Can regional nutrient status be used to predict plant biomass, canopy structure and epiphyte biomass in the temperate seagrass Amphibolis antarctica?
Simon R. BryarsSouth Australian Research and Development Institute (Aquatic Sciences), PO Box 120, Henley Beach, SA 5022, Australia. Present address: Department for Environment and Heritage, GPO Box 1047, Adelaide, SA 5001, Australia. Email: bryars.simon@sa.gov.au
Marine and Freshwater Research 60(10) 1054-1067 https://doi.org/10.1071/MF08194
Submitted: 27 June 2008 Accepted: 30 March 2009 Published: 20 October 2009
Abstract
The seagrass Amphibolis antarctica is an important component of coastal soft-sediment ecosystems across southern Australia. Large-scale losses of A. antarctica at several locations have been linked to anthropogenic nutrient inputs. The present study comprised a field survey to test whether the spatial patterns of plant biomass, canopy structure and epiphyte biomass in A. antarctica could be predicted based on expectations related to nutrient status across two regions within Gulf St Vincent, South Australia. Specific predictions were that: (1) plant biomass, plant density, plant height, leaf cluster frequency and leaf frequency are all lower in the east (higher nutrient) region than in the west region; and (2) epiphyte biomass and epiphyte load are higher in the east than in the west. Regional nutrient status was a poor predictor of most of the parameters measured, with the opposite trends to those predicted often occurring. Plant biomass, canopy structure and epiphyte biomass appear to be a result of several site-specific factors that are not fully understood at this time. The results of the present study have significant implications for making generalised predictions and for monitoring A. antarctica on urbanised coasts, and will also be useful for informing ecological studies on plant–epiphyte and plant–animal interactions in A. antarctica ecosystems.
Additional keywords: epiphyte load, Gulf St Vincent, plant morphology, seagrass monitoring, South Australia.
Acknowledgements
The Natural Heritage Trust provided funding. Special thanks go to Dennis Gonzalez for processing most of the samples. Thanks also go to Mandee Theil, Jodi Lill, Greg Collings, Yvette Eglinton and Lisa Cousins for field and laboratory assistance. Thanks go to Mike Steer and Greg Collings for fruitful discussions about Amphibolis, sampling and analysis. Jason Tanner, Ib Svane, Greg Collings, two anonymous reviewers and the Editor of MFR provided many useful comments on draft versions of the manuscript. Seagrass was collected under a general exemption held by SARDI Aquatic Sciences.
Bryars, S. , and Wear, R. (2008). Investigator Group Expedition 2006: seagrasses of the Investigator Group region: Posidonia meadow condition in a pristine offshore marine environment. Transactions of the Royal Society of South Australia 132, 75–88.
Collier, C. J. , Lavery, P. S. , Masini, R. J. , and Ralph, P. J. (2007). Morphological, growth and meadow characteristics of the seagrass Posidonia sinuosa along a depth-related gradient of light availability. Marine Ecology Progress Series 337, 103–115.
| Crossref | GoogleScholarGoogle Scholar |
Connell, S. D. , Russell, B. D. , Turner, D. J. , Shepherd, S. A. , and Kildea, T. , et al. (2008). Recovering a lost baseline: missing kelp forests from a metropolitan coast. Marine Ecology Progress Series 360, 63–72.
| Crossref | GoogleScholarGoogle Scholar |
Horinouchi, M. (2007). Review of the effects of within-patch scale structural complexity on seagrass fishes. Journal of Experimental Marine Biology and Ecology 350, 111–129.
| Crossref | GoogleScholarGoogle Scholar |
Moltschaniwskyj, N. A. , and Pecl, G. T. (2003). Small-scale spatial and temporal patterns of egg production by the temperate loliginid squid Sepioteuthis australis. Marine Biology 142, 509–516.
Peterson, C. H. , Luettich, R. A. , Micheli, F. , and Skilleter, G. A. (2004). Attenuation of water flow inside seagrass canopies of differing structure. Marine Ecology Progress Series 268, 81–92.
| Crossref | GoogleScholarGoogle Scholar |
Russell, B. D. , Elsdon, T. S. , Gillanders, B. W. , and Connell, S. D. (2005). Nutrients increase epiphyte loads: broad-scale observations and an experimental assessment. Marine Biology 147, 551–558.
| Crossref | GoogleScholarGoogle Scholar |
Steer, M. A. , and Moltschaniwskyj, N. A. (2006). The effects of egg position, egg mass size, substrate and biofouling on embryo mortality in the squid Sepioteuthis australis. Reviews in Fish Biology and Fisheries 17, 173–182.
| Crossref | GoogleScholarGoogle Scholar |
![](../../media/share/OpenURL_Image.gif)
Udy, J. W. , and Dennison, W. C. (1997). Growth and physiological responses of three seagrass species to elevated sediment nutrients. Journal of Experimental Marine Biology and Ecology 217, 253–277.
| Crossref | GoogleScholarGoogle Scholar |
![](../../media/share/OpenURL_Image.gif)
Underwood, A. J. (1981). Techniques of analysis of variance in experimental marine biology and ecology. Oceanography and Marine Biology: an Annual Review 19, 513–605.
![](../../media/share/OpenURL_Image.gif)
Verduin, J. J. , and Backhaus, J. O. (2000). Dynamics of plant–flow interactions for the seagrass Amphibolis antarctica: field observations and model simulations. Estuarine, Coastal and Shelf Science 50, 185–204.
| Crossref | GoogleScholarGoogle Scholar |
![](../../media/share/OpenURL_Image.gif)
Walker, D. I. (1985). Correlations between salinity and growth of the seagrass Amphibolis antarctica (Labill.) Sonder & Aschers., in Shark Bay, Western Australia, using a new method for measuring production rate. Aquatic Botany 23, 13–26.
| Crossref | GoogleScholarGoogle Scholar |
![](../../media/share/OpenURL_Image.gif)
Walker, D. I. , and McComb, A. J. (1988). Seasonal variation in the production, biomass and nutrient status of Amphibolis antarctica (Labill.) Sonder ex Aschers. and Posidonia australis Hook. F. in Shark Bay, Western Australia. Aquatic Botany 31, 259–275.
| Crossref | GoogleScholarGoogle Scholar |
![](../../media/share/OpenURL_Image.gif)
Walker, D. I. , and McComb, A. J. (1992). Seagrass degradation in Australian coastal waters. Marine Pollution Bulletin 25, 191–195.
| Crossref | GoogleScholarGoogle Scholar |
![](../../media/share/OpenURL_Image.gif)
Wood, N. , and Lavery, P. (2000). Monitoring seagrass ecosystem health – the role of perception in defining health and indicators. Ecosystem Health 6, 134–148.
| Crossref | GoogleScholarGoogle Scholar |
![](../../media/share/OpenURL_Image.gif)