Marine protected areas (MPAs) are one of the most widely used tools for conserving and managing marine areas including coral reefs. Each MPA is managed for conservation purposes based on a legal and institutional framework which outlines restrictions and controls on potentially damaging marine-based activities such as fishing, anchoring, tourism use (diving and snorkelling) and pollution. Although MPAs are not specifically designed for the conservation of coral reefs alone, they can offer protection to reefs by limiting their exposure to threats which may cause structural damage to the reef framework (e.g. careless anchoring and accidental breakage from contact with SCUBA-divers and snorkelers) as well as changes in population densities of predator and competitive species as a result of over-fishing. MPAs usually consist of a series of ‘zones’ which function as designated areas for activities with the aim of protecting the marine environment and separating conflicting activities. These zones tend to focus heavily on the restriction of fisheries.
Approximately 27% of the world’s coral reefs (67,350 km2 of an estimated 250,000 km2) are located within 2,679 MPAs. The remaining 73% of coral reefs lie outside MPAs and as a consequence do not receive any protection from any formal management framework. The extent of protection provided to coral reefs located within these MPAs, however, varies widely between MPAs due to their differing designs as well as the effectiveness of their implementation. In some support and/or they are ignored by local stakeholders with conflicting interests resulting in ineffective policies and MPAs. In other cases, MPAs may be considered extremely effective although their location is such that they were traditionally exposed to circumstances, MPAs exist only as ‘paper parks’ as their management framework is not enforced by implementing agencies often due to a lack of financial limited threats (e.g. far from human populations thus few people accessing and extracting resources from the area). This shows the poor placement of some MPAs.
A recent evaluation of the effectiveness of 1,147 of the 2,679 MPA which contain areas of coral reef shows that nearly half (47 percent) of these MPAs are ineffective in reducing over-fishing. This study also revealed that the greatest proportion of ineffective MPAs are located in the most threatened regions of world, for example, 69 percent of MPAs in Southeast Asia were rated as ineffective. Alarmingly, when these figures are considered in relations to total area of corals reefs that are locals within MPAs, only 6 percent of the world’s coral reefs lie in effectively managed MPAs while a further 13% are located with MPAs that are considered to be partially effective ineffective nature of these MPAs means that coral reefs continue to be exposed to threats from fisheries and other potentially damaging activities.
Other management frameworks and policies that benefit coral reefs
As well as the protection offered by MPA frameworks, coral reefs can benefit from a number of independently applied policies. For example, a number of laws and conventions control the discharge of waste from ships and pollutants released into the ocean from coastal industries and sewage works which can lessen the threat of changes in ocean chemistry resulting from marine pollution and effluent nutrient loading.
Coral reef conservation
Endangered Species International (ESI) is deeply involved in protecting and restoring coral reefs. ESI works in many fronts to promote effective coral reef and ocean conservation via strong innovative education, law enforcement, creation of marine protected areas, reforestation (reducing sedimentation flushing into ocean), and monitoring.
Other efforts to mitigate threats to coral reefs (and other marine resources) should also include promoting the sustainability of fisheries practices, increased stakeholder participation in marine resource management, creation of alternative livelihoods, and reducing human population.
The creation of alternative livelihood opportunities within coastal communities, in particular for the fisherfolk, can help in reducing pressure on coral reef ecosystems. The practice of seaweed farming to produce carrageenan (found in a huge range of products from ice-cream to shampoo) for international markets has been widely adopted by coastal communities throughout the Philippines and Indonesia as an alternative source of income to fishing.
Reef rehabilitation and restoration
As well as protecting coral reefs through MPAs and the creation of alternative livelihood opportunities, scientists have been working on methods to physically restore coral reef ecosystems using coral garden nurseries, coral transplants and the deployment of artificial structures as substrate for coral recruitment. Artificial structures include concrete-based Reef Beef balls and coral frames.
The process of restoring lost or destroyed coral reef habitats through coral gardening and transplantation occurs in two stages. Firstly, coral seedlings are reared in nurseries under controlled and favourable conditions until they reach a suitable size for planting. Secondly, these nursery-farmed coral colony seedlings are transplanted and attached onto the damaged reef framework where, if successful, they will continue to grow as part of the original framework.
The success rate of nursery rearing and transplantation of coral colonies can be highly variable. While there have been a number of recent advances in coral larvae rearing in nurseries, scientists are still uncertain of the long term success of coral transplantation in terms of their ability to survive and reproduce. Like in naturally occurring coral reef frameworks, coral larvae gardens and transplanted nursery grown coral are vulnerable to natural and human disturbances which can lead to detachment from the substrate or framework, tissue damage, bleaching and mortality. In light of this, coral transplantations should not take place in areas of absent or ineffective management plans.
Although restoration can enhance conservation efforts, reef restoration practices face regular criticism with regards to the impact on donor coral colonies as well as project costs and scale. While ‘corals of opportunities’ (live coral fragments that have naturally detached from the existing reef framework) may provide a source of materials for transplantation, it is unlikely that they will satisfy the full demand required for the reef restoration project, particularly when the project is for an extensive area of reef. The coral transplants must therefore be sourced elsewhere. Healthy reefs found close to the restoration site have regularly been used as donor reefs with up to 10% (maximum amount that is recommended to be removed) of coral colonies being extracted for transplantation. The removal of these coral fragments from donor reefs with little certainty of survival once transplanted could therefore represent a further loss of existing reef cover instead of the desired increase in coral cover. The development of coral nurseries has, however, helped lessen the pressure on existing donor reefs (Edwards and Fisk 2010) by providing a means for rearing coral fragments (initially sourced from ‘corals of opportunities’ or donor reefs) which go on to become the future source of transplants as their colonies grow in size.
To date, restoration projects have been small scale (mostly sub-hectare) with the ‘largest’ project restoring about 7 hectares. When the scale of these ‘large’ restoration projects are considered in relation to the total area of degraded reefs around the world they can appear insignificant.
Although restoration can enhance conservation efforts, restoration is always a poor second to the preservation of original habitats. The cost of restoring even a small area of coral reef can be extremely high. Where the reef framework remains intact providing suitable substrate for transplantation, the cost of transplanting corals over an area of 1 hectare will amount to tens of thousands of US dollars. Where physical restoration of the reef framework is required, transplantation costs increase 10- to 100-fold with recent data from ship-grounding sites in the Caribbean indicating restoration costs of approximately US$2–6.5 million per hectare. When the costs of restoring an area of coral reef is considered in comparison with the average costs of managing an MPA it is clear that coral reef management is a more cost effective tool for protecting coral reefs.
Approximately 19% of the world’s coral reefs are severely degraded representing an area of tens of thousands of square kilometres. In the Philippines for example only 1% of the coral reefs are in pristine state. As coral reefs are quickly disappearing, ESI cannot save coral alone, we need your help. JOIN US NOW TO SAVE CORAL REEFS!
ESI thanks Lucy Buckingham for her great research and compiling work, and Paddy Ryan and Pierre Fidenci for the use of their photographs.