title: Counting whales in a challenging, changing environment.
abstract: 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.
authors.affiliation: Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews KY16 8LB, UK.
authors.forename: R
authors.initials: R
authors.lastname: Williams
authors.affiliation: 1] CSIRO Computational Informatics and Wealth from Oceans Flagship, Hobart, Tasmania, 7000, Australia [2] Australian Marine Mammal Centre, Kingston, Tasmania, 7050, Australia.
authors.forename: N
authors.initials: N
authors.lastname: Kelly
authors.affiliation: Alfred Wegener Institute, Bremerhaven, Germany.
authors.forename: O
authors.initials: O
authors.lastname: Boebel
authors.affiliation: 1] Marine Geospatial Ecology Lab, Duke University Marine Laboratory, Beaufort, NC 28516, USA [2].
authors.forename: A S
authors.initials: AS
authors.lastname: Friedlaender
authors.affiliation: Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Buesum, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Herr
authors.affiliation: Johann Heinrich von Thünen Institute, Institute of Sea Fisheries, Hamburg, Germany.
authors.forename: K-H
authors.initials: KH
authors.lastname: Kock
authors.affiliation: Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Buesum, Germany.
authors.forename: L S
authors.initials: LS
authors.lastname: Lehnert
authors.affiliation: Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, USA.
authors.forename: T
authors.initials: T
authors.lastname: Maksym
authors.affiliation: Marine Geospatial Ecology Lab, Duke University Marine Laboratory, Beaufort, NC 28516, USA.
authors.forename: J
authors.initials: J
authors.lastname: Roberts
authors.affiliation: IMARES, Institute for Marine Resources and Ecosystem Studies, 1970 AB IJmuiden, The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: Scheidat
authors.affiliation: Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover, Foundation, Buesum, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Siebert
authors.affiliation: Pelagic Ecology Research Group, Scottish Oceans Institute, School of Biology, University of St Andrews, St Andrews, KY16 8LB, Scotland UK.
authors.forename: A S
authors.initials: AS
authors.lastname: Brierley
mesh_terms: D000818:Animals; D000864:Antarctic Regions; D057231:Climate Change; D003247:Conservation of Natural Resources; D003625:Data Collection; D017753:Ecosystem; D046448:Ice Cover; D050636:Minke Whale; D009792:Oceans and Seas; D011156:Population Density; D011157:Population Dynamics