Geology topics
T. J. O'Shea
Publications and source records attributed to T. J. O'Shea.
Distribution, status, and biogeography of the West Indian manatee
No abstract available.
The past, present, and future of manatees in the southeastern United States: realities, misunderstandings and enigmas
A review of the historical and recent (1970s-1980s) literature on the distribution, abundance, and mortality of West Indian manatees ( Trichechus manatus ) in the southern United States is presented. Recent unpublished data on mortality, Florida boat registrations, size of certain manatee wintering populations, and records outside of Florida are also given. Manatees never regularly occurred outside of Florida, except during the summer in Georgia. Current distribution is also limited largely to Florida and coastal Georgia in summer, with extralimital records in other southeastern states. In winter the range contracts and is centered around warm water sources in Florida. The historical record on past abundance is inconclusive, but does not provide any compelling evidence to claim that manatees ever nearly became extinct. There are no satisfactory means to estimate manatee population size. However, within Florida, manatees have become more widespread and possibly more abundant during the past 30 years due to protection, greater availability of warm water in winter, and in some areas, increased exotic vegetation. Deliberate killing for food was long a historical pressure on manatee populations in Florida, but is not almost non-existent. Nevertheless, recent increasing trends in accidental mortality caused by boats, coupled with an understanding of manatee population dynamics, suggests that the future for manatees is not secure. Ample justification exists for continued manatee conservation efforts.
Tolerance of West Indian manatees to capture and handling
Ninety-two West Indian manatees (Trichechus manatus) have been captured in the southeastern United States from October 1975 through November 1983 with no evidence of an unusual susceptibility to capture myopathy. Of these, 53 were radio-tracked or observed in the field following capture with no evidence of delayed capture stress. Blood samples obtained at capture for 20 wild individuals displayed no elevation in biochemical variables typically seen in mammalian capture myopathy cases. Thirty-one manatees captured for rescue and rehabilitation generally did not exhibit symptoms of capture myopathy, although in one case marked elevations in creatinine phosphokinase were observed, probably related to lengthy transport. Necropsy findings for 20 terminal cases that died of various causes unrelated to their rescue or handling did not indicate the involvement of any gross or histological lesions of capture myopathy. Historical records for the capture and handling of about 150 West Indian manatees during the 1900s also suggest a tolerance to these activities. Recent observations on the probable susceptibility of dugongs (Dugong dugon) to capture stress apparently cannot be extended to West Indian manatees.
Lead concentrations and reproduction in highway-nesting barn swallows
Swallows (Hirundo rustica) collected within the right-of-way of a major Maryland highway were greater than those found in Barn Swallows nesting within a rural area. Lead concentrations in the feathers of adults from the highway colony were also greater than Lead concentrations in the carcasses and stomach contents of adult and nestling Barn those of rural adults, but concentrations in the feathers of nestlings from the two locations were similar. Activity of u-aminolevulinic acid dehydratase in red blood cells was lower in highway-nesting adults and their young than in their rural counterparts, although hemoglobin concentrations and hematocrits did not differ. The number of eggs, nestlings, and body weights of the latter at 16-18 days of age were similar in the two colonies, as were body weights of adults from the two areas. These results suggest that contamination of roadside habitats by lead from automotive emissions does not pose a serious hazard to birds that are aerial feeders.
Polychlorinated biphenyls in a wild mink population
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Phthalate plasticizers: Accumulation and effects on weight and food consumption in captive starlings
No abstract available.
DDT contamination at Wheeler National Wildlife Refuge
Disposal of industrial waste resulted in massive DDT contamination at Wheeler National Wildlife Refuge, Alabama. Nearly a decade after the cessation of DDT manufacturing at the facility responsible, concentrations of DDT residues in the local fauna are still high enough to suggest avian reproductive impairment and mortality. Populations of fish-eating birds are low, endangered species are being exposed, and muscle lipids of game birds contain up to 6900 parts of DDT (isomers and metabolites) per million.
Organochlorine pollutants in small cetaceans from the Pacific and south Atlantic Oceans, November 1968-June 1976
Organochlorine residues were analyzed in blubber, brain, or muscle tissues of 69 individuals representing 10 species of small cetaceans. Collections were made from November 1968 through June 1976 at localities in the Eastern Tropical Pacific and along the coasts of California, Hawaii, Japan, and Uruguay, Relations of residue concentrations between tissues are described for DDE and PCBs in two dolphin species. sigma DDT and PCB residues in blubber of most of the 19 individuals of the five southern California species sampled exceed concentrations that are associated with reproductive impairment in pinnipeds, although the nature of such associations is not well defined. The sigma DDT residue of 2,695 ppm in blubber of one California coastal Tursiops truncatus is one of the highest concentrations reported in tissues of members of any population of wild mammals. Except for one rough-toothed dolphin (Steno bredanensis) from Maui, Hawaii, all individuals from all localities surveyed were contaminated with organochlorine compounds. Seventeen different organochlorines were detected; greatest diversity occurred near Japan and California. This is the first report of several of these compounds in tissues of any species of marine mammals. The o,p'-isomers and metabolites of DDT were detected unusually frequently. Ratios of p,p'-DDT to p,p'-DDE in blubber of cetaceans from waters off countries where use of this pesticide has been relatively recent and ongoing were at least an order of magnitude higher than in cetaceans from United States waters.
Influence of a local source of DDT pollution on statewide DDT residues in waterfowl wings, northern Alabama, 1978-79
Heavy DDT contamination resulting from a former DDT manufacturing plant in northern Alabama has influenced statewide averages of DDT, DDE, and TDE residues in duck wings tested in the National Pesticide Monitoring Program. In states where contaminant levels in duck wings are high, residue analyses of wings categorized by finer geographic subdivision may be useful in defining the areas of heaviest contamination.