Environmental Issues

This paper addresses a current BBC news headline on the long term effects of major oil spills on local ecology and what we learn from such disasters.  It also summarizes a research article addressing this issue, discussing the potential for Sea Otter Enhydra lutris exposure to subsurface oil residues 17 years following the Exxon Valdez oil spill.  Finally it relates the two by discussing how the scientific research confirms or negates the concerns reported in the news story.

There has long been concern about the effects of industry on ecological sustainability.  For decades companies have often moved forward with new technologies and expansion with little regard to how manufacturing waste and disposal affects the environment.  It is only recently that business has moved towards a more global earth conscious outlook and in doing so it has become important to revisit past indiscretions to understand the long term effects of environmental negligence.  When the Exxon Valdez spilled oil off the coast of Alaska in 1989 there was an immediate impact on the local ecology, but we are now seeing how difficult it can be for populations to recover through research done with Sea Otter populations in the area.  Sea Otter populations in northern Knight Island, Alaska have failed to recover at the same rate as other organisms, so research has been done to determine if this is due to continued exposure to oil residues from the 1989 spill.  Need more specific details from 2009 news story and need to reference.
In March of 2009 BBC revisited the Exxon Valdez oil spill and its affects on the environment and the industry in Stephen Dowlings article, What we learned from the Exxon Valdez.  He mentions how the long term effects have changed industry practice, but also comments on how not just the spill, but inappropriate cleaning practices did as much damage to Prince William Sound as the oil itself.  Prince William Sound is a sheltered area with predominantly soft sandy sediment.  Fresh sand deposits easily bury oil and so it is difficult to know the entirety of areas affected.  He also discussed how industry practice in oil clean up has been modified to do less damage to the existing ecology.  Following the spill, cleaning crews scoured the coastline to get rid of oil sludge which damaged much of the vital bottom layer of the food chain.  Many of these organisms are also important to breaking down the oil.  Damaging this vital part of the chain slows the recovery of larger organisms which also saw the greatest immediate damage.  Oil remnants in the sandy sediment and the destruction of the base layer of the trophic system could be one of the major contributors to the slow recovery of Sea Otters and other organisms in this area.

In a 2007 research article from Environmental Science and Technology, researchers Paul Boehm, Davis Page, Jerry Neff and Charles Johnson discuss the potential continued effects the 1989 oil spill could have on the Sea Otter population in the northern Knight Island area of Prince William Sound, Alaska.  Researchers chose this area based of previous surveys done on the presence of subsurface oil in this area and the presence of Sea Otter foraging sites.  Specifically they were looking for pits of clam foraging, as clams make up 70 of the Sea Otters diet and would have the largest effect on sustained health of the species.  The digging of clams would also be how Sea Otters would be exposed to SSO settles in the substrate.  They surveyed 43 shoreline segments that had been documented by previous NOAA shoreline surveys.  They also surveyed previous SSO sites that no longer contained residues and non-SSO sites as a frame of reference on Sea Otter foraging patterns and distribution.  They classified a foraging site as 20 pits located in an area, which proved to be a conservative estimate, as areas that fit that criteria had hundreds to thousands of pits.  Researches found only one of 29 SSO sites to also be an otter foraging site.  They hypothesized that because of spatial separation of Sea Otter pits from SSO sites that there a low likelihood of SSO exposure to foraging otters and their findings supported their hypothesis.  Their research proposed a possible correlation between Sea Otter foraging and shoreline type.  It also noted that the areas of highest SSO concentration are rockier areas where foraging has been least preferred even prior to the Exxon Valdez spill.
Though it appears as if there is little possibility of exposure to SSO residue from Sea Otter foraging there was still foraging in SSO areas and no research was done on Sea Otter biology and levels of exposure.  There was also no data about which Sea Otters were foraging in which areas.  There could be a connection between reproductive function and exposure or there is the possibility more ecologically fit Sea Otters are foraging in the more difficult areas where there is a higher concentration off SSO residue.  Though research suggests exposure to SSO residue is minimal resulting from foraging, there are still other ways in which Sea Otters could be exposed.  The study did not look into chemical levels present in the clams as a result of oil present in the sediment or organisms on which clams feed.  The BBC news story mentioned the difficulty of finding oil in the sandy sediments of that area and so it follows that biological magnification could be an explanation for slow Sea Otter recovery, not necessarily direct exposure from foraging.   There could also be a multitude of other reasons, unrelated to the spill that populations have failed to recover since the spill.  The research done in the northern Knight Island area didnt support or negate the BBC news story as there wasnt sufficient evidence to say that oil is not affecting the Sea Otter population in other ways.  The BBC article brought up new questions not covered by the research in its discussion of what we learned from the spill and hopefully that will aid in future ecologic studies of population recovery in this region.