SHORT NOTE Lawrence K. Duy á Michelle K. Hecker Gail M. Blundell á R. Terry Bowyer An analysis of the fur of river otters in Prince William Sound, Alaska: oil related hydrocarbons 8 years after the Exxon Valdez oil spill Accepted: 26 August 1998 Abstract Approximately 8 years after the Exxon Valdez oil spill, river otters (Lutra canadensis) were trapped from the shoreline in both oiled (Knight Island) and nonoiled (Jackpot Bay) areas of Prince William Sound, Alaska. Captive river otters were wiped with isopro- panol-soaked gauze and the gauze extracts were ana- lyzed by gas chromatography with mass spectrometry detection. Dierences in pentacosane (C-25) levels in the fur were observed between the oiled and nonoiled sites, while lower molecular weight aliphatics and aromatics were absent. These data are useful when evaluating the role of fur grooming in the long-term exposure of river otters to hydrocarbons and the expression of P450-1A in Knight Island otters. Introduction River otters (Lutra canadensis) are widely distributed along the subarctic shores of Alaska (Bowyer et al. 1994; Ben-David et al., in press). As nearshore foragers on marine ®shes and invertebrates in intertidal and subtidal zones (Bowyer et al. 1994), they are potentially excellent indicators of pollution (Baker et al. 1981; Clark et al. 1981; Wren 1991), such as that from the Exxon Valdez oil spill of March, 1989. In that spill, over 39,000 metric tons of North Slope crude oil spread over >3,500 km of shoreline in Prince William Sound (Estes 1991). Earlier, we documented (Duy et al. 1993, 1994a,b) that, 2 years post-spill, river otters from a heavily oiled area had lower body mass, as well as elevated levels of blood haptoglobins and liver enzymes. River otters inhabiting oiled areas could be discriminated from those living in nonoiled areas using biomarkers, such as fecal pro®les of porphyrins (Blajeski et al. 1996). Moreover, there were corresponding ecological eects associated with oil ex- posure including changes in diet, habitat selection, and sizes of home ranges for river otters (Bowyer et al. 1994, 1995). In a 1989 survey on dead sea otters that appeared lightly oiled, Ballachey and Kloecker (1997) reported the presence of various compounds present in crude oil on a patch of hair taken from the carcasses of sea otters. More recently, Mazet et al. (1997) reported the devel- opment of a ®eld wipe assay to detect the presence of oil on sea otter fur. In their wipe test on sea otter fur, an immunochemical detection system was used. In 1996 Hecker et al. (1997), using that immunochemical detec- tion system, were unable to measure oil in river otter fur at a sensitivity less than 1 ppm. Nonetheless, they re- ported the presence of C-15 and C-16 aliphatic hydro- carbons using GC-MS. To improve the wipe test to detect the presence of oil on pelage that was not visible, we expanded the analysis to include C-25 and C-26 ali- phatics, as well as the aromatics, phenanthrene and chrysene. The long-term objective of this study was to address the question of residual oil exposure to river otters in Prince William Sound (PWS), Alaska. Materials and methods River otters were trapped from the shoreline in both oiled (Knight Island; n 12) and nonoiled (Jackpot Bay; n 13) areas of Prince William Sound during the spring and summer of 1996 and 1997. They were captured at latrine sites using either Hancock or no.11 Sleepy Creek double jaw leg-hold traps (Hecker et al. 1997; Blundell et al., in press). Once captured, animals were wiped with gauze (2 by 2 inch swab) that had been presoaked in isopropanol. Areas of pelage, including the ventral as- pect of the neck, the abdomen and swaths along each side and the length of back, were wiped for approxi- Polar Biol (1999) 21: 56±58 Ó Springer-Verlag 1999 L.K. Duy (&) á M.K. Hecker á G.M. Blundell á R.T. Bowyer Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775, USA e-mail: fychem@aurora.alaska.edu, Fax: +1-907-4745101