Abstract
The Southern Ocean is undergoing rapid environmental change, which has impacted its ecosystems and food webs. There is need for ecosystem models that incorporate all levels of the biotic system and consider physical context. Using an end-to-end ecosystem model of the Prince Edward Islands (PEIs), we investigated the importance of the input of oceanic nutrients, oceanic plankton, and run-off of terrestrial ammonium to nearshore production. We compared ecosystem state as group production rates and as the relative scale of pelagic versus demersal food web pathways under alternate ocean current regimes, assumptions of macrozooplankton advection into shelf waters, and assumptions of plankton retention within the nearshore region. The major outcomes are: (1) oceanic plankton, more than oceanic nutrients or terrestrial nutrients, is the major driver of production for all groups within the nearshore ecosystem. Island run-off of ammonium is a minor driver of production but is most important among groups with higher reliance upon detrital food chains (benthic invertebrates, demersal fishes, Gentoo penguins); (2) groups most sensitive to changes in ocean current regime and assumptions of macrozooplankton advection into shelf waters are planktivores (southern rockhopper penguins, Macaroni penguins) and piscivores whose diets rely heavily upon planktivorous fishes; (3) zooplankton populations cannot support estimated levels of predation pressure within the nearshore ecosystem if they behave as purely passive drifters. Our findings suggest changes to physical processes, such as a postulated southward shift in the position of the sub-Antarctic front leading to intensification of currents approaching the islands, has already had and will continue to have significant impacts on the PEIs ecosystem.







Similar content being viewed by others
References
Allan EL, Froneman PW, Durgadoo JV, McQuaid CD, Ansorge IJ, Richoux NB. 2013. Critical indirect effects of climate change on sub-Antarctic ecosystem functioning. Ecology and Evolution 3:2994–3004.
Ansorge IJ, Lutjeharms JRE. 2002. The hydrography and dynamics of the ocean environment of the Prince Edward Islands (Southern Ocean). Journal of Marine Systems 37:107–27.
Ansorge IJ, Durgadoo JV, Pakhomov EA. 2009. Dynamics of physical and biological systems of the Prince Edward Islands in a changing climate. Papers and Proceedings of the Royal Society of Tasmania 143:15–18.
Ansorge IJ, Froneman PW, Pakhomov EA, Lutjeharms JR, Perissinotto R, van Ballegooyen RC. 1999. Physical–biological coupling in the waters surrounding the Prince Edward Islands (Southern Ocean). Polar Biology 21:135–45.
Atkinson A, Siegel V, Rothery P. 2004. Long-term decline in krill stock and increase in salps within the Southern Ocean. Nature 432:100–3.
Atkinson A, Whitehouse MJ, Priddle J, Cripps GC, Ward P, Brandon M. 2001. South Georgia, Antarctica: a productive, cold water, pelagic ecosystem. Marine Ecology Progress Series 216:279–308.
Ballerini T, Hofmann EE, Ainley DG, Daly K, Marrari M, Ribic CA, Smith WO Jr, Steele JH. 2014. Productivity and linkages of the food web of the southern region of the western Antarctic Peninsula continental shelf. Progress in Oceanography 122:10–29.
Bennett JR, Stark JS, Bennett JR, Shaw JD, Terauds A, Smol JP, Aerts R, Bergstrom DM, Blais JM et al. 2015. Polar lessons learned: long-term management based on shared threats in Arctic and Antarctic environments. Frontiers in Ecology and the Environment 13:316–24.
Bost CA, Cotte C, Bailleul F, Cherel Y, Charrassin JB, Guinet C, Ainley DG, Weimerskirch H. 2009. The importance of oceanographic fronts to marine birds and mammals of the southern oceans. Journal of Marine Systems 78:363–76.
Chown SL, Convey P. 2012. Spatial and temporal variability in terrestrial Antarctic biodiversity. In: Rogers AD, Johnston NM, Murphy EJ, Clarke A, Eds. Antarctic ecosystems: an extreme environment in a changing world. Oxford: Wiley-Blackwell. p 13–43.
Christensen V, Walters CJ. 2004. Ecopath with Ecosim: methods, capabilities and limitations. Ecological Modelling 172:109–39.
Clark GF, Stark JS, Johnston EL, Runcie JW, Goldsworthy PM, Raymond B, Riddle MJ. 2013. Light-driven tipping points in polar ecosystems. Global Change Biology 19:3749–61.
Constable AJ, Melbourne-Thomas J, Corney SP, Arrigo KR, Barbraud C, Barnes DKA, Takahashi KT et al. 2014. Climate change and Southern Ocean ecosystems I: how changes in physical habitats directly affect marine biota. Global Change Biology 20:3004–25.
Cushing DH, Humphrey GH, Banse K, Laevastu T. 1958. Report of the Committee on Terms and Equivalents. Rapports et Proces-verboux des Reunions du Conseil Permonent Internationa pour l’Exploration de la Mer 14:15–16.
Deacon GER. 1983. Kerguelen, Antarctic and Subantarctic. Deep-Sea Research A 30:77–81.
Department of Environmental Affairs (DEA). 2013. Prince Edward Islands declared a Marine Protected Area. https://www.environment.gov.za/?q=content/princeedwardislands_declaredmarineprotectedarea, accessed 12 April 2013.
Doney SC, Ruckelshaus M, Duffy JE, Barry JP, Chan F, English CA, Galindo HM, Grebmeier JM, Hollowed AB et al. 2012. Climate change impacts on marine ecosystems. Annual Review of Marine Science 4:1–27.
Ducklow HW, Baker K, Martinson DG, Quetin LB, Ross RM, Smith RC, Stammerjohn SE, Vernet M, Fraser W. 2007. Marine pelagic ecosystems: the West Antarctic Peninsula. Philosophical Transactions Royal Society B 362:67–94.
Froneman PW, Pakhomov EA. 1998. Biogeographic study of the planktonic communities of the Prince Edward Islands (Southern Ocean). Journal of Plankton Research 20:653–69.
Ganachaud A, Wunsch C. 2000. Improved estimates of global ocean circulation, heat transport and mixing from hydrographic data. Nature 408:453–7.
Gurney LJ. 2013. An ecosystem study of the Prince Edward Archipelago (Southern Ocean). PhD thesis, University of British Columbia, Vancouver, Canada. http://hdl.handle.net/2429/45694.
Gurney L, Pakhomov EA, Christensen V. 2014. An ecosystem model of the Prince Edward Island archipelago. Ecological Modelling 294:117–36.
Hoegh-Guldberg O, Bruno JF. 2010. The impact of climate change on the world’s marine ecosystems. Science 328:1523–8.
Hofmann EE, Murphy EJ. 2004. Advection, krill, and Antarctic marine ecosystems. Antarctic Science 16:487–99.
Holt J, Allen JI, Anderson TR, Brewin R, Butenschön M, Harle J, Huse G, Lehodey P, Lindemann C et al. 2014. Challenges in integrative approaches to modelling the marine ecosystems of the North Atlantic: physics to fish and coasts to ocean. Progress in Oceanography 129:285–313.
Hunt BPV, Gurney LJ, Pakhomov EA. 2008. Time-series analysis of hydrological and biological variability on the Prince Edward Island (Southern Ocean) shelf. Polar Biology 31:893–904.
Hunt BPV, Pakhomov EA, McQuaid CD. 2001. Short-term variation and long-term changes in the oceanographic environment and zooplankton community in the vicinity of a sub-Antarctic archipelago. Marine Biology 138:369–81.
Hunt BPV, Pakhomov EA, McQuaid CD. 2002. Community structure of mesozooplankton in the Antarctic Polar Frontal Zone in the vicinity of the Prince Edward Islands (Southern Ocean): small-scale distribution patterns in relation to physical parameters. Deep-Sea Research II 49:3307–25.
IPCC. 2014. Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing Team, Pachauri RK, Meyer LA, editors]. IPCC, Geneva, Switzerland.
Lutjeharms JRE. 1985. Location of frontal systems between Africa and Antarctica: some preliminary results. Deep-Sea Research 32:1499–509.
Lutjeharms JRE, Ansorge IJ. 2008. Oceanographic setting of the Prince Edward Islands.
Macdonald A, Wunsch C. 1996. An estimate of global ocean circulation and heat fluxes. Nature 382:436–9.
Meyer B. 2012. The overwintering of Antarctic krill, Euphausia superba, from an ecophysiological perspective. Polar Biology 35:15–37.
Moline MA, Claustre H, Frazer TK, Schofield O, Vernet M. 2004. Alteration of the food web along the Antarctic Peninsula in response to a regional warming trend. Global Change Biology 10:1973–80.
Moloney CL, St John MA, Denman KL, Karl DM, Köster FW, Sundby S, Wilson RP. 2011. Weaving marine food webs from end to end under global change. Journal of Marine Systems 84:106–16.
Murphy EJ, Hofmann EE. 2012. End-to-end in Southern Ocean ecosystems. Current Opinion in Environmental Sustainability 4:264–71.
Murphy EJ, Cavanagh RD, Hofmann EE, Hill SL, Constable AJ, Costa DP, Pinkerton MH, Johnston NM, Trathan PN. 2012. Developing integrated models of Southern Ocean food webs: including ecological complexity, accounting for uncertainty and the importance of scale. Progress in Oceanography 102:74–92.
Pakhomov EA, Chown SL. 2003. The Prince Edward Islands: Southern Ocean oasis. Ocean Yearbook 17:348–79.
Pakhomov EA, Froneman PW. 1999. The Prince Edward Islands pelagic ecosystem, south Indian Ocean: a review of achievements, 1976–1990. Journal of Marine Systems 18:355–67.
Pakhomov EA, Ansorge IJ, Froneman PW. 2000a. Variability in the inter-island environment of the Prince Edward Islands (Southern Ocean). Polar Biology 23:593–603.
Pakhomov EA, Froneman PW, Ansorge IJ, Lutjeharms JRE. 2000b. Temporal variability in the physico-biological environment of the Prince Edward Islands (Southern Ocean). Journal of Marine Systems 26:75–95.
Pakhomov EA, McClelland JW, Bernard K, Kaehler S, Montoya JP. 2004. Spatial and temporal shifts in stable isotope values of bottom-dwelling shrimp Nauticaris marionis at the sub-Antarctic archipelago. Marine Biology 144:317–25.
Perissinotto R, Duncombe Rae CM. 1990. Occurrence of anti-cyclonic eddies on the Prince Edward plateau (Southern Ocean): effects on phytoplankton productivity and biomass. Deep-Sea Research I 37:777–93.
Perissinotto R, McQuaid CD. 1992. Land-based predator impact on vertically migrating zooplankton and micronekton advected to a Southern Ocean archipelago. Marine Ecology Progress Series 80:15–27.
Perissinotto R, Lutjeharms JRE, Van Ballegooyen RC. 2000. Biological-physical interactions and pelagic productivity at the Prince Edward Islands, Southern Ocean. Journal of Marine Systems 24:327–41.
Renner AHH, Thorpe SE, Heywood KJ, Murphy EJ, Watkins JL, Meredith MP. 2012. Advective pathways near the tip of the Antarctic Peninsula: trends, variability and ecosystem implications. Deep-Sea Research Part I: Oceanographic Research Papers 63:91–101.
Rintoul SR, Sparrow M, Meredith MP, Wadley V, Speer K, Hofmann E, Summerhayes C, Urban E, Bellerby R, Eds. 2012. The Southern Ocean observing system: initial science and implementation strategy. Paris: Scientific Committee on Antarctic Research.
Ruzicka JJ, Brodeur RD, Emmett RL, Steele JH, Zamon JE, Morgan CA, Thomas AC, Wainwright TC. 2012. Interannual variability in the Northern California Current food web structure: changes in energy flow pathways and the role of forage fish, euphausiids, and jellyfish. Progress in Oceanography 102:19–41.
Ryan PG, Bester MN. 2008. Pelagic predators. In: Chown SL, Froneman PW, Eds. The Prince Edward Islands: land–sea interactions in a changing ecosystem. Stellenbosch: Sun Press. p 121–64.
Schofield O, Ducklow HW, Martinson DG, Meredith MP, Moline MA, Fraser WR. 2010. How do polar marine ecosystems respond to rapid climate change? Science 328:1520–3.
Smith WO Jr, Ainley DG, Arrigo KR, Dinniman MS. 2014. The oceanography and ecology of the Ross Sea. Annual Review of Marine Science 6:469–87.
Steele JH, Ruzicka JJ. 2011. Constructing end-to-end models using ECOPATH data. Journal of Marine Systems 87:227–38.
Trathan PN, Agnew D. 2010. Climate change and the Antarctic marine ecosystem: an essay on management implications. Antarctic Science 22:387–98.
Trathan PN, Forcada J, Murphy EJ. 2007. Environmental forcing and Southern Ocean marine predator populations: effects of climate change and variability. Philosophical Transactions of the Royal Society B 362:2351–65.
Treasure AM. 2012. Climate change and invasion impacts in the sub-Antarctic. PhD thesis, Stellenbosch University.
Treasure AM, Ruzicka JJ, Moloney CL, Gurney LJ, Ansorge IJ. 2015. Land–sea interactions and consequences for sub-Antarctic marine food webs. Ecosystems 18:752–68.
von der Meden CEO, Atkinson LJ, Branch GM, Asdar S, Ansorge IJ, van den Berg M. 2017. Long-term change in epibenthic assemblages at the Prince Edward Islands: a comparison between 1988 and 2013. Polar Biology 40:2171–85.
Whitehead TO, Connan M, Ropert-Coudert Y, Ryan PG. 2017. Subtle but significant segregation in the feeding ecology of sympatric penguins during the critical pre-moult period. Marine Ecology Progress Series 565:227–36.
Wilkins D, van Sebille E, Rintoul SR, Lauro FM, Cavicchioli R. 2013. Advection shapes Southern Ocean microbial assemblages independent of distance and environment effects. Nature communications 4:2457. https://doi.org/10.1038/ncomms3457.
Acknowledgements
AMT was supported by the South African National Research Foundation (NRF). JJR was supported by US National Science Foundation Project 1258667.
Author information
Authors and Affiliations
Corresponding author
Additional information
Author contributions
AMT, JJR and IJA conceived of the study. JJR, AMT and EAP performed the research. JJR ran and analysed the ECOTRAN model. AMT, JJR, EAP and IJA wrote and edited the manuscript.
Electronic supplementary material
Below is the link to the electronic supplementary material.
Rights and permissions
About this article
Cite this article
Treasure, A.M., Ruzicka, J.J., Pakhomov, E.A. et al. Physical Transport Mechanisms Driving Sub-Antarctic Island Marine Ecosystems. Ecosystems 22, 1069–1087 (2019). https://doi.org/10.1007/s10021-018-0326-1
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10021-018-0326-1