State of Fisheries: Protecting mangroves ensures sustainable fish farming
Text and Photos by Henrylito D. Tacio
(Second of Three Parts)
By protecting the mangroves, fishermen are assured that growing fish in cages can be sustained.
The coastal town of Sta. Cruz in Davao del Sur has proven this. People are raising bangus in floating cages in barangay Tagabuli, where mangroves thrive. The municipality has around 92 hectares of mangrove forest that also spans 9 other coastal barangays: Bato, Tuban, Zone IV, Zone III, Zone II, Zone I, Astorga, Darong, and Inawayan.
“We believe that the mangroves present in the area have helped bangus raisers to make their harvest feasible and profitable,” explains Julius Paner, the municipal tourism officer who is trying to make the place a destination for their guests and visitors.
Ideal for bangus farming
With its brackishwater, the Tagabuli Bay in Sta. Cruz, Davao del Sur, is an ideal area for growing bangus. In the 1980s, the National Bangus Breeding Project (NBBP) was established in collaboration with the regional office of the Department of Agriculture, Southeast Asian Fisheries Development Center, Japan International Cooperation Agency, and the provincial agriculture office of Digos City.
In 1992, it became a Research Fishery Outreach Station under the agriculture department. Before long, it was converted into a Regional Fishery Research Development Center. Today, it has become the Technology Outreach Station for Marine and Brackishwater (TOSMB) of the Bureau of Fisheries and Aquatic Research (BFAR).
The BFAR launched a multispecies hatchery (MSH), which includes the production of bangus fingerlings (called hatirin or garungan) from fry.
The MSH encompasses multiple objectives. For one, it aims to enhance food security in the region by boosting fish production through the provision of bangus fingerlings to marginalized fisherfolk.
For another, it seeks to invigorate the economy by facilitating fish cage livelihood initiatives in collaboration with the provincial fishery offices (PFO) and city fishery offices (CFO) within the region.
Finally, the MSH offers support to fisherfolk by supplying equipment for the collection of wild fry, specifically fry dozers.
Right now, the BFAR hatchery has about 1,500 spawning sabalo (mother bangus) and another 500 (about four years old) for sabalo development. In addition, about 3,000 two-year-old bangus are also being managed to become sabalo.
If it is unable to meet the demand for fry, the MSH acquires them from a commercial producer via the government’s procurement process.
Marine fish cage project
Traditionally, bangus was cultivated in ponds and pens. In the year 2000, the TOSMB initiated the bangus marine fish cage project, which provided training for fishers in an alternative method of raising the fish to a marketable size. The floating enclosures utilized synthetic netting, bamboo screens, or other materials arranged in the shape of an inverted mosquito net (hapa type).
The project was designed to be managed by the community. Upon learning about the initiative, several fishermen established an organization, as this was a prerequisite for participation. Most of the members were involved in various economic activities and did not rely solely on fishing for their income.
Some members had prior experience in fish cage culture, having previously worked as caretakers for private fish cage operators.
Barangay residents who joined the cooperative included fishers operating both motorized and non-motorized boats, seaweed farmers, fish vendors, employees, traders, and individuals engaged in other minor income-generating activities such as swine raising and mat weaving.
To support the bangus culture project, the wives of cooperative members received training in bangus processing techniques, including deboning and marinating the fish.
Initially, the project experienced success. However, over the years, it became clear that its sustainability was in question. Rising costs associated with fingerlings and feed rendered the venture unprofitable. The study indicated that “the operation of a marine fish cage project is most effectively managed as a family enterprise rather than a community-oriented initiative.”
Current situation
Currently, the community has adapted to this insight. There are over 500 fish cages, each measuring 10 meters by 10 meters by 5 meters, in operation within the area. These cages are predominantly owned by local residents, although some private investors from the Davao region are also involved.
Most of them acquire their bangus fingerlings for stocking from private nursery operators in nearby areas. They also buy fingerlings from fishery nurseries in Tagum and Malita. There are also operators who are supplied by the Finfish Hatcheries, Inc. (FHI), the first and largest commercial bangus fry hatchery in the country.
At the Tagabuli Bay fish cages, operators are giving bangus commercial feeds daily. About 70% of the operation goes to commercial feeds, purchase of fingerlings, and salary of those maintaining the fish cages. “The bulk of expenses comes from feeds,” says Vilma M. Montojo, TOSMB’s senior aquaculturist.
The stocking density is from 10,000 to 12,000 fingerlings. From this, they harvest 4-5 tons per cropping. The culture period is 5-6 months although in some instances it may go up to seven months. “The culture period becomes higher if they stock the cages with more than what is being recommended,” Montojo says.
Selective harvesting is practiced; only uniformly grown bangus from the cages are harvested using seine or gillnets, retaining the undersize fish and harvesting only the commercial sized stocks, with an average body weight of 250 grams or larger.
Harvesting is done twice daily; one in the morning and another in the afternoon. They harvest only what is needed by the buyers (viajedors, those who travel in various parts of the country and compradors or those who buy in bulk and supply them to retailers). About 5 tons to 15 tons are harvested each day.
The bangus harvested are sold in the local market and nearby provinces. The viajedors, however, bring them to such areas as Cagayan de Oro, Bukidnon, Surigao, Tacloban, Cebu, Dumaguete and Iloilo.
Sizes of bangus matter. Those weighing 600 grams to 1.2 kilograms per piece are sold for export. If it weighs 599 and below, it is sold for local consumption.
Mangrove protection
Due to the prevalence of mangroves in the area, the municipal government urged those who are fish farming not to disturb the mangrove ecosystem. Currently, only 6.62 hectares of the 80 hectares available in Tagabuli Bay are allocated for bangus production.
As the area falls under the jurisdiction of Sta. Cruz, the local government is working towards establishing the Tagabuli Bay Mariculture Park.
“Presently, the Sangguniang Bayan is in the process of formulating the mariculture ordinance,” says Joylen L. Dominice, aquaculturist II of the Municipal Agriculture Office.
The Tagabuli Bay Mariculture Park can serve as a model for other coastal municipalities that have transformed their mangrove areas into ponds for the cultivation of fish and various aquatic resources.
Dr. Jurgenne H. Primavera, a dedicated researcher of mangroves, identified the conversion of these vital ecosystems into brackish water fishponds as a significant factor contributing to the alarming rate of mangrove loss in the country. This is the reason why the fishery office of Sta. Cruz is actively working to prevent similar developments in Tagabuli Bay.
Importance of mangroves to fish production
Dr. Rafael D. Guerrero III, the former director of the Philippine Council for Marine and Aquatic Resources Research and Development, has also acknowledged that the degradation of mangroves is a contributing factor to the decline in the country’s fishery production.
Mangroves, after all, are “fish factories.” “They serve as nursery grounds for fishes by providing their fry with food such as zooplankton,” explained Dr. Guerrero, an academician with the National Academy of Science and Technology. “They also serve as breeding or spawning grounds for fishes, shrimps and mollusks.”
The FISH (Fisheries Improved for Sustainable Harvest) Project, a program initiated by BFAR, has identified mangroves as vital to fish production. “Mangroves serve as crucial spawning, nursery, feeding, and temporary shelter habitats for numerous fish species, crustaceans, and invertebrates, thereby fostering a diverse and thriving marine ecosystem,” it said.
The muddy waters surrounding mangroves are abundant in nutrients derived from decomposing leaves and organic material generated by the mangroves, as well as from the sediment trapped around their roots.
“Many commercial marine species such as bangus (milkfish) and prawns spend their early life within the mangrove area where they find food and protection from predators,” FISH Project states. “Juveniles of some deep-sea fishes also spend some time in the mangroves before moving on to other ecosystems such as seagrasses or coral reefs.”
Mangroves not only provide essential breeding habitats for fish but also act as a crucial barrier against monsoon waves and storm surges. More importantly, they play a significant role in combating climate change.
Research indicates that mangroves absorb carbon dioxide from the atmosphere and sequester it within their roots, trunks, and leaves. This phenomenon is referred to as biological carbon sequestration.
According to several studies, mangroves can sequester four to five times more carbon than terrestrial forests. In response to this, the local government has established the Tagabuli Mangrove Protected Area. “Our goal is to expand mangrove coverage rather than diminish it,” stated Dominice.
The Community Environment and Natural Resources Office (CENRO) is actively involved in planting mangroves in areas where they are already present. In addition, individuals participating in on-the-job training at the BFAR office are mandated to prepare mangrove seedlings for future planting initiatives.
Excellent for tourism destination
In addition to offering sustainable livelihood opportunities and income-generating projects for the residents of barangay Tagabuli, the area also plays a significant role in the town’s tourism initiatives.
“This greatly benefits the tourism sector as it forms a key part of our seascape tour route. As our guests navigate through the area, they are afforded a unique insight into the management of fish cages by local fishers,” Paner said.
Earlier this year, the Tagabuli Bay Floating Cottage was inaugurated for public use. This solar-powered facility is well-suited for small group meetings, gatherings, and picnics, accommodating between 30 to 40 individuals. Visitors can engage in various activities, including kayaking through the mangrove forest, exploring Secret Island and the fish cages, snorkeling, birdwatching, and swimming.
