image: Weddell seal in the Ross Sea along the Victoria Land Coast. view more
Credit: PNAS
Differences in movement patterns of marine animals in open oceans and coastal habitats suggest differing resilience to environmental change, according to a study. Animal movement patterns are thought to be dictated by not only environmental but also intrinsic factors, such as body length and mass, metabolism, and speed of locomotion. To determine the influence of intrinsic versus extrinsic factors on animal movement, Ana Sequeira and colleagues analyzed satellite telemetry data on more than 2,600 large marine vertebrates of an array of species with diverse modes of movement from 2.8 million locations around the world. In contrast to terrestrial animals, marine vertebrates' effective speed, measured as mean displacement per day across tropical, temperate, and polar habitats, was unaffected by body length or mass, with a few exceptions. Individual variability in horizontal movement patterns was high for species that move along the coasts, which differ in physical features, prey and predator abundance, and human disturbances; by contrast, individual movement variability was low for species that move largely in the open ocean, which is free of the constraints imposed by continental shelves. Because marine vertebrates such as polar bears, whales, and sharks face anthropogenic threats, uncovering the direct link between habitat complexity and movement patterns might aid conservation efforts in the face of rising sea levels and shrinking Arctic ice. The high variability in behavior of marine animals in coastal habitats also raises the possibility of resilience to deteriorating coastal environments, according to the authors.
Article #17-16137: "Convergence of marine megafauna movement patterns in coastal and open oceans," by Ana Sequeira et al.
MEDIA CONTACT: Ana Sequeira, University of Western Australia, Perth, AUSTRALIA; tel: +61 8 6488 2219, +61 4 32 637 716; e-mail: <ana.sequeira@uwa.edu.au>
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