Coral reefs are highly diverse, highly productive ecosystems. They are able to support huge, intricate food webs, from tiny microorganisms that live within and build the reef, to top level predators, thereby supporting a high biomass. In so doing, coral reefs contribute an estimated US$ 375 billion annually, in terms of their value to the biosphere. Coral reefs also provide a wealth of functions, ecological services and goods to people in coastal areas, including food security for millions of people in coastal communities. As a result, they are considered “one of the essential global life support systems necessary for food production, health and other aspects of human survival and sustainable development” (UNEP/IUCN 1988).
Owing to their valuable resources, coral reefs support vast fisheries in many parts of the world. However, as the global human population continues to rise, particularly in coastal areas, harvesting effort on coral reefs is increasing at an unsustainable rate. In addition, coral reefs face severe threat from climate related sea temperature rise and ocean acidification. Consequently, many coral species face a high risk of extinction. By 2008, an estimated 19% of the world’s coral reefs had already been ‘effectively lost’, meaning that they are comprised of few live corals, and have been seriously overfished, with few large predators and algal grazing fish. A further 15% is thought to be in a ‘critical’ state, and may become ‘effectively lost’ within the next two decades, while 20% is considered to be in a ‘threatened’ state, with potential loss in the next 20 to 40 years.
Coral Reefs of East Africa
The coral reefs of East Africa contribute significantly to coastal productivity in the south Western Indian Ocean. These reefs have long provided valuable resources for coastal communities, including a rich source of food and foreign currency generation through tourism, and a large number of people depend on these resources for their livelihoods. Coral reefs support an estimated 7 million people in coastal communities in Mozambique, as well as major artisanal fisheries and tourism industries in Tanzania and Kenya. However, East Africa’s coral reefs have suffered high levels of bleaching and are under severe threat, with some of the greatest proportions of “critical stage” coral reefs worldwide. Overfishing and destructive fishing can have detrimental impacts on coral reef ecosystems. Major ecological impacts can occur through overfishing, such as changes in community structure where the removal of algal grazers can result in coral communities being replaced by algae. Destructive fishing practices, such as blast fishing and netting, can have devastating effects on the fish community and on the coral reef itself. These activities have resulted in severe reductions in biomass (sizes and numbers) and changes in fish community structure in this region.
We don’t have the data to understand ecosystem changes
Despite the high value and high level of dependence on these resources, little scientific work has focused on quantitative assessment of the effects of human activities on these coral reefs, and the magnitudes and effects of such impacts remain largely quantified. Furthermore, fisheries management efforts in East African countries are hindered by a lack of accurate catch data, and monitoring and assessments of coral reefs are often based on data collected on small geographic areas that are not representative of the entire region. This needs to change and is why the African Marine MegaTransect Expedition is such a vital initiative in the region.
According to the UN Sustainable Development Goals (SDGs) the following targets are to be met:
- (14.1) By 2025, prevent and significantly reduce marine pollution of all kinds.
- (14.2) By 2020, sustainable manage and protect marine and coastal ecosystems.
- (14.4) By 2020, minimize impacts of ocean acidification at all levels through scientific cooperation.
- (14.5) By 2020, Conserve at least 10% of coastal and marine areas, based on best available scientific information.
- (14.B) Increase scientific knowledge, develop research capacity in order to improve ocean health.
- (14.C) Enhance the conservation and sustainable use of the oceans and their resources.
Watch the trailer of the new series Ocean Warriors, where Mike Markovina and JD Kotze work with the Tanzanian Multi-Agency Task Team (MATT) to fight blast fishing activities. The series highlights the devastation the coral reefs in Tanzania are facing. The African Marine MegaTransect is imperative in quantifying this destruction and to find solutions to save it.