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. 2021 Oct 6;8(10):211052.
doi: 10.1098/rsos.211052. eCollection 2021 Oct.

Influence of environmental variation on spatial distribution and habitat-use in a benthic foraging marine predator

Cassie N Speakman  1 , Andrew J Hoskins  2 , Mark A Hindell  3 , Daniel P Costa  4 , Jason R Hartog  5 , Alistair J Hobday  5 , John P Y Arnould  1
Affiliations

Influence of environmental variation on spatial distribution and habitat-use in a benthic foraging marine predator

Cassie N Speakman et al. R Soc Open Sci. .

Abstract

The highly dynamic nature of the marine environment can have a substantial influence on the foraging behaviour and spatial distribution of marine predators, particularly in pelagic marine systems. However, knowledge of the susceptibility of benthic marine predators to environmental variability is limited. This study investigated the influence of local-scale environmental conditions and large-scale climate indices on the spatial distribution and habitat use in the benthic foraging Australian fur seal (Arctocephalus pusillus doriferus; AUFS). Female AUFS provisioning pups were instrumented with GPS or ARGOS platform terminal transmitter tags during the austral winters of 2001-2019 at Kanowna Island, south-eastern Australia. Individuals were most susceptible to changes in the Southern Oscillation Index that measures the strength of the El Niño Southern Oscillation, with larger foraging ranges, greater distances travelled and more dispersed movement associated with 1-yr lagged La Niña-like conditions. Additionally, the total distance travelled was negatively correlated with the current year sea surface temperature and 1-yr lagged Indian Ocean Dipole, and positively correlated with 1-yr lagged chlorophyll-a concentration. These results suggest that environmental variation may influence the spatial distribution and availability of prey, even within benthic marine systems.

Keywords: Arctocephalus; El Niño Southern Oscillation (ENSO); Indian Ocean Dipole (IOD); central-place foraging (CPF); marine predator; otariid.

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Figures

Figure 1.
Figure 1.
Location of the Kanowna Island breeding colony (black circle) within south-eastern Australia and inflow of major water bodies (SAC—South Australian Current; SASW—Sub-Antarctic Surface Waters; EAC—East Australian Current) into Bass Strait. Solid lines represent current flow and dashed lines represent water flow into Bass Strait. Red lines indicate warm water and blue lines represent cool water. The shaded box indicates the region for which local-scale environmental conditions were derived, which encompasses the main foraging area of female AUFS.
Figure 2.
Figure 2.
Representative tracks showing the variability in spatial distribution and habitat use of female AUFS during the austral winter, illustrating the reduction in total distance travelled with more positive 1-yr lagged IOD values ((a) mid/late-lactation 2006 (N = 6) and (b) mid/late-lactation 2019 (N = 7)) and the increase in total distance travelled and variation in mean bearing with more positive 1-yr lagged SOI values ((c) mid/late-lactation 2016 (N = 5) and (d) mid/late-lactation 2009 (N = 12)).
Figure 3.
Figure 3.
Conditional effects plot for the influence of local- and large-scale environmental conditions on the total distance travelled (km) by female AUFS.
Figure 4.
Figure 4.
Conditional effects plot for the influence of 1-yr lagged SOI on the 95% home range estimate (km2) used by female AUFS.
Figure 5.
Figure 5.
Influence of 1-yr lagged SOI on the mean bearing travelled by female AUFS during foraging trips.
See this image and copyright information in PMC

References

    1. Bertram DF, Mackas DL, McKinnell SM. 2001The seasonal cycle revisited: interannual variation and ecosystem consequences. Prog. Oceanogr. 49, 283-307. (10.1016/S0079-6611(01)00027-1) - DOI
    1. Misarti N, Finney B, Maschner H, Wooller MJ. 2009Changes in northeast Pacific marine ecosystems over the last 4500 years: evidence from stable isotope analysis of bone collagen from archeological middens. The Holocene 19, 1139-1151. (doi:10.1177%2F0959683609345075)
    1. Mantua NJ, Hare SR. 2002The Pacific decadal oscillation. J. Oceanogr. 58, 35-44. (10.1023/A:1015820616384) - DOI
    1. Middleton JF, Arthur C, Van Ruth P, Ward TM, McClean JL, Maltrud ME, Gill P, Levings A, Middleton S. 2007El Niño effects and upwelling off South Australia. J. Phys. Oceanogr. 37, 2458-2477. (10.1175/jpo3119.1) - DOI
    1. Jenkins GP. 2005The influence of climate on the fishery recruitment of a temperate, seagrass-associated fish, the King George whiting Sillaginodes punctata. Mar. Ecol. Prog. Ser. 288, 263-271. (10.3354/meps288263) - DOI

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