Rationale and Introduction
The municipality of Siaton has one of the longest—if not the one with the longest—coastlines in Negros Oriental at about 51 km. The municipality is also blessed to have two bays, Tambobo and Siit Bay, which have big potential impacts to the economy of the municipality.
In this very long stretch of coastline, sadly, there are very few marine protected areas compared to the nearby town of Dauin, which has 9 MPAs in a coastline that’s about half of what Siaton is blessed with.
This report contains the results of the technical surveys conducted in Siaton last 2008. The data presented is part of a bigger study involving MPAs in the municipalities of Basay, Siaton, Zamboanguita and Dauin. It is hoped that the data presented herein can be of use for future coastal resource management initiatives and other development programs in the coastal zone of the municipality.
Study sites
The surveys for fish and coral were conducted from July-August 2008 in Siaton. The areas surveyed were Bonbonon MPA, Andulay-Siit MPA, and the Antulang proposed MPA ( see Fig.1). Each of these study areas had a corresponding nearby control site with similar reef topography.
The Andulay reserve was put up on 1993, and is currently managed by the Andulay Fisherfolk’s Association. The Bonbonon MPA was put up in 1995, is currently managed by the Bonbonon Fisherfolk’s Association. Both of these reserves were established during the CEMRINO and DED projects, who assisted the province in the establishment of MPAs during the 1990s. The Antulang proposed marine reserve was established in December 2007 by Dive Hub (a private resort); the resort is also managing and constantly guarding the reserve at present.
Materials and Methods
Standard survey methods for fish (Fish Visual Census) and corals (Point Intercept method) (English et al., 1997) were used in this survey. Fish pecies identification was confirmed using field guides (Allen and Steene 1997; Allen, Steene, Humann, and Deloach, 2003). Only easily visible, non-cryptic species were included. Corals were classified only according to life-forms (massive, branching, etc.) For each study area, a deep (10-12 m) and a shallow (3-5m) station was surveyed, each station composing of
three 50-m transects. The transects were laid out in a consistent depth following the contour of the reef, separated by 10 m in between transects.
Fish biomass was calculated using the formula: W= a x Lb, where a and b are constants that were obtained from FishBase 2000. Fish density is expressed as the average number of fish observed for 500 m2 in three transects. Fish were also categorized as target (those that are often targeted by fishers, such as parrotfishes (Scaridae), breams (Nemipteridae), fusiliers (Caesionidae), goatfishes (Mullidae), snappers (Lutjanidae), emperors (Lethrinidae), jacks (Carangidae) and groupers (Serranidae) among others. The last 4 families are considered as “Predators”. Non-target fish are butterflyfishes (Chaetodontidae), damselfishes (Pomacanthidae), angelfishes (Pomacentridae), wrasses (labridae), anthias (Anthininae), cardinalfishes (Apogonidae), and others.
For corals, percentage cover for a particular substrate was determined using the following formula: __number of substrate points_ ¬¬¬¬¬ x 100
Total number of points (100)
The category LHC or Live Hard Coral is determined by adding up the following catergories: CB (branching non-acroporid), CBA (branching acroporid), CE (encrusting corals), CF (foliose coral), CFUNG (fungiid), CM (massive corals), and CSUB (sub-massive corals).
RESULTS
CORALS
The Bonbonon marine reserve had a fair live hard coral cover of 25% in the slope area and 33% in the flat area. Soft coral cover in the slope was 24%, and there was also a considerable percentage of rubble in both of these areas. Taking the coverage of the slope and flat area, the reserve had an average LHC of 28.9%. The control area on the other side of the bay, however, had better average LHC at 36.6% (41% and 33% for the slope and flat areas respectively (Fig.2A and 2B).
In Andulay Siit, the reserve had a good coral cover of 30% in the slope area, and 44% in the flat area, or an average LHC of 38% (Fig. 3A). The nearby control area had an average LHC of 30% (Fig. 3B). There was a considerable percentage of soft coral cover in both of these areas, which is a trend in the Siaton reefs. An alarming result however, is the high percentage of rubble in the reserve area, most probably brought about by the destructive placement of fish traps on top of the corals by the local fishermen. A bigger damage also occurs when they pull out the traps that they place underneath the coral, oftentimes dragging them up and leaving plenty of rubble in its path.
The proposed MPA at Antulang (Dive Hub) has relatively less live hard coral compared to the other two MPAs due to its very small size (Fig. 4 A and 4B). It must be noted that this MPA has an area only of about 3,000 sq. m (about 1/3 of a hectare) compared to the other two MPAs that are contain several hectares of reef. The reef topography is patchy and has a notable cover of seagrass in many places.
Over-all, live hard coral cover in the Siaton sites range from “Poor” (less than 25% LHC) to Fair (25-50% LHC) (Fig. 5). Although these might seem low in the scale, these values are representative of the bigger area in Negros Oriental and are not really the most important consideration in determining the functionally of a reserve. These just indicate that the habitats are still in “working condition” and thus have a chance to improve given proper protection and management.
FISH
Fish—and its parameters of biomass, density and diversity—are the best indicators of a functionality of a mariner reserve or MPA. Several studies have shown that with proper protection, biomass and density of target species increase exponentially over time (see Russ and Alcala 1996, Alcala et al 2005). Top predators are usually the first to disappear in exploited reefs, and the last to return. With protection, the diversity of fish increases, due to the lack of human disturbance. With this comes increased biomass and density over time, and when there are enough “prey”, the top predator eventually return. However, it is important to note that protection should be constant for all of these to happen.
Species Diversity
Among all the sites surveyed in Siaton, the Dive Hub reserve site had the highest diversity at 204 fish species observed. It should be noted that this very high diversity is probably the result of protection, as the area is well protected compared to other MPAs who only get intermittent protection.
Reef Fish Density
The sites in Siaton had average reef fish density compared to other sites that were surveyed for this study. There are few target species and predator species observed for all areas because of the lack of strict enforcement. The Andulay and Bonbonon MPAs had relatively low densities despite their ages, probably due to the lack of enforcement in the area. It should be noted that the high density observed in Dive Hub is mainly due to the presence of a large number of indicator (non-target species). The sanctuary is also very young and thus, it is expected that with sustained protection, the density will increase in the coming years.
A. Fish biomass
Reef Fish Biomass
Among the sites surveyed in Siaton, the Andulay MPA had the highest total fish biomass at 29.1 kg/500m2. The top predator biomass for the Andulay MPA however, is very low at 3.1 kg/500 m2(about 6.2 tons/sq.km.), which is typical for unprotected or newly established reefs. Top predator biomass is the best indication for long term-protection—it can reach up 10 25 tons/sq.km. for reefs that have been protected for a long time. The top predator biomass in Dive Hub is higher (4.7 kg/500m2) compared to the older Andulay MPA primarily because this area is protected from poaching at all times.
B. Trends in Density and Biomass
Data from this year’s survey and that from a previous survey conducted last 2007 by B. Stockwell in Bonbonon indicate declining trends for density and biomass in this reserve site. (Fig. 9 and Fig. 10). The biomass in the Bonbonon reserve dropped from 23.5 kg/500m2 to 6.8 kg/500m2 in 2008. The present biomass in Bonbonon is only 28.9% of last year’s figure. The density of reef fish in this MPA also showed a decline compared to the previous year.
Declines in both parameters indicate that the protection regime in the Bonbonon MPA is not effective and should be improved to halt this negative trend.
Discussion of Results
Marine protected areas are established so that the communities where these are located can realize its main benefits: increased diversity of fishes, improved habitats and improved fisheries. However, in order for these benefits to be realized, MPAs have to be fully protected for a number of years. Full protection is not easy and is costly, that’s why in many areas, co-management between the community, NGOs, and the local government unit is the preferred mode of management.
Results of this survey indicate extensive damage to the reefs in the Andulay reserve area, as evidenced by the high percentage of coral rubble and soft corals. Soft corals are non-reef building corals and have a transitory nature and they thrive in rubble areas; furthermore, they hinder the settlement of hard corals, which is the most important component in building a suitable habitat for reef fishes. Also, majority of the hard corals in the Andulay reserve are acroporids, which are fragile and prone to damage. The large percentage of soft corals in the control reef outside the Andulay reserve is undoubtedly due to mechanical damage: large areas of reef were damaged over time due to fish trap and set netting practices. Also, prevalent spearfishing in the area probably removed the biggest breeders in the reefs at the reserve and immediately outside, which will have profound impacts in the ability of the fish populations to eventually bounce back.
The same alarming trend in fish biomass decline has also been noted in Bonbonon, with the reserve area showing a steeper decline compared to the non reserve area. Protection has to be stricter in both these reserves if these are to properly function.
The results from this study indicate primarily that the established MPAs in Siaton (Andulay and Bonbonon) are non-functional. Based on their ages, they should have already have high recorded biomass, density and diversity of fish. However, this is not the case in the field.
The importance of constant protection is clearly illustrated when one looks at the data set from the Dive Hub Antulang proposed MPA and the other two established ones. The constant protection of this small area translated to higher diversity, higher density and higher biomass of top predatory species in a very short time. With continued protection, there is no doubt that this small area will realize the benefits that a fully protected MPA should give: better fishing in the areas adjacent to the reserve, improved habitats and greater biodiversity.
Recommendations
Based on the results of this study, we strongly recommend that enforcement efforts in the Andulay reserve be stepped up, because this site is very good in terms of coral cover; however, this is seriously being threatened by the bobo (fish trap) operations in the area, as retrieving the fish traps cause a lot of damage to the live hard corals. Similarly, the Bonbonon MPA should also be better protected. This MPA is suffering further from severe siltation coming from Tambobo Bay. Control of siltation from Tambobo Bay can be addressed in different ways, but ultimately, it would require some control of human activities in the Bay that directly and indirectly cause pollution and siltation in the waters around it.
We also strongly recommend that the Dive Hub/Antulang MPA be officially declared as a marine protected area through a barangay ordinance, a municipal ordinance or both. Declaring this area as an MPA would make it a legal entity and thus be entitled to legal police support. This way, the area would be better protected, and this in turn will ensure that the fishing community around it will realize the benefits of the MPA sooner and in a sustained manner.
Acknowledgements
The survey team would like to thank the following people who have helped us in one way or another for this study: the municipal government of Basay (Mayor Beda Cañamaque) and Siaton (Mayor Bing Arbolado) Ms. Aloha Marie Sala, MAO Ed Cayang of Basay, Jungco Beach Resort, Kookoo’s Nest Beach Resort, Gena and Martin Jordan of Dive Hub Antulang, Capt. Dede Bondocan and Kag. Richard Abdasaldo of Brgy. Siit, Capt. Rosita Palarpalar of Bonbonon, Kag. Alfa Salome Lagos of Siaton, Mr. Mating Calumpong, and Yayoy Uy. Funding for this survey was provided by EcoGov2 under the project “Strengthening the MPA HUTASAKAB cluster in southern Negros Oriental” implemented by the Salonga Center for Law and Development of Silliman University.
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References
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