Glacial ice calved from tidewater glaciers in Alaska provides an important haulout habitat for harbor seals Phoca vitulina richardsi, and its extent and ecological influence is being reduced by climate change. The number of harbor seals using glacial ice adjacent to Aialik Glacier, central Gulf of Alaska, declined by 93% from 1979 to 2009. During this time, seals demonstrated variability in their selection of haulout locations, particularly during the molt. Near Pedersen Glacier, 6 km south of Aialik Glacier, the number of seals doubled from 2005 to 2007; this was followed by an equivalent loss from 2007 to 2009. This influx, which occurred during a period of cold marine conditions, was associated with the arrival of seals from locations outside Aialik Bay, rather than from movements of seals from Aialik Glacier. Nearly all pups were born near Aialik Glacier. Pup production, which was stable from 1979 to 1983, subsequently declined by 12.4% yr -1 through 1994. Although the rate of decline abated, the numbers of pups continued to decline by 4.6% annually from 1994 to 2009. The persistent decline of harbor seals in Aialik Bay is similar to that observed in Glacier Bay, southeast Alaska, but contrasts with trends at nonglacial sites in the Gulf of Alaska and southeast Alaska where populations have been increasing since the mid-1990s. Results indicate flexibility in selection of haulout location and potentially the proportion of time seals are present on the ice. The persistent decline in pup production, however, raises concern over the future of harbor seals in previously important glacial pupping habitats and the integrity of unique glacial fjord ecosystems.
Marine and coastal tourism has rapidly expanded worldwide in the past 2 decades, often occurring in once secluded habitats. In Alaska, tourism near tidewater glaciers has attracted millions of visitors and increased the presence of ships, tour vessels, and coastal development. Although sustainable tourism, resulting from balanced effects on wildlife and client satisfaction, is a goal of most tourism operators, it is not always achieved. Voluntary compliance with viewing guidelines and codes of conduct have been encouraged, but few assessments have the longitudinal scope to evaluate long‐term changes in impacts on wildlife and the ability of vessel operators and kayak guides to sustain lower impact operating practices over time. This study assessed vessel and kayak visitation and resulting impacts on harbor seals in the Kenai Fjords National Park, southcentral Alaska. We obtained observations from 2002 to 2011, using remotely controlled video cameras located near Aialik and Pedersen Glaciers in the Kenai Fjords National Park. Overall, disturbance was associated with 5.1% of vessel sightings, 28% of vessel interactions (vessel observed within approx. 300 m of seals), 11.5% of kayak sightings, and 61% of kayak interactions. Results demonstrated that voluntary changes in operations significantly reduced vessel and kayak disturbance of seals by 60–80%. Even with prior establishment of operating guidelines, tour vessel captains were able to further reduce their effect on wildlife with more careful operations. Rapid growth of guided kayak excursions that occurred during this study caused greater disturbance to seals than motorized vessels but guide trainings helped reduce disturbances. Diminished impacts of motor vessels and kayakers persisted across years although effects of kayaks were less consistent than motor vessels, which reflected greater variability in inter‐annual spatial use patterns by kayakers. Long‐term monitoring, including assessments of wildlife responses to vessel and kayak operations, combined with 2‐way communication with vessel operators and guides, enhanced the effectiveness of mitigation and facilitated adaptive adjustments to mitigation protocols over time. © 2013 The Wildlife Society.
Bromodiphenyl ethers (BDEs) are a class of synthetic flame retardants and are widely present in the environment. Analysis of higher BDE congeners has proven to be a challenge. We report the development of a method that enhances their analysis by splitting the eluent of a gas chromatograph (GC) between an electron capture detector (ECD) and an ion trap mass spectrometer (ITMS): 1:10, ECD:ITMS. This allowed the quantitation of the lower molecular weight (MW) BDE congeners (Br1-Br7) with the ITMS and of the higher MW BDEs (Br8-Br10) with the highly sensitive ECD. The IT temperature, ionization mode, and MS/MS parameters (excitation amplitude and stability parameter) were optimized. This method took the advantages of the best detector for the different BDE homologues and was suitable for the analysis of BDEs in environmental and biological samples. Average recoveries were 52-112% for BDEs from spiked sand samples and 57-126% from spiked lard samples after accelerated solvent extraction followed by silica gel and alumina column clean-up. Average recoveries ranged from 51% to 130% for 13C-labeled BDEs spiked in the real and in matrix samples. The method detection limits for specific congeners were 0.18-120 pg/g of the BDEs in animal tissue samples, and 0.05-40 pg/g in soil and indoor dust samples. The utility of the method was demonstrated by analyzing actual harbor seal blubber, indoor dust and soil samples. The concentration of each BDE ranged from non-detectable (nd) to 41 ng/g in the dry soil sample, nd to 1042 ng/g in the indoor dust, nd to 15 ng/g wet weight in the Alaskan harbor seal blubber sample, and 0.02 to 11 ng/microL of the identified 23 of the 42 breakdown products from BDE-209 after zerovalent iron treatment. Finally, an interlaboratory comparison showed high correspondence between the GC/ITMS-ECD method and a GC high-resolution MS system for the analysis of BDEs in soil samples.
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