title: Large-scale geographic variation in distribution and abundance of Australian deep-water kelp forests.
abstract: Despite the significance of marine habitat-forming organisms, little is known about their large-scale distribution and abundance in deeper waters, where they are difficult to access. Such information is necessary to develop sound conservation and management strategies. Kelps are main habitat-formers in temperate reefs worldwide; however, these habitats are highly sensitive to environmental change. The kelp Ecklonia radiate is the major habitat-forming organism on subtidal reefs in temperate Australia. Here, we provide large-scale ecological data encompassing the latitudinal distribution along the continent of these kelp forests, which is a necessary first step towards quantitative inferences about the effects of climatic change and other stressors on these valuable habitats. We used the Autonomous Underwater Vehicle (AUV) facility of Australia's Integrated Marine Observing System (IMOS) to survey 157,000 m2 of seabed, of which ca 13,000 m2 were used to quantify kelp covers at multiple spatial scales (10-100 m to 100-1,000 km) and depths (15-60 m) across several regions ca 2-6° latitude apart along the East and West coast of Australia. We investigated the large-scale geographic variation in distribution and abundance of deep-water kelp (>15 m depth) and their relationships with physical variables. Kelp cover generally increased with latitude despite great variability at smaller spatial scales. Maximum depth of kelp occurrence was 40-50 m. Kelp latitudinal distribution along the continent was most strongly related to water temperature and substratum availability. This extensive survey data, coupled with ongoing AUV missions, will allow for the detection of long-term shifts in the distribution and abundance of habitat-forming kelp and the organisms they support on a continental scale, and provide information necessary for successful implementation and management of conservation reserves.
authors.affiliation: Sydney Institute of Marine Science, Mosman, New South Wales, Australia; Centre for Marine Bio-Innovation and School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales, Australia.
authors.forename: Ezequiel M
authors.initials: EM
authors.lastname: Marzinelli
authors.affiliation: Australian Centre for Field Robotics, University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Stefan B
authors.initials: SB
authors.lastname: Williams
authors.affiliation: CSIRO Marine and Atmospheric Research, Brisbane, Queensland, Australia.
authors.forename: Russell C
authors.initials: RC
authors.lastname: Babcock
authors.affiliation: Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, Australia.
authors.forename: Neville S
authors.initials: NS
authors.lastname: Barrett
authors.affiliation: Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, Australia.
authors.forename: Craig R
authors.initials: CR
authors.lastname: Johnson
authors.affiliation: Department of Primary Industries, New South Wales Government, Port Stephens Fisheries Institute, Nelson Bay, New South Wales, Australia.
authors.forename: Alan
authors.initials: A
authors.lastname: Jordan
authors.affiliation: Oceans Institute and School of Plant Biology, University of Western Australia, Perth, Western Australia, Australia.
authors.forename: Gary A
authors.initials: GA
authors.lastname: Kendrick
authors.affiliation: Australian Centre for Field Robotics, University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Oscar R
authors.initials: OR
authors.lastname: Pizarro
authors.affiliation: Oceans Institute and School of Plant Biology, University of Western Australia, Perth, Western Australia, Australia; Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth, United Kingdom.
authors.forename: Dan A
authors.initials: DA
authors.lastname: Smale
authors.affiliation: Sydney Institute of Marine Science, Mosman, New South Wales, Australia; Centre for Marine Bio-Innovation and School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales, Australia.
authors.forename: Peter D
authors.initials: PD
authors.lastname: Steinberg
mesh_terms: D000220:Adaptation, Biological; D001315:Australia; D057231:Climate Change; D017753:Ecosystem; D044423:Kelp / Q000502:physiology*; D008386:Marine Biology; D011153:Population; D012623:Seawater / Q000032:analysis*