Aquaculture makes up a substantial proportion of the overall output of Philippine fisheries. It 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 + Philippine water resources Area Details Total ocean Shallow marine water (≤ deep) Inland waters Freshwater swamps Brackish swamps Lakes Rivers Reservoirs Philippine marine waters include of ocean surrounding of coasts. Inland waters are made up of both brackish and freshwater areas, and include 23 lakes over . The Philippine fisheries in these waters include a large aquaculture component, which as of 2022 produced 54.15% of total fisheries volume.
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 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. In total, there are of fish ponds, of which are brackish and freshwater.
Products farmed
Overall, the top five commodities are milkfish, tilapia, jumbo tiger shrimp, seaweed, and mudcrab. The main two fish commodities are 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 jumbo tiger shrimp is a native species, and can be grown in fresh and salty water. 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
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. Aquaculture products are grown both from stock hatched in captivity and from wild-caught juveniles. Milkfish can be bred artificially to stock ponds, although many still use wild-caught fry. The orange-spotted spinefoot rabbitfish can be hatched in captivity. Giant freshwater prawn farms rely on seedstock grown in hatcheries or imported. Milkfish aquaculture is thought to use 1.5 billion fry each year. This also requires imports to sustain, with most coming from Indonesia and Taiwan.
Fish ponds Fish ponds, especially in brackish water, are the historical method of aquaculture, and remain widespread. Traditionally, these fishponds are tidally supplied with water and food. It has since developed into a multi-pond system, with fish, especially milkfish, shifted between ponds as they grow. The use of supplementary feed has developed from using rice waste to using commercially produced feed, allowing pond farming to become both more productive and less vulnerable to weather changes.
Milkfish farming in brackish fish ponds uses a variety of techniques used in varying intensities. Shrimp, mostly jumbo tiger shrimp, are also farmed in brackish ponds, sometimes on their own, or sometimes together with or in rotation with milkfish. Intensive shrimp production began on Negros and Panay, although it has spread to other areas. Scylla crabs are also taken from these ponds, with bamboo fences used to keep them inside. Some strains of tilapia have been developed which can survive in brackish water, to allow them to also be farmed in the ubiquitous ponds. The presence of tilapia may also improve the quality of shrimp ponds, producing phytoplankton less likely to facilitate the growth of bacteria that cause the luminous vibriosis disease. Rabbitfish and spadefish can also be farmed in brackish and saltwater enclosures, but more slowly than milkfish. Seabass are occasionally farmed in brackish ponds. As rabbitfish are herbivores, they are cheap to feed.
Freshwater ponds are far less common, as they compete for land with other forms of agriculture, and freshwater fish are not as popular. Where they are used, they mostly farm tilapia, which are much easier for individual farmers to breed than milkfish. Tilapia can also grow in some brackish water, although they are usually considered pests in competition with or predating on milkfish and shrimp. There is a history of small amounts of freshwater pond farming of other introduced species. A small amount of rice-fish systems function as freshwater ponds. These are often unsuccessful, as pesticides may harm fish, and rice growing cycles may not align with fish growing cycles.
A 1977 national study found that around 15% of fish ponds were smaller than , although in total there were less than 1% of all fish pond areas. Over half of fishponds were officially above , including 5% which were above . In 1979, 70% of fish ponds in Central Luzon were smaller than . 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. Large brackish fishponds often require multiple workers, and large owners often do not work at the ponds. 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. Almost all freshwater fishponds are privately owned.
Fish pond land can be leased from the government for a minimum of 25 years and a maximum of 50 years under the Fisheries Code of 1998. Private land registered as being used for fish ponds can be most valuable as land in itself, and ponds can thus be underdeveloped. Fish pond productivity can be negatively affected by the El Niño–Southern Oscillation. Diseases such as luminous vibriosis impede shrimp farming, and some diseases have become resistant to antibiotics. Other diseases affecting shrimp farms include white spot syndrome, monodon baculovirus, infectious hypodermal and hematopoietic necrosis, hepatopancreatic parvovirus, yellowhead disease, Taura syndrome, shell disease, infectious myonecrosis, and filamentous bacterial disease.
Fish pens and cages
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. Both allow for water to naturally flow through the enclosures. Fish pens can be constructed using bamboo connected with fishing net. They can have high capital costs, that are greatest per unit area for smaller pens. In freshwater areas, they are generally used to farm tilapia, while in marine areas they are often used to farm groupers. Milkfish are farmed in both environments. Different pen sizes are recommended for different species. Fish pens can be damaged by natural disasters, and their operation can be impeded by water hyacinth.