Geology topics

T.P. Lipscomb

Publications and source records attributed to T.P. Lipscomb.

5 recordsLinked to original sources

USGS2014

Synthesis of nearshore recovery following the 1989 Exxon Valdez oil spill: sea otter liver pathology and survival in Western Prince William Sound, 2001 – 2008

We examined livers and liver biopsies collected from captured sea otters in WPWS, 2001–2008, to determine whether indicators of liver health correlated with history of oil contamination from the 1989 Exxon Valdez oil spill. Sea otters captured in oiled areas had a significantly higher proportion of livers with gross pathological change, based on visual inspection at the time of capture, than those from unoiled areas. Of the 10 histopathology variables scored on liver biopsies, only two (vacuolar change and pigment) differed between animals from oiled and unoiled areas, and neither correlated with gross pathology scores. Vacuolar change indicates physiological disturbance, which is consistent with potential effects from oil exposure but also could be influenced by a number of other factors. We concluded that, as of 2008, some differences in liver health were evident between sea otters from oiled and unoiled areas; these differences were consistent with, but not specific to, effects that might be expected with sublethal exposure to lingering Exxon Valdez oil. We also quantified variation in survival of radiomarked sea otters within oiled areas of WPWS in relation to age, sex, body condition, selected blood serum chemistry variables, and histological scores indicative of liver health. Of the variables considered, only the serum enzyme aspartate aminotransferase (AST) and the ratio of serum proteins albumin and globulin (A/G) were correlated with survival, with higher levels of AST and lower levels of A/G associated with increased likelihood of mortality. High AST and low A/G both may be indicative of liver disease. Taken together, results reported here suggest that liver health of sea otters in oiled areas was slightly poorer than those from unoiled areas and, ifurther, that this may have translated to poorer survival through 2008, nearly 2 decades after the spill. More recently collected information indicated that mortality patterns and abundance had returned to pre-spill conditions between 2010 and 2013, suggesting that the effects that we detected through 2008 may have represented the end of effects related to exposure to lingering oil.

Alaska↗

USGS1995

Clinical and clinical laboratory correlates in sea otters dying unexpectedly in rehabilitation centers following the Exxon Valdez oil spill

Following the Exxon Valdez oil spill, 347 oiled sea otters ( Enhydra lutris) were treated in rehabilitation centers. Of these, 116 died, 94 within 10 days of presentation. Clinical records of 21 otters dying during the first 10 days of rehabilitation were reviewed to define the laboratory abnormalities and clinical syndromes associated with these unexpected deaths. The most common terminal syndrome was shock characterized by hypothermia, lethargy, and often hemorrhagic diarrhea. In heavily and moderately oiled otters, shock developed within 48 hours of initial presentation, whereas in lightly oiled otters shock generally occurred during the second week of captivity. Accompanying laboratory abnormalities included leukopenia with increased numbers of immature neutrophils (degenerative left shift), lymphopenia, anemia, azotemia (primarily prerenal), hyperkalemia, hypoproteinemia/hypoalbuminemia, elevations of serum transaminases, and hypoglycemia. Shock associated with hemorrhagic diarrhea probably occurred either as a direct primary effect of oiling or as an indirect effect secondary to confinement and handling in the rehabilitation centers. Lightly oiled otters were less likely to die from shock than were heavily oiled otters (22% vs. 72%, respectively). Heavily oiled otters developed shock more rapidly and had greater numbers of laboratory abnormalities, suggesting that exposure to oil was an important contributing factor.

Alaska↗

USGS1994

Pathology of sea otters

In the months following the Exxon Valdez oil spill (EVOS), 994 sea otters ( Enhydra lutris ) from oil-spill-affected areas died (Doroff et al. 1993). Carcasses collected from these areas and otters that died in rehabilitation centers are included in this number. The actual number that died was probably much greater. Within days of the spill, the Exxon Company (USA) funded an effort to rehabilitate oil-contaminated sea otters (Davis 1990). Initially, clinical veterinarians working on the rehabilitation effort performed partial necropsies on some of the sea otters that died. Soon, veterinary pathologists from the University of Alaska and the U.S. Environmental Protection Agency provided assistance. Later, rehabilitation centers were constructed and other veterinarians with special training in pathology were hired by Exxon to provide diagnostic support. In late April 1989, veterinary pathologists from the U.S. Fish and Wildlife Service (USFWS) assumed responsibility for pathologic evaluation of oil-spill-affected sea otters. The USFWS requested assistance from veterinary pathologists of the Armed Forces Institute of Pathology (AFIP) in June 1989. Eventually, as part of the Natural Resources Damage Assessment program, AFIP veterinary pathologists were asked to carry out histopathological studies of the tissue specimens collected by all parties and to perform necropsies on carcasses that had been collected and frozen. A veterinary clinical pathologist was requested to assess hematology and clinical chemistry findings in otters that had been held in the rehabilitation centers. In spite of the best efforts of many dedicated people working under extremely difficult conditions, there are significant limitations in the pathological studies. The absence of a detailed necropsy protocol and of full documentation of necropsy findings during the first several weeks after the spill resulted in important data being lost. Often, samples of all major organs were not collected. In some cases, no necropsy report was available. Specimens for toxicologic analysis for petroleum hydrocarbons were not consistently collected. The absence of a detailed toxicology protocol suggests that the samples may not have been collected properly. The lack of a consistent numbering system for identification of specimens caused major problems; some samples were useless because they could not be identified. Many blood samples could not be transported to laboratories quickly enough to prevent significant deterioration of the samples because of inclement weather and the remote locations of the rehabilitation centers. Thus, in a number of cases, data could not be used because significant deterioration of the specimens was considered likely to have occurred. Since more than one laboratory was used to analyze blood samples, problems with comparability of results were encountered. The laboratory tests were performed to aid the clinical veterinarians in diagnosis and treatment of individual animals, not as part of a consistent protocol; thus, there is variation in the amount and type of laboratory data available for each otter. These problems illustrate the need for development of contingency plans that include detailed protocols before disasters occur.

Alaska↗

USGS1993

Histopathologic lesions in sea otters exposed to crude oil

Following the Exxon Valdez oil spill in Prince William Sound, Alaska, sea otters ( Enhydra lutris ) that appeared to be contaminated with oil, that were in danger of becoming contaminated, or that were behaving abnormally were captured and taken to rehabilitation centers. Exposure to oil was assessed by visual examination when otters arrived at the centers. Degree of oil exposure was graded according to the following criteria: oil covering greater than 60% of the body - heavily contaminated; oil covering 30–60% of the body - moderately contaminated; oil covering less than 30% of the body or light sheen on fur - lightly contaminated. If there was no oil visible, otters were considered uncontaminated. Tissues from 51 oil-contaminated sea otters (14 males, 37 females) and from six uncontaminated sea otters (three males, three females) that died in rehabilitation centers were examined histologically. Among oil-contaminated sea otters, 19/46 had interstitial pulmonary emphysema, 13/40 had gastric erosion and hemorrhage, 11/47 had centrilobular hepatic necrosis, 14/47 had periportal to diffuse hepatic lipidosis, and 10/42 had renal tubular lipidosis. Of the uncontaminated sea otters, 1/6 had gastric erosion and hemorrhage and 1/6 had diffuse hepatic lipidosis. Histologic examinations were performed on tissues from five sea otters (three males, two females) found dead with external oil present 15 to 16 days after the spill. Periportal hepatic lipidosis and renal tubular lipidosis were found in 3/5, and interstitial pulmonary emphysema was found in 1/5. Tissues from six apparently normal sea otters (four males, two females) collected from an area not affected by an oil spill were examined histologically, and none of these lesions were found. We conclude that interstitial pulmonary emphysema, centrilobular hepatic necrosis, and hepatic and renal lipidosis of sea otters were associated with exposure to crude oil. Gastric erosion and hemorrhage may have been associated with stress of captivity and/or oil exposure.

Alaska↗

USGS1990

Procedures and rationale for marking sea otters captured and treated during the T/V Exxon Valdez oil spill

Four methods were used for marking sea otters ( Enhydra lutris ) captured and treated during the response to the T/V Exxon Valdez oil spill. Colored and numbered flipper tags were placed on each sea otter that was brought to the otter treatment centers. These tags allowed individual recognition and permitted the tracking of individuals through the treatment and holding processes. Recovery of tagged carcasses may provide a crude measure of the fates of rehabilitated otters. Seven sea otters were instrumented with radio transmitters attached to flipper tags as part of a pilot release program. The results of that study were inconclusive. Forty-five sea otters were implanted with radio transmitters as part of a study to assess the fate of rehabilitated sea otters. Specific objectives of the study include estimating survived rates and monitoring the reproductive success of the sample of rehabilitated sea otters and comparing the results with similar variables in a control population. Transponder chips were injected in the perianal region of all but seven of the instrumented sea otters, and all were tagged with red flipper tags. The advantages and disadvantages of each type of tag are discussed.

Alaska↗