The paper detailed about the ancillary living marine resources of Lakshadweep. Sea weeds, crustaceans, molluscs, sponges, echinoderms, reptiles such as turtles, birds etc, are treated here as ancillary resources

Appukuttan, K K

George, K C

Gopakumar, G

Thomas, P A

CMFRI Digital Repository

V. MARINE FISHERIES INFORMATION SERVICE SPECIAL rSSlJE ON LAKSHADWEEP 71° 72 BITRA 0 .» CHETLAT 'J» KIUTAN ^KADMAT rhinakara, ^ *>•> j'/ Bangarairy,S> ,'' / K<3lP'* ' . 2 , ^KAVARATTI Suheli valiakara. Suheli cheriakard 71' No, 68 1986 LAKSHADWEEP GROUP OF ISLANDS Names of inhabited islands Q\% written inronnan letters and uninhabited in ifalics ANCILLARY LIVING MARINE RESOURCES OF LAKSHADWEEP K. C. George, P. A. Thomas, K. K. Appukuttan and G. Gopakumar Central Marine Fisheries Research Institute, Cochin Introduction Till recently the Lakshadweep archipelago was not investigated upon seriously from a resource point of view. In the latter half of the 19th century attempts have been made by some British naturalists to study the fauna and flora of the Lakshadweep and Maldive Archi-pelagoes. (Alcock, 1895 - 1900, 1902; Borradaile, 1903; Betts, 1930 and Burton, 1940). Obser-vations of a general nature on fish and fisheiies of the islands were subsequently made by Ayyangar (1922), Mathew and Ramachandran (1956) and Balan (1958). However, published information on the marine living resources of the Lakshadweep, other than those of tunas and corals are rather scattered and scanty. While the major commercially important resources like the corals, tunas and other fish resources of the archipelago are dealt with elsewhere in this volume, here the potential ancillary resources are touched upon. Sea weeds, crustaceans, molluscs, sponges, echino-derms, reptiles such as turtles, birds etc, are treated here as ancillary resources. There are few others like the beautiful coral reef fishes which are of potential value as an export item for marine aquaria all over the world. Of the above, only the marine algae have been syste-matically surveyed from a resource assessment angle (Anon, 1979), by the Central Salt and Marine Chemicals Research Institute. Information on the others are based on faunistic observations conducted now and then by dilferent workers. Algae Ten islands (Kavaratti, Agatti, Bangaram, Amini, Kadmat, Chetlat, Kiltan, Androth, Kalpeni and Mini-coy) were surveyed for the marine algal resources during the 1977-79 period and estimates of the standing crops were made. Marine algal distribution was generally sparce and heterogenous. All islands except Bangaram supported the growth of marine algae. The biomass estimates (wet) of the standing crop for all Lakshadweep islands covering an area of l,334ha was estimated to be within 4,940-10,110 tonnes con-sisting of 980-2, 100 tonnes of agarophytes, 10-16 tonnes alginophytes and 3,950-7,980 tonnes of others. The major agarophytes observed were Gelidiella acerosa, Gracilaria edulis, Gelidium rigidum and Gelidio-psis repens. Alginate resources were meagre represen-ted by Turbinaria and Sargassum, observed in Kalpeni, Androth and Minicoy. Among the sea weeds categoried as 'others' Halimeda, Dictyota, Laurencia, Jania, Toly-piocladia, Caulerpa and Chondrococcus constitute more than 75% and are potentially useful sea weeds. Altogether 82 species of sea weeds were collected during the survey, of which only 60 species are found in esti-mable quantities. Fig. 1. Gelidiella acerosa one of the very common sea weed resource in the Lakshadweep. 46 Halimedia gracilis was the most abundant form occurring in lagoon and reef areas. Gelidiella acerosa occurred in all islands except Chetlat and Kihan. It is reported that the agarophyte resource with a preponderance of Gelidiella acerosa offer an immedia-tely exploitable resource for establishing an Agar agar production unit. Kalpeni, Kavaratti, Agatti and Kadmat islands have more agarophytes around them. Caulerpa, Dictyota and Laurencia can be used as food in different forms. Regulated harvest of the sea weeds up to 50% level of the resources is recommended in the report (Anon, 1979). Crustacea The prawns and crabs are not fished in Laksha-dweep. The brachyuran crabs and lobsters of Laksha-dweep have been studied by Alcock (1895, 1896, 1898, 1899 & 1900) and Borradaile (1903 & 1906). Alcock reported 41 species of crabs and Borradaile 52 species of crabs and two species of lobsters. Sankaran-kutty (1961) recorded 36 species of crabs from the Lakshadweep out of these 27 were from Minicoy, and the rest trom Kavaratti, Aminidivi and Bitra islands. The species include representatives of the familes Portunidae, Grapsidae, Ocypodidae, Xanthidae, Maiedae, Parthenopidae and Calappidae. Fig. 2. Panulirus penicillatus, another lobster found in Lakshadweep. Fig. 3. Panulirus homarus, a common lobster of economic value in the Lakshadweep. The significant abundance of any particular family is not stated in the above literature, since they were mainly fauni&tic or taxonomic studies bas£d on one time or intermittent collections by different authors. Kathirvel (MS) collected 28 species of brachyuran crabs and one species of Panulirid lobster from Kiltan atoll. Meiyappan and Kathirvel (1978) published records of the brachyuran crab Grapsus albolineatus, Cardiosoma carnifex and the lobsters Parribacus antarcticus and Panulirus homarus from Minicoy. Filial, et al. (1985) 47 recorded P. versicolor mostly during November-Janu-ary period in Minicoy. P. versicolor is found to be the most common. The distribution pattern of the lobsters was found to be seasonal, more common on the Fig. 4. Painted rock lobster Panulirus versicolor - a. potential reef resource in the Lakshadweep. reef flats during November-January period. Meiyappan and Kathirvel (1978) found P. penicillatus to be the most common lobster in Minicoy in the late seventies while Pillai et al. (1984) found P. versicolor as the the major lobster at Minicoy. This species is also recorded from Kiltan atoll (Kathirvel, MS). Mollusca Smith (1906) listed Corns, Terebra, Sistrum, Pur-pura, Nassa, Oliva. Solarium, Trochus and Circe as the common genera widely distributed in Maldives and Lakshadweep. Burton (1940) reported the common occurrence of the giant clam Tridacna over the reef of Chetlat Island when he visited the Lakshadweep in 1935. He recorded the shells of Pterocera from Bitra. Octopus was recorded from Chetlat and Bitra where they were found in plenty over the reef. In recent times on an average 20 tonnes of these are landed annually in the Lakshadweep islands. Octopus macropus and O. vulgaris are common in Minicoy, the former forming about 80% of the catch. Both species inhabit crevices in the reef-flat. The islanders use them as food and as bait for fishing. Appukuttan (1973) observed nine species of coral boring bivalves causing destruction to the fringing reefs of the Islands. They belong to the genera Lithophaga Botula, Petricola, Gastrochaena and Jeuannetia. Appu-kuttan and Pillai (MS) observed that the molluscan fauna of Lakshadweep is similar to that of other islands Fig. 5. Tridacna sp. the giant clam that grows to more than half a metre in length. in the Indian Ocean. They have listed 48 gastropods and 12 bivalves and found the abundance of gastropods in number and species particularly in the httoral and eulittoral reef-flat habitats. 48 The important families of gastropods observed in Lakshadweep are PatelUdae, Trochidae, Neritidae, Littorinidae, Planaxidae, Strombidae, Cassididae, Cypraedae, Muricidae, Buccinidae, Conidae, Vasidae, Terebridae, Ellobidae and Cerethidae. Among the bivalves Arcidae, Mytihdae, Pectinidae, Ostreidae, Chamidae, Tridacnidae, Veneridae, Mactridae, Labi-tinidae, Tellinidae, Teredinidae and Pholadidae are the most important groups. Among the gastropods found in these islands, Top shells (Trochidae), Spider conch (Strombidae), Cone shells (Conidae), Cowries (Cypraedae) and Helmet shells (Cassididae) are commercially important. Trochus radiatm, Lambis spp., Arabica arabica, Coitus spp., Charonia tritonis and Cassis cornuta are some of the beautiful shells available in good quantity in these islands. Giant clams Tridacna maximum is found in good num-bers in all the islands in the lagoon. Till 1980 good population of the giant clam was observed in the lagoon of Minicoy but at present dead shells of this clam are-found in large numbers along with corals. The pro-bable reason for large scale mortality can be siltation due to the dredging operation done in the harbour area. There was also an incidence of aggregation of large spider shells (Lambis truncata) numbering 400-500 ranging 20-25 cm in length and weighing 1.15 kg in the lagoon during January, 1984 when water was calm. This species is not found very often in reef flat. It is understood from the older generation of fishermen of the islands that there was good settlement of green mussel Perna viridis in Amini Island 20 years back and was used for edible purpose by local people. At present no settlement of mussel is reported from any of the islands. Cyprea monita is found in plenty in the inner reef-flat and 1 kg of shell is valued at Rs. 30-40. Usually during low tide large quantities of shells are picked up by women and this has got a good market in the mainland. Sponges Thomas (1973, 1979 & MS) mentions 41 species of sponges from Minicoy including typical coral and shell boring species, such as Spirastrella cuspidifera, S. inconstance and Cliona spp. The common Indian bath sponge Spongia officianalis has been observed in Minicoy. Many sponges recorded from Minicoy are rich in Bro-mine and Iodine. Echinodermata Gardiner (1903) observed surface living holothuri-ans very commonly, in Minicoy and mentioned about large numbers of a white variety living in sand. Burton (1940) recorded holothurians of several varieties in every Fig. 6. Holothuria atra • and lagoon. a common sea cucumber on reef-flat Fig. 7. Thelenota ananas - a holothurian used in the prepa-ration of Beche-de-mer, an export product. (Plioto courtesy : D. B. James) 49 pool in Chetlat. Holothuria atra, H. seabra, Actino-pyga mauritiana, and A. echinites are the most abundant species in Minicoy. Ten species of echinoderms were recorded by James (MS) from Kiltan atoll of the nor-thern part of the Lakshadweep. These include the S." . . "A: • • * • * " •••• / t V i Fig. 8. Bohadschia marmorata - another holothurian used in preparation of Beche -de - mer. (Photo courtesy: D. B. James) holothurians Stichopus chloronotus, Bohadschia marmor-ata, Holothuria rigida, H. impatiens, H. pardalis, H. leu-cospilota and Actinopyga mauritiana. The cake urchin Clucila novaeguineae and ophiuroid Ophiocoma orinaceus were the other echinoderms collected around Kiltan. These information point to the possibility for a modest Beche-de-mer industry in a suitable location in the Lakshadweep. Turtles Bhaskar (1984) reports four species of turtles which occur and nest in Lakshadweep. They are the hawks-bill (Erethmochelys imbricata), the olive-ridley (Lepido-chelysolivacea),the green turtlefCheloniamydasjandthe leather-back (Dermochelys coriacea). The last one is reportedly very rare. The green turtles nest mainly during the southwest monsoon (June-September) on the Suheli Valiakara, Suheli Cheriakara, Tinnakara, Bangaram and Parah. A feeding and nesting population of green turtles are observed in Minicoy. A few hawks-bills and olive-ridleys also nest on Androth, Kadmat and Agatti islands. Trading in hawks-bill scutes through Man-galore existed in earlier years. Turtle fat especially that of the green, olive-ridley and the leather-back is used by islanders for water proofing the wooden boats. A cautious approach to exploitation of the turtle population of Lakshadweep archipelago is necessary as their existence here with least human predation serves to conserve them in this niche. Therefore future acti-vities of constrLctions, agricultural operations etc. along known nesting beaches may be carefully planned. Bitds Alcock (1902) found the whole sand banks of Pitti island literally covered with the young of two species of terns. The only specific study on the birds of the Lakshadweep islands seems to be that of Belts (1938). Of the 44 species of birds reported by Belts there were several shore and water birds like plovers, terns, sand pipers, shear waters, teals and herons. Marine ornamental fishes and other marine organisms Trade in marine ornamental fishes for home aqua-ria in different parts of the world started some time in the mid sixties. Philippines, Indonesia, Singapore and Sri Lanka are some of the countries exporting marine ornamental fishes. Mostly marine species caught in the wild are used in this trade. Most salt water orna-mental fishes come from coral reefs. Cheap to very expensive ornamental fishes are available. Sri Lanka price for a specimen of the file fish is reportedly 50 US $. (Kvalvas Gnaes, 1982). Varieties such as Abudefduf, Amphiprion, Apogon, Coris, Balistes, Platax and several other beautiful coral reef fishes are available in Lakshadweep. Ornamen-tal invertebrate such as sea anemones, crustaceans, echinoderms and sedentary tube worms are also reared in marine aquaria and hence have marketing possibilities. Limited exploitation of these hitherto untouched resources for capturing a share of the worlds ornamen-tal marine organisms trade is worth attempting. 50 

Ancillary living marine resources of Lakshadweep

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Ancillary living marine resources of Lakshadweep

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