Fish aggregating device

A fish aggregating (or aggregation) device (FAD) is a man-made object used to attract ocean going pelagic fish such as marlin, tuna and mahi-mahi (dolphin fish). They usually consist of buoys or floats tethered to the ocean floor with concrete blocks. FADs attract fish for numerous reasons that vary by species.

Fish tend to move around FADs in varying orbits, rather than remaining stationary below the buoys. Both recreational and commercial fisheries use FADs.

Before FADs, commercial tuna fishing used purse seining to target surface-visible aggregations of birds and dolphins, which were a reliable signal of the presence of tuna schools below. The demand for dolphin-safe tuna was a driving force for FADs.[1]

Fish behaviour

Fish are fascinated with floating objects. They use them to mark locations for mating activities. They aggregate in considerable numbers around objects such as drifting flotsam, rafts, jellyfish and floating seaweed. The objects appear to provide a "visual stimulus in an optical void",[2] and offer refuge for juvenile fish from predators.[3] The gathering of juvenile fish, in turn, attracts larger predator fish. A study using sonar in French Polynesia, found large shoals of juvenile bigeye tuna and yellowfin tuna aggregated closest to the devices, 10 to 50m. Further out, 50 to 150m, was a less dense group of larger yellowfin and albacore tuna. Yet further out, to 500m, was a dispersed group of various large adult tuna. The distribution and density of these groups was variable and overlapped. The FADs were also used by other fish, and the aggregations dispersed when it was dark.[4]

FAD types

Drifting FADs are not tethered to the bottom and can be man made, or natural objects such as logs or driftwood.

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 to locate. In some cases the upper section of rope is made from heavier-than-water metal chain so that if the buoy detaches from the rope, the rope sinks and thereby avoids damage to passing ships who no longer use the buoy to avoid getting tangled in the rope.[5]

Smart FADs include sonar and GPS capabilities so that the operator can remotely contact it via satellite to determine the population under the FAD.

Scope

Drifting FADs are widespread in the Atlantic, Pacific and Indian ocean purse seine fisheries. They catch over 1 million tons of tuna (nearly one-third of the global tuna total) and over 100,000 tons of by-catch in the vicinity of FADs as of 2005.[6] Skipjack Katsuwonus pelamis, Bigeye tuna Thunnus obesus and yellowfin Thunnus albacares tuna are the three primary tropical tuna species that FADs target. Other fish include albacore, dolphin fish, wahoo, blue marlin, striped marlin, mako shark, silky shark, whitetip shark, galapagos shark, mackerel, and bonito.[5]

Before FADs, pelagic purse seiners targeted free-swimming schools of tuna. Increasing FAD use over the past 30 years has increased the productivity of the fishing fleet, but has significant side-effects. The average FAD-caught fish is smaller and comes with relatively large bycatch raising concern about declining populations of several species of pelagic sharks.

The U.S. state of Hawaiʻi operates 55 surface FADs around its islands to support sport fishing and marine research.[5]

See also

References

  1. ^ Armstrong WA and Oliver CW (1996) Recent use of fish aggregation devices in the eastern tropical Pacific tuna purse-seine fishery: 1990-1994 Administrative report LJ-96-02, Southwest Fisheries Science Center, NOAA.
  2. ^ Hunter, JR and Mitchell CT (1966) "Association of fishes with flotsam in the offshore waters of Central America". US Fishery Bulletin, 66: 13-29. https://www.st.nmfs.noaa.gov/spo/FishBull/66-1/hunter.pdf
  3. ^ Kingsford MJ (1993) [ "Biotic and abiotic structure in the pelagic environment: Importance to small fishes] Bulletin of Marine Science, 53(2):393-415. https://www.researchgate.net/publication/233550840_Biotic_and_Abiotic_Structure_in_the_Pelagic_Environment_Importance_to_Small_Fishes
  4. ^ Josse E, Dagorn L and Bertrand A (2000) "Typology and behaviour of tuna aggregations around Fish Aggregating Devices from acoustic surveys in French Polynesia" Aquatic Living Resources, 13(4): 181-190. doi= 10.1016/S0990-7440(00)00051-6
  5. ^ a b c "The FAD FAQ". Retrieved September 2, 2009.
  6. ^ "Does fishing on drifting fish aggregation devices endanger the survival of tropical tuna?". Science News. 15 May 2008. Retrieved September 3, 2009.

External links

Bite indicator

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Clonk (fishing)

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The process of clonking may look an easy job at first, but it requires some practice. The air bubble produced when the clonk strikes the water is cut by the fork and this produces a unique sound similar to opening a wine bottle. This sound stimulates the defensive instinct in nearby catfish and they attack the "intruder", which in this case is the bait.

Dropline

A dropline is a commercial fishing device, consisting of a long fishing line set vertically down into the water, with a series of fishing hooks attached to snoods.

Droplines may be set either down underwater cliffs or just in the water column. They have a weight at the bottom of the line and a float at the top. They are not usually as long as longlines and have fewer hooks.

Droplines can be contrasted with trotlines. Whereas a dropline has a series of hooks suspended vertically in the water, a trotline has a series of hooks suspended horizontally in the water.

Fad (disambiguation)

A fad is a practice or interest followed for a time with exaggerated zeal.

Fad or FAD may also refer to:

Flavin adenine dinucleotide is a redox cofactor chemical compound.

Fad Browne (1906–1991), Irish politician

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First appearance datum, the date of the oldest known fossil of a living species

Fish aggregating device, for fishing

Wagi language of Papua New Guinea, ISO 639-3 code

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Finished After Deadline, a sailing finish occurring after the official timing of the race has ended; compare with Did Not Finish

Fishing basket

A fishing basket is a basket used for fishing.

Fishing gaff

In fishing, a gaff is a pole with a sharp hook on the end that is used to stab a large fish and then lift the fish into the boat or onto shore. Ideally, the hook is placed under the backbone. Gaffs are used when the weight of the fish exceeds the breaking point of the fishing line or the fishing pole. A gaff cannot be used if it is intended to release the fish unharmed after capture, unless the fish is skilfully gaffed in the lip, jaw, or lower gill using a thin gaff hook.

A "flying gaff" is a specialized type of gaff used for securing and controlling very large fish. The hook part of the gaff (the head) detaches when sufficient force is used, somewhat like a harpoon's dart. The head is secured to the boat with a length of heavy rope or cable.

Fishing rod tapers

Fishing rod tapers describe how much a fishing rod bends or flexes under pressure. Different tapers are used for different fishing scenarios as well as for personal preference.

Hawaiian sling

The Hawaiian sling is a device used in spearfishing. The sling operates much like a bow and arrow does on land, but energy is stored in rubber tubing rather than a wooden or fiberglass bow.

Hip boot

Hip boots, or hip waders as they are sometimes called, are a type of tall boot initially designed to be worn by river fishermen. Hip boots are typically made out of rubber, and completely cover the legs, up to the tops of the thighs or all the way up to the waist. Hip boots are designed to protect the fisherman from water, and allow wading out into deeper waters in hopes of getting a bigger catch. They also help to keep the feet and legs warm in autumn and winter. Hip boots are also worn by many ecologists and environmental scientists who do tests in swamps or lakes to determine the quality of water.

Hip boots are necessary footwear during flooding, and can be a part of everyday city raingear in order to protect from heavy showers (currently most popular in Japan and Russia as female footwear, usually worn with jeans and raincoat).

Hookset

In recreational fishing terminology, the hookset (setting the hook or striking) is a motion made with a fishing rod in order to "set" a fish hook into the mouth of a fish once it has bitten a fishing lure or bait. That is, in order to secure the fish on the hook, a sharp motion is performed to push the barb of the hook into the fish's mouth, preferably in the corner. If this motion were not performed, while it is possible for a fish to set itself, the likelihood of successfully landing the fish is minimal since, without the barb of the hook secured, the fish could shake the hook out of its mouth. The motion is usually a sharp, sweeping motion of the rod, either upwards or to the side, depending on the orientation of the rod at the moment the fish bites. Some fishermen will perform several hooksets in quick succession to ensure that the fish is securely hooked, especially on fish with tough mouths such as some saltwater species. In contrast, anglers using circle hooks needn't set the hook, since the hook's design allows it to set itself when the angler reels in.

Lift net

Lift nets, also called lever nets, are a method of fishing using nets that are submerged to a certain depth and then lifted out of the water vertically. The nets can be flat or shaped like a bag, a rectangle, a pyramid, or a cone. Lift nets can be hand-operated, boat-operated, or shore-operated. They typically use bait or a light-source as a fish-attractor. Lift nets are also sometimes called "dip nets", though that term applies more accurately to hand nets.

Major General Wallace F. Randolph (ship)

USAMP Major General Wallace F. Randolph, sometimes also known as MG Wallace F. Randolph, was a 188.2-foot (57.4 m) mine planter built by the Marietta Manufacturing Company, and delivered to the United States Army Mine Planter Service in 1942. The ship was transferred to the U.S. Navy in 1951, placed directly into the Atlantic Reserve Fleet without being commissioned classed as the auxiliary minelayer ACM-15, then reclassified minelayer, auxiliary (MMA) and named MMA-15, and finally given the name Nausett without any active naval service. After being stricken from the Naval Vessel Register, the ship was transferred to different owners, and eventually was scuttled off the coast of Florida as an artificial reef and fish aggregating device. The site is currently known as the Thunderbolt Wreck, and is considered to be an excellent and challenging dive site for advanced divers.

Muroami

The muro-ami fishing technique, employed on coral reefs in Southeast Asia, uses an encircling net together with pounding devices. These devices usually comprise large stones fitted on ropes that are pounded into the coral reefs. They can also consist of large heavy blocks of cement that are suspended above the sea by a crane fitted to the vessel. The pounding devices are repeatedly and violently lowered into the area encircled by the net, literally smashing the coral in that area into small fragments in order to scare the fish out of their coral refuges. The "crushing" effect of the pounding process on the coral heads has been described as having long-lasting and practically totally destructive effects.

Payaos

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Power pro

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One note in using Power Pro, the drag has to be set at a much lighter strength than compared to monofilament due to the propensity for Power Pro to dig into itself while fighting large fish.

Sandsinker

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Spoonplug

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Surrounding net

A surrounding net is a fishing net which surrounds fish and other aquatic animals on the sides and underneath. It is typically used by commercial fishers, and pulled along the surface of the water. There is typically a purse line at the bottom, which is closed when the net is hauled in.

Swimbait

Swimbaits are a loosely defined class of fishing lures that imitate fish and tend to be distinct in design from a typical crankbait.Swimbaits are usually different from crankbaits by the way they generate lure action. Some are rubber "paddle tail" lures that appear to swim when the tail flutters during retrieve. Some are jointed baits that wave like a flag in the water when retrieved, without any obvious mechanism to generate motion. Some are large jointed crankbaits or crankbait/plastic lure hybrids.

Swimbaits originated as lures designed to imitate the planted

rainbow trout in Southern California reservoirs that

Largemouth Bass and Striped Bass

fed on. They were larger and more lifelike imitations than most

available mass-produced lures.

The term swimbait is often used to indicate plastic "paddle tail" lures, regardless of size or appearance.

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