Bottom current velocity

Bottom current velocity can affect abundance and biodiversity of benthic fauna by altering disturbance regimes, changing available habitats, and regulating nutrient flows. The intermediate disturbance hypothesis predicts maximum biodiversity at a frequency of disturbance where recruitment is able to replace lost individuals but inter-specific processes don’t have time to exclude species (Connell 1978). Thus, highest biodiversity will be generally associated with occasional episodes of strong bottom current velocity (e.g. bed shear stress on GBR in (Pitcher and Centre 2007)). Bottom current velocity can interact with substrate type to affect biodiversity, with sediment stability dependent on slope, particle size and the degree of water motion on the bed (Bagnold 1963). For example, mobile sandy or fine gravel substrates in strong currents typically show much lower richness.  

Strong bottom current velocities may contribute to primary space being made available by increasing sheer stress which can remove sediment and expose hard substrate or by mechanical abrasion or damage caused by moving sediment or projectiles (Sousa 2001). Species composition often varies dramatically between consolidated (i.e. hard) and unconsolidated (i.e. soft) substrate (Williams and Bax 2001, Beaman and Harris 2007), with hard substrates generally acting as habitat to a larger proportion of sessile suspension feeders and soft sediments as home to infauna and a larger proportion of small, discretely motile invertebrates.  Limited research exists on the effects of bottom current velocity on biodiversity in the North and North-West.

Use the interactive map below to explore how a related variable - sheer stress - vary around Australia's coastline.  

How to use the map

 Click on this icon at the top left of the map to see a full screen version and legend.

   Click on this icon also at the top left of the map to zoom in closer to (+ ) or further from (-) the map.

 

References

Bagnold, R. A. 1963. Mechanics of Marine Sedimentation. Pages 507-527 in M. N. Hill, editor. The Sea. Wiley, New York.

Beaman, R. J. and P. T. Harris. 2007. Geophysical proxies as predictors of megabenthos assemblages from the northern Great Barrier Reef, Australia. Pages 241-258 in B. J. Todd and G. Greene, editors. Mapping the Seafloor for Habitat Characterization. Geological Association of Canada, Toronto.

Bouchet, P. J., J. J. Meeuwig, C. P. Salgado Kent, T. B. Letessier, and C. K. Jenner. 2014. Topographic determinants of mobile vertebrate predator hotspots: current knowledge and future directions. Biological Reviews:n/a-n/a.

Brown, C. J., A. J. Hewer, W. J. Meadows, D. S. Limpenny, K. M. Cooper, J. L. Rees, and C. M. G. Vivan. 2001. Mapping of Gravel Biotopes and an Examination of the Factors Controlling the Distribution, Type and Diversity of Their Biological Communities. Centre for Environment, Fisheries, and Aquaculture Science, Lowestoft.

Butler, A. J., T. Rees, P. Beesley, and N. J. Bax. 2010. Marine Biodiversity in the Australian Region. PLoS ONE 5:e11831.

Connell, J. H. 1978. Diversity in tropical rain forests and coral reefs. Science 199:1302-1310.

Currie, D. R., S. J. Sorokin, and T. M. Ward. 2009. Infaunal macroinvertebrate assemblages of the eastern Great Australian Bight: effectiveness of a marine protected area in representing the region's benthic biodiversity. Marine and Freshwater Research 60:459-474.

Dell'Anno, A., M. L. Mei, A. Pusceddu, and R. Danovaro. 2002. Assessing the trophic state and eutrophication of coastal marine systems: a new approach based on the biochemical composition of sediment organic matter. Marine Pollution Bulletin 44:611-622.

Edgar, G. 2001. Australian Marine Habitats in Temperate Waters. REed New Holand Publishers Australia Pty Ltd, Sydney.

Etter, R. J., M. A. Rex, M. R. Chase, and J. M. Quattro. 2005. Population differentiation decreases with depth in deep-sea bivalves. Evolution 59:1479-1491.

Gray, J. S. 2001. Marine diversity: the paradigms in patterns of species richness examined. Scientia Marina 65:41-56.

Heap, A. D. and P. T. Harris. 2008. Geomorphology of the Australian margin and adjacent seafloor. Australian Journal of Earth Sciences 55:555-585.

Hillebrand, H., D. S. Gruner, E. T. Borer, M. E. Bracken, E. E. Cleland, J. J. Elser, W. S. Harpole, J. T. Ngai, E. W. Seabloom, J. B. Shurin, and J. E. Smith. 2007. Consumer versus resource control of producer diversity depends on ecosystem type and producer community structure. Proc Natl Acad Sci U S A 104:10904-10909.

Levin, L. A., R. J. Etter, M. A. Rex, A. J. Gooday, C. R. Smith, J. Pineda, C. T. Stuart, R. R. Hessler, and D. Pawson. 2001. Environmental influences on regional deep-sea species diversity. Annual Review of Ecology and Systematics 32:51-93.

Long, B. G. and I. R. Poiner. 1994. Infaunal benthic community structure and function in the Gulf of Carpentaria, northern Australia. Australian Journal of Marine and Freshwater Research 45:293-316.

McArthur, M., B. Brooke, R. Przeslawski, D. A. Ryan, V. Lucieer, S. Nichol, A. W. McCallum, C. Mellin, I. D. Cresswell, and L. C. Radke. 2010. On the use of abiotic surrogates to describe marine benthic biodiversity Estuarine Coastal and Shelf Science 88:21-32.

Pitcher, C. R. and C. R. R. Centre. 2007. Seabed biodiversity on the continental shelf of the Great Barrier Reef World Heritage Area CSIRO Marine and Atmospheric Research, Cleveland.

Przeslawski, R., M. A. McArthur, and T. J. Anderson. 2013. Infaunal biodiversity patterns from Carnarvon Shelf (Ningaloo Reef), Western Australia. Marine and Freshwater Research 64:573-583.

Przeslawski, R., A. Williams, S. L. Nichol, M. G. Hughes, T. J. Anderson, and F. Althaus. 2011. Biogeography of the Lord Howe Rise region, Tasman Sea. Deep Sea Research Part II: Topical Studies in Oceanography 58:959-969.

Samadi, S., L. Bottan, E. Macpherson, B. R. De Forges, and M. C. Boisselier. 2006. Seamount endemism questioned by the geographic distribution and population genetic structure of marine invertebrates. Marine Biology 149:1463-1475.

Schlacher, T. A., M. A. Schlacher-Hoenlinger, A. Williams, F. Althaus, J. N. A. Hooper, and R. Kloser. 2007. Richness and distribution of sponge megabenthos in continental margin canyons off southeastern Australia. Marine Ecology-Progress Series 340:73-88.

Snelgrove, P. V. R. 2001. Diversity of marine species. Pages 748-757 in J. Steele, S. Thorpe, and K. Turekian, editors. Encyclopedia of Ocean Sciences. Academic Press, Oxford.

Snelgrove, P. V. R. and C. A. Butman. 1994. Animal-seidment relationships revised: cause versus effect. Oceanography and Marine Biology - An Annual Review 32:111-177.

Sousa, W. P. 2001. Natural disturbance and the dynamics of marine benthic communities. Pages 85-132 in M. D. Bertness, S. D. Gaines, and M. E. Hay, editors. Marine Community Ecology. Sinauer Associates, Inc., Sunderland.

Williams, A. and N. J. Bax. 2001. Delineating fish-habitat associations for spatially based management: an example from the south-eastern Australian continental shelf. Marine and Freshwater Research 52:513-536.

Williams, A., K. Gowlett-Holmes, and F. Althaus. 2006. Biodiversity of seamounts and slopes of the Norfolk Ridge and Lord Howe Rise: final report to the Department of the Environment and Heritage (National Oceans Office). Department of Environment and Heritage, Hobart.