Atolls are ring shaped coral reefs including a coral rim that encircles a lagoon partially

or completely and with or without a coral island/cays on the rim. Most of the world’s atolls

are in the Pacific Ocean and Indian Ocean. Lakshadweep islands, Maldives and the Chagos

Archipelago are the atolls in the Indian Ocean. Lakshadweep are the only atoll islands in

India. They lie scattered in the Arabian Sea between Latitude 8.26° to 12.4° N and Longitude

71.7°-73.75° E, comprising of 36 islands, 3 reefs and 5 submerged banks. These islands

consist of coral formations built upon the Laccadive-Chagos submarine ridge rising steeply

from a depth of about 1500 m to 4000 m off the west coast of India. While the total land

area is 30 sq.km, the length of the coastline is 132 km and lagoon area of 4200 sq.km. Its

territorial water spread is 20000 sq.km and it constitutes 0.4 million sq.km to the EEZ of

Indian Union. Out of the 36 islands, 11 are inhabited with a population of 64,473 (2011

census). The atolls have 4 distinct biomes comprising of the islands, lagoons, reefs and the

Open Ocean. Few threats to the atoll systems are sea level rise, salt water intrusion, reduced

availability of fresh water, coral bleaching, disturbances to reef ecosystem, shrinking of

livelihood and excessive dependence on external resources, excessive harvest of reef

resources etc

Abdul Azeez, P

Koya, Mohammed

CMFRI Digital Repository

Winter School on Structure and Function of the Marine Ecosystem : Fisheries 381Fisheries in atolls- tradeoffs between harvest and conservationIntroductionAtolls are ring shaped coral reefs including a coral rim that encircles a lagoon partiallyor completely and with or without a coral island/cays on the rim. Most of the world’s atollsare in the Pacific Ocean and Indian Ocean. Lakshadweep islands, Maldives and the ChagosArchipelago are the atolls in the Indian Ocean. Lakshadweep are the only atoll islands inIndia. They lie scattered in the Arabian Sea between Latitude 8.26° to 12.4° N and Longitude71.7°-73.75° E, comprising of 36 islands, 3 reefs and 5 submerged banks. These islandsconsist of coral formations built upon the Laccadive-Chagos submarine ridge rising steeplyfrom a depth of about 1500 m to 4000 m off the west coast of India. While the total landarea is 30 sq.km, the length of the coastline is 132 km and lagoon area of 4200 sq.km. Itsterritorial water spread is 20000 sq.km and it constitutes 0.4 million sq.km to the EEZ ofIndian Union. Out of the 36 islands, 11 are inhabited with a population of 64,473 (2011census). The atolls have 4 distinct biomes comprising of the islands, lagoons, reefs and theOpen Ocean. Few threats to the atoll systems are sea level rise, salt water intrusion, reducedavailability of fresh water, coral bleaching, disturbances to reef ecosystem, shrinking oflivelihood and excessive dependence on external resources, excessive harvest of reefresources etc.Marine Biodiversity of Lakshadweep: Corals are represented by 148 species; fish-126 families and 601 species; crustaceans-68 species; mollusks-227 species; sponges-91species; mangroves-2 species; seaweeds-114 species; echinoderms-78 species, sea grass-6species; sea turtles-4 species; 101 species of birds and 12 species of cetaceans. Pitti, a tinysand bank situated nearly 24km northwest of Kavaratti with an area of only 1.21 ha is anIsland of Birds. This is a breeding ground for 4 species of terns and therefore the island hasgreat significance since such breeding colonies are very rare in the Indias territorial areas.Fishes: The fishes that occur in the coralline niches of the lagoon exhibit the characteristicvariety of colours and mainly consist of perches, gar-fishes, half-beaks, scarids, goat-fishes,carangids, grey mullets, antherinids, spyraenids, polynemids, balistids, blennids and globe-fishes (Balan, 1958; Kumaran et al., 1989). Jones and Kumaran (1980) recorded 603 speciesof fish from the Laccadive archipelago. The offshore fishery is constituted by fishes viz.,tunnies, wahoo, sharks, rays, sail fish, flying fish, carangids etc. Fishes such as Crenimugilcrenilabis, Polynemus sexfilis, Naso tuberosus, Naso unicornis, Gomphousus varius,48C H A P T E R FISHERIES IN ATOLLS- TRADEOFFSBETWEEN HARVEST AND CONSERVATIONK. Mohammed Koya and Abdul AzeezPelagic Fisheries DivisionICAR-Central Marine Fisheries Research InstituteWinter School on Structure and Function of the Marine Ecosystem : Fisheries382Fisheries in atolls- tradeoffs between harvest and conservationNovacutichthys taeniurus and Anampses diadematus are common in the waters ofLakshadweep (James et al., 1989). Of the 603 species of marine fishes belonging to 126families that are reported from the islands, at least 300 species are of ornamental value. Theornamental fish such as Abudefdus, Amphiprion, Apogon, Coris, Balistes, Platax are commonin Lakshadweep lagoons (Murthy et al., 1989).Fisheries in the islandsPresent day fisheries in Lakshadweep are built on the traditional fishing and tradepractices prevalent ever since settlement in the islands. Fishing here range from hand picking,cloth fishing, spear fishing, cast netting etc. in the lagoons to pole and line, troll line, handline,harpooning etc. in the deeper areas of the sea around the islands. Plank built country canoesor modified country canoes with or without outboard motors are the basic craft. Opendecked Pablo type boats, motorized using inboard engines are the major fishing crafts in allthe islands. Principal fishing method- Pole & Line is presently practiced in such boats. Oflate, a modified version of these boats, which are larger and with wheel house on the stemare gaining popularity in the islands.The fisheries in the islands can be broadly divided into Tuna Fishery and Non Tunafisheries. Tuna fisheries comprise mainly of capture of oceanic tunas- skipjack (Katsuwonuspelamis) and Yellwofin tuna (Thunnus albacores). Other tunas like the Little tunny (Euthynusaffinis), Bullet tunas (Auxis spp) and the Dog tooth tuna (Gymnosarda unicolor) also formcatch at varying rates in differentseasons. Non-tuna f isheriescomprises of fishing for other largepelagic resources like rainbowrunner, Mahi mahi, Wahoo, sharksrays etc. and Reef associated fisheslike snappers, groupers, carangids,full beaks, half beaks etc. The fishinggrounds for these resources are thedeep sea in the vicinity of all theislands, reef areas and submergedbanks. It may be noted that theprincipal f ishing methods in theislands are hook and line based,which are considered to be the mostideal fishing tackle in view of itsselectivity and harvest limitations. Use of gillnet, the only major net used for fishing arelimited to reef and lagoon areas for reef associated resources like the fullbeaks and halfbeaks.Fig. 1. Gross catch composition of island fisheriesWinter School on Structure and Function of the Marine Ecosystem : Fisheries 383Fisheries in atolls- tradeoffs between harvest and conservationTuna fisheriesLakshadweep islands have situational advantage of being located in the migratory pathsof the oceanic tunas like the skipjack and yellowfin. Tunas constitute nearly 78% of the totalcatch with skipjack alone forming nearly 50% of the fish landing in the islands followed byYellowfin (nearly 25%). Tunas are principally caught by the Pole & Line method contributingnearly 80% of the tuna catch followed by troll lines and handlines. Skipjack tuna is almostentirely caught by the Pole and Line method and Yellowfin by Handline and Pole & Line.Troll line fishing is used mainly for catching neritic tunas like the Little tunny and Bullettunas though skipjack and yellowfin are also occasionally caught in this gear. The Dogtooth tuna is almost entirely caught by handlines.Pole and Line: A sustainable fishing methodThe traditional system of pole and line fishing for capturing tunas is widely employedin all the islands. Minicoy, Agatti and Kavaratti are the islands leading in pole and linefishing. This ifhsing method has been Minicoy’s asset from time immemorial which waslater extended to all other islands in the 1960s. Nationwide mechanization drive in the1970s added impetus to adopting pole and line fishing by fishers of all the islands. Animportant mechanization in this fishing method was the replacement of hand splashing ofwater with mechanical water spraying system, using a pump connected to an auxiliaryengine introduced by the fisheries department in 1984. This modification, besides savinglabor costs improved the efficiency of the fishing method considerably.The hook and line fishing methods are targeted fishing gears and have very less or nobycatch. All these gears catch one fish at a time, popularly known as ‘one-by-one’ fishing.Such fishing gears are selective as they fish from identified shoals of fishes. Bycatch, especiallysensitive bycatch like turtles, mammals, birds, juveniles etc. don’t form catch in most often.Pole & Line is an efficient fishing method catching more fishes in short time. Live-baits areessential for the pole & line fishing and hence this method of fishing has a subsidiaryfishing activity for collection of live baits. Live baits are collected from the lagoons and nearreef areas using boat seines and stored in the live bat tank on board. Live-bait collection isdone during the early morning hours. After collecting sufficient baits, the boats set out tothe deep sea beyond the lagoons scout for tuna shoals often in the vicinity of the islands.Once, a shoal is located, the boats steer close to the shoal and move in the direction of thefish shoal, splashing water continuously with occasional broadcasting of live baits. The pole& line fishermen will now swing into action and hooking of fishes will continue until theboat is filled up or till the shoal disappear.Winter School on Structure and Function of the Marine Ecosystem : Fisheries384Fisheries in atolls- tradeoffs between harvest and conservationFishery for Other resourcesThe major non-tuna species or groups that form considerable fishery in the islands arethat for full beak and half beak using gillnets fished inside or outside the lagoons, especiallyduring the monsoons months. Wahoo fishing using spear and troll lines are good fisheryduring post monsoon months. Mahimahi, rainbowrunner, carangids, barracudas etc. formminor catch in troll lines all through the year. The reef associated fishes that are caughtusing handlines in the near reef areas and seamounts are the groupers, snappers, grunts,sweet lips, parrotfishes, wrasses, trigger fishes etc.Shark fishery: Shark fisheries are one the ancient fishery still continued though at avery low scale following traditional single or multi-hook long lines in most of the islands.Fig. 2. Pole & line boatFig. 3. Bait fishingWinter School on Structure and Function of the Marine Ecosystem : Fisheries 385Fisheries in atolls- tradeoffs between harvest and conservationLarge mesh drift gillnetting done during monsoon months also catch sharks along withother large pelagics. The most common species of sharks that occur in Lakshadweep arethe Spade-nose shark/Yellow dog shark, Scoliodon laticaudus and the Milk shark, Rhizopriodonacutus (Devdoss et al., 1985). The Blacktip Shark, Carcharhinus limbatus and Hammerheadshark, Sphyrna mokarran are also commonly found in the waters around Lakshadweep(Hanfee, 1997; Basudev Tripathy, Pers. Obs.).Other Traditional Fishing practices in the islandsOwing to the typical geographical features of an atoll and its natural isolation frommainland, the people of the islands have used varieties of indigenous methods for catchingfishes and other marine creatures from lagoon and the adjoining sea for food. Some of theimportant fishing activities/gears used in lagoons given in table 1.Table 1: fishing activities/gears used in lagoonsLocal Name Description Target ResourceAppal kuthal Octopus hunting using sharp iron spears OctopusChilla Fishing using wooden spike Flying fishes, Garfishes, half beaksChadal Harpooning for catching fish WahooBala adiyal Shore seine, used mainly in the western Juvenile and sub-adults of reeflagoon associated fishesBala attal Long, small meshed nets used inside the Juvenile and sub-adults of reeflagoons around the island associated fishesBala fadal Large drag net involving 15-30 people, Juvenile and sub-adults of reefoperated in both eastern and western associated fisheslagoons together with scare linesBala idal Set gillnets in the lagoon Reef associated fishes, sharks, rays etc.Cast net Small mesh cast net operated in the lagoon Juvenile of carangids, surgeons,from shore during low tide damsels etc.Nool bikel Baited hook and line set from shore or from Snappers, carangids etc.a boatKalmoodal  “Boulder trap” – a net set around a coral Juvenile of reef associated fishesboulder which is then agitated using rods todrive out fish.Kurakkal Light and spear or sword. Not commonlyused, only practised in shallow water Juvenile of reef associated fishesRod and line Baited hook and line, used opportunistically Sub adults of Reef associated fishesaround the island and mainly from the shoreShal kakal Gillnet set in reef channels, used mainly Reef associated fishes like snappers,during the monsoon and at spring tide. carangids, etc.Winter School on Structure and Function of the Marine Ecosystem : Fisheries386Fisheries in atolls- tradeoffs between harvest and conservationCoral reefs and their importance to island fisheriesIslands are formed inside the lagoon of atoll through continuous accumulation of coralsand due to wave action driven mainly by the South-west monsoon. Shore of these islandsare protected from the hazards of the waves by the reef crest as all the waves surf on thereef crest before proceeding to the shore as low energy waves. The lagoons are doing anexcellent service by way of being the nursery grounds for the fishes and other organismsbesides being home to a plethora of flora and fauna, especially the corals. It is estimatedthat the coral lagoon of Lakshadweep is the habitat for about 75 species of marine ornamentalfishes belonging to 13 families. Similarly, the lagoon is the source of live-bait fishes, whichis the most essential component of the Pole & Line fishery of Tuna. The rich bio-diversity ofthe coral lagoon is also the base for the development of tourism in the Lakshadweep forevents like coral reef diving and snorkeling. Therefore, the survival of these islands fullydepends on the survival of the coral reefs and the lagoon ecosystem. Scientific managementof resources within the coral reefs therefore is of paramount importance.Conservation of the Atoll EcosystemExtraction of marine resources is the major anthropogenic threat to the ecosystem.Harvest of the natural resources therefore should be at levels that can be regained withnatural recruitment and rebuilding. Every organism in the lagoon performs an ecologicalservice and therefore the harvest should be balanced not affect the ecosystem functioning.Many fishes inhabiting the lagoons like the parrot fishes do the service of cleaning the coralboulders of algae and other foulers to create space suitable for attachment by the corallarvae leading replenishment of corals. Similarly, many herbivore fishes like the surgeonfishes, butterfly fishes etc. do such services. Dependence of lagoon for fish supply is muchlimited in Lakshadweep as the major commercial fishing activity is tuna based. This makesthe fishing in the islands more sustainable. Besides, there are quite a lot of conservationsmeasures adopted by the Govt in tandem with the international obligations.Compliance to National and International ObligationsThe point number 11 of the Aichi biodiversity targets, says that “By 2020, at least 17percent of terrestrial and Inland water, and 10 percent of coastal and marine areas, especiallyareas of particular importance for biodiversity and ecosystem services are conserved througheffectively and equitably managed, ecologically representative and well connected systemsof protected area and other effective area based conservation measures, and integratedinto the wider landscape and seascapes”, which is integrated in India’s National BiodiversityTargets, 2012-2020. The Environment Protection Act (1986) provides for identification ofecologically sensitive areas based on the sensitivity and conservation value of a spatial unit.In case of Lakshadweep islands, the Integrated Island Management Plans, prepared as perWinter School on Structure and Function of the Marine Ecosystem : Fisheries 387Fisheries in atolls- tradeoffs between harvest and conservationthe Island Protection Zone Notification (2011), demarcate the preservation and conservationzones for spatial conservation of the coral reef areas. The Pitti Island, because of being abird nesting area has been declared as an MPA. The report of the Planning Commission ofIndia (2008) proposed to declare one or two reefs among the Suheli par, Baliyapani par,Cheriyapani par and Perumal par as Marine National Park to protect and preserve the marinebiodiversity. The Bombay Natural History Society, based on a detailed study on the giantclam resources in the Islands proposed declaring the reefs of Agatti Island to be aconservation reserve. International Union for Conservation of Nature (IUCN) andoceanographer Sylvia Earle of Mission Blue named 31 new hope spots, among them Andaman& Nicobar and Lakshadweep islands have been named as the new “hope spots” from India.A Hope Spot is an area of ocean that merits special protection because of its wildlife andsignificant underwater habitats. Some are already formally protected, while others still needprotection.

Fisheries in atolls- Tradeoffs between harvest and conservation

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Fisheries in atolls- Tradeoffs between harvest and conservation

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