By Joy Erlenbach
Coastal areas within Katmai National Park in Alaska are home to dense populations of iconic brown bears, which are an important part of the ecosystem, the viewing experience of park visitors, and the economy of the region. Yet habitats used by bears within the park are faced with impacts from tourism, the potential for oil spills, increasing ocean acidification, and other threats, which all have the capacity to severely alter the habitat and food resources available to coastal bears.
This summer is the third and final field season for my collaborative project with the National Park Service and US Geological Survey studying the potential effects of oil spills, increases in visitation, and ocean acidification on Katmai’s bears.
The project involves using Global Positioning Satellite (GPS) collars to track bear movements, determine which habitats they prefer, and understand how their habitat-use affects body composition (mass and fat gains). We are also characterizing diets of coastal bears using stable isotope analysis to understand the magnitude and breadth of marine-derived foods in bear diets (clams, mussels, otters, seals, salmon), as well as their effects on the body composition of bears.
Other areas of our study include using video collars to further understand bear diet and habitat selection, conducting behavioral observations to document foraging rates on different food resources, and using activity sensors to elucidate what bears are doing in different habitats. All of this work will aid in the management of park resources for bears, visitors, and other wildlife.
This summer, as in previous summers, my time will be spent finding bears using a helicopter, collecting measurements from the bears, and fitting them with a GPS collar. The remainder of my time will be spent camping in remote areas of Katmai collecting observations of non-collared bears and their foraging preferences.
The project is challenging: living in a tent for 60 days each summer, being so remote your only rescue is by plane, not showering for weeks at a time, getting eaten alive by mosquitoes, having to put on the same damp socks and pants you’ve worn for the last week, among other things… But it has also been rewarding. The chance to get to live with and learn to understand bears at such a deep level is something that has not only been a dream of mine but also important for helping people understand the true nature of bears as well as some of the ways bears have been misrepresented in popular media.
You can learn more about the Changing Tides project here: