Community hub
Recent from talks
Knowledge base stats:
Talk channels stats:
Members stats:
Fish aggregating device
A fish aggregating (or aggregation) device (FAD) is a man-made object used to attract pelagic fish such as marlin, tuna and mahi-mahi (dolphin fish). They usually consist of buoys or floats tethered to the ocean floor. Various types of FADs have been employed in the traditional fishing cultures of Island Southeast Asia (especially in the Philippines), Japan, and Malta for centuries. Modern FADs are increasingly being used in modern commercial and sport fishing.
Fish are fascinated with floating objects, which they use to mark locations for mating activities. They aggregate around objects such as drifting flotsam, rafts, jellyfish and floating seaweed. The objects appear to provide a "visual stimulus in an optical void", and offer refuge for juvenile fish from predators. The juvenile fish, in turn attract predators. A study using sonar in French Polynesia, found large shoals of juvenile bigeye tuna and yellowfin tuna aggregated closest to the devices, at distances of 10 to 50m. Further out, 50 to 150m, a less dense group of larger yellowfin and albacore tuna gathered. Yet further out, to 500m, was a dispersed group of mature tuna. The distribution and density of these groups was variable and overlapped. The FADs were also used by other fish, and the aggregations dispersed after dark.
Drifting FADs float with the currents, are not tethered to the bottom and can be man made, or natural objects such as logs or driftwood. They can include sonar and GPS capabilities so that operators can contact it via satellite to assess associated populations.
Moored FADs occupy a fixed location and attach to the sea bottom using a weight such as a concrete block. A rope made of floating synthetics such as polypropylene attaches to the mooring and in turn attaches to a buoy. The buoy can float at the surface (lasting 3–4 years) or lie subsurface to avoid detection and surface hazards such as weather and ship traffic. Subsurface FADs last longer (5–6 years) due to less wear and tear, but can be harder for fishers to locate. In some cases the upper section of rope is made from metal chain so that if the buoy detaches from the rope, the rope sinks and thereby avoids damage to passing ships.
Fish aggregating devices have been traditionally used for centuries by fishermen in Island Southeast Asia, Japan, and Malta.
They are most widespread in the Philippines where traditional FADs are known as payao. Payao are semi-permanent bamboo rafts anchored to the seafloor with rocks. They are usually placed in very deep water, but coastal and shallow-water versions also exist. The rafts are around 4 m (13 ft) long, 1.5 m (4.9 ft) wide, and tapering at one end. Beneath the raft are palm fronds (usually coconut or nipa palm) suspended with weights, usually to a depth of 30 m (98 ft). They have several variants, including simple horizontal bamboo bundles or flat bamboo rafts with attached trailing palm fronds (bonbon), to vertical bamboo bundles with palm fronds on the upper end and "roots" on the submerged end (arong), to double-layered rafts where palm fronds are present both underwater and above-water.
Modern payao have cylindrical, bullet-shaped, or rectangular steel floats that can better withstand rough seas, with cement anchors sunk to depths of up to 5,000 m (16,000 ft) deep. They are harvested using handline fishing, surface trolling, or small-scale purse seining. They are traditionally used to catch pelagic fish (like tuna, mackerel scad, and kawakawa). Payaos can produce catches of up to 200 metric tons of fish. There are thousands of payao anchored in dense networks throughout the Philippines. Payao FADs have been introduced to traditional fishermen in Vietnam, Thailand (where it is known as sung), Fiji, the Solomon Islands, the Federated States of Micronesia, Papua New Guinea, and other countries in Oceania.
In Indonesia, Malaysia, Timor-Leste, and among the Moken people of Myanmar, a very similar traditional method is known as rumpon or roempon in Malay. It uses an anchored bamboo raft supporting a lure line with palm leaves or bundles of grass attached along its length. Fish attracted to the rumpon are caught using dip nets or encircling nets.
Hub AI
Fish aggregating device AI simulator
(@Fish aggregating device_simulator)
Fish aggregating device
A fish aggregating (or aggregation) device (FAD) is a man-made object used to attract pelagic fish such as marlin, tuna and mahi-mahi (dolphin fish). They usually consist of buoys or floats tethered to the ocean floor. Various types of FADs have been employed in the traditional fishing cultures of Island Southeast Asia (especially in the Philippines), Japan, and Malta for centuries. Modern FADs are increasingly being used in modern commercial and sport fishing.
Fish are fascinated with floating objects, which they use to mark locations for mating activities. They aggregate around objects such as drifting flotsam, rafts, jellyfish and floating seaweed. The objects appear to provide a "visual stimulus in an optical void", and offer refuge for juvenile fish from predators. The juvenile fish, in turn attract predators. A study using sonar in French Polynesia, found large shoals of juvenile bigeye tuna and yellowfin tuna aggregated closest to the devices, at distances of 10 to 50m. Further out, 50 to 150m, a less dense group of larger yellowfin and albacore tuna gathered. Yet further out, to 500m, was a dispersed group of mature tuna. The distribution and density of these groups was variable and overlapped. The FADs were also used by other fish, and the aggregations dispersed after dark.
Drifting FADs float with the currents, are not tethered to the bottom and can be man made, or natural objects such as logs or driftwood. They can include sonar and GPS capabilities so that operators can contact it via satellite to assess associated populations.
Moored FADs occupy a fixed location and attach to the sea bottom using a weight such as a concrete block. A rope made of floating synthetics such as polypropylene attaches to the mooring and in turn attaches to a buoy. The buoy can float at the surface (lasting 3–4 years) or lie subsurface to avoid detection and surface hazards such as weather and ship traffic. Subsurface FADs last longer (5–6 years) due to less wear and tear, but can be harder for fishers to locate. In some cases the upper section of rope is made from metal chain so that if the buoy detaches from the rope, the rope sinks and thereby avoids damage to passing ships.
Fish aggregating devices have been traditionally used for centuries by fishermen in Island Southeast Asia, Japan, and Malta.
They are most widespread in the Philippines where traditional FADs are known as payao. Payao are semi-permanent bamboo rafts anchored to the seafloor with rocks. They are usually placed in very deep water, but coastal and shallow-water versions also exist. The rafts are around 4 m (13 ft) long, 1.5 m (4.9 ft) wide, and tapering at one end. Beneath the raft are palm fronds (usually coconut or nipa palm) suspended with weights, usually to a depth of 30 m (98 ft). They have several variants, including simple horizontal bamboo bundles or flat bamboo rafts with attached trailing palm fronds (bonbon), to vertical bamboo bundles with palm fronds on the upper end and "roots" on the submerged end (arong), to double-layered rafts where palm fronds are present both underwater and above-water.
Modern payao have cylindrical, bullet-shaped, or rectangular steel floats that can better withstand rough seas, with cement anchors sunk to depths of up to 5,000 m (16,000 ft) deep. They are harvested using handline fishing, surface trolling, or small-scale purse seining. They are traditionally used to catch pelagic fish (like tuna, mackerel scad, and kawakawa). Payaos can produce catches of up to 200 metric tons of fish. There are thousands of payao anchored in dense networks throughout the Philippines. Payao FADs have been introduced to traditional fishermen in Vietnam, Thailand (where it is known as sung), Fiji, the Solomon Islands, the Federated States of Micronesia, Papua New Guinea, and other countries in Oceania.
In Indonesia, Malaysia, Timor-Leste, and among the Moken people of Myanmar, a very similar traditional method is known as rumpon or roempon in Malay. It uses an anchored bamboo raft supporting a lure line with palm leaves or bundles of grass attached along its length. Fish attracted to the rumpon are caught using dip nets or encircling nets.