Photo byORI
Loss of Coastal and Marine Biodiversity
There are many threats to biodiversity and habitat loss, not all directly attributable to human activities. A number of naturally occurring events such as tropical cyclones, storm surges, tsunamis and eruptions can cause, albeit temporarily, massive loss of habitat and disruption to the abundance and life cycles of species. However, human activities generally result in more significant, persistent and permanent impacts. It is therefore important that we understand the environmental impact of our actions so as to mitigate and minimise these.
Photo byKierran Allen
Development Pressure
Coastal lands are used for a range of activities, including human settlement, agriculture, trade and user amenities. They are also used as a base for a range of maritime activities such as shipping, fishing and mining. The coast is a favoured residential and holiday destination, resulting in it being under constant pressure for development. Coastal managers and planners need to identify areas and corridors for coastal conservation that are "no go" development areas. Not only will this ensure the natural functioning of the coastal zone, it will also ensure that the developments and infrastructure themselves are not damaged by natural coastal processes.
Photo byORI
Coastal Pollution and Litter
The marine environment has an amazing capacity to assimilate man’s waste and has been doing so for centuries. However, there are absolute limits to the quantities, concentrations and the nature of the waste. Exceed any of these and the entire assimilative capacity can be destroyed and pollution results. The negative impacts of pollution on the KZN coast is an ongoing concern and it is thus important to assess, monitor and predict the impacts of pollutants on South African marine ecosystems to ensure long term sustainability of their resources.
Photo bySimon Bundy
Climate Change
Climate change is no longer an abstract topic debated by a fringe group of scientists; the evidence of climate change is unequivocal. In view of its serious global impact, the UN established a team of top international scientists to objectively evaluate all available climate data. This Intergovernmental Panel on Climate Change (IPCC) first met in 1988 and periodically produces definitive assessment reports, progressively reflecting improvements in data collection. The effects of climate change are very real for the marine and coastal environments and the livelihoods of many, coastal KZN included.
Photo bySimon Bundy
Coastal Hazards
Coastal hazards can result in loss of infrastructure, properties, resources and unique coastal habitats. The risk of vulnerability is exacerbated by the combination of development pressures and stressed ecosystems. Coupled with the predicted effects of climate change, the effects of hazard events become significantly higher and more costly to manage. The effects of sea-level rise and coastal erosion are of particular concern for KZN.
Photo byBronwyn Goble
Sand Mining in Estuaries
Sandy beaches are dynamic ecosystems with sand continuously on the move and in need of replenishment. The deposition of new sand on the beaches of KZN is derived from riverine sources via its 76 estuaries. Interruption of the supply of sand and beach nourishment causes beaches to fade and disappear over time. Port cities such as Durban know only too well what happens when the natural supply of sand to their beaches is compromised. However, the construction industry values this supply of clean sand, and often “mine” their sand from environmentally vulnerable estuaries. This sand mining has contributed to the reduction of natual buffers, predisposing sections of the coastline to damage from increasingly variable seas and storm surge events, and impacts on the biological function of estuaries has also been recorded. Estuarine sand mining needs to be better managed and preferably, other terrestrial sources of sand should be utilised.
Photo byCamilla Floros
Species at Risk
The marine and coastal environment of KZN is enormously rich and diverse in plant and animal species. Marine species are generally considered to have low risk of extinction because of the size of the world’s oceans which create large continuous habitats, and due to the open nature of marine habitats and the life-history characteristics of many marine species. This is no basis for complacency, as various threats to our marine fauna and flora exist, and critical population declines of marine species have occurred. A considerable number of KZN species are vulnerable including sawfishes, several sharks, the coelacanth, and one species of sea turtle.
Contributors
ORI • University of KwaZulu Natal • eThekwini Municipality • University of Ulster
Research Funders
EDTEA • ORI
Acknowledgements
Bronwyn Goble • Rudy van der Elst • Mariana Tomalin • Alan Smith • Andrew Mather • Andrew Cooper