| Summary: | © The Author(s), 2014. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Scientific Reports 4 (2014): 4170, doi:10.1038/srep04170. Estimating abundance of Antarctic minke whales is central to the International Whaling Commission's conservation and management work and understanding impacts of climate change on polar marine ecosystems. Detecting abundance trends is problematic, in part because minke whales are frequently sighted within Antarctic sea ice where navigational safety concerns prevent ships from surveying. Using icebreaker-supported helicopters, we conducted aerial surveys across a gradient of ice conditions to estimate minke whale density in the Weddell Sea. The surveys revealed substantial numbers of whales inside the sea ice. The Antarctic summer sea ice is undergoing rapid regional change in annual extent, distribution, and length of ice-covered season. These trends, along with substantial interannual variability in ice conditions, affect the proportion of whales available to be counted by traditional shipboard surveys. The strong association between whales and the dynamic, changing sea ice requires reexamination of the power to detect trends in whale abundance or predict ecosystem responses to climate change. This work received funding from the following institutions: Alfred Wegener Institute for Polar and Marine Research (AWI); Dutch Ministry of Agriculture, Nature and Food Quality (EL & I); German Federal Ministry of Food, Agriculture and Consumer Protection (BMELV); German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU); the Institute for Marine Resources and Ecosystem Studies (Wageningen IMARES); Johann Heinrich von Thu¨nen Institute (Federal Research Institute for Rural Areas, Forestry and Fisheries); the Netherlands Polar Programme (NPP) of the Netherlands Organisation for Scientific Research (NOW); Research and Technology Centre Westcoast (FTZ) of the University Kiel. RW ...
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