- Coral Reef support rich life - Sarah Curran-Ragan
Destructive fishing practices in South East Asia have laid waste to vast areas of coral reefs in the most diverse marine region on Earth. Such destruction has caused heavy losses in fisheries, coastal protection and tourism generated by undamaged coral reefs. The tracts of coral rubble make recovery all but impossible, often taking decades for coral recruits to settle and recolonise. Threatened globally by pollution, overfishing and destructive fishing, disease and climate change, it has been estimated that 35% of coral reefs are under threat and that 19% are now considered non functional globally. In South East Asia estimates are much higher at 45% and 40% respectively.
Using Rehabilitation tfor Damaged Coral Reefs
In order to maintain and enhance damaged reefs, managers are increasingly turning to restoration and rehabilitation. There is a range of methods to rehabilitate coral reefs such as reef balls, artificial reefs, transplanting corals and electric fields to encourage coral growth. These methods all require research and expense. Coral reef managers further invest time and money into rehabilitating damaged areas of coral reef and by tackling destructive and illegal fishing. But how effective are they and where should managers be putting their dollar?
Reporting in Conservation Letters, Kelly Hansfield from The World Wildlife Fund in Washinton, and her team, compared the relative cost of reef rehabilitation to expenditure on enforcement activities. Most marine protected areas are underfunded so money is limited for all but essential activities and trade offs need to be made. Blast fishing is widespread in South East Asia where local fishers use home made bombs to detonate into schools of fish causing large areas of broken coral rubble. Blasted reefs can take decades to recover if they ever do so.
Enforcement More Cost Effective Than Rehabilitation of Coral Reefs
Hansfield and her team compared the cost effectiveness of protecting reefs through enforcement activities to that of stabilising blasted reefs with locally quarried rocks. The team modelled seven years of future coral growth and management costs. The results showed that preventing damage to reefs by enforcement activities is more effective than restoring reef habitat through restoration methods.
The team used two methods to assess their relative successes, one using a straight cost effectiveness economic analyses and another comparing cost per area. They found that enforcement activities in Komodo National Park are 5 times more cost effective and 70 times more effective when comparing cost per area than reef rehabilitation activities. Hansfield also found that unlike rehabilitation and restoration, enforcement costs were cheaper as they didn’t require the research required to undertake them that restoration activities did.
Enforcement also had effects on protecting local livelihoods through controlling illegal fishing and attracting continued tourism to undamaged reefs. “Rehabilitation” they say “must therefore be seen in a mosaic of management choices, taking into consideration the condition of the reef and available human and financial resources”. They further stress that their results are simplified since they focussed only on changes in coral cover and other issues such as education, monitoring and prevention should also be taken into account.
They point out that rehabilitation also provides critical habitat and can therefore improve fisheries production. The authors suggest that more cost effective rehabilitation needs to be considered by managers and that increasing investment in enforcement activities will “yield higher dividends” and improve marine resources.
Sources
Haisfield,M et al (2010) An ounce of prevention: cost effectiveness of coral reef rehabilition relative to enforcment. Conservation Letters. February 2010.
Sarah Curran-Ragan - Sarah Curran Ragan is a Marine Biologist with 20 years experience and has worked in the UK, The Philippines, Tanzania, Indonesia and ...
