Sea Cucumbers, Weeds, Urchins and the Pearly Shells of Baliangao Reef

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Worldwide the management of the small-scale coastal fisheries is still at a very embryonic stage. Governments focus their attention, with some success, on the medium and large-scale fisheries. In many countries with few employment opportunities earning a decent living as a small-scale fisher is often one of the few options left. These fishers often bring invaluable species of very good quality that are in high demand that fetch a good price. Unfortunately, these valuable fish are from stocks that are more and more under pressure and in need of management.

Partnership for Rural & Technical Services (PARTS), Inc, a non-government organization based in Oroquieta City, initiated a project that picks up the challenge to unify 260 fishers and gleaners around the management of the fish, squid, shells, sea-urchins, and sea cucumbers. With the help from WEGA Aide Humanitaire, a development organization in Luxembourg, and the local government, PARTS hopes to increase the stocks, biodiversity and the sustainable harvestable production from the coastal fringe. If successful, the approach will surely spread to neighboring areas.

The study site is located in the Municipality of Baliangao in the Province of Misamis Occidental, a Southern Island of Mindanao, Philippines. It sprawls on the edge of the Sulu Sea with the world-famous Tubataha Reef National Park at the center. The town lies on a peninsula; its narrowest part that connects to the mainland is only 150 meters wide. Here the road is bordered by remnants of mangrove forests and abandoned fishponds. The reef front is located one kilometer to the North of the town and named the Special Fisheries Demarcated Area (SFDA). It covers 52 hectares of a reef flat and another 48 hectares of shallow (< 15 meters isobaths) and deeper reef until 50 meters from the reef crest. In 2016, the project started with the inventory of the current stocks and harvest.

Data show that sea cucumbers and fish are extremely low in standing stock biomass (SSB); the shells and sea urchin stocks are also low (red in the table below). Shells harvest was to be much too high. If this continues, it will result in a much lower SSB of shells in the coming years.

The results of the surveys coincide with the observation of the resource users. Catch recording in 2016 was sufficient to paint the picture but it needs improvement to get a reliable illustration for appropriate resource management. Pressure on the tidal flat is high with 3.8 daytime and nighttime gleaners per hectare that glean an average of 2.6 days a month.

Seeing the problem, resource users proposed and supported a range of management measures that should be implemented. Good management will result in a sustainable fish harvest that is at least thrice the current volume and 5 times the total current value with a higher biomass of fish in the reef. Good management of the gleaners’ resources could also result in more “profit” from the reef flat, especially if sea cucumbers are managed to optimize value and production.

Fishing techniques and ways of gleaning

Fishing in the coastal zone can be subdivided into 5 more or less distinct ways of harvesting. The widest term mangingisda (root word isda = fish) or those who fish can be used as an overarching term but mostly this term is reserved for those who fish using boats. Aside from this, there are also different ways of gleaning the reef:

1. Mangingisda (Fishers): fishing using boats and targeting fish and other moving organisms

2. Manginhas (root word kinhason = shell): daytime gleaning (low-tide) targeting mainly sessile organisms like shells, sea cucumbers, and sea-urchins

3. Manolo (root word solo = light): night-time gleaning (low-tide) using lights targeting sessile organisms and fish

4. Magsalum (root word salum = underwater): daytime gleaning at medium tide using goggles/diving masks

5. Malabyug (root word labay = throw): fishing not using a boat but standing on the edge of the reef fishing with hook and line.

Resource users’ attitude towards fisheries management

The majority of resource users see the need for management. They also acknowledge their role in resource management. The minority (15%) sees a much bigger role for the municipal government. Some fishers look towards PARTS and external partners to mitigate the effects on the income of temporarily harvesting than to restoring the SSB.

Proposed alternative management

The current management of the area can be characterized as an open access fishery. Harvests depend on the available alternative income opportunities, SSB of the resources and prices in the market. Gear use is hardly regulated; only the use of explosives is banned. Residents in the area feel the need for management as expressed in their answers during the Resource Users Survey conducted in 2016.

 Management measure proposed and accepted by the resource users

By way of interviews, the resource users were asked about management measures they think are helpful and they are willing to support:

• (Re)establishing a sanctuary is well supported. Only 20 out of 260 respondents oppose such measures.

• The suggestion of minimum harvestable size for sea-urchins (swaki) and certain shells was supported with only 8 respondents opposing.

• Few opposed the minimum size of mesh nets for fishing on coral reef-associated species. (What mesh-size should be allowed is also still subject for discussion).

• A six-month ban on the harvest of sea cucumbers was very acceptable with no person opposing.

What can and should be the aim of improved management?

Based on earlier research in Danao Bay, the SFDA could sustainably produce 150 kg/ha/year in fish over the whole area. Other researches predict the potential Maximum Sustainable Harvestable Production of Fish (MSHPF). Management should aim at a targeted standing stock biomass of fish on the reef flat (intertidal zone) of 100 kg/ha during daytime at incoming tide when the sea is at around 1 meter deep (on reef flat sanctuary 250 kg/ha). Target SSBF in the outer reef till 30-meter isobath: 250 kg/ha (in the sanctuary area 600 kg/ha). During the implementation of the management plan, the maximum SHPF can be more scientifically established in a process involving fishers, managers, and academe. Ideally, the monitoring of the stocks through transects involves representatives of the resource users.

Good management will result in a sustainable fish harvest that is at least 2.5 times current volume and 5 times current value with 3 times higher biomass of fish in the reef.

Getting a grip on the potential MSHPS3 (shells, sea cucumbers, and sea-urchins) also needs better catch registration and continued involvement of resource users in monitoring. The production of these organisms could be more than 150 kg/ha/year from the reef flat. With good management, the valuable sea cucumbers could make up a much larger part of this 150 kg/ha/year than it has now. The investment needed to increase SSBF and SSBS3 to the optimum level will be calculated as part of a project proposal with a business plan including the costs for maintaining the SSB at the desired level.

Not everything can be calculated in monetary terms. For some of the resource users self-esteem and a feeling of self-reliance can be as important as the net profit from the SFDA.


[1] Balisco, R.A., in: The Palawan Sientist vol. 7, no. 1 (2015) Notes on the Gracious Sea Urchin (Tirpneustes gratilla) in Pag-asa Island, Kalayaan, Palawan, Philippines.

[2] Kriegisch, N. PLOS One, 2016, 11(12). Phase-Shift Dynamics of Sea Urchin Overgrazing on Nutrified Reefs.

[3] Dolorosa, R.G. 2017, SPC Beche-de-mer information Bulletin #37 March 2017. Seacucumber fisheries in Rasa Island Wildlife Sanctuary, Narra, Palawan, Philippines.

Categories: Researches


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