Spatial variation in the structure of mangrove forests with respect to seawalls
C. Heatherington A and M. J. Bishop A B
+ Author Affiliations
- Author Affiliations
A Department of Biological Sciences, Macquarie University, Sydney, New South Wales, Australia.
B Corresponding author. Email: melanie.bishop@mq.edu.au
Marine and Freshwater Research 63(10) 926-933 https://doi.org/10.1071/MF12119
Submitted: 30 April 2012 Accepted: 14 September 2012 Published: 23 October 2012
Abstract
Artificial structures, such as seawalls, are increasingly disrupting the transition zones between terrestrial and marine systems. They can impede the transport of resources across habitat boundaries and impact adjacent sedimentary ecosystems by modifying hydrodynamics which, in turn, influence sedimentology and erosion. We assessed how structural elements of Avicennia marina mangrove forests along the Parramatta River estuary, Sydney, Australia, differ in the presence or absence of a seawall on the landward side of the forest. These forests are of importance to resident and transient fauna. Sampling of paired mangrove forests, with and without seawalls, supported our hypotheses of structural differences between them. Mangrove forests with seawalls were in some instances less than a third of the width of unconstrained mangrove forests, and had up to twice the pneumatophore density. They often contained less leaf litter and had fewer saplings than forests without seawalls. These results suggest that as shoreline armouring continues, urban mangrove forests and their important ecosystem functions may be negatively impacted. Studies are now needed to ascertain the mechanisms by which seawalls modify these systems.
Additional keywords : bulkhead, coastal engineering, coastal squeeze, revetment, urbanisation.
References
AECOM (2010). ‘Parramatta River estuary processes study.’ (AECOM: Sydney.)Airoldi, L., Abbiati, M., Beck, M. W., Hawkins, S. J., Jonsson, P. R., Martin, D., Moschella, P. S., Sundelöf, A., Thompson, R. C., and Åberg, P. (2005). An ecological perspective on the deployment and design of low-crested and other hard coastal defense structures. Coastal Engineering 52, 1073–1087.
| An ecological perspective on the deployment and design of low-crested and other hard coastal defense structures.Crossref | GoogleScholarGoogle Scholar |
Alongi, D. M. (2008). Mangrove forests: resilience, protection from tsunamis, and responses to global climate change. Estuarine, Coastal and Shelf Science 76, 1–13.
| Mangrove forests: resilience, protection from tsunamis, and responses to global climate change.Crossref | GoogleScholarGoogle Scholar |
Barbier, E. B., Hacker, S. D., Kennedy, C., Koch, E. W., Stier, A. C., and Silliman, B. R. (2011). The value of estuarine and coastal ecosystem services. Ecological Monographs 81, 169–193.
| The value of estuarine and coastal ecosystem services.Crossref | GoogleScholarGoogle Scholar |
Bishop, M. J., Byers, J. E., Marcek, B. J., and Gribben, P. E. (2012). Density-dependent facilitation cascades determine epifaunal community structure in temperate Australian mangroves. Ecology 93, 1388–1401.
| Density-dependent facilitation cascades determine epifaunal community structure in temperate Australian mangroves.Crossref | GoogleScholarGoogle Scholar |
Boorman, L. A. (1992). The environmental consequences of climatic change on British salt marsh vegetation. Wetlands Ecology and Management 2, 11–21.
| The environmental consequences of climatic change on British salt marsh vegetation.Crossref | GoogleScholarGoogle Scholar |
Bozek, C., and Burdick, D. (2005). Impacts of seawalls on saltmarsh plant communities in the Great Bay Estuary, New Hampshire USA. Wetlands Ecology and Management 13, 553–568.
| Impacts of seawalls on saltmarsh plant communities in the Great Bay Estuary, New Hampshire USA.Crossref | GoogleScholarGoogle Scholar |
Bulleri, F. (2005). The introduction of artificial structures on marine soft- and hard-bottoms: ecological implications of epibiota. Environmental Conservation 32, 101–102.
| The introduction of artificial structures on marine soft- and hard-bottoms: ecological implications of epibiota.Crossref | GoogleScholarGoogle Scholar |
Bulleri, F., and Chapman, M. G. (2010). The introduction of coastal infrastructure as a driver of change in marine environments. Journal of Applied Ecology 47, 26–35.
| The introduction of coastal infrastructure as a driver of change in marine environments.Crossref | GoogleScholarGoogle Scholar |
Chapman, M. G., and Blockley, D. G. (2009). Engineering novel habitats on urban infrastructure to increase intertidal biodiversity. Oecologia 161, 625–635.
| Engineering novel habitats on urban infrastructure to increase intertidal biodiversity.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD1MrlsF2htA%3D%3D&md5=c9e4ad82dbf81e939bc7f91f5f87a4f2CAS |
Chapman, M. G., and Bulleri, F. (2003). Intertidal seawalls– new features of landscape in intertidal environments. Landscape and Urban Planning 62, 159–172.
| Intertidal seawalls– new features of landscape in intertidal environments.Crossref | GoogleScholarGoogle Scholar |
Chapman, M. G., and Underwood, A. J. (2011). Evaluation of ecological engineering of “armoured” shorelines to improve their value as habitat. Journal of Experimental Marine Biology and Ecology 400, 302–313.
| Evaluation of ecological engineering of “armoured” shorelines to improve their value as habitat.Crossref | GoogleScholarGoogle Scholar |
Clarke, P. J., and Myerscough, P. J. (1993). The intertidal distribution of the grey mangrove (Avicennia marina) in southeastern Australia: the effects of physical conditions, interspecific competition and predation on propagule establishment and survival. Australian Journal of Ecology 18, 307–315.
| The intertidal distribution of the grey mangrove (Avicennia marina) in southeastern Australia: the effects of physical conditions, interspecific competition and predation on propagule establishment and survival.Crossref | GoogleScholarGoogle Scholar |
Dahdouh-Guebas, F., De Bondt, R., Abeysinghe, P. D., Kairo, J. G., Cannicci, S., Triest, L., and Koedam, N. (2004). Comparative study of the disjunct zonation pattern of the grey mangrove Avicennia marina (Forsk.) Vierh. in Gazi Bay (Kenya). Bulletin of Marine Science 74, 237–252.
Dahdouh-Guebas, F., Kairo, J. G., De Bondt, R., and Koedam, N. (2007). Pneumatophore height and density in relation to micro-topography in the grey mangrove Avicennia marina. Belgian Journal of Botany 140, 213–221.
Dick, T. M., and Osunkoya, O. O. (2000). Influence of tidal restriction floodgates on decomposition of mangrove litter. Aquatic Botany 68, 273–280.
| Influence of tidal restriction floodgates on decomposition of mangrove litter.Crossref | GoogleScholarGoogle Scholar |
Dugan, J. E., Hubbard, D. M., Rodil, I. F., Revell, D. L., and Schroeter, S. (2008). Ecological effects of coastal armoring on sandy beaches. Marine Ecology (Berlin) 29, 160–170.
| Ecological effects of coastal armoring on sandy beaches.Crossref | GoogleScholarGoogle Scholar |
Harmsworth, G. C., and Long, S. P. (1986). An assessment of saltmarsh erosion in Essex, England, with reference to the Dengie Peninsula. Biological Conservation 35, 377–387.
| An assessment of saltmarsh erosion in Essex, England, with reference to the Dengie Peninsula.Crossref | GoogleScholarGoogle Scholar |
Harris, J. H. (1981). Study to determine the impact of landward bulkheads or alternative structures on marshes. National Marine Fisheries Service, Gloucester, Massachusetts, USA.
Hoffmans, G., Akkerman, G. J., Verheij, H., van Hoven, A., and van der Meer, J. W. (2008). The erodibility of grassed inner dike slopes against wave overtopping. In ‘Proceedings of 31st Conference on Coastal Engineering, Hamburg, Germany’. pp. 3224–3236. (World Scientific Publishing: Singapore.)
Hughes, R. G., and Paramor, O. A. L. (2004). On the loss of saltmarshes in south-east England and methods for their restoration. Journal of Applied Ecology 41, 440–448.
| On the loss of saltmarshes in south-east England and methods for their restoration.Crossref | GoogleScholarGoogle Scholar |
Huisman, T., Van Langevelde, F., and De Boer, W. F. (2009). Local positive feedback and the persistence and recovery of fringe Avicennia marina (Forssk.) Vierh. mangroves. Wetlands Ecology and Management 17, 601–611.
| Local positive feedback and the persistence and recovery of fringe Avicennia marina (Forssk.) Vierh. mangroves.Crossref | GoogleScholarGoogle Scholar |
Jackson, A. C., and McIlvenny, J. (2011). Coastal squeeze on rocky shores in northern Scotland and some possible ecological impacts. Journal of Experimental Marine Biology and Ecology 400, 314–321.
| Coastal squeeze on rocky shores in northern Scotland and some possible ecological impacts.Crossref | GoogleScholarGoogle Scholar |
Keddy, P. A. (1985). Wave disturbance on lakeshores and the within-lake distribution of Ontario’s Atlantic coastal plain flora. Canadian Journal of Botany 63, 656–660.
| Wave disturbance on lakeshores and the within-lake distribution of Ontario’s Atlantic coastal plain flora.Crossref | GoogleScholarGoogle Scholar |
Kennedy, C. W., and Bruno, J. F. (2000). Restriction of the upper distribution of New England cobble beach plants by wave-related disturbance. Journal of Ecology 88, 856–868.
| Restriction of the upper distribution of New England cobble beach plants by wave-related disturbance.Crossref | GoogleScholarGoogle Scholar |
Lin, B. B., and Dushoff, J. (2004). Mangrove filtration of anthropogenic nutrients in the Rio Coco Solo, Panama. Management of Environmental Quality 15, 131–142.
| Mangrove filtration of anthropogenic nutrients in the Rio Coco Solo, Panama.Crossref | GoogleScholarGoogle Scholar |
Martínez, M. L., Intralawan, A., Vazquez, G., Perez-Maqueo, O., Sutton, P., and Landgrave, R. (2007). The coasts of our world: ecological, economic and social importance. Ecological Economics 63, 254–272.
| The coasts of our world: ecological, economic and social importance.Crossref | GoogleScholarGoogle Scholar |
Morrisey, D. J., Swales, A., Dittmann, S., Morrison, M. A., Lovelock, C. E., and Beard, C. M. (2010). The ecology and management of temperate mangroves. Oceanography and Marine Biology 48, 43–160.
| The ecology and management of temperate mangroves.Crossref | GoogleScholarGoogle Scholar |
Nagelkerken, I., Blaber, S. J. M., Bouillon, S., Green, P., Haywood, M., Kirton, L. G., Meynecke, J. O., Pawlik, J., Penrose, H. M., Sasekumar, A., and Somerfield, P. J. (2008). The habitat function of mangroves for terrestrial and marine fauna: a review. Aquatic Botany 89, 155–185.
| The habitat function of mangroves for terrestrial and marine fauna: a review.Crossref | GoogleScholarGoogle Scholar |
Nicastro, A., Onoda, Y., and Bishop, M. J. (2012). Direct and indirect effects of tidal elevation on eelgrass decomposition. Marine Ecology Progress Series 456, 53–62.
| Direct and indirect effects of tidal elevation on eelgrass decomposition.Crossref | GoogleScholarGoogle Scholar |
NSW DNR (2006). Estuaries in NSW. http://www.dnr.nsw.gov.au/estuaries/inventory/index_ns.shtml [Accessed 13 November 2010].
Polis, G. A., Anderson, W. B., and Holt, R. D. (1997). Toward an integration of landscape ecology and food web ecology: the dynamics of spatially subsidized food webs. Annual Review of Ecology and Systematics 28, 289–316.
| Toward an integration of landscape ecology and food web ecology: the dynamics of spatially subsidized food webs.Crossref | GoogleScholarGoogle Scholar |
Reice, S. R., Spira, Y., and Por, F. D. (1984). Decomposition in the mangal of Sinai: the effects of spatial heterogeneity. In ‘Hydrobiology of the Mangal’. (Eds F. D. Por and I. Dor.) pp. 193–200 (Dr W. Junk: The Hague: The Netherlands.)
Rogers, K., Wilton, K. M., and Saintilan, N. (2006). Vegetation change and surface elevation dynamics in estuarine wetlands of southeast Australia. Estuarine, Coastal and Shelf Science 66, 559–569.
| Vegetation change and surface elevation dynamics in estuarine wetlands of southeast Australia.Crossref | GoogleScholarGoogle Scholar |
Saintilan, N., and Williams, R. J. (1999). Mangrove transgression into saltmarsh environments in South-East Australia. Global Ecology and Biogeography 8, 117–124.
| Mangrove transgression into saltmarsh environments in South-East Australia.Crossref | GoogleScholarGoogle Scholar |
Saintilan, N., and Williams, R. J. (2000). The decline of saltmarshes in southeast Australia: results of recent surveys. Wetlands 18, 49–54.
Sheaves, B., and Molony, B. (2000). Short-circuit in the mangrove food chain. Marine Ecology Progress Series 199, 97–109.
| Short-circuit in the mangrove food chain.Crossref | GoogleScholarGoogle Scholar |
Shutes, R. B. E. (2001). Artificial wetlands and water quality improvement. Environment International 26, 441–447.
| Artificial wetlands and water quality improvement.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3MXkslOju7s%3D&md5=93ec1733668357d296d0acd7ce9b6bf8CAS |
Toma, T., Nakamura, K., Patanaponpaiboon, P., and Ogino, K. (1991). Effect of flooding water level and plant density on growth of pneumatophores of Avicennia marina. Tropics 1, 75–82.
| Effect of flooding water level and plant density on growth of pneumatophores of Avicennia marina.Crossref | GoogleScholarGoogle Scholar |
Underwood, A. J. (1994). On Beyond BACI: sampling designs that might reliably detect environmental disturbances. Ecological Applications 4, 3–15.
| On Beyond BACI: sampling designs that might reliably detect environmental disturbances.Crossref | GoogleScholarGoogle Scholar |
Underwood, A. J., and Chapman, M. G. (1997). Statistical program GMAV.5 for Windows. Institute of Marine Ecology, University of Sydney, Australia.
Wolters, M., Bakker, J. P., Bertness, M. D., Jefferies, R. L., and Moller, I. (2005). Saltmarsh erosion and restoration in south-east England: squeezing the evidence requires realignment. Journal of Applied Ecology 42, 844–851.
| Saltmarsh erosion and restoration in south-east England: squeezing the evidence requires realignment.Crossref | GoogleScholarGoogle Scholar |
Wong, P. P. (2003). Where have all the beaches gone? Coastal erosion in the tropics. Singapore Journal of Tropical Geography 24, 111–132.
| Where have all the beaches gone? Coastal erosion in the tropics.Crossref | GoogleScholarGoogle Scholar |
