Marine Environment
Author: Dr Samantha Petersen - Senior programme manager:Marine WWF-SA
( Article Type: Explanation )
The state of our oceans
The challenge South Africa is strongly influenced by the characteristics of its oceans. The confluence of two great currents, the cold Benguela Current on the west coast and the warm Agulhas Current on the east coast, contributes to the high levels of marine biodiversity and the numbers of species found nowhere else, also referred to as endemic species. These waters provide many economic goods and services, including an important source of protein and income to many coastal communities and a source of enjoyment and recreation to the broader South African public.
Our oceans and coastline are facing a number of key threats, but most notable is the threat of over-fishing. The proportion of over-exploited or depleted fish stocks increased from 10% in 1974 to 32% in 2008, bringing the proportion of global stocks fished to their limit or beyond to 85%. At present the demand for seafood is at an all-time high with a per capita consumption of 17.2kg recorded in 2009. As many bycatch species are top marine predators, the unmonitored and uncontrolled discarding of these animals can have knock-on impacts on the functioning of marine ecosystems. Furthermore, many fishing techniques such as trawling, directly impact marine habitats. South Africa has a long history of responsible fisheries management with some excellent examples of successful management that include many of the more industrialised fisheries such as the large and small pelagic, and trawl fisheries. Remaining challenges in this sector revolve primarily around the need for the implementation of an Ecosystemic Approach to Fisheries management including bycatch and spatial management in particular.
However, the inshore fisheries resources are in a state of crisis. These coastal ecosystems are also the most diverse, many inshore species have vulnerable life histories or biology and the zone is easily accessible by multiple users. Other challenges to responsible fisheries management include limited information and the lack of updated stock assessments on which to base management, complicated political agendas, the sector being poorly organized and limited compliance and enforcement with a strong incentive to cheat due to the social and economic status of many fishing communities who are heavily dependent on these resources for their food security and livelihood.
Aquaculture, which is often heralded as the solution to overfishing, is growing rapidly. However, while it has the potential to meet global food (protein) security needs it has a number of environmental challenges. One of the major challenges is that aquaculture is a strong driver of fishing pressure – 80% of all fish oil and 60% of all fish meal produced by wild capture fisheries is used to feed fish in aquaculture production worldwide. Coupled with this is large scale habitat and genetic loss as well as disease and impact on freshwater supplies. Aquaculture is a relatively new and small industry in South Africa which presents an ideal opportunity to engage with the sector to develop in a responsible manner from the outset. This sector been identified by the Department of Agriculture, Forestry and Fisheries as a priority for growth and job creation. Habitat damage and fragmentation of important ecosystems are further key threats to the marine environment. A number of activities in the ocean impact on habitats or result in fragmentation of important habitats, including desalination plants, unregulated coastal development, diamond mining, oil and gas exploration and some fishing techniques such as bottom trawling or farming practises such as sea cage culture. Important habitats include estuaries, which include the portion of a river system that interacts with the sea and plays an important function in providing sheltered habitat or nursery areas for juvenile fish or fish larvae. Concern about the state of South Africa’s estuaries dates back to the 1970s, when few estuaries were found to be in their original state, especially in KwaZulu-Natal. However, overall the health of South Africa’s estuaries is considered relatively good with 59% in excellent or good condition, 25% in a fair condition, and 15% in a poor condition. Concerning though, is the level of management and protection afforded to South African estuaries which is low with only 41 estuaries included within protected areas, and 14 (5.4%) considered to have a sufficiently high level of protection.
This falls dramatically short of the recommended minimum target of 30% of estuaries protected (State of Estuaries Report 2004). Our oceans are also increasingly impacted by a number of sources of pollution including land-based effluent, rubbish, oil spilled during exploration and extraction or from vessels. Probably the most publically recognised is the effect of oil spills on marine wildlife especially seabirds and marine mammals including disasters such as the Exxon Valdez in 1989, more locally the Treasure oil spill in 2000 and the recent Gulf of Mexico disaster in 2010. Equally concerning are the increasing numbers of hypoxic areas or dead zones caused by eutrophication where high nutrient concentrations stimulate algal blooms which reduce water clarity, deplete oxygen and ultimately destroy the functioning of the ecosystem. The main cause of eutrophication is excess nitrogen run-off from farm fertilizers, sewage and industrial pollutants. Furthermore, the impacts of invasive species can be widespread and extremely damaging to native species and environments, humans, and the economy. For example, a study published in 2000 found that the environmental and other costs caused by the estimated 50,000 invasive species that have been introduced into the U.S. could be over US$137 billion per year. This is more than any other natural disasters combined. Alien species are typically introduced through ballast water, aquaculture or through the trade of seafood. A number of alien invasive species (10 confirmed extant alien and 22 cryptogenic species) have been recorded in South Africa. All 10 alien species now have well-established populations and the majority of these remain restricted in distribution to sheltered bays, estuaries and harbours. Only one species, the Mediterranean mussel Mytilus galloprovincialis, has spread extensively along the coast and caused significant ecological impacts. Considerable economic benefits have resulted from this invasion because M. galloprovincialis forms the basis of the South African mussel culture industry.
According to a UNESCO report, about 20-25 million tons of CO2 are being added to the oceans each day. This unprecedented amount of CO2 absorption will lead to increased acidity of the water and will threaten the survival of many marine species. This development in turn could disrupt marine food chains and alter ocean biogeochemistry in ways that are not yet understood or predictable. Such dramatic changes have not been observed for more than 20 million years of the earth’s history. As the other threats including over-fishing, habitat damage, pollution etc reduce the resilience of marine ecosystems so they become more vulnerable to the effects of global climate change.
The Response: Ecosystems Approach to Fisheries (EAF) The EAF is an approach enshrined in the UN Law of the Sea (UNCLOS) and was adopted by the United Nations Food and Agriculture Organisation (FAO) in 2003. The overarching aim of the EAF is to protect marine ecosystems, including their human components, as a whole. This approach balances the multiple needs and desires of all who use, enjoy and depend on the ocean, both now and in the future. This approach provides a framework for addressing some of the key challenges highlighted above, including over-fishing, habitats, alien invasive species, pollution, climate etc. in a holistic manner. The importance of applying an ecosystemic approach to fisheries management is now widely recognized worldwide, and South Africa, along with many other nations, committed to implementing the EAF at the World Summit on Sustainable Development held in Johannesburg in 2002.
Spatial management of our oceans: As traditional marine management systems are failing to maintain the productivity and biodiversity of marine ecosystems, Marine Protected Areas (MPAs) are being increasingly implemented to protect ecosystems and habitats which - amongst other things - support and maintain the diversity of commercially and ecologically important species. Currently 22% of the South African coastline is protected by MPAs, 9% of which consists of no-take protected areas, while 13% of the coast is protected through a variety of different zonations that restrict fishing effort to some degree. The Department of Environmental Affairs’ (DEA) objective is to achieve the implementation of no-take reserves across 20% of the Exclusive Economic Zone (EEZ). Currently only 0.4% of South Africa’s EEZ is protected by MPAs. The National Protected Area Expansion Strategy sets targets for the implementation of MPA’s to ensure a fully representative suite of protected areas that cover all coastal and offshore habitats.
Consumer awareness, eco-labels and seafood market transformation: Coupled with increasing consumer and retailer awareness of environmental and sustainability issues is an increasing demand for environmentally friendly and sustainable seafood products. Recognising that this growing market represents a very powerful force in shaping what happens out at sea, over the last decade a number of global conservation initiatives have been developed to harness the power of the market and incentivise responsible fisheries and suppliers. By providing retailers, restaurants and consumers with information about the relative sustainability of their seafood choices, sustainable seafood initiatives have increasingly empowered consumers to make ocean-friendly choices. The last decade has seen a steady increase in the development of global eco-labelling organisations such as the Marine Stewardship Council (MSC) and more recently, the Aquaculture Stewardship Council (ASC). Unlike sustainable seafood initiatives including SASSI (Southern African Sustainable Seafood Initiative) - which provide broad information for all seafood species on the market - eco-labels provide consumers with the assurance of sustainability by certifying that the source fishery has met the organisation’s standard for a sustainable seafood product. This also provides an important tool to facilitate change in key fisheries through a market-based incentive. In many cases fish stocks are in a state of crisis because of an over-reliance on regulatory systems which have to a large extent failed to effectively and sustainably manage marine resources.
