title: Climate change and Southern Ocean ecosystems I: how changes in physical habitats directly affect marine biota.
abstract: Antarctic and Southern Ocean (ASO) marine ecosystems have been changing for at least the last 30 years, including in response to increasing ocean temperatures and changes in the extent and seasonality of sea ice; the magnitude and direction of these changes differ between regions around Antarctica that could see populations of the same species changing differently in different regions. This article reviews current and expected changes in ASO physical habitats in response to climate change. It then reviews how these changes may impact the autecology of marine biota of this polar region: microbes, zooplankton, salps, Antarctic krill, fish, cephalopods, marine mammals, seabirds, and benthos. The general prognosis for ASO marine habitats is for an overall warming and freshening, strengthening of westerly winds, with a potential pole-ward movement of those winds and the frontal systems, and an increase in ocean eddy activity. Many habitat parameters will have regionally specific changes, particularly relating to sea ice characteristics and seasonal dynamics. Lower trophic levels are expected to move south as the ocean conditions in which they are currently found move pole-ward. For Antarctic krill and finfish, the latitudinal breadth of their range will depend on their tolerance of warming oceans and changes to productivity. Ocean acidification is a concern not only for calcifying organisms but also for crustaceans such as Antarctic krill; it is also likely to be the most important change in benthic habitats over the coming century. For marine mammals and birds, the expected changes primarily relate to their flexibility in moving to alternative locations for food and the energetic cost of longer or more complex foraging trips for those that are bound to breeding colonies. Few species are sufficiently well studied to make comprehensive species-specific vulnerability assessments possible. Priorities for future work are discussed.
authors.affiliation: Australian Antarctic Division, Channel Highway, Kingston, Tasmania, 7050, Australia; Antarctic Climate and Ecosystems Cooperative Research Centre, Private Bag 80, Hobart, Tasmania, 7001, Australia.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Constable
authors.forename: Jessica
authors.initials: J
authors.lastname: Melbourne-Thomas
authors.forename: Stuart P
authors.initials: SP
authors.lastname: Corney
authors.forename: Kevin R
authors.initials: KR
authors.lastname: Arrigo
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authors.lastname: Barbraud
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authors.initials: DK
authors.lastname: Barnes
authors.forename: Nathaniel L
authors.initials: NL
authors.lastname: Bindoff
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authors.initials: PW
authors.lastname: Boyd
authors.forename: Angelika
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authors.lastname: Brandt
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Costa
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Davidson
authors.forename: Hugh W
authors.initials: HW
authors.lastname: Ducklow
authors.forename: Louise
authors.initials: L
authors.lastname: Emmerson
authors.forename: Mitsuo
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authors.lastname: Fukuchi
authors.forename: Julian
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authors.lastname: Gutt
authors.forename: Mark A
authors.initials: MA
authors.lastname: Hindell
authors.forename: Eileen E
authors.initials: EE
authors.lastname: Hofmann
authors.forename: Graham W
authors.initials: GW
authors.lastname: Hosie
authors.forename: Takahiro
authors.initials: T
authors.lastname: Iida
authors.forename: Sarah
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authors.lastname: Jacob
authors.forename: Nadine M
authors.initials: NM
authors.lastname: Johnston
authors.forename: So
authors.initials: S
authors.lastname: Kawaguchi
authors.forename: Nobuo
authors.initials: N
authors.lastname: Kokubun
authors.forename: Philippe
authors.initials: P
authors.lastname: Koubbi
authors.forename: Mary-Anne
authors.initials: MA
authors.lastname: Lea
authors.forename: Azwianewi
authors.initials: A
authors.lastname: Makhado
authors.forename: Rob A
authors.initials: RA
authors.lastname: Massom
authors.forename: Klaus
authors.initials: K
authors.lastname: Meiners
authors.forename: Michael P
authors.initials: MP
authors.lastname: Meredith
authors.forename: Eugene J
authors.initials: EJ
authors.lastname: Murphy
authors.forename: Stephen
authors.initials: S
authors.lastname: Nicol
authors.forename: Keith
authors.initials: K
authors.lastname: Reid
authors.forename: Kate
authors.initials: K
authors.lastname: Richerson
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Riddle
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Rintoul
authors.forename: Walker O
authors.initials: WO
authors.lastname: Smith
authors.forename: Colin
authors.initials: C
authors.lastname: Southwell
authors.forename: Jonathon S
authors.initials: JS
authors.lastname: Stark
authors.forename: Michael
authors.initials: M
authors.lastname: Sumner
authors.forename: Kerrie M
authors.initials: KM
authors.lastname: Swadling
authors.forename: Kunio T
authors.initials: KT
authors.lastname: Takahashi
authors.forename: Phil N
authors.initials: PN
authors.lastname: Trathan
authors.forename: Dirk C
authors.initials: DC
authors.lastname: Welsford
authors.forename: Henri
authors.initials: H
authors.lastname: Weimerskirch
authors.forename: Karen J
authors.initials: KJ
authors.lastname: Westwood
authors.forename: Barbara C
authors.initials: BC
authors.lastname: Wienecke
authors.forename: Dieter
authors.initials: D
authors.lastname: Wolf-Gladrow
authors.forename: Simon W
authors.initials: SW
authors.lastname: Wright
authors.forename: Jose C
authors.initials: JC
authors.lastname: Xavier
authors.forename: Philippe
authors.initials: P
authors.lastname: Ziegler
mesh_terms: D000864:Antarctic Regions; D059001:Aquatic Organisms; D058448:Biota; D057231:Climate Change; D017753:Ecosystem; D046448:Ice Cover; D009792:Oceans and Seas; D014872:Water Movements; D014919:Wind
keywords: Antarctica; benthos; climate change; krill; marine ecosystems; marine mammals; ocean acidification; penguins; plankton; sea ice