not statistically significant. There is no evidence of a decline in Least Tern populations in South Carolina over the past 30 years such as observed in many other parts of the range of the species. A number of the current nesting islands seem secure from adverse environmental perturbations, although several colonies are on islands that are in danger of extensive development.

South Carolina↗
USGS1979

Effects of organochlorine residues on eggshell thickness, reproduction, and population status of brown pelicans (Pelecanus occidentalis) in South Carolina and Florida, 1969-76

Shells of brown pelican (Pelecanus occidentalis) eggs collected in South Carolina from 1969 through 1975 and in Florida during 1969, 1970, and 1974 were significantly thinner (P greater than 0.05) than eggshells collected before 1947. Thickness of South Carolina eggshells increased in 1975, and mean thickness of eggshells collected in Florida during 1974 was greater than that of eggshells collected during 1969 and 1970, primarily in Gulf Coast colonies. Residues of 13 organochlorines were found in eggs and tissues of pelicans found dead during 1974 and 1975, although residues in brains of these specimens were not high enough to cause death. Residues of organochlorines, except PCBs, declined through 1975. PCBs increased in eggs from Atlantic Coast colonies. Reproductive success and population status of brown pelicans in South Carolina have improved markedly since authors began their studies in 1969. Good reproductive success was reported in 3 of 5 years from 1973 through 1977.

Pesticides Monitoring Journal↗
USGS1979

Organochlorine residues in six species of estuarine birds, South Carolina, 1971-75

In South Carolina between 1971 and 1975, authors evaluated the occurrence of organochlorine residues in the laughing gull (Larus atricilla), white ibis (Eudocimus albus), glossy ibis (Plegadis falcinellus), American oystercatcher (Haematopus palliatus), willet (Catoptrophorus semipalmatus), and ruddy turnstone (Arenaria interpres). Tissues of birds found dead and eggs were analyzed, eggshell thicknesses were measured, and incidental observations were made of reproductive success and population status. Eggshell thickness of the white bis, American oystercatcher, and laughing gull were not significantly different (P less than 0.05) from the pre-1947 norms. DDE and polychlorinated biphenyls (PCBs) were found most frequently and at the highest concentration in eggs. DDE residues declined significantly in oystercatcher eggs, and declined slightly in laughing gull eggs; no change was noted in white ibis eggs. No consistent trends were found for dieldrin and PCBs. Authors found no obvious problems with reproductive success of any species. Populations of the five species breeding in South Carolina appear stable. The white ibis and laughing gull in South Carolina have experienced population explosions over the past 50 years; the glossy ibis has increased substantially since the first documented breeding records in 1947.

Pesticides Monitoring Journal↗
USGS1978

Avian cholera and organochlorine residues in an American oystercatcher

Pasteurella multocida , the causative bacterium of avian cholera, was isolated from cultures of the liver and heart blood of a female, adult American oystercatcher ( Haematopus palliatus ) found dead on the Cape Romain National Wildlife Refuge, South Carolina, in May 1973. This is apparently the first record of avian cholera in the oystercatcher. Low levels of DDE were identified in tissues of the oystercatcher.

South Carolina↗
USGS1977

Ruptured-yolk peritonitis and organochlorine residues in a royal tern

Ruptured-yolk peritonitis was responsible for the death of a royal tern. Lodgment of eggs in the oviduct was probably due to reverse peristalsis brought about by breakage of the thin-shelled eggs and secondary bacterial infection. The thin shells were apparently not related to the low levels of DDE and other organochlorine pollutants found in tissues and egg contents.

Avian Diseases↗