Cytochrome P4501A biomarker indication of the timeline of chronic exposure of Barrow’s goldeneyes to residual Exxon Valdez oil

Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Marine Pollution Bulletin 62 (2011): 609-614, doi:10.1016/j.marpolbul.2010.11.015.We examined hepatic EROD activity, as an indicator of CYP1A induction, in Barrow's goldeneyes captured in areas oiled during the 1989 Exxon Valdez spill and those from nearby unoiled areas. We found that average EROD activity differed between areas during 2005, although the magnitude of the difference was reduced relative to a previous study from 1996/97, and we found that areas did not differ by 2009. Similarly, we found that the proportion of individuals captured from oiled areas with elevated EROD activity ( 2 times unoiled average) declined from 41% in winter 1996/97 to 10% in 2005 and 15% in 2009. This work adds to a body of literature describing the timelines over which vertebrates were exposed to residual Exxon Valdez oil and indicates that, for Barrow's goldeneyes in Prince William Sound, exposure persisted for many years with evidence of substantially reduced exposure by 2 decades after the spill.This research was supported primarily by the Exxon Valdez Oil Spill Trustee Council

Appendix A. Form of the transition matrix model and modifier functions used to model source and sink population demographic rates, along with baseline survival and fecundity rates and final “best model” parameter estimates.

Form of the transition matrix model and modifier functions used to model source and sink population demographic rates, along with baseline survival and fecundity rates and final “best model” parameter estimates

Supplement 1. All data used to fit modifications to source and sink population survival rates.

<h2>File List</h2><blockquote> <a href="survey_data.txt">survey_data.txt</a><br> <a href="post_spill_carc_data.txt">post_spill_carc_data.txt</a><br> <a href="live_data_kni.txt">live_data_kni.txt</a><br> <a href="live_data_mon.txt">live_data_mon.txt</a> </blockquote><h2>Description</h2><blockquote> <p>The survey_data.txt file is a tab-delimited file. It contains sea otter population abundance estimates derived from aerial survey data for western Prince William Sound, Alaska and the northern Knight Island subarea of Prince William Sound from 1993–009.</p> <p>Column definitions</p> <ol> <li>Survey year</li> <li>Western Prince William Sound sea otter abundance estimate (N)</li> <li>Western Prince William Sound variance</li> <li>Northern Knight Island sea otter abundance estimate (N)</li> <li>Northern Knight Island variance</li> </ol> <p>Missing values are represented as “-9”</p> <p>Checksum values are:</p> <blockquote> Column 2 (WPWS N): SUM = 39113; 5 missing values<br> Column 3 (WPWS var): SUM = 2796491; 5 missing values<br> Column 4 (northern KNI N): SUM = 985; 6 missing values<br> Column 5 (northern KNI var): SUM = 4214; 6 missing values </blockquote> <p>The post_spill_carc_data.txt file is a tab-delimited file. It contains annual age-at-death distributions derived from carcasses collected in oiled areas of western Prince William Sound, Alaska from 1990–2009.</p> <p>Column definitions</p> <ol> <li>Age</li> <li>1990 distribution</li> <li>1991 distribution</li> <li>1992 distribution</li> <li>1993 distribution</li> <li>1994 distribution</li> <li>1995 distribution</li> <li>1996 distribution</li> <li>1997 distribution</li> <li>1998 distribution</li> <li>1999 distribution</li> <li>2000 distribution</li> <li>2001 distribution</li> <li>2002 distribution</li> <li>2003 distribution</li> <li>2004 distribution</li> <li>2005 distribution</li> <li>2006 distribution</li> <li>2007 distribution</li> <li>2008 distribution</li> <li>2009 distribution</li> </ol> <p>Missing values are represented as “-9”</p> <p>Checksum values are:</p> <blockquote> Column 2 (1990 distribution): SUM = 59; 0 missing values<br> Column 3 (1991 distribution): SUM = 14; 0 missing values<br> Column 4 (1992 distribution): SUM = 23; 0 missing values<br> Column 5 (1993 distribution): SUM = 23; 0 missing values<br> Column 6 (1994 distribution): SUM = 21; 0 missing values<br> Column 7 (1995 distribution): SUM = 10; 0 missing values<br> Column 8 (1996 distribution): SUM = 22; 0 missing values<br> Column 9 (1997 distribution): SUM = 22; 0 missing values<br> Column 10 (1998 distribution): SUM = 51; 0 missing values<br> Column 11 (1999 distribution): SUM = 29; 0 missing values<br> Column 12 (2000 distribution): SUM = 54; 0 missing values<br> Column 13 (2001 distribution): SUM = 32; 0 missing values<br> Column 14 (2002 distribution): SUM = 16; 0 missing values<br> Column 15 (2003 distribution): SUM = 37; 0 missing values<br> Column 16 (2004 distribution): SUM = 26; 0 missing values<br> Column 17 (2005 distribution): SUM = 25; 0 missing values<br> Column 18 (2006 distribution): SUM = 16; 0 missing values<br> Column 19 (2007 distribution): SUM = 18; 0 missing values<br> Column 20 (2008 distribution): SUM = 32; 0 missing values<br> Column 21 (2009 distribution): SUM = 0; 21 missing values </blockquote> <p>The live_data_kni.txt file is a tab-delimited file. It contains live female age distributions from the northern Knight Island area (i.e. oiled area) of western Prince William Sound, Alaska from 1996–2009.</p> <p>Column definitions</p> <ol> <li>Age</li> <li>1990 distribution</li> <li>1991 distribution</li> <li>1992 distribution</li> <li>1993 distribution</li> <li>1994 distribution</li> <li>1995 distribution</li> <li>1996 distribution</li> <li>1997 distribution</li> <li>1998 distribution</li> <li>999 distribution</li> <li>2000 distribution</li> <li>2001 distribution</li> <li>2002 distribution</li> <li>2003 distribution</li> <li>2004 distribution</li> <li>2005 distribution</li> <li>2006 distribution</li> <li>2007 distribution</li> <li>2008 distribution</li> <li>2009 distribution</li> </ol> <p>Missing values are represented as “-9”</p> <p>Checksum values are:</p> <blockquote> Column 2 (1990 distribution): SUM = 0; 21 missing values<br> Column 3 (1991 distribution): SUM = 0; 21 missing values<br> Column 4 (1992 distribution): SUM = 0; 21 missing values<br> Column 5 (1993 distribution): SUM = 0; 21 missing values<br> Column 6 (1994 distribution): SUM = 0; 21 missing values<br> Column 7 (1995 distribution): SUM = 0; 21 missing values<br> Column 8 (1996 distribution): SUM = 52; 0 missing values<br> Column 9 (1997 distribution): SUM = 55; 0 missing values<br> Column 10 (1998 distribution): SUM = 46; 0 missing values<br> Column 11 (1999 distribution): SUM = 37; 0 missing values<br> Column 12 (2000 distribution): SUM = 37; 0 missing values<br> Column 13 (2001 distribution): SUM = 32; 0 missing values<br> Column 14 (2002 distribution): SUM = 44; 0 missing values<br> Column 15 (2003 distribution): SUM = 43; 0 missing values<br> Column 16 (2004 distribution): SUM = 40; 0 missing values<br> Column 17 (2005 distribution): SUM = 25; 0 missing values<br> Column 18 (2006 distribution): SUM = 16; 0 missing values<br> Column 19 (2007 distribution): SUM = 0; 21 missing values<br> Column 20 (2008 distribution): SUM = 32; 0 missing values<br> Column 21 (2009 distribution): SUM = 0; 21 missing values </blockquote> <p>The live_data_mon.txt file is a tab-delimited file. It contains live female age distributions from the Montague Island area (i.e. unoiled area) of western Prince William Sound, Alaska from 1996–2009.</p> <p>Column definitions</p> <ol> <li>Age</li> <li>1990 distribution</li> <li>1991 distribution</li> <li>1992 distribution</li> <li>1993 distribution</li> <li>1994 distribution</li> <li>1995 distribution</li> <li>1996 distribution</li> <li>1997 distribution</li> <li>1998 distribution</li> <li>1999 distribution</li> <li>2000 distribution</li> <li>2001 distribution</li> <li>2002 distribution</li> <li>2003 distribution</li> <li>2004 distribution</li> <li>2005 distribution</li> <li>2006 distribution</li> <li>2007 distribution</li> <li>2008 distribution</li> <li>2009 distribution</li> </ol> <p>Missing values are represented as “-9”</p> <p>Checksum values are:</p> <blockquote> Column 2 (1990 distribution): SUM = 0; 21 missing values<br> Column 3 (1991 distribution): SUM = 0; 21 missing values<br> Column 4 (1992 distribution): SUM = 0; 21 missing values<br> Column 5 (1993 distribution): SUM = 0; 21 missing values<br> Column 6 (1994 distribution): SUM = 0; 21 missing values<br> Column 7 (1995 distribution): SUM = 0; 21 missing values<br> Column 8 (1996 distribution): SUM = 26; 0 missing values<br> Column 9 (1997 distribution): SUM = 23; 0 missing values<br> Column 10 (1998 distribution): SUM = 34; 0 missing values<br> Column 11 (1999 distribution): SUM = 0; 21 missing values<br> Column 12 (2000 distribution): SUM = 0; 21 missing values<br> Column 13 (2001 distribution): SUM = 13; 0 missing values<br> Column 14 (2002 distribution): SUM = 9; 0 missing values<br> Column 15 (2003 distribution): SUM = 0; 21 missing values<br> Column 16 (2004 distribution): SUM = 15; 0 missing values<br> Column 17 (2005 distribution): SUM = 12; 0 missing values<br> Column 18 (2006 distribution): SUM = 8; 0 missing values<br> Column 19 (2007 distribution): SUM = 10; 0 missing values<br> Column 20 (2008 distribution): SUM = 24; 0 missing values<br> Column 21 (2009 distribution): SUM = 0; 21 missing values </blockquote> </blockquote

Gene Expression Profiles in Two Razor Clam Populations: Discerning Drivers of Population Status

With rapidly changing marine ecosystems, shifts in abundance and distribution are being documented for a variety of intertidal species. We examined two adjacent populations of Pacific razor clams (Siliqua patula) in lower Cook Inlet, Alaska. One population (east) supported a sport and personal use fishery, but this has been closed since 2015 due to declines in abundance, and the second population (west) continues to support commercial and sport fisheries. We used gene expression to investigate potential causes of the east side decline, comparing razor clam physiological responses between east and west Cook Inlet. The target gene profile used was developed for razor clam populations in Alaska based on physiological responses to environmental stressors. In this study, we identified no differences of gene expression between east and west populations, leading to two potential conclusions: (1) differences in factors capable of influencing physiology exist between the east and west and are sufficient to influence razor clam populations but are not detected by the genes in our panel, or (2) physiological processes do not account for the differences in abundance, and other factors such as predation or changes in habitat may be impacting the east Cook Inlet population

Long-term effects of the ‘Exxon Valdez’ oil spill: sea otter foraging in the intertidal as a pathway of exposure to lingering oil

The protracted recovery of some bird and mammal populations in western Prince William Sound (WPWS), Alaska, and the persistence of spilled ‘Exxon Valdez’ oil in intertidal sediments, suggests a pathway of exposure to consumers that occupy nearshore habitats. To evaluate the hypothesis that sea otter (Enhydra lutris) foraging allows access to lingering oil, we contrast spatial relations between foraging behavior and documented oil distribution. We recovered archival time-depth recorders implanted in 19 sea otters in WPWS, where lingering oil and de - layed ecosystem recovery are well documented. Sea otter foraging dives ranged from +2.7 to −92 m below sea level (MLLW), with intertidal accounting for 5 to 38% of all foraging. On average, female sea otters made 16 050 intertidal dives per year and 18% of these dives were at depths above the +0.80 m tidal elevation. Males made 4100 intertidal dives per year and 26% of intertidal foraging took place at depths above the +0.80 m tidal elevation. Estimated annual oil encounter rates ranged from 2 to 24 times yr−1 for females, and 2 to 4 times yr−1 for males. Exposure rates increased in spring when intertidal foraging doubled and females were with small pups. In summer 2008, we found sea otter foraging pits on 13.5 of 24.8 km of intertidal shoreline surveyed. Most pits (82%) were within 0.5 m of the zero tidal elevation and 15% were above 0.5 m, the level above which most (65%) lingering oil remains. In August 2008, we detected oil above background concentrations in 18 of 41 (44%) pits excavated by sea otters on beaches with prior evidence of oiling, with total PAH concentrations up to 56 000 ng g−1 dry weight. Our estimates of intertidal foraging, the widespread presence of foraging pits in the intertidal, and the presence of oil in and near sea otter foraging pits documents a pathway of exposure from lingering intertidal oil to sea otters foraging in WPWS