Assessment of the Genetic Toxicological Impacts of the Exxon Valdez Oil Spill on Pink Salmon (Oncorhynchus gorbuscha) may be Confounded by the Influence of Hatchery Fish

ABSTRACT The authors review studies of four taxa—pink salmon, sea otters, harbor seals, and several species of sea-birds—widely believed to have suffered severe impacts from the Exxon Valdez oil spill. These studies were conducted over a 10-year post-spill period and included pre-spill information where possible. They demonstrated earlier suggestions of negative impacts may have been unfounded (harbor seals) or the species either exhibited no obvious detrimental effects from the spill (pink salmon population runs, population density and habitat occupancy of half the 23 seabird species examined) or indicated impacts followed by clear evidence of subsequent recovery (sea otters, the remaining seabird species). These species' apparent resilience to perturbations such as oil spills may be related to these ecosystems' high natural variability. Evaluating spill effects is enhanced by long-term studies that recognize the natural variability of marine environments and use a rigorous study design. The results of such studies also must be interpreted objectively, free of preconceptions about spill effects and divorced from advocacy positions.

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Resolving allegations of oil damage to incubating pink salmon eggs in Prince William Sound

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f01-055 ◽

2001 ◽

Vol 58 (6) ◽

pp. 1070-1076 ◽

Cited By ~ 4

Author(s):

Ernest L Brannon ◽

Keya CM Collins ◽

Lawrence L Moulton ◽

Keith R Parker

Keyword(s):

Oil Spill ◽

Pink Salmon ◽

Oncorhynchus Gorbuscha ◽

Sensitive Period ◽

Time Sampling ◽

Prince William Sound ◽

Pink Salmon Oncorhynchus Gorbuscha ◽

Salmon Eggs ◽

Original Survey ◽

Oil Exposure

The Exxon Valdez Oil Spill Trustee Council concluded that oil caused mortality of pink salmon (Oncorhynchus gorbuscha) eggs in Prince William Sound streams. Their conclusion was based primarily on Alaska Department of Fish and Game (ADF&G) studies which reported that mean mortality of embryos in eggs was higher in oiled than non-oiled streams when sampled shortly after spawning completion. However, developing embryos are vulnerable to shock mortality for a period of 20 days after fertilization, and the embryos in eggs from the latest spawners were still in the sensitive period at the time sampling took place. We argue that the original ADF&G analysis should have included sample timing in statistical comparisons of mortality between streams. Analysis of a subset of the ADF&G data showed that sampling shock was a major source of embryo mortality in these samples, and that source of mortality in the original survey would likely have been mistakenly interpreted as an oiling effect. Compensating for sample timing removed all statistical evidence for an oiling effect in the data subset. We conclude that the ADF&G study design confounded the ability to assess for the effect of oil exposure on pink salmon eggs.

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SALMON SURVIVE OIL SPILL

PEDIATRICS ◽

10.1542/peds.88.3.a72 ◽

1991 ◽

Vol 88 (3) ◽

pp. A72-A72

Keyword(s):

Oil Spill ◽

Pink Salmon ◽

Prince William Sound ◽

Washington Post ◽

Exxon Valdez ◽

Exxon Valdez Oil Spill ◽

Better Than

When the Exxon Valdez hit the rocks of Prince William Sound last year, there were predictions of a near-apocalypse for Alaska's salmon industry. Well, this year's salmon catch is coming to an end and it turns out it will be the biggest in history... So far, the Washington Post reports that 40 million salmon have been caught, far outstripping the 1987 record harvest of 29 million. Many of the salmon were hatched last spring in the very waters fouled by the Exxon Valdez oil spill. The rest were released from hatcheries in Prince William Sound and swam through the same waters on their way to the ocean. At the largest hatchery in the area, the number of pink salmon returning to the sound this summer was double the average of recent years. Last year's oil spill apparently had little effect on the growth of plankton in the sound, the main source of food for young salmon. Salmon hatcheries report plankton growth was better than ever this year.

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SENSITIVITY OF FISH EMBRYOS TO WEATHERED CRUDE OIL: PART II. INCREASED MORTALITY OF PINK SALMON (ONCORHYNCHUS GORBUSCHA) EMBRYOS INCUBATING DOWNSTREAM FROM WEATHERED EXXON VALDEZ CRUDE OIL

Environmental Toxicology and Chemistry ◽

10.1897/1551-5028(1999)018<0494:sofetw>2.3.co;2 ◽

1999 ◽

Vol 18 (3) ◽

pp. 494 ◽

Cited By ~ 96

Author(s):

Ron A. Heintz ◽

Jeffrey W. Short ◽

Stanley D. Rice

Keyword(s):

Crude Oil ◽

Pink Salmon ◽

Oncorhynchus Gorbuscha ◽

Exxon Valdez ◽

Pink Salmon Oncorhynchus Gorbuscha ◽

Fish Embryos

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A Quantitative Evaluation of Survival to the Adult Stage and Other Characteristics of Pink Salmon (Oncorhynchus gorbuscha) Produced by a Revised Hatchery Method Which Simulates Optimal Natural Conditions

Journal of the Fisheries Research Board of Canada ◽

10.1139/f72-171 ◽

1972 ◽

Vol 29 (8) ◽

pp. 1151-1167 ◽

Cited By ~ 11

Author(s):

R. A. Bams

Keyword(s):

Growth Rate ◽

Adult Stage ◽

Pink Salmon ◽

Relative Survival ◽

Oncorhynchus Gorbuscha ◽

Adult Size ◽

Natural Conditions ◽

Pink Salmon Oncorhynchus Gorbuscha ◽

Hatchery Fish ◽

Yolk Utilization

To evaluate a hatchery method utilizing a gravel medium and filtered water during incubation, comparisons were made between naturally and artificially propagated parts of one native stock of pink salmon (Oncorhynchus gorbuscha) of the Tsolum River, B.C. Yolk utilization (growth rate) of fry was unimpeded in the hatchery environment, but hatchery fry migrated about 6 days earlier than creek fry. Hatchery survival was about six times that in the creek. The main test criterion — relative survival to the adult stage of fish from both treatments following migration from the creek — was tested by release of two similar groups of fry identified by a double finclip and recovery of marked adults upon return. Both groups survived at virtually the same rate. Numbers of actual mark recoveries were adequate to demonstrate statistically that survival of hatchery fish following release was not less than 90% of creek fry survival and that the final gain ratio of the hatchery treatment was not less than 5.44 (P <.005). Adult size, sex ratio, fecundity, and timing were not adversely affected by the hatchery treatment.

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APPLICATION OF ECOLOGICAL RISK ASSESSMENT PRINCIPLES TO NATURAL RESOURCES DAMAGE ASSESSMENT

International Oil Spill Conference Proceedings ◽

10.7901/2169-3358-1997-1-1025 ◽

1997 ◽

Vol 1997 (1) ◽

pp. 1025-1026 ◽

Cited By ~ 1

Author(s):

Alan W. Maki ◽

Ernest Brannon ◽

Jerry M. Neff ◽

Walter D. Pearson ◽

William A. Stubblefield

Keyword(s):

Risk Assessment ◽

Natural Resources ◽

Oil Spill ◽

Ecological Risk ◽

Ecological Risk Assessment ◽

Damage Assessment ◽

Pink Salmon ◽

Prince William Sound ◽

Exxon Valdez ◽

Exxon Valdez Oil Spill

ABSTRACT Ecological risk assessment principles are basic to the assessment of environmental injury during the Natural Resources Damage Assessment (NRDA) process; however, what is sought is quantified injury, rather than quantified risk, to valued ecosystem components. These principles were used to develop an NRDA program for studies of injury to herring and pink salmon populations in Prince William Sound (PWS), Alaska, following the Exxon Valdez oil spill. Overall, exposures and subsequent effects of the spill on herring and salmon were minimal and post-spill harvests of the year's classes that were at greatest risk of spill injury were at or near record levels.

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