Current studies show that the lingering oil is no longer bioavailable and key injured resources are no longer being affected by the lingering oil. Injured populations met the recovery criteria established by the EVOS Trustee Council for sea otters (between 2009 and 2014, 20 to 25 years post-Spill) and harlequin ducks (by 2013, 24 years post-Spill) (Ballachey et al., 2014; Esler 2015). Recovery, as defined by the EVOS Trustee Council, generally requires a return to conditions that would have been present had the Spill not occurred, as well as cessation of exposure of animals to oil lingering since the Spill. Lacking pre-Spill baseline studies, researchers contrasted a number of metrics between oiled and unoiled areas, including abundance, survival, habitat use, physiology, biomarkers of oil exposure, and population trajectories based on models.
The Council conducted two surveys in 2004 and 2014 to determine the status of subsistence use of fish and wildlife in Exxon Valdez-affected area communities. The 2014 update, ADF&G - Jim Fall: Update on the Status of Subsistence Uses in Exxon Valdez Oil Spill Area Communities, 2014, surveys the subsistence use of fish and wildlife in the communities affected by the Exxon Valdez oil spill. An executive summary and the 400- page final report is at: http://www.evostc.state.ak.us/Store/FinalReports/2015-15150122-Final.pdf. Excerpted from the Update:
Assessing the recovery of subsistence uses also includes the difficult task of separating the potential lingering effects of the oil spill from other concurrent environmental, economic, social, and cultural factors. The study found potential evidence of a lack of a full recovery from EVOS effects but noted it is likely not solely related to EVOS and some changes might not be connected to EVOS conditions at all. As explanations for lower harvests and uses, respondents cited personal reasons, work commitments, and general lower levels of effort as often, or more often, than natural resource conditions, and few directly cited spill effects as a single or primary cause of changing subsistence patterns. For example, respondents in Chenega Bay, Cordova, and Tatitlek linked heavy snowfalls that reduced deer populations to lower deer harvests. Respondents in Nanwalek and Port Graham attributed lower subsistence Pacific halibut harvests to increased pressure from sport fishing charter operations; and in Chenega Bay and Nanwalek, respondents discussed competition between subsistence salmon fisheries and commercial fisheries. Nanwalek residents are concerned about the effects of erosion on the sockeye salmon stocks of the English Bay River, which they attribute to both climate change and road and trail development. Rising costs of equipment and fuel inhibit or limit harvest effort in all the study communities. A drop in involvement in commercial fisheries in several communities has also affected access to harvest areas and equipment as well as a source of cash income linked to local resources. Respondents in Nanwalek and Port Graham discussed an overall decline in populations of marine invertebrates that they attributed to a variety of factors, including commercial overharvests, sea otter predation, local overharvests, water pollution, and warming water temperatures.