Aquaculture in the Philippines

A fish pond in Ivisan

Aquaculture in the Philippines makes up a substantial proportion of the overall output of Philippine fisheries. Aquaculture has a long history in the archipelago, with wild-caught milkfish being farmed in tidally-fed fish ponds for centuries. Modern aquaculture is carried out in freshwater, brackish water, and seawater throughout the country through a variety of methods.

The most prominent farmed commodities are milkfish and tilapia. Tilapia is farmed in freshwater, while milkfish can be farmed anywhere. Other fish species are also farmed, as well as shrimp, crabs, lobsters, and molluscs. Seaweed is mostly farmed to produce carrageenan. Regulation of aquaculture generally falls to the cities and municipalities in which aquaculture farms are located, and public land and water can be rented for aquaculture from the national government.

Aquaculture has made up an increasingly large proportion of fisheries products produced in the Philippines, and there has been considerable research into improving aquacultural output. Philippine output in total makes up 1% of global aquaculture production, and the country is the fourth-largest producer of seaweed. Aquaculture products are sold alongside wild-caught products in ports. Resulting seafood products are often consumed domestically, although some high-value goods are exported.

The aquaculture industry directly employs over 230,000 individuals. While some workers own their output, many are employees of influential landowners. The creation of aquaculture ponds has destroyed large areas of mangroves, and the establishment of aquaculture in water bodies has created friction with capture fisheries. Some species imported for aquaculture have become invasive species, and aquaculture has directly introduced pollution into some ecosystems.

Resources

Territorial waters and exclusive economic zone of the Philippines

Philippine waters include 2,200,000 square kilometres (850,000 sq mi) of ocean surrounding 36,289 kilometres (22,549 mi) of coasts, of which 184,600 square kilometres (71,300 sq mi) is on continental shelf of 200 metres (660 ft) deep or less. Inland waters include 246,063 hectares (608,030 acres) of swamplands (106,328 hectares (262,740 acres) freshwater, 137,735 hectares (340,350 acres) brackish), 200,000 hectares (490,000 acres) of lakes, 31,000 hectares (77,000 acres) of rivers, and 19,000 hectares (47,000 acres) of reservoirs. There are 23 lakes over 100 hectares (250 acres). The Philippine fisheries in these waters include a large aquaculture component.

Aquaculture is carried out in fresh, brackish, and marine water. Philippine waters are highly productive due to large amounts of sunlight, and stable and warm temperatures. Aquaculture generally occurs in areas under local government (city and municipal) jurisdiction, which includes their land area and the sea up to 15 kilometres (9.3 mi) from their shoreline. Aquaculture infrastructure can be built on land, in inland waters, or in coastal and nearshore areas.

Most brackish fish ponds are developed from mangrove areas, with agricultural land being too valuable to convert to fish ponds. Exceptions have occurred during conducive economic conditions, such as in the 1980s when sugarcane plantations were converted to shrimp ponds in Negros Occidental, amid a global slump in sugar prices and increasing shrimp prices. Coastal aquaculture ponds are commonly used to rear shrimp and milkfish. Different species have different ideal habitat conditions for successful rearing.

Products farmed

Milkfish have been farmed in the Philippines for centuries

The main two fish commodities in agricultural production are the milkfish and tilapia (mainly the Nile tilapia, followed by the Mozambique tilapia). Fish farmed to a lesser extent include carps (notably Bighead carp, as well as some Eurasian carp), catfish (Clarias species such as the walking catfish and Clarias gariepinus, as well as Pangasius species), the mudfish Channa striata, the giant gourami, barramundi, Epinephelus grouper species, rabbitfish (orange-spotted spinefoot and vermiculated spinefoot), and the Scatophagus argus spadefish.

The rabbitfish orange-spotted spinefoot and vermiculated spinefoot, as well as Scatophagus argus, have been farmed sporadically in Pangasinan and elsewhere. Barramundi is only desired in the Western Visayas, which combined with high costs has inhibited successful farming. Low-level Epinephelus farming, while expensive, is more successful due to high demand in Chinese restaurants. It is farmed in Capiz, where tilapia is sometimes used as feed.

The shrimp species farmed include the jumbo tiger shrimp, Indian prawn, Penaeus merguiensis, whiteleg shrimp, Metapenaeus ensis, and the giant freshwater prawn. The main crabs farmed are the mudcrabs Scylla serrata and Scylla oceanica. Lobsters farmed include species of the Panulirus genus and the slipper lobster family.

For molluscs, oysters farmed include Crassostrea species, Magallana bilineata, and rock oyster species. Abalone that have been farmed are those of the Haliotis genus, particularly Haliotis asinina. The green mussel Perna viridis is also widely farmed. Less frequent marine aquaculture products include giant clams, nacre (pearl shell), green snails, and Trochus.

Of seaweeds, the farming of carrageenophytes is mainly Eucheuma species such as Eucheuma denticulatum, and Kappaphycus alvarezii. Agarophytes farmed are mostly Gracilaria species and Gracilariopsis balinae. Lastly, Chlorophyceae of the Caulerpa genus such as Caulerpa lentillifera are also farmed.

Tilapia, carp, and catfish are usually farmed in freshwater. Tilapia is farmed in both ponds and cages. Shrimp and crab farming usually takes place in brackish water. Saltwater farms (mariculture) are used to farm seaweed, as well as green mussels. Some fish, such as groupers and rabbitfish, are farmed in both brackish and salt water. Milkfish is farmed in fresh, brackish, and salt water.

Methods

A crab pond in the Bakhawan Eco-Park

Different species are farmed with different levels of technology, ranging from simple ponds with wild-caught fry to more complicated methods of raising genetically modified fish strains. Fish ponds, especially Brackish areas, are the historical method of aquaculture and remain widespread. A 1977 national study found that around 15% of fish ponds were smaller than 1 hectare (2.5 acres), although in total there were less than 1% of all fish pond areas. Over half of fishponds were officially above 5 hectares (12 acres), including 5% which were above 50 hectares (120 acres). In 1979, 70% of fish ponds in Central Luzon were smaller than 0.5 hectares (1.2 acres). However, the largest 2% of fish ponds took up 68% of total fish pond area. Such figures do not account for the area of multiple owners being operated together, or for land being operated by someone who is not the owner. Of fish ponds being leased from the government, the majority are leased by individuals with addresses in different locations to those of their fish ponds. Milkfish farming in brackish fish ponds uses a variety of techniques used in varying intensities.

Fish pens in the Bued River

Fish pens are enclosures in which the seabed or lakebed provides the floor. They have high capital costs but can produce large yields even without supplementary feeding. Fish cages are distinguishable from fish pens due to having an artificial bottom. This bottom means fish cages can be small, and are a cheaper alternative to fish pens. These cages can be floating, fixed to the ground, or submerged. In freshwater areas, they are generally used to farm tilapia, while in marine areas they are often used to farm groupers. The initial tests of milkfish in oceanic pens found that with artificial feed they grew larger than in freshwater pens while maintaining the right flavor. Oceanic cages have high capital costs, both for the cages and for effective mooring mechanisms. Fish cages are more labor intensive than fish ponds.

Mussel farming is most commonly carried out with a simple bamboo substrate. Bamboo poles fixed into mussel beds can produce a harvestable crop in six months. Rope web substrates have also been proven. Mussel and oyster farming is a small part of overall aquaculture, with limited domestic demand. Farming is often undertaken alongside other jobs. Harmful algal blooms impact mussel and oyster farming, especially in Manila Bay.

Seaweed farming is profitable at a small scale, to the point that the small cost of investment is exceeded by the revenue from the first harvest (105-135 days). Caulerpa and Eucheuma are the most profitable, followed by Gracilaria. Gracilaria grows better in canals with flowing water than in still ponds. Eucheuma is farmed in both shallow water, often on stakes, and in deep water, where it grows on single lines, rafts, and spider web nets. Caulerpa lentillifera is able to be grown in milkfish ponds by propagating cuttings.

Productivity

Aquaculture structure in a river near the coast of Bulacan

Aquaculture and municipal capture fisheries combined produced 73% of all catch from 2011 to 2020. In 2018, the aquaculture sector produced 826.01 thousand tons of fish, crustaceans, and mollusks, worth $1.89 billion, the 11th-largest national production in the world accounting for 1.01% of global production. This included 1.48 million tons of seaweed and other aquatic plants, 4.56% of 2018's global seaweed production. In 2020, the aquaculture sector made up 41.82% of the total value of Philippine fisheries, directly employing 233,725 people. In 2021, there were 1.34 million tons of seaweed produced, 3.82% of global production, 4th largest in the world. 93% of the 913.40 tons of brackish aquaculture production in 2020 was milkfish. Most (53.34%) brackish water aquaculture takes place in Bangsamoro, with a quarter (25.18%) taking place in Region I. The most commonly farmed shrimp is the jumbo tiger shrimp, which made up 42,453.94 tons of the total 70,474.77 2020 shrimp production. The second most farmed was the whiteleg shrimp, of which 20,612.48 tons were produced.

Of the 170,939.11 tons of freshwater fish pond production in 2020, 96% was tilapia. Other farmed species include milkfish, carp, catfish, mudfish, gourami, and prawns. A substantial majority of freshwater aquaculture (132,827.85 tons) takes place in Region III. Freshwater cage aquaculture is also dominated by tilapia, which makes up 86.82% of production. Milkfish, carp, and catfish are also farmed in freshwater fish cages. Region IV-A produced 64,576.88 metric tons of the total 74,010.90 farmed from freshwater cages. Freshwater fish pens produce 39,847.67 tons, of which 17,020.75 (42.71%) is tilapia, 12,039.36 (30.21%) is milkfish, and 10,781.00 (27.06%) is carp. Most fish pen production (26,575.91 tons) also takes place in Region IV-A. Of the 114.41 tons produced in small farm reservoirs, 73% was tilapia, with milkfish, carp, catfish, gourami, and mudfish also farmed. A small amount, 5.21 tons, is produced in rice-fish systems, with 3.70 tons (71.02%) of this being tilapia. Region I hosts 42.80% of rice-fish farming.

Fish cages in Maitum

Marine fish cages produce 149,661.38 tons, 99.91% of which is milkfish. Region I hosts 68.14% of this production. Milkfish similarly dominates marine fish pen production, making up 832.68 tons of the 846.38 total. Region I hosts 36.61% of marine fish pen production, while Region IV-A hosts 23.33%. Mariculture activities produce 1,540,914.30 tons, of which 1,468,653.27 (95.3%) is seaweed, 53,032.06 is oyster, and 19,228.97 is mussel. Seaweed aquaculture helped make Bangsamoro the most productive fisheries region in 2020.

The production of algae through aquaculture grew from 707.0 thousand tonnes in 2000 to around 1,500 thousand tonnes annually in the years since then. In 2012, the Philippines 1.75 million tons of farmed seaweed produced made the country the world's third-largest producer. Carrageenan makes up 94% of seaweed exports. In 2022, seaweed exports were 48,491 metric tons, exported to the United States, the Netherlands, Spain, Germany, and China. Seaweed and oyster farming products are often sold to exporters of high-value goods, rather than being farmed directly for local food supply.

Philippine aquaculture is hampered by the lack of a "trash fish" — a cheap fish that can be used to feed farmed fish — as most fish in the Philippines are directly valuable for human consumption. Milkfish fry are deliberately wild-caught as juveniles to stock aquaculture ponds. Shellfish farming is vulnerable to red tides, and is thus risky as a sole source of income. The damage caused by the annual typhoon season means coastal aquaculture is more developed than ocean mariculture. Production is also affected by the El Niño–Southern Oscillation.

Impact

Socioeconomic

A shrimp hatchery in Macabebe

Aquaculture provides food security, employment, and export goods. In some areas, it is the dominant industry. Riverine and marine aquaculture provide an economic opportunity for poorer individuals, as access to water is much more available than access to land, which is often the property of rich landowners. As of 2020, there were 233,725 individuals involved in aquaculture. Aquaculture products are often sold in ports, where there are established fish markets that buy and sell products from capture fisheries. They take up 0.83% of the average spend of urban populations (compared with 0.54% for wild-caught fish), and 0.80% of the average rural spend (compared with 0.67%).

Small-scale fishermen often have difficulty accessing credit, with informal loans having interest as high as 20%. Credit is sometimes provided by buyers, in exchange for a guarantee of future produce. Some formal loans are issued by the government through various funds. In addition, under Presidential Decree 717, banks must have 25% of their loanable funds restricted to agriculture and fisheries projects. Compliance with this mandate has been patchy, and most bank loans go to larger companies. Fees for fish pond rental are small, and some interest-free loans are defaulted.

A fish pen in Meycauayan city

Fish ponds are often not worked by their owners, with the workers instead being caretakers or renters. Lobbying by the fish pond industry is influential. Although initially included in the Comprehensive Agrarian Reform Program, fish ponds were later exempted from this land reform effort. Meanwhile, the rental price of government land was kept at below-market rates. The possession of land is often valuable on its own, even if little effort is put into fish pond productivity. Almost all freshwater aquaculture is from private enterprise. The government has more ownership of brackish ponds, although these are often leased to private bodies on a long-term basis.

As fish pens are capital intensive, they exacerbated inequality in Laguna de Bay. Artisanal fisheries were forced to navigate around water now occupied by fish pens, and conflict emerged due to fears of poaching. Public pressure to dismantle fish pens has not overcome the political influence of fish pen owners. While the overall productivity and value of waters with fish pens in them may increase, resulting value is concentrated amongst fishpen owners rather than other users of the area. In 1997, fish cages located where Laguna de Bay flows into the Pansipit River were ordered to be demolished, to allow for fish migration and to improve scenic beauty.

While some aquaculture-related jobs are performed by both genders, many, particularly those requiring more demanding physical labor, are predominantly held by men. Women play a notably prominent role in seaweed farming, post-harvest processing, and marketing. Some fish farmers have formed NGOs that serve as advocacy groups. These sometimes come into conflict with wild-fishery NGOs, due to the competing priorities of aquaculture and capture fishing.

Environmental

Aquaculture in Taal Lake

The conversion of mangroves into fish ponds and shrimp ponds has been a major contributor to the loss of mangrove forests in the Philippines. It has also removed significant ecosystem services from local communities often producing much less value in return. Freshwater farming has less impact on the environment, and its wastewater can be used for irrigation.

Fish pens congest water bodies, and divert resources from the natural ecosystem. This can affect not only wild fish populations, but also crustaceans and mollusks. While less immediately damaging to the benthic environment than fish pens, fish cages still cause the introduction of excess nutrients. They are recorded as having caused the level of dissolved oxygen in Lake Sampaloc to decrease, creating a dead zone a few meters below the surface. The disturbance of such a lake, bringing deoxygenated water closer to the surface, can cause a mass fish kill, even of caged fish. The presence of aquaculture infrastructure, both for ponds and for aquatic structures, can affect sediment and water flow.

Chemicals and antibiotic compounds introduced to water systems by aquaculture can pollute the local environment. Mariculture also introduces nutrient pollution into the water that can lead to fish kills. The water quality of affected areas varies throughout the year. Oyster, mussel, and seaweed farms are relatively low impact, both environmentally, due to the simple material requirements, and visually, due to their being mostly underwater.

Aquaculture species are mostly non-native. Since 1907, 169 freshwater foreign species have been introduced (not all for aquaculture purposes), of which at least 82% have formed invasive wild populations. Introduced Eurasian carp and Nile tilapia have impacted multiple native species, for example, endemic species of Mount Isarog National Park. Tilapia played a role in bringing the native sinarapan fish to the brink of extinction and greatly reduced the population of flathead grey mullet in Naujan Lake. In Laguna de Bay, walking catfish, Hypostomus plecostomus janitor fish, and clown featherback knifefish harm aquaculture and native species. The walking catfish directly outcompetes the native broadhead catfish. Sailfin molly have harmed native insect populations. The Pterygoplichthys disjunctivus janitor fish has become established in Agusan Marsh. Tilapia may have introduced the Arctodiaptomus dorsalis copepod, which competes with native copepods. While the establishment of some invasive populations was accidental, like those of janitor fish and clown featherbacks, some populations were created intentionally, like those of Nile tilapia. Many introductions took place from the 1970s to the 1990s. Aside from fish, invasive Pontederia crassipes water hyacinth and Chinese softshell turtles also damage aquaculture. The release of captive native species poses risks to the genetic variability of wild populations.

Management

A fish farm in Agoo

Fishery resources fall under the Department of Agriculture, which contains the Bureau of Fisheries and Aquatic Resources (BFAR), the Philippine Fisheries Development Authority (PFDA), and the National Fisheries Research and Development Institute (NFRDI). PFDA manages ports. NFRDI was created by the Fisheries Code of 1998.

The Fisheries Decree of 1975 blocked the privatization of government-owned fish ponds. The Local Government Code of 1991 devolved responsibility for fisheries licensing and regulation to cities and municipalities (with the exception of leasing public land for fish ponds, which remains with BFAR). RA 8435, the Agriculture and Fisheries Modernization Act, was passed on December 22, 1997, quickly followed by RA 8550, the Philippine Fisheries Code, on February 25, 1998.

The Fisheries Code of 1998 has provisions that affect or are directly targeted at aquaculture. This code mandates that aquaculture areas, including privately-owned ones, be registered with their Local Government Unit. It maintained the block against privatization. The Fisheries Code initially banned fish pens, cages, and traps, in lakes, although this provision was not included in widely debated drafts. Sea-based cages are supposedly restricted from the migration routes of wild fish populations. The Comprehensive Agrarian Reform Program of 1998 includes the guarantee of water resource access for seaweed farmers. BFAR's Fisheries Administrative Order (FAO) No. 214 (2001), also known as the Code of Practice for Aquaculture mandates environmental impact assessments for aquaculture projects, as does the more general Fisheries Code of 1998. The Wildlife Resources Conservation and Protection Act of 2001 and the BFAR Fisheries Administrative Order 233-1 of 2010 promote the protection of native species, including those important for aquaculture.

Bodies of water are public property, and their use requires local government approval. Under the Fisheries Code, while public water bodies can be leased for use, they cannot be sold. Only 10% of the surface area can be used for aquaculture. Fish ponds can be under 25-year leases from BFAR, shorter leases, or on private property. Mangrove areas are considered forests, and fall under the jurisdiction of the national government. Theoretically, mangroves are protected and cannot be converted, limiting potential fish pond area. Laws regulating the use of public natural resources, such as requiring 50 metres (160 ft) of mangroves near the water's edge, are often flouted. Under the Fisheries Code of 1998, all unused or underused fish farms should be restored to mangrove forests, although rent costs being so low means classifying a fish pond as underused is difficult.

Grouper fish cages in Del Gallego

Local governments are responsible for licensing aquaculture structures, such as fish pens, cages, and traps. Where multiple local governments share a water body, a joint Fisheries and Aquatic Resources Management Council (FARMC) can be formed. These councils include not only local government or barangay officials, but representatives from NGOs, fisherfolk groups, and the private sector. BFAR is responsible for fish pond lease agreements, imports and exports, and food safety.

Fisheries in Laguna de Bay are regulated by the Laguna Lake Development Authority (LLDA). The LLDA's approval is required for any construction in the lake, including aquaculture infrastructure such as fish pens and fish corrals. While the Laguna Lake Development Authority limits individual pens to 5 hectares (12 acres), and corporate pens to 50 hectares (120 acres), these rules have at some times been bypassed through the use of paper corporations. The appearance of the invasive clown featherback in Laguna de Bay, possibly washed into the lake by Typhoon Ketsana in 2009, reduced the native populations of not only the wild Leiopotherapon plumbeus, but farmed bighead carp, milkfish, and Nile tilapia. Native species in the lake such as the climbing perch, Manila sea catfish, Celebes goby, broadhead catfish, and mudfish can also be used for aquaculture.

Research has often involved government bodies. The Department of Science and Technology (DOST) carries out research related to fisheries, including through its Philippine Council for Aquatic and Marine Research and Development (PCAMRD). Many colleges have fishery courses that offer majors in Inland Fisheries, Marine Fisheries, and Fish Processing Technology. The Inland Fisheries majors have a strong focus on pond aquaculture. The Southeast Asian Fisheries Development Center carries out aquaculture research in Iloilo. A Comprehensive National Fisheries Industry Development Plan (CNFIDP) was put in place for 2006-2025, and included plans to increase aquaculture. The most recent revision was issued for 2021-2025.

History

Further information: History of fisheries in the Philippines

Early aquaculture

The first farmed fish is thought to be milkfish (locally called bangus), collected from tidal waters and raised in brackish ponds. The water of these ponds was supplied by the tides, with food either coming with the tide or caught from the wild. A series of ponds allowed the fish to be moved as they grew larger. The practice likely came from the East Javan mainland or its offshore island of Madura prior to the Spanish arrival to the Philippines. The traditional practice persisted in Mactan, Cebu, until 1921.

Freshwater fish ponds were likely first used sometime in the early 20th century, although there is history of small-scale rice-fish system use. In 1915, Eurasian carp began to be farmed, being imported from Hong Kong. In the years after, the carp was also introduced into natural lakes in Mindanao. Giant gourami were imported from Thailand in 1927. Later introductions include Trichogaster gourami species in 1938, and bighead carp, silver carp, and Indian carp in 1967 and 1968. Despite this, production remained limited due to competition with cropland and a cultural preference for marine fish. Freshwater farming did not significantly expand until the introduction of Nile tilapia in the 1970s.

Oyster farming was established in 1931 in Hinigaran, Negros Oriental, using the "broadcast" method where oysters are simply laid on the seabed. In the years afterward it spread to Binakayan in Cavite, leading to the area around Manila Bay becoming the center of oyster farming in the Philippines. It later spread throughout the country, and where shipping navigation was not a potential issue, it was able to be farmed with deliberately placed substrates.

In 1937, the government through Fisheries Administrative Order No. 14 set up a standard system through which government-owned land could be rented to fish ponds. These leases were initially 10 years and renewable for up to 50 years, with 200 hectares (490 acres) as the maximum size. Due to the reliance on wild catch to support traditional milkfish ponds, shrimp fry often also ended up in these ponds. When this happened, such shrimp were also harvested from milkfish ponds. Species known to have been farmed as a secondary product include jumbo tiger shrimp, Indian prawns, and Penaeus merguiensis. Metapenaeus ensis may also have been farmed. Fish ponds were also occasionally contaminated with seaweed, such as sea lettuce. Seaweed was already harvested wild for eating, and gained increasing use as fish food.

Industrialization

The fishing of milkfish in the sea was banned on August 5, 1949, through Fisheries Administrative Order 25 in order to ensure fry would be available to stock inland lakes and aquaculture. Dedicated and intensive shrimp faming, especially of jumbo tiger shrimp, began in Negros Occidental during the 1950s. As sugar exports declined, sugar fields were often converted into aquaculture farms. Accidental Caulerpa lentillifera contamination shifted to deliberate cultivation in Mactan during the early 1950s to meet local demand, becoming the first commercially farmed seaweed species.

In the 1950s, intensive shrimp farming methods were applied to milkfish when the rapid shift to industrial shrimp ponds led to oversaturation and disease, and artificial feeding of milkfish became more common. Shrimp farming remained limited by a reliance on wild-caught fry. In the 1960s, crabs of the Scylla genus, which had previously been opportunistically farmed in milkfish ponds, began to be more actively managed. Economic benefits were limited by the high cost of feeding meat to crabs. Farming crabs within natural mangrove forests is one method used to reduce overhead costs.

Mozambique tilapia were imported from Thailand by Deogracias Villadolid, Director of the Bureau of Fisheries, in 1950. Tilapia were much easier to breed than milkfish, making it possible for anyone to maintain a small-scale tilapia farm in a simple backyard pond as small as 10 square metres (110 sq ft). In many cases, ponds became overcrowded, leading to fish becoming stunted. Unwanted fish were released into the wild, where they have become an invasive species affecting not only the environment but also milkfish farms. Distribution of this tilapia was not driven by BFAR, but by politicians seeking to curry favor with their constituents.

The maximum area that could be leased to an individual to create fish ponds was decreased in 1954 to 100 hectares (250 acres). This was further decreased to 50 hectares (120 acres) in 1959, although the area that could be leased to corporations increased to 400 hectares (990 acres). Land area restrictions were often bypassed, for example by having multiple individuals within one family apply separately. The lease length was extended to 20 years in 1960 through Fisheries Administrative Order No. 60 and to 25 years in 1979 through Fisheries Administrative Order No. 129. A system through which applications could be made for leased areas to be purchased from the government was ended for all applications after November 9, 1972, by Presidential Decree No. 704 of 1975.

Mussel farming began with a 300 square metres (3,200 sq ft) Perna viridis farm in Binakayan, Cavite, established by the Bureau of Fisheries in 1955. This saw mussels grown on bamboo poles. Production remained around Manila Bay until the 1970s, due to the limited natural range of Perna viridis. (The widespread Modiolus metcalfei is unsuitable for aquaculture.) Perna viridis eventually spread to other areas, such as Sapian Bay and Batan Bay in Panay and Maqueda Bay Samar, possibly as biofouling pollution in bilge water.

International demand for Eucheuma, which contains carrageenan, spurred its deliberate cultivation in the 1960s after natural sources became depleted. Early farms were located in Mindoro, Sulu, and Tawi-Tawi. In 1973, the faster growing Kappaphycus alvarezii began to be cultivated in its place, starting in Sulu. Eucheuma denticulatum is also farmed. Gracilaria, which had been grown on a small scale as food for milkfish around Manila Bay, also began to be commercially farmed, possibly after 1973, to produce agar.

Jumbo tiger shrimp were successfully bred in the 1970s, and as new markets opened in the 1980s, especially in Japan, jumbo tiger shrimp farming expanded rapidly, becoming the largest marine export of the Philippines, reaching a high of USD 300 million in exports in 1992. The expansion was slowed by the death of Japanese emperor Hirohito in 1989, which reduced demand. Meanwhile, intensive farming had led to antibiotic-resistant diseases spreading within Negros Occidental. While there was a substantial decline in production due to these events, shrimp farming continued outside of Negros. Farming of the other shrimp species did not expand to the same amount. While the shrimp of other Penaeus species could be bred, this cost the same as breeding jumbo tiger shrimp and produced smaller adults. Farming of Modiolus metcalfei continued to rely on wild-caught fry. Giant freshwater prawns have been sporadically cultivated since the relevant technology was introduced in the 1970s.

Fish cages were first introduced in 1965 to Laguna de Bay to farm common carp, tawes, and goby, although their use remained limited. In the 1970s, bamboo and net milkfish pens were established in the freshwater Laguna de Bay. This was an initiative of the Laguna Lake Development Authority, and initial tests showed a pen could produce 1,500 kilograms (3,300 lb) without any fertilizer or extra feeding. This success led to wide adoption, with 4,800 hectares (12,000 acres) of pens present by 1973. These pens produced as much fish as the remaining 85,000 hectares (210,000 acres) of lake produced in wild-caught fish. Fish ponds continued to grow, reaching 7,000 hectares (17,000 acres) in 1980, and 34,000 hectares (84,000 acres) in 1983. This oversaturation decreased the productivity of individual pens, lengthening milkfish maturation time to 7-8 months from 4-5 and causing the need for supplemental feed. Microcystis algal blooms caused milkfish and tilapia from the lake to have an "earthy-muddy" taste, reducing market value. Many fish pens became economically unfeasible and were abandoned, especially after being damaged by typhoons. By 1998, there were only 167 registered fish pens which altogether covered only 4,425 hectares (10,930 acres), which even when taking into account unregistered fish pens represented a substantial decrease.

Nile tilapia were introduced in the 1970s. In the same period, it became possible to farm single-gender ponds so no breeding occurred. Initial ponds were monosexed through the use of androgens, with later ponds being bred from genetically modified males with YY chromosomes. These two changes allowed freshwater tilapia farming to expand from a small-scale seasonal enterprise into commercial production. Monosex hybrids of different species have been tested, but did not become farmed commercially.

The National Rice-Fish Culture Program (Palay-isdaan in Tagalog, from palay, unhusked rice, and palaisdaan, fish pond) was launched in 1979, with Nile tilapia and common carp being stocked in rice fields modified to have a long ditch and higher dikes. The program did not achieve much success, with theoretical yields not being obtained due to a number of practical impediments. Monitoring ceased after 1986 following decreasing take-up.

Barramundi, which had opportunistically been raised in existing ponds, saw attempts to specifically farm them in the 1980s. A 1980 ban on the conversion of mangroves to aquaculture was ineffective, with conversion rates increasing in the following years. A 1982 study by the government and the FAO suggested the country had 9,145 hectares (22,600 acres) of potential oyster farming areas and 4,925 hectares (12,170 acres) that would be conducive to mussel farming.

The 1980s also saw a rise in fish cage use in Laguna de Bay, usually to farm tilapia. From producing 7,187 million tons in 1985, freshwater fish cages produced 35,362 million tons in 1993. That year saw marine fish cage use become large enough to be recorded, and combined production reached 43,000 million tons in 1997. The National Freshwater Fisheries Technology Center (then called the Fish Hatchery and Fishery Extension Center) was established by the BFAR with the assistance of USAID, becoming a significant national producer and distributor of tilapia fingerlings.

From 1981 to 1997, total seaweed production increased from 83,000 million tons to 627,105 million tons. Of the 12 provinces in which it was farmed in 1987, Tawi-Tawi was the largest with an estimated 5,000 hectares (12,000 acres) of seaweed farms. In 1986, only 199 farms were officially licensed in Tawi-Tawi, possibly only one-fifth of the total number. From 1992 to 1997, seaweed farming expanded by 17% annually, and by 1997 farms were present in 30 provinces and cities. Many seaweed farms are small-scale and farmer-owned. Seaweed farming was often carried out alongside other methods of obtaining income, such as fishing. In 1991, BFAR began a project to grow Gracilaria in eastern Sorsogon, with the assistance of UNDP and the FAO. This developed into the National Seaweed Culture Center.

Under the 1987 constitution

Fish ponds in Orion, Bataan

In 1986, President Corazon Aquino re-included fish ponds in the Comprehensive Agrarian Reform Program through executive order, which was reinforced through law in 1988. This measure was intended to redistribute fish ponds if their size exceeded 5 hectares (12 acres). Lobbying against this measure, supported by BFAR, resulted in fish ponds once again being exempted in 1995. This was justified as a measure to protect the shrimp farming industry, although it declined nonetheless.

Development of genetically improved farmed tilapia (GIFT) began at Central Luzon State University in 1988. This university partnered with BFAR and the International Center for Living Aquatic Resources in 1992. It began to be used commercially in the mid-1990s.

In the 1990s, fish pens began to be used in Lingayen Gulf and other shallow marine areas, before spreading further both inland and in the ocean. Fish pens were imported from Norway in 1996. Imports from the United States could be used in deeper water and were installed off the east coast. Milkfish continued to dominate aquaculture throughout this period, being able to be farmed across varied environmental conditions. After conflict arose between fish farmers and artisanal fishermen in Pangasinan, due to conflicts over space the environmental damage of supplemental fish farm feeding, 95% of the 3,000 fish pens in Pangasinan were dismantled in 1997 following an Executive Order from President Fidel V. Ramos.

In 1988, aquaculture produced 26.4% of fisheries output. Aquaculture grew 5.42% annually in the decade leading to 1997. In 1995, the Philippines was the fourth-largest aquaculture producer. In 1997, Philippine aquaculture produced 957,546 million tons, which was 34.6% of overall fisheries output and worth PHP27,400 million. At this time, 68% of all freshwater fish ponds were in Central Luzon.

The fishpond land lease system was preserved in the Philippine Fisheries Code of 1998, although the maximum area was decreased to 250 hectares (620 acres) for corporations. In 1998, the first commercial farming of tilapia able to survive in brackish water took place in Negros Occidental, in this case a hybrid of Mozambique tilapia and Oreochromis urolepis hornorum. Tilapia farming began to replace milkfish farming. The GIFT project was spun out into an independent foundation.

From 1980 to 2010, capture fisheries were dominant. Since this time, aquaculture has since increased in relative prominence. In 2012, aquaculture produced an estimated PHP92.3 billion of products. The most farmed product was seaweed, which accounted for 70% of all produce. Aside from seaweed, marine production made up 5% of produce, with brackish water and freshwater making up 12.5% each. There were 790,900 tonnes of fish produced, making up 25.4% of all fish production. The most farmed animals were milkfish, tilapia, and jumbo tiger shrimp.

Municipal fisheries and aquaculture combined produced 73% of all catch from 2011 to 2020. From 2012 to 2021, aquaculture was far more productive than municipal fisheries, whose productivity was in turn slightly higher than that of commercial fisheries. In terms of value the difference was not as large. In 2013, aquaculture made up 41% of fisheries production. From 2013 to 2022, aquaculture production by volume has fluctuated slightly, although its value has increased. In 2019, the Philippines was producing 2.07% of global fisheries (including fish, shellfish, and aquatic plants) production, the eighth-largest amount in the world. This included a 1.01% share of non-plant aquaculture production (858.28 thousand metric tons), and a 4.19% share of total plant aquaculture production (1.50 million metric tons). The production of seaweed through aquaculture grew from 707.0 thousand tonnes in 2000 to around 1,500 thousand tonnes annually in the years since then.

In 2021, 2.25 million metric tons were produced from aquaculture, 52.88% of all fisheries production. The most produced item was seaweed (1.34 million metric tons, or 31.63% of all fisheries production), which was also among the most exported products. The region with the highest production was Bangsamoro. Nationally, 2.19 million people were employed in fisheries, 11.28% in aquaculture. Bangsamoro produced the most aquaculture products by volume, although in terms of value aquaculture in other regions produced more.

In 2022, there were 2.35 million metric tons of aquaculture products created in the Philippines, 54.15% of all fisheries products in the Philippines, with a total value of around PhP 124.00 billion. The biggest item by volume was seaweed, which at 1.54 million metric tons made up 65.8% of aquaculture production. The largest environment for aquaculture aside from seaweed farms was brackish ponds, followed by freshwater ponds and marine cages. By product type, the second largest by volume and highest by value was milkfish, of which 184,162.33 metric tons (47.47%) were produced in fish ponds and 180,290.27 metric tons (46.47%) were produced in fish cages. Tilapia was third by volume and third by value, with 77.19% of these tilapia being farmed in fish ponds. Shrimp was fourth by volume and second by value, with the most produced and most valuable shrimp being jumbo tiger shrimp. Seaweed farms produced the fourth-most value.

In 2022, seaweed was the highest-produced product by volume, with 1,544,959.98 metric tons produced. This created a value of PhP 16,60 billion, less than some other fishery products due to seaweed having a lower value per unit weight. Large volumes of seaweed production meant Bangsamoro was the region producing the most aquaculture products, with its 1,042,064.26 metric tons being 97.95% seaweed (66.07% of national seaweed production). The region producing the most value from aquaculture however was Region III, which produced 300,345.65 metric tons worth over PhP 40 billion. Much of this was tilapia, which made up 48.61% of Region III’s production by volume and 28.25% by value. The value of Bangsamoro’s aquaculture products was PhP 11.57 billion.

External links

• Fisheries Administrative Order No. 214 Code of Practice for Aquaculture in the Philippines
• P. B. Sivickis (March 30, 1929). "Modes of Distribution of the Mudfish in the Philippines". Nature. 123: 493. doi:10.1038/123493a0.
• "Mudfish breeding and culture" (PDF). Bureau of Fisheries and Aquatic Resources. December 2012.