Stanley Rice on the Long-Term Effects and Lessons of the Exxon Valdez Spill

Special Topic of Oil Spills Interview, September 2010

Stanley D. RiceOur Special Topics analysis of oil spills publications over the past decade shows that the work of Dr. Stanley "Jeep" Rice ranks at #8 by total cites and #12 by number of papers, based on 18 papers cited 368 times. In the Web of Science®, his record includes 38 papers cited a total of 539 times between January 1, 2000 and August 14, 2010.

Rice the Program Manager for Habitat Assessment & Marine Chemistry at the Auke Bay Fisheries Laboratory of the National Oceanic and Atmospheric Administration's National Marine Fisheries Service in Juneau, Alaska.

Below, talks with him about his research related to oil spills.

SW: Please tell us about your educational background and early research experiences.

After finishing my Ph.D. in comparative physiology at Kent State University in 1971, I took the only job offered in far off Alaska. My future boss was interested in my dissertation which was on ammonia toxicity in trout, which was as close as he could find to a toxicologist to start a new program on oil toxicity research relevant to Alaska.

One of my first jobs was to aid in the drafting of the environmental impact statement for the yet-to-be-approved Trans-Alaska pipeline. In support of that work, I established a small group of biologists and chemists to work on oil/fishery related problems. With the recent discoveries of oil in Alaska, it was easy to predict that there would be several future conflicts between oil and fishing industry, for years to come.

While our group did not have experience with oil spills, the laboratory tests that we conducted over the next decade prepared us to be able to analyze for petroleum compounds in water, sediments, and tissues; and to be wary of short-term acute toxicity tests. When the spill came in 1989, we were set begin damage assessment and partner with other researchers/agencies, as few, if any, had chemists and toxicologists in Alaska.

SW: What first drew your interest to oil spills?

By the late 1980s, Alaska's economy was well entrenched in both fisheries and oil production. Conflicts in lease sales started in the 1970s; concern for spills in fishery habitat was a concern throughout the state. If the pipeline were to flow oil for 30-plus years, we assumed that eventually there would be an accidental spill event.

Photo 1

Stanley D. Rice

Subsurface Exxon Valdez oil found during surveys in 2004, Knight Is., Prince William Sound. Photo by: M. Lindeberg, NOAA Fisheries.

Our laboratory established baseline sites in Prince William Sound to verify the low petroleum loads in the sediments and mussels, to be a basis for comparison if there was a spill. We conducted a series of tests looking for lowest effective doses that would hinder shrimp and crab larvae from molting and effect growth in juvenile salmonids.

Fisheries and oil production were going to have to co-exist; if  so, what protections were needed? What monitoring was needed? We have participated in these discussions since the 1970s.

SW: One of your highly cited papers in our analysis is the 2003 Science paper, "Long-term ecosystem response to the Exxon Valdez oil spill" (Peterson CH, et al., 302[5653]: 2082-6, 19 December 2003). Would you tell us about the research behind this paper, and its most significant findings?

This paper was the brain child of Pete Peterson, who was never an active researcher on the Exxon Valdez event, but was a long time peer reviewer of both proposals and results for the Exxon Valdez Trustee Council. After more than a decade of research, a synthesis of the major findings was needed, particularly the long-term effects, which are more subtle and less glitzy than the spill event. Pete pulled together a small group of researchers who were still finding persistent oil and long-term effects well past the 10-year anniversary (1999).

None of the effects were devastating compared to the acute mortalities occurring in the weeks after the spill, when oil was everywhere and carcasses were common on the shoreline. But, when added up collectively, and over time, it was a significant story, and was published in Science.

Unlike all previous spills, Exxon Valdez was the most-studied spill in world history, not only in intensity, but also in duration. The long-term persistence coupled with long-term effects was a story that was not documented in earlier spills to the extent that was anywhere near the Exxon Valdez event.

SW: You're still looking at the effects of the Exxon Valdez spill today. What are some of the long-lasting effects? Do you expect the area to ever get back to "normal"?

Two pods of killer whales were affected by the spill, losing 40% of each population in the year following the spill. One pod will become extinct sometime in the next two decades, as no reproductive females have survived (Matkin CO, et al., "Ongoing population-level impacts on killer whales Orcinus orca following the 'Exxon Valdez' oil spill in Prince William Sound, Alaska," Marine Ecology-Progress Series 356: 269-81, 2008).

Pink salmon embryos were impacted in the field for four years past the spill from lingering oil on the banks of the small streams crossing the intertidal zone (Alaska Department of Fish & Game). The controlled laboratory tests that confirmed the mechanism (embryos are sensitive at the part-per-billion level of polycyclic aromatic hydrocarbons) have changed the toxicity paradigm (from acute toxicity at the part-per-million level to embryo toxicity at the part-per-billion level; Heintz RA, et al., "Delayed effects on growth and marine survival of pink salmon Oncorhynchus gorbuscha after exposure to crude oil during embryonic development," Marine Ecology-Progress Series 208: 205-16, 2000).

The persistence of oil in the intertidal zone was surprising, particularly the quantity of liquid oil that was unweathered and trapped about 5-10 cm below the surface where it was anoxic (Short JW, et al., "Slightly weathered Exxon Valdez oil persists in Gulf of Alaska beach sediments after 16 years," Environmental Science & Technology 41[4]: 1245-50, 15 February 2007). The case has been made by Bodkin/Balchey that sea otters forage in the lower intertidal zone where oil and clams overlap; elevated P-450 in the sea otters correlates with where the oil is and where the population has not fully recovered.

These long-term consequences were surprising and required long-term studies in an area where there were few other confounding factors, such as an adjacent urban area.

"As long lasting as some of these effects are, Prince William Sound has recovered strongly from the damage in 1989, and will continue the process for several more years."

As long lasting as some of these effects are, Prince William Sound has recovered strongly from the damage in 1989, and will continue the process for several more years. Fisheries are back for the most part, waters are clean. Killer whale extinction of one pod, and the lack of recovery in herring are the two issues that continue to be disappointing.

Herring are an enigma; one year class (1989) was directly affected by the spill in 1989, yet the continued lack of recovery from the 1993 crash is difficult to explain, along with the lack of recovery. No other herring population in Alaska has declined so rapidly, nor stayed depressed for so long, for no known reason. The oil spill is suspected as a cause, yet the direct connection is difficult to make.

SW: You mention in your April 2010 University of St. Thomas Law Journal paper that the Exxon Valdez spill was scientifically valuable because Prince William Sound was so pristine before the spill, that scientists were able to learn a lot about spills and their effects. How will these findings be useful/applicable to the current situation in the Gulf of Mexico?

Every spill is different in many ways: how the event started, volume and thickness (viscosity) of the oil, which influences the dispersability, habitats and species, and many other factors. So, direct comparisons are not appropriate. Both spills are large-scale events; both will have short- and long-term damage problems, both will have politics and law suits for decades (Exxon Valdez still has one major legal law suit between state/federal governments and Exxon for $100 million pending).

Yet, because Exxon Valdez is the most-studied spill in history, there are lessons learned that can be applied to the Gulf. Fauna that live or breath at the surface will be grossly affected (Exxon Valdez is not new with this observation, but it has excellent documentation—500,000 birds and 5,000 sea otters, for example, died in the first weeks of the spill).

Oil will persist a long time if it gets into anoxic sediments, yet be toxic and damaging if perturbed. Embryos are easily affected by low concentrations of toxic chemicals. Embryos are sensitive to the chemicals and vulnerable to predation. Expect recruitment of the 2010 year class to be among the lowest recorded, and be thankful if they are not.

The dispersants used in the Gulf of Mexico do not have a comparison with Exxon Valdez as virtually no dispersants were used in the earlier spill. There are a bunch of unknowns to watch out for. And then there are the possible "surprises" (such as herring), where oil in concert with ecosystem changes may create some unpredicted consequences that will be difficult to explain. 

SW: How much have we learned about oil spills in the past decade? What advances would you like to see in the future of oils spills research?

The Deepwater Horizon spill is now the largest spill, over a long period of time. It is capped now, but it is important to understand the long term consequences of the spill that will continue to play out for some time. The Gulf of Mexico is probably a resilient body of water with temperature and microbes favoring metabolism of the petroleum hydrocarbons and rapid recovery—or will they?

How fast will the recovery be for many of the key species (shrimp, oysters, blue fin tuna, birds, turtles), and how will the recovery be for the deep-water habitat where we have a meager understanding? How long will the oil persist in deep water, and the near shore; how long can we detect effects in both of these very different habitats?

Given the unprecedented dispersant use in the DWH spill, we need to follow the damages and the biological production in these waters for a number of years so that we can evaluate the pros/cons with dispersant use on this scale for future events.End

Stanley D. Rice, Ph.D.
Auke Bay Fisheries Laboratory
Alaska Science Center
National Marine Fisheries Service
National Oceanic and Atmospheric Administration
Juneau, AK, USA


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Photo 1:

Stanley D. Rice

Photo 1: Subsurface Exxon Valdez oil found during surveys in 2004, Knight Is., Prince William Sound. Photo by: M. Lindeberg, NOAA Fisheries.


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