Fish aggrigrating devices(fad)

A fish aggregating device is a man-made object used to attract ocean going pelagic fish such as marlin, tuna and mahi-mahi. 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.
Fisheries aggregating devices (FADs) are human-made structures anchored offshore that attract fish, making them easier to catch so you can have a great fishing experience.

1. FISH AGGREGATING DEVICES(FADs) Ashish sahu

2. INTRODUCTION structures facilitate attraction and aggregation of fish Mediterranean , Southeast Asia and the western and central Pacific Ocean (WCPO) -FADs for the first time... The fishers nicknamed the FAD as “ Fish Bank”.

3. WHAT ARE FADs? Permanent, semi-permanent or temporary structure made of any material used to lure fish Drifting or anchored buoys or rafts that attract and aggregate fish Easier to find and catch Principle- thigmotropism Either drifting or anchored

4. OBJECTIVES to enhance biological productivity and fisheries resources, to rehabilitate and conserve marine habitats that have been adversely affected by fishing activities to generate the recovery, conservation and increase the fisheries resources

5. FLOATING OBJECTS AGGREGATES FISH BECAUSE, they provide a refuge from predators a meeting place for schooling companions a place of orientation a substrate for species undergoing a change from pelagic to other modes of existence a feeding place they duplicate natural aggregators such as Sargassum seaweed .

6. Various Hypotheses Of Fish Aggregating Devices Tuna aggregation theories Forage base hypothesis Predator avoidance FADs aggregate prey items for the tunas Meeting point hypothesis The ecological trap hypothesis

7. ADVANTAGES Biological productivity in the coastal waters. Rehabilitate and conserve the depleting stocks. Increases the catch rate with a reduction in the cost of production. Reducing the scouting time. Enhances the fishery resources. Enhances the income and standard of living

8. DESIGN Drifting FADs are not attached to the bottom -can be natural objects such as logs or man-made. Moored FADs occupy a fixed location ,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 (mid water FAD) to avoid detection and surface hazards such as weather and ship traffic.

9. midwater FADs – only surface component - a small marker buoy - less subject to stress from wind and waves and the risk of damage by ships. subsurface FADs last longer (5–6 years) due to less wear and tear, but can be harder to locate the upper section of rope is made from heavier-than-water metal chain buoy detaches - rope sinks and there by avoids damage to passing ships Smart FADs include sonar and GPS capabilities - remotely contact it through satellite - determine the population under the FAD.

10. CLASSIFICATION OF FADs

11. ANCHORED FADs FADs occupy a fixed location and attach to the sea bottom using a weight such as a concrete block. placed either on the surface or submerged in the water column Principal components –a float, mooring line ,anchor and underwater structures and attractant

12. DRIFTING FADs drifting /floating objects(trees, logs, planks, abandoned fishing nets and buoys , or around live animals- whale sharks, large marine Mammals). man-made drifting FADs , natural drifting FADs, floating objects and live animal FADs. with radio buoys- radio signals-pre-set frequencies fitted with transmitter beacons or sonar

13. Anchored FAD Drifting FAD

14. category Fad types User groups objective catch Industrial Drifting and anchored Purse seine and pole and line fleets Used by fishing comp anies in support of industrial scale vessels that target large tuna schools. High artisanal All anchored(offshore , near shore and lagoon) Subsistence ,recreational and artisanal fishers Set by government fisheries agencies to improve food security and small scale domestic fisheries’ development, including sport fishing tourism. low

15. Benefits of artisanal FADs Food security Vessel efficiency Coastal resource management (fishing efforts from reef to open ocean) Climate change adaptation:(resilience of coral reefs) Tourism & Safety at sea (defined fishing zones around FADs) increased catch per unit effort (CPUE) Reduction in fishing costs (mainly fuel)

16. Problems With Artisanal FADs short lifespan user conflicts budget constraints: (insufficient human financial resources)

17. Benefits Of Industrial FADs Increased catch rate Efficiency. Domestic development. Distribution of effort and license revenue( to some EEZs where fishing on non-FAD schools is inefficient.

18. Problems with industrial FAD fishing Over fishing Juvenile fishing (purse seine) Non targeted fishing

19. SITE SELECTION CRITERIA FOR INSTALLATION OF FAD firm seabed with sandy bottom & areas with a gentle sloping sea floor than a steep drop-off free from strong currents & should be accessible to fishermen. should have adequate water quality selected area should be away from navigational routes . reasonable depth of water (750 to 1500 m for offshore FADs and 200 to 400 m for inshore FADs),distance between two FADs (usually 10 - 12 nm apart).

20. Specifications For Anchored FAD Sites away from the coast, reefs, reserves or whale sanctuaries so as not to interfere with natural fish aggregations. 4–5nm from the shore or reefs & 10–12 nm apart, water depth -100 and 1500m currents-stronger near narrow passes and around points-area should be avoided. shipping lanes, submarine communications cables, underwater pipelines, and any other submarine structures can be avoided. permit to install from the competent authorities and a detailed survey initiated.

21. MATERIAL SELECTION FOR FAD Should be durable & long lasting Should be cheap & easily available Should not have toxic content Ease of handling & transportation

22. CONSTRUCTION Anchored FAD - principal components: an upper mooring, a lower mooring, and a catenary curve. The main cost-in the mooring line - the deeper the FAD site, the greater the cost. Braided mooring rope is undoubtedly stronger than three-strand rope & not having the propensity to twist,but cost 2 - 3times. Other factors -type of buoy and the type and size of anchor.

23. radar reflectors, solar panels, GPS homing transmitters and echo sounder Concrete and grapnel anchors - expensive Steel and cement readily available ,have to be transported great distances or imported Abandoned machinery parts- complete removal of oil, fluids or any other toxic materials

24. BUOYS FAD buoys usually have some sort of flag, light, or radar reflector or a combination of all. Lights, radar reflectors, electronic devices such as solar panels, GPS homing transmitters, and echo sounders =cost of buoy. Some are more sophisticated with solar panels to charge batteries for the lights echo sounders and sensors (to monitor SST), transmit this data to a vessel or land station. Anchored FADs can also be equipped with a locator beacon.

25. MOORING ROPE entire length of mooring or anchor line - about 120 percent of the depth of water(20%-scope & 100%-mooring line). scope-creating additional jerking forces on the mooring line avoid anchored FAD loss-have too much scope on the surface or on the bottom, the principle of the catenary. chain in the upper mooring - anchored spar buoy FADs-counterweight -spar upright and reduce theft and vandalism.

26. ANCHOR SYSTEM keep the FADs in its proper location FAD anchors -concrete blocks , discarded machinery such as forklift counterweights , oil drums filled with steel tyre rims and concrete , or grapnel anchors made from steel pipe and rebar. Concrete block anchors and rebar grapnel anchors can be expensive to fabricate.

27. CONCRETE BLOCK FAD ANCHOR. FORKLIFT COUNTERWEIGHT FAD ANCHOR. FAD ANCHORS MADE WITH CONCRETE FILLED STEEL OIL DRUMS. GRAPNEL FAD ANCHOR

28. AGGREGATORS aggregators-attached to the buoy or the upper mooring line. of old rope, discarded fishing net, plastic strapping, mussel rope, coconut & nipa frond, mangrove leaves, rubber tyres. any material (bio-degradable material - prefers) aggregate fish by increasing the surface area for marine growth Plastic straps-most effective material for appendages-durable, inexpensive, present minimal drag on FADs system and simple to attach to the mooring line.

29. FAD DEPLOYMENT Buoy first method Safest method deploy the buoy at the site and then steam in a big circle(circumference = length of mooring), . As the vessel- to the original site -all of the mooring rope - in the water then anchor is connected to the mooring and deployed.

30. Straight line method . buoy is deployed at a distance away from the actual anchored FAD site equal to ¾ of the length of the mooring. The vessel then steams toward the site- paying out the mooring rope. It passes over the site continuing to pay out the remaining ¼th of mooring rope. Then the anchor is connected to the mooring rope and deployed. The drag of the mooring and buoy should pull the anchor to the chosen anchored FAD site, much like a pendulum.

31. MAINTENANCE upper mooring -most damage and wear and tear occurs. most vulnerable parts -steel components –shackles & swivels. buoy and top end of the upper mooring should be hauled onto the boat for inspection and repair. buoy, flag, radar reflector, and any lights or electronic devices - serviced at this time.

32. Risks And Threats For & By Anchored FAD Over exploitation Anchored FADs in wrong place-disturb delicate ecosystems. FADs too close together-increased investment coast marine debris:-Anchored FADs break from their moorings short life span pollute beaches and reefs and the open seas

33. ghost fishing alteration of the benthic environment creating a hazard to navigation introduction of synthetic materials into the marine food web additional clean-up cost both anchored FADs and drifting FADs can be a hazard to shipping and boats, particularly at night. conflict between users creates anchored FAD losses and in the long term can undermine the benefits.

34. REFERENCE Journal of aquatic biology and fisheries : Srinivasa Gopal , T.K.and Leela Edwin Anchored fish aggregating devices for artisanal fisheries in south and southeast Asia:benefits and risks :Steve Beverly,Don Griffiths and Robert Lee

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