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RESEARCH ARTICLE
Contents Vol 60(10)

Sources of nutrients driving production in the Gulf of Carpentaria, Australia: a shallow tropical shelf system

Michele A. Burford A D , Peter C. Rothlisberg B and Andrew T. Revill C
+ Author Affiliations
- Author Affiliations

A Australian Rivers Institute, Griffith University, Nathan, Qld 4111, Australia.

B CSIRO Marine and Atmospheric Research, PO Box 120, Cleveland, Qld 4163, Australia.

C CSIRO Marine and Atmospheric Research, GPO Box 1538, Hobart, Tas. 7001, Australia.

D Corresponding author. Email: m.burford@griffith.edu.au

Marine and Freshwater Research 60(10) 1044-1053 https://doi.org/10.1071/MF08291
Submitted: 14 October 2008  Accepted: 3 March 2009   Published: 20 October 2009

Abstract

The tropical Gulf of Carpentaria, Australia, has recently been identified as one of the world’s least impacted marine areas, presenting a unique opportunity to understand the nutrient drivers of productivity. The present study examined the nitrogen (N) sources and transformations in this pristine area and the role of N in fuelling primary productivity, principally based on summer data. The N budget estimates on a whole-of-Gulf basis suggest that river N inputs are unlikely to be major contributors to primary productivity. In the deeper waters of the Gulf, beyond the coastal boundary current, the main source of N is estimated to be N fixation by cyanobacteria, principally the abundant genus Trichodesmium. The present study measured high N fixation rates and depleted δ15N–N ratios in the particulate matter in the water column during a summer bloom. During summer, bottom N concentrations increased and δ15N–N ratios were depleted, suggesting that benthic mineralisation is occurring. It is therefore likely that detrital material from N-rich Trichodesmium is an important contributor to benthic processes. During winter, wind-driven mixing results in N from the bottom waters reaching the euphotic zone, and fuelling primary productivity. Therefore, Trichodesmium has an important direct and indirect role in contributing to primary productivity in this pristine tropical ecosystem.

Additional keywords: nitrogen budget, nitrogen fixation, Trichodesmium.


Acknowledgements

We acknowledge the help of the captain and crew of the RV Southern Surveyor and FV Flinders Pearl, Robert Pendrey, Frank Coman, Andrew Cook and Catherine Leigh in undertaking field sampling, Neale Johnson undertook the nutrient analyses, Jason Kerr measured ethylene production, Scott Condie and Eric Wolanski provided data on physical processes in the Gulf, Andrew Brooks provided river flow rate data, Wayne Rochester provided data and data management expertise, Catherine Leigh provided a figure, Miles Furnas provided nutrient data from Torres Strait, and Scott Condie and one anonymous reviewer provided comments on the manuscript.


References

Agawin, N. S. R. , Rabouille, S. , Veldhuis, M. J. W. , Servatius, L. , and Hol, S. , et al. (2007). Competition and facilitation between unicellular nitrogen-fixing cyanobacteria and non-nitrogen-fixing phytoplankton species. Limnology and Oceanography 52, 2233–2248.
|  CAS | Airey D., and Sandars G. (1987). Automated analysis of nutrients in seawater. Marine Laboratories Report No. 166. Commonwealth Scientific and Industrial Research Organisation, Hobart.

Alongi, D. M. , and McKinnon, A. D. (2005). The cycling and fate of terrestrially derived sediments and nutrients in the coastal zone of the Great Barrier Reef shelf. Marine Pollution Bulletin 51, 239–252.
| Crossref | GoogleScholarGoogle Scholar | CAS | PubMed | American Public Health Association (1995). ‘Standard Methods for the Examination of Water and Wastewater.’ 20th edn. (Eds A. E. Greenburg, L. S. Clesceri and A. D. Eaton.) (American Public Health Association: Washington.)

Anderson, D. M. , Glibert, P. M. , and Burkholder, J. M. (2002). Harmful algal booms and eutrophication: nutrient sources, composition and consequences. Estuaries 25, 704–726.
| Crossref | GoogleScholarGoogle Scholar | Dalsgaard T., Nielsen L. P., Brotas V., Viaroli P., Underwood G., et al. (2000). ‘Protocol Handbook for NICE – Nitrogen Cycling in Estuaries: A Project Under the EU Research Programme.’ (Marine Science and Technology (MAST III), National Environmental Research Institute: Silkeborg, Denmark.)

Davis, C. S. , and McGillicuddy, D. J. (2006). Transatlantic abundance of the N2-fixing colonial cyanobacterium Trichodesmium. Science 312, 1517–1520.
| Crossref | GoogleScholarGoogle Scholar | CAS | PubMed | Jeffrey S. W., and Welshmeyer N. A. (1997). Spectrophotometric and fluorometric equations in common use in oceanography. In ‘Phytoplankton Pigments in Oceanography’. (Eds S. W. Jeffrey, R. F. C. Mantoura and S. W. Wright.) pp. 597–615. Monographs on Oceanographic Methodology No. 10. UNESCO Publication, Paris.

Knapp, A. N. , Sigman, D. M. , and Lipschultz, F. (2005). N isotopic composition of dissolved organic nitrogen and nitrate at the Bermuda Atlantic time series study site. Global Biogeochemical Cycles 19, GB1018.
| Crossref | GoogleScholarGoogle Scholar | Knowles R. (1990). Acetylene inhibition techniques: development, advantages, and potential problems. In ‘Denitrification in Soil and Sediment’. (Eds N. P. Revsbech and J. Sørensen.) pp. 151–166. (Plenum Press: New York.)

Loneragan, N. R. , Bunn, S. E. , and Kellaway, D. M. (1997). Are mangroves and seagrasses sources of organic carbon for penaeid prawns in a tropical Australian estuary? A multiple stable-isotope study. Marine Biology 130, 289–300.
| Crossref | GoogleScholarGoogle Scholar | Longhurst A. R., and Pauly D. (1987). ‘Ecology of Tropical Oceans.’ (Academic Press: San Diego, CA.)

Molina, V. , Farias, L. , Graco, M. , Rivera, C. , and Pinto, L. , et al. (2004). Benthic nitrogen regeneration under oxygen and organic matter spatial variability off Concepcion (~36°S), central Chile. Deep-Sea Research. Part II, Topical Studies in Oceanography 51, 2507–2522.
| Crossref | GoogleScholarGoogle Scholar | CAS | Roelofs A., Coles R., and Smit N. (2005). A survey of intertidal seagrass from Van Diemen Gulf to Castlereagh Bay, Northern Territory, and from Gove to Horn Island, Queensland. Report to the National Oceans Office, Department of the Environment and Heritage, Australian Government.

Rothlisberg P. C., White N. J., and Forbes A. M. G. (1989). Hydrographic atlas of the Gulf of Carpentaria. CSIRO Marine Laboratories Report No. 209.

Rothlisberg, P. C. , Pollard, P. C. , Nichols, P. D. , Moriarty, D. J. W. , and Forbes, A. M. G. , et al. (1994). Phytoplankton community structure and productivity in relation to the hydrological regime of the Gulf of Carpentaria, Australia, in summer. Australian Journal of Marine and Freshwater Research 45, 265–282.
| Crossref | GoogleScholarGoogle Scholar | Wolanski E., and Ridd P. (1990). Mixing and trapping in Australian coastal waters. In ‘Coastal and Estuarine Studies, Vol. 38’. (Ed. R. T. Cheng.) pp. 165–183. (Springer-Verlag: New York.)

Zehr, J. P. , Waterbury, J. B. , Turner, P. J. , Montoya, J. P. , and Omoregle, E. , et al. (2001). Unicellular cyanobacteria fix N2 in the subtropical North Pacific Ocean. Nature 412, 635–638.
| Crossref | GoogleScholarGoogle Scholar | CAS | PubMed |