The following are sections from Ugu Lwethu - Our Coast (Goble et al., 2014). Contributions are from a range of authors all of whom are credited per section.
The coastal environment is under constant pressure from coastal development, extraction of resources, erosion and pollution, to name a few. These in turn threaten coastal habitats, biodiversity and the sustainability of coastal resources. Potentially, these are exacerbated by the threats posed by climate change. This section provides an overview of some of the main pressures and threats facing the KZN coastal environment.
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 hurricanes, 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.
Photo: Bronwyn Goble
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 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.
Photo: Judy Mann
Photo: Simon Bundy
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.
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. Effects of sea-level rise and coastal erosion are of particular concern for KZN.
Sand Mining in Estuaries
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.
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. These create large continuous habitats, 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. Critical population declines of marine species have occurred.
Photo: Camilla Floros
Pressures and Threats PDF