Why marine protected
areas need expansion
Philippine coral reefs provide many ecosystem services to our people, especially those living in coastal areas, including 20 to 30 percent of the total capture fisheries. They are also home to more than 500 species of corals and a few thousand fish species, both of which help make the country well known for its mega-biodiversity. And this biodiversity is one major reason why the country has become a tourist attraction.
A coral reef with good coral cover and moderate to high rugosity provides 15-30 metric tons of fish belonging to all trophic levels without human input other than protection from fishing, as well as other fishery and related products per year.
Unfortunately, less than 10 percent of the 25,000 sq km of Philippine reefs are in the state of good health and have “good to excellent” coral cover, thus severely reducing their fishery production potential.
It is not surprising, therefore, to find that degraded reefs have, at present, very low fish abundance and very low fish biomass--- 5 to 20 tons/sq km--- in contrast to pristine reefs in the 1930s and 1940s, which had about 100 tons/sq. km on the average (e.g. Tubbataha Reefs).
Under such conditions, small-scale fishers cannot be expected to have substantial fish catches. Catch rates of hook and line fishers at the present time in coastal areas without MPAs average 0.5 kg/person/per hour. This contrasts with catch per unit effort of 1 to 1.5 or even more kg/per person per hour in areas immediately outside the boundaries of no-take MPAs.
Fully protected no-take MPAs, which are a popular and widely accepted strategy for marine resource protection and management, increase fishery yields. No-take MPAs build up large biomass and large fish abundance over decades of full protection. Our experience shows that fish biomass in MPAs, such as Sumilon and Apo, reach 100-160 metric tons per sq km, approximating those of pristine reefs in the early 1900s.
The larger catch per unit effort of hook and line fishers, and the stable fish catch of 15-20 metric tons at Apo fished area, is in part due to the spillover of adult fish from the no-take reserve to the fished area, based on our research findings. But this spillover can take place only if large biomass of fish exists in the no-take MPA.
In fact, not only adult fish but also fish larvae are exported from the no-take reserves to areas outside of these reserves, thus sustaining high fishery yields from coral reefs.
For areas in the country that have low fish abundance (and there are many such areas), there is a need to set up no-take MPAs or networks of them throughout the country for the purpose of building large biomass of fish in these no-take MPAs, thus ensuring export of fish outside the MPAs for fishers to catch.
It is very important that governments (local and national) invest large amounts of money for the purpose of establishing fully protected no-take MPAs and networks of marine protected areas to avert a fishery crisis in the future.
At this time, only 5 percent of the 25,000 sq km of coral reefs (=1,250 sq km) have varying levels of protection from fishing. The biomass and abundance of fish in the 1,600 MPAs in the country at present is generally not known except, those in the Visayas, where only about 30 percent of the 564 MPAs have relatively moderate to high fish biomass. Those with fairly high biomass are probably exporting adult fish to fished areas and enhancing fish catches of fishers.
What is urgently needed is to establish at least 20 percent or 5,000 sq km of fully protected areas in order to keep the integrity of our coral reef ecosystem and to attain the full potential for reef fishery production and biodiversity conservation. But this is only possible if government invests more funds for the program on no-take MPAs and networks of MPAs.*