Under Water Visual Census of Reef Fishes in Tuticorin Group of Islands, Gulf of Mannar, Southeastern India

Indian Journal of Geo-Marine Science Vol.44 (10), October 2015 pp. 1585-1597

Under water visual census of reef fishes in Tuticorin group of islands, Gulf of Mannar, Southeastern India

G. Mathews*, R.L. Laju and K. Diraviya Raj

Suganthi Devadason Marine Research Institute, 44-Beach Road, Tuticorin - 628 001, India

Received 12 November 2013; revised 25 February 2014

Reef fishes are integral part of coral reef ecosystem as they play major role in ecological balance. Visual census of fish assemblages on coral reefs in the vicinity of four islands in Tuticorin group, Gulf of Mannar, Southeast coast of India was conducted between August 2011 and November 2012. Under water data collection on reef fish abundance and diversity was done by following belt transect method involving scuba diving. A total of 78 species from 24 families were recorded during the study period. . Kariyachalli Island was recorded the highest density and diversity of reef fishes (64 species) among the four islands and this dominance is corroborated to the comparatively higher live coral cover (46.61%). The study reveals that habitat complexity determines the abundance and diversity of reef fishes in a reef area. Presently, anthropogenic and natural factors threaten coral reefs and protection of reef habitat is inevitable for the survival and existence of reef fishes and ultimately the livelihood of the dependant people.

[Key words: Gulf of Mannar, reef fishes, visual census, corals, carnivores]

Introduction between latitude 8º47’ N and 9º15’N and longitude 78º12’E and 79º14’E and the average Understanding the origination and distance of these islands from mainland is about 8 maintenance of global biodiversity is a core km. Pillai (1986)6 provided a comprehensive challenge in ecology, evolution and conservation account of coral fauna of the Gulf of Mannar and science. In the marine biome, coral reefs are the diversity includes 94 species of 37 genera with hotspots of species richness and endemism, with most common being Acropora sp., Montipora sp. the 10 richest reefs accounting for between 44 and and Porites sp. and Edward et al., (2007)7, 1 54% of restricted-range marine species . Coral updated the species list to 117 species of 40 reefs are particularly important for global genera. vertebrate diversity as they harbour the greatest species richness of fishes on earth2, with up to A fundamental principle in ecology 1000 species coexisting within a single location3. assumes abiotic and biotic variables influence the distribution of all organisms, including marine Reef fishes are an important component of marine 8,9 biodiversity and include species that provide both fishes . Abiotic variables such as temperature, top down control of reef ecosystems through salinity, depth, current, and topographic tropic cascades4 and the biomass of recreational complexity, and ecological processes including and commercial fisheries5. recruitment, competition, food availability, and predation all play roles in determining fish species 10,11 Gulf of Mannar has been known for its distribution and abundance . Coral reefs have rich biodiversity, especially for its coral reefs. declined over the course of human history, Coastal area covering 560 sq. km between culminating in the dramatic increase in coral mortality and reef degradation of the past 20-50 Rameswaram and Tuticorin including 21 islands 12 in the Gulf of Mannar were declared as Marine years . Coral reefs and associated reef fishes of National Park in 1986 by the Government of Gulf of Mannar have been damaged severely due to the rampant coral mining which was happening Tamil Nadu for the purpose of protecting marine 13 wild life and its environment. Gulf of Mannar until 2004 . Destructive fishing methods such as Marine Biosphere was declared in 1989 by the trap fishing, near-shore trawling, sedimentation Government of India, covering 10,500 sq.km and pollution are causing considerable damage to the coral reefs, threatening the reef fisheries of the areas between Rameswaram and Kanniyakumari. 14-16 Reefs in the Gulf of Mannar are developed around Gulf of Mannar . the 21 uninhabited islands which are located 1586 INDIAN J MAR SCI VOL 44, NO.10 OCTOBER 2015

The composition of local reef fish located in the central and southern parts of the communities in the Indo-Pacific region is directly island. Island has fringing reefs extending up to a dependent on habitat variability17 and thus damage depth of 3 m and the live coral cover in this island to coral reefs directly impacts the dependant has been recorded as 33.13 %7. The Island is fishery resources of an area. Decline in the facing severe erosion nowadays. abundance of coral associated fish due to coral bleaching in 1998 was reported by Kumaraguru et Koswari Island (08º51’34’’ N - 08º52’32’’N al. (2003)18. But, Studies on coral reef and 78º13’07’’ E - 78º14’07’’E) is an elongated ichthyofauna of Indian seas are mainly restricted island with a sharp corner along its northwestern to the Lakshadweep groups of islands19 and end. The island has a long, narrow and sandy observations are lacking for the other coral reefs coast with coral rubbles. It has sand dunes that ecosystems, particularly, along the southeast extent to a height of about 1 m from mean sea coast. Understanding of the diversity of reef fishes level and shrubby vegetation in the interior. The in reef ecosystem is important not only interior of the Island has a small depression which ecologically but economically also. At this gets filled with sea water during high tide. A juncture, the present study has been taken up with fringing reef is observed along this Island the intentions to assess the reef fish resources of extending up to 2.8 m in depth. Live coral cover in this Island has been recorded as 15.27 %7. Tuticorin group of islands in the Gulf of Mannar to characterize their diversity, abundance and Kariyachalli Island(08º56’54’’ N - threats. 08º57’3’’N and 78º14’46’’ E - 78º15’28’’E) is an ellipsoid shaped Island with a sharp corner at its Materials and Methods northwestern side and a small depression on its northwestern side and a small depression on its The assessment of reef fish was carried eastern side that gets inundated during high tide. out in four Tuticorin group of Islands (Vaan, The Island which is approximately 1 meter above Koswari, Kariyachalli and Vilanguchalli) of Gulf sea level has a low sandy coastline and coral of Mannar during the period between August rubbles dominate the southern coast. Fringing reefs are observed around the Island extending up to a depth of 3 m. Live coral cover in this Island has been recorded as 46.61 %7.

Vilanguchalli Island (08º52’32’’ N - 08º55’54’’N and 78º15’42’’ E - 78º16’58’’E) Island is completely submerged under 1m of water. This island is surrounded by a narrow, elongated reef. Live coral cover in this Island has been recorded as 24.35 %7.

Fish assessment - Visual census

The belt transect method20 was used for visual survey of fishes which involves scuba diving. 50 m transects were laid for the assessment and the number of transects differed from each Island according to the size of the reef. 2011 and November 2012 (Fig. 1). Number of transects were 14, 17, 24 and 19 respectively for Vaan, Koswari, Kariyachalli and Fig. 1— Map showing Tuticorin group of 4 islands in Gulf of Vilanguchalli islands. To minimize diver impacts, Mannar each fish census commenced 15 minutes after the tape is laid out. Fishes were recorded by Vaan Island (08º49’34’’ N - 08º50’34’’N and swimming along each transect within a 50 x 10 m 78º12’09’’ E - 78º13’15’’E) has a long narrow corridor, identifying the species that are found sandy coast with coral rubbles along its south, near or at visible distance of each transect. Divers southeastern and south western coastlines. This swam slowly and randomly searching for fish island is about 1 m above mean sea level with species in a dive which lasts for 15 minutes. small sand dunes that are covered with shrubs

MATHEWS et al.: UNDER WATER VISUAL CENSUS OF REEF FISHES 1587

Diversity, density and size class of the observed Koswari were having 43 species from 16 families fishes were noted in underwater slates. and 32 species from 14 families respectively. Underwater photographs were taken using Nikon Total number of fishes counted was highest in AW100 under water digital camera. Reef fish Kariyachalli Island with 7242 followed by identification was carried out using fish base Koswari Island with 3260 while it was 2252 and identification keys21 and Reef fish Identification 1525 in Vaan and Vilanguchalli islands Tropical Pacific Manual22. respectively. Densities of each species in each Island are given in the table 1. Shannon- Wiener The number of individuals belonging to diversity (H’) ranged from 1.12 (Vilanguchalli different species, families and trophic levels are island) to 1.72 (Kariyachalli Island) which is divided into trophic group using literature data23- 25 portrayed in the figure 2. Plieous’s Eveness (J’) . In order to establish spatial variation in trophic was observed with the range between 0.95 assemblages, observed species were categorised (Kariyachalli island) and 0.98 (Vilanguchalli to one of the 8 trophic levels using data from 26-28 island) illustrated as in the figure 3 and Richness previous studies described in literature and (S) ranged between 14 (Vilanguchalli island) and from fish base (fishbase.org). Following are the 6 64 (Kariyachalli island) as illustrated in figure 4. categories, herbivore, omnivore, browser of sessile invertebrates, carnivore, piscivore, and planktivore. Species diversity was statistically 2.00 assessed using the Shannon diversity index (H’) in natural log. Species richness (S’) and evenness 1.50 (J’) were also calculated using statistical software Biodiversity Pro (ver.2). 1.00 versity (H')

D i 0.50 Results

A total of 78 species of reef fishes 0.00 belonging to 45 genera from 24 families were Vaan Kariyachalli Koswari Vilanguchalli recorded in Tuticorin region during the study period. Following are the 24 families recorded in the present study, Acanthuridae (8 species), Fig. 2—Shannon Diversity (H') of reef fishes in Tuticorin group of Balistidae (3 species), Carangidae (2 species), Islands Chaetodontidae (8 species), Diodontidae (4 species), Haemulidae (2 species), Holocentridae 1.5 (2 species), Labridae (6 species), Lutjanidae (9 species), Pomacanthidae (4 species), Pomacentridae (7 species), Scaridae (3 species), 1 Siganidae (4 species), Serranidae (6 species), Caesionidae (1 species), Gobiidae (1 species), 0.5 Mullidae (1 species), Nemipteridae (1 species), enness Index (J') Pempheridae (1 species), Platacidae (1 species), E v Scorpaenidae (1 species), Tetradontiidae (1 0 species), Zanciidae (1 species), Leiognathidae (1 Vaan Kariyachalli Island Koswari Island Vilanguchalli Island species). Details are given in the table 1.

Among the four islands Kariyachalli Fig. 3—Plieou's Eveness (J') indices of Reef fishes in Tuticorin Island was the most diverse in reef fishes with 64 group of Islands species from 24 families and Vilanguchalli Island was the least in diversity with 14 species from 11 families while the other two islands Vaan and 1588 INDIAN J MAR SCI VOL 44, NO.10 OCTOBER 2015

under 24 families. Caranx heberi, Abudefduf 80 saxitalis, followed by Acanthurus nigricauda and 70 60 Balistodes viridescens were the dominant fish 50 species found with the densities of about 302, 262 2 chness (S')40 and 246 no/50 m respectively. Carnivores were R i 30 the dominant with 47% representing 18 species. 20 Herbivore, Omnivore and Browser of sessile 10 0 invertebrates (14%) were the second most highly Vaan Kariyachalli Koswari Vilanguchalli represented with 9 species. Planktivore (6%) and Piscivore (5%) were similarly represented with lesser percentage in trophic levels (Table 2 and Fig. 4—Richness (S) of reef fish diversity in Tuticorin group of Islands Fig. 5).

80 Overall number of fishes recorded in Vaan 70 Island was 2252. The species diversity in this 60 Island was observed as 36 species belonging to 16 50 40 families. Gnathonodon speciosus followed by 30 ophic level20 (%) Balistoides viridiscens and Chaetodon T r 10 octofasciatus were the dominant fish species 0 found with the densities of 177, 159 and 122 Herbivore Omnivore Browser of Carnivore Planktivore Piscivore 2 Sessile no/50 m respectively. Carnivores were the invertebrates

dominant trophic category contributing 42% of Vaan Island Koswari Island Kariyachalli Island Vilanguchalli Island the total representing 18 species. Herbivores (21%) were the second most highly represented with a total of 9 species and the least represented Fig. 5— Trophic guild of reef fishes in Tuticorin group of category was Browser of sessile invertebrates Islands

(18%), Planktivore (7%), Piscivore (5%) and Omnivore (7 %) (Table 2; Fig. 5). Overall number of fishes recorded in Vilanguchalli Island was 1525. The species Overall number of fishes recorded in Koswari diversity in this Island was observed as 14 species Island was 3260. The species diversity in this under 11 families. Lutjanus decussatus followed Island was observed as 32 species belonging to 14 by Gnathodon speciosus and Abudefduf vaigiensis families. Thalassoma lunare followed by were the dominant fish species found with the 2 Abudefduf saxitalis and Lutjanus lunulatus were densities of about 158, 141 and 139 no/50 m . the dominant fish species found with the densities Carnivores existed to be dominant (72%) of about 196, 184 and 161 no/50 m2 respectively. representing 10 species, followed by Herbivore Carnivores were found to be dominant showing (7%), Omnivore (14%) and Planktivore (7 %). 56% representing 30 species. Browser of sessile Browser of sessile invertebrates and Piscivore invertebrates (13%) was the second most highly were not represented with any trophic levels represented, with 9 species. Herbivores (10%), (Table 2 and Figure 5). The underwater Planktivores (6%), Piscivores (9%) and photographs of few reef fishes in Tuticorin coast Omnivores (6%) were similarly represented with are given in the figures. 6 - 8. lesser ranges (Table 3 and Fig. 5).

Overall number of fishes recorded in Kariyachalli Island was 7242. The species diversity in this Island was observed as 64 species

MATHEWS et al.: UNDER WATER VISUAL CENSUS OF REEF FISHES 1589

Table —2 Trophic guild of reef fishes - Tuticorin group of Islands Trophic level Vaan Kariyachalli Koswari Vilanguchalli

Herbivore 7 3 9 1 Omnivore 3 2 9 2 Browser of Sessile 0 8 4 9 invertebrates

Carnivore 14 18 30 10 Planktivore 3 2 4 1 Piscivore 1 3 3 0

Table 1— Total density of reef fishes in Tuticorin group of Islands Species Family Vaan Kariyachalli Koswari Vilanguchalli

Acanthurus bleekeri Acanthuridae 25 - - - Acanthurus dussumieri Acanthuridae - - - - Acanthurus lineatus Acanthuridae 91 118 - - Acanthurus mata Acanthuridae - 147 - - Acanthurus nigricauda Acanthuridae 77 246 - - Acanthurus xanthopterus Acanthuridae - - 114 - Naso hexacanthus Acanthuridae 42 109 53 127 Zebrasoma veliferum Acanthuridae - 63 - - Abalistes stellatus Balistidae - 224 - - Balistoides viridescens Balistidae 159 246 - - Odonus niger Balistidae 17 141 108 42 Pterocaesio tile Caesionidae - 22 - - Caranx heberi Carangidae - 302 - - Gnathonodon speciosus Carangidae 177 130 149 141 Chaetodon oxycephalus Chaetodontidae 29 - - - Chaetodon auriga Chaetodontidae 63 64 - - Chaetodon collare Chaetodontidae 59 - - - Chaetodon decussatus Chaetodontidae 35 118 153 - Chaetodon lineolatus Chaetodontidae - - 76 - Chaetodon octofasciatus Chaetodontidae 122 193 66 - Chaetodon plebieus Chaetodontidae 41 105 142 - Heniochus acuminatus Chaetodontidae 115 114 70 72 Canthigaster solandri Diodontidae - 152 - - Lactoria cornuta Diodontidae - 112 - - Ostracion gibbosus Diodontidae - 148 - - Ostracion nasus Diodontidae - 88 - - Bathygobius laddi Gobiidae - 143 - - Diagramma pictum Haemulidae - 189 - - Plectrohinchus orientalis Haemulidae 42 218 - 71 Myripristis bemdti Holocentridae - 43 - - Sargocentron rubrum Holocentridae 24 162 - - Coris formosa Labridae 77 - - - Halichoeres zeylonicus Labridae 22 152 91 127 Labroides dimidius Labridae - - 94 -

1590 INDIAN J MAR SCI VOL 44, NO.10 OCTOBER 2015

Thalassoma lunare Labridae - 78 196 - Thalassoma purpureum Labridae - 136 128 98 Xyrichthys pavo Labridae 23 101 122 - Leiognathus sp. Leiognathidae - 106 148 - Lutjanus decussatus Lutjanidae 43 51 109 158 Lutjanus ehrenbergii Lutjanidae 81 - 107 82 Lutjanus fulviflamma Lutjanidae - 10 - - Lutjanus fulvus Lutjanidae - 175 - - Lutjanus lunulatus Lutjanidae 91 172 161 - Lutjanus lutjanus Lutjanidae - 86 69 - Lutjanus malabaricus Lutjanidae - 24 76 - Lutjanus quinquelineatus Lutjanidae - 60 96 - Lutjanus rivulatus Lutjanidae - 222 128 131 Paraupeneus indicus Mullidae 84 204 99 129 Scolopsis vosmeri Nemipteridae - 145 42 - Pempheris vanicolensis Pempheridae 61 152 - 110 Platax orbicularis Platacidae - 39 80 - Apolemichthys xanthurus Pomacanthidae - 26 - - Pomacanthus annularis Pomacanthidae 49 88 - - Pomacanthus imperator Pomacanthidae 17 55 - - Dascyllus trimaculatus Pomacanthidae 83 - 83 - Abudeduf saxitalis Pomacentridae - 262 184 - Abudefduf vaigiensis Pomacentridae - - - 139 Amphiprion clarkii Pomacentridae 45 74 - - Amphiprion sebae Pomacentridae - 36 - - Dascyllus sp Pomacentridae 44 199 - - Neopomacentrus sp. Pomacentridae - 212 - - Pomacentrus caeruleus Pomacentridae 46 96 - - Scarus ghibbus Scaridae 80 106 - - Scarus niger Scaridae 58 42 - - Scarus russelii Scaridae - 34 - - Pterois russelii Scorpaenidae 45 35 - - Cepahlopholis boenak Serranidae - 68 - - Cephalopholis formosa Serranidae 47 28 45 - Epinepheleus tauvina Serranidae - - 68 - Epinephelus formosa Serranidae 56 23 83 - Epinephelus malabaricus Serranidae - 66 - 98 Epinephelus merra Serranidae - 24 42 - Chelinus sp. Siganidae - - 78 - Siganus canaliculatus Siganidae - 117 - - Siganus javus Siganidae 82 - - - Siganus lineatus Siganidae - 59 - - Arothron mappa Tetradontiidae - 51 - - Zanculus cornutus Zanciidae - 31 - - Total 2252 7242 3260 1525

MATHEWS et al.: UNDER WATER VISUAL CENSUS OF REEF FISHES 1591

Epinepheleus tauvina Siganus sp.

Chaetodon sp. Caranx sp.

Chaetodon sp. Lutj anus sp.

Fig. 6— Underwater photographs of few reef fishes in Tuticorin coast 1592 INDIAN J MAR SCI VOL 44, NO.10 OCTOBER 2015

Plectrohinchus sp. Sargocentron rubrum

Abudefduf saxitalis Pempheris vanicolensis

Pomacanthus sp. Gnathonodon sp.

Fig. 7— Underwater photographs of few reef fishes in Tuticorin coast

MATHEWS et al.: UNDER WATER VISUAL CENSUS OF REEF FISHES 1593

Heniochus sp. Pterois russelli

Amphiprion sebae Cephalopholis formosa

Scolopsis vosmeri Plectrohinchus sp.

Fig. 8— Underwater photographs of few reef fishes in Tuticorin coast

1594 INDIAN J MAR SCI VOL 44, NO.10 OCTOBER 2015

Discussion found adjacent to seagrass beds, and strong linkages have been observed between these Quantitative assessment of habitat and habitats38. Coral reefs and seagrasses have a living recourses within a proposed reserve area is linkage in fish migration for food, shelter and essential to determine potential benefits of reserve reproduction39. Many coral reef fish use seagrass protection, and to establish a baseline for beds either as a nursery habitat or as a feeding or 29 evaluating reserve effects . Reefs are active resting habitat40-43. Healthy seagrass beds have producers of carbonate skeletal material. Their been recorded between the islands and the high rates of carbonate production allow the mainland in Gulf of Mannar44. Vilanguchalli construction of complex and massive calcareous Island was observed to have the least diversity in 30 structures . Reef fishes are strongly influenced by terms of reef fishes which could be attributed to the structure of their habitat, with more complex its distance from the mainland where seagrass 31-33 coral reefs generally supporting more fish . On cover is comparatively less and which limits the coral reefs, numbers of shelter holes, rugosity, and quantity of migratory fishes in this Island. percent of live coral have been identified as important aspects of complexity determining fish Venkatachalam (2004)45 states that there has distribution34.It is evident in this study that the been a definite and steady decline of the marine density and diversity of reef fishes are highest in fishery in Tuticorin region after it reached its peak Kariyachalli Island where the highest percentage in 1989. Globally, the fish production increased of live corals are also recorded among the four from 19.3 million tonnes in 1950 to more than Tuticorin group of islands. 100 million tonnes in 1989 and 134 million tonnes in 2002, where marine capture fisheries are Research on coral reef fishes in Indian reefs the largest contributors to world fish production46. are scarce simply because most of the marine Degradation of habitat due to coastal development biologists are not divers and the works done so far can contribute to the decline of the spawning on reef fishes are solely on the basis of landing stock biomass (SSB) of some important fish data. For example, a total of 183 species species to the critical level, the level that could belonging to 51 families were recorded from Gulf result in the collapse of the fishery37. Land-based 35 of Mannar by Varghese (2011) through landing activities such as deforestation, agriculture data including those of the trawlers. From the data intensification, industrialization and domestic collected from the landing, the fishes cannot be waste disposal have been identified as activities segregated exclusively to reef fish category. The that indirectly affect the water quality of coral introduction of scuba diving technique in 1950s reefs, home to many fish species, but coral for mobilization underwater has resulted in more mining, dynamite fishing and other destructive studies of coral reef fish with a much wider fishing methods have greater and more 36 coverage . Using visual census technique, widespread impact47-49. A total of 62 species of experienced SCUBA divers can identify, count reef-dwelling fishes and seven species of reef- and measure the coral fish, so that an estimate of associated fishes were recorded by Mathews et al. 37 biomass can be performed . Visual census (2012)50. It was reported that reef fishes in Gulf of 20 techniques have many advantages, compared Mannar are reducing in number as they become with other sampling techniques. This rapid common to rare and to threatened status because quantitative method is non-destructive and of anthropogenic disturbances50. Thus this study 37 repeatable . Hence, the observations from this becomes important as it provides baseline study exclusively targeted the reef dwelling fishes information about the reef fishes of Tuticorin by adopting under water visual census techniques. region which would help the conservation managers for a better management of declining In total, 78 species from 24 families were fish population. reported from this study in Tuticorin coast and 64 of them were recorded in Kariyachalli Island, According to Harmelin –Vivien (1979)28, followed distantly by Vaan Island with 36 species carnivore levels on a healthy reef are usually which has the second better live coral cover. This between 60-80%, depending on the geographic high reef fish diversity in Kariyachalli Island can location. In this study also carnivores were the easily be correlated with the highest coral cover dominant category representing 42 to 72% of the among the Tuticorin group of islands. Reef and total. As there is a huge demand for marine seagrass habitats are juxtaposed in many areas of ornamental fishes, fishermen set indigenous fish the world. In warmer waters, such as the traps in the reef areas or along the outer reef of Caribbean and Indo-Pacific, coral reefs are often Gulf of Mannar. To hide the traps in the reef, the

MATHEWS et al.: UNDER WATER VISUAL CENSUS OF REEF FISHES 1595

fishermen break off live coral, mostly massive Acknowledgement corals, to cover them and the reefs are also disturbed while retrieving the traps. With the use Authors are thankful to the University of these traps, reef dwelling herbivorous parrot Grants Commission, Govt. of India for the fishes (Scarus ghobban) are caught widely, which financial support; PCCF & Chief Wildlife in turn causes the proliferation of algae over live Warden, Govt. of Tamil Nadu and Wildlife coral colonies due to lack of grazing pressure, Warden, Gulf of Mannar Marine National Park leading to coral mortality and also ecological for research permission; and SDMRI for facilities imbalance51. Though Islands are coming under and underwater photographs. Marine National Park area and the entry is restricted, fishermen enter illegally to fish very Acknowledgement near the islands with their indigenous traps. Authors are thankful to the University Grants The Gulf of Mannar has been experiencing Commission, Govt. of India for the financial severe anthropogenic impacts since 4-5 decades. support; PCCF & Chief Wildlife Warden, Govt. Mahadevan and Nayar, (1972)13 reported that the of Tamil Nadu and Wildlife Warden, Gulf of exploitation of corals was about 60,000 cubic Mannar Marine National Park for research meters (about 25,000 metric tones) per annum permission; and SDMRI for facilities and from Palk Bay and Gulf of Mannar together. underwater photographs. Destructive fishing methods (including blast fishing), near-shore trawling, sedimentation and References pollution are causing considerable damage to the 1 Roberts, C M., McClean, C J., Veron, J .E. N., Hawkins, coral reefs, threatening the reef fisheries of the J P., Allen, G R., McAllister D E., Mittermeier, C G., 14, 15, 16 Gulf of Mannar . Coral mining, which Schueler, F W., Spalding, M., Wells, F., Vynne, C. and reduces the function of reefs as natural barriers Werner, T B., Marine Biodiversity hotspots and and lead to increased beach erosion, has conservation priorities for tropical reefs. Science, 295 52, 53 (2002) 1280–1284. transformed the coast , and is probably 2 Harmelin-Vivien, M L., Energetics and fish diversity on responsible for the submersion of Vilanguchalli coral reefs. In: Coral Reef Fishes. Dynamics and Island7. Moreover, new threats such as annual Diversity in a Complex Ecosystem (ed. Sale, P.F.). coral bleaching54 trap fishing51, coral-algal phase Academic Press, Boston., (2002) 265–274. shift55, exotic algae (Kappaphycus alvarezii) 3 Bellwood, D R and Wainwright, P C., The history and 56, 57 biogeography of fishes on coral reefs. In: Sale PF (ed) invasion and coral diseases are adding more Coral Reef Fishes. Academic, New York., (2002) 5–32. 58-60 stress to reefs in Gulf of Mannar . 4 Babcock, R C., Kelly, S., Shears, N T., Walker, J W. and Willis, T J., Changes in community structure in In spite of all the threats, the reefs of Gulf of temperate marine reserves. Mar. Ecol .Prog. Ser., 189 Mannar exhibit signs of resilience, especially (1999) 125–134. 5 Henry, G W. and Lyle, J M., The national recreational since 2005 after coral mining was halted and with and indigenous fishing survey. FDRC Project No a reduction in destructive fishing activities due to 99/158, Tasmanian Aquaculture Fisheries Institute, the combined effects of awareness creation and Hobart., (2003). strict enforcement activities. The live coral cover 6 Pillai, C S G., Recent corals from the south east coast of increased from 36.98±13.12% in 2005 to India. In: Recent advances in marine biology. New Delhi., (1986) 107-201. 42.85±10.74% (mean ± SD) in 2009 and the coral 7 Patterson Edward, J K., Mathews, G., Jamila Patterson., 61 recruit density also has increased significantly . Dan Wilhelmsson., Jerker Tamelander. and Olof Hence, this is the high time to study the biology Linden., Coral reefs of the Gulf of Mannar, and ecology of the reef fishes further to prepare a Southeastern India – Distribution, Diversity and Status. SDMRI Special Research Publication., 12 (2007) 113. perfect management strategy. Laboratory rearing 8 Putman, R J. and Wratten, S D., Principles of Ecology, of reef fishes and sea ranching in the reef areas University of California, USA, (1984). can provide positive results if the suitable culture 9 Recksiek, C W., Murphy, B R., Appeldoorn, R S. and techniques are perfected. Lindeman, K C., Integrating fish fauna and habitat assessments: A first step in developing marine fishery reserve design criteria. Proc. Gulf Carib. Fish. Inst., 52 (2001) 654-666.

1596 INDIAN J MAR SCI VOL 44, NO.10 OCTOBER 2015

10 Sale, P F., The ecology of fishes on coral reefs. 29 Craig P Dahlgren., Jack A Sobel. and Douglas E Academic Press, San Diego, California, USA., (1991a). Harper., Assessment of the reef fish community, Habitat 11 Sale, P F., Reef fish communities: open nonequilibrial and Potential for larval Dispersal from the proposed systems. In: P. F. Sale, editor. The ecology of fishes on Tortugas south ecological reserve. GCFI., 52 (2001). coral reefs. Academic Press, San Diego, California, 30 Ogdes, J C., and Gladfelter, E.H., Coral reefs, Seagrass USA., (1991b) 564–598 beds and Mangroves: Their interaction in the coastal 12 Pandolfi, J M., Bradbury, R H., Sala, E., Hughes, T P., zones of the Caribbean. UNESCO Report in Marine Bjorndal, K A., Cooke, R G., McArdle, D., Science 23. (1983). McClenachan, L., Newman, M J H., Paredes, G., 31 Sedberry, G R. and Carter, J., The fish community of a Warner, R R. and Jackson, J B C., Global trajectories of shallow tropical lagoon in Belize, Central America, the long-term decline of coral reef ecosystems. Science., Estuaries., 16 (1993) 198-215. 301(2003) 955-958. 32 Nagelkerken, I., Dorenbosch, M., Verberk., Cocheret de 13 Mahadevan, S. and Nayar, K N., ‘Distribution of coral la moriniere, E. and Van der Velde ,G., Importance of reefs in Gulf of Mannar and Palk Bay and their shallow- water biotopes of a Caribbean bay for juvinels exploitation and utilization’, In: Proceedings of coral reef fishes: Pattern in biotope association and Symposium on Coral Reef, Mandapam, (1972) 181-190. spatial distribution. Marine Ecology Progress series., 14 James, D B., Management of Beche-de-mer industry in 202 (2000) 175-192. India. In: K. Rengarajan, and James, D B., (Eds.). 33 Mateo, I. and Tobias, W J., Distribution of shallow Proceedings of the National Workshop on Beche-de- water coral reef fishes on the northern coast of St. mer. Bulletin of CMFRI., 46 (1994) 17-22. Croix, USVI. Caribbean Journal of Science., 37(2001) 15 Bakus, G., Arthur, R., Ekaratne, S. and Jinendradasa, S 210-226. S., India and Sri Lanka, In: McClanahan, T.R., Coral 34 Luckhurst, B. and Luckhurst, K., Analysis of the reefs of the Indian Ocean: their ecology and influence of substrate variables on coral reef conservation., (2000) 295-324. communities. Marine Biology., 96 (1978) 469-478. 16 Edward, J K. and Muley, E V., Reef restoration- An 35 Molly Varghese, S E., Mary K Manisseri., Ramamurthy, overview. Proceedings of the National Seminar on N., Geetha, P M., Thomas, V J. and Gandhi, A., Coral Marine and Costal Ecosystems. SDMRI Research reef fishes of Gulf of Mannar, Cochin Fishing Chimes., Publication., 2(2002) 120- 124. 31(2011) 38-40. 17 Allen, G R. and Adrim, M., Coral reef fish of Indonesia, 36 Sladek Nowlis, J., Friedlander, A. and Crowder, L B., Zool Stu., 42(2003) 1-72. Marine conservation biology: the science of maintaining 18 Kumaraguru, A K., Jayakumar, K. and Ramakritinan, C the seas biodiversity. Island Press., (2004). M., Coral bleaching 2002 in the Palk Bay, southeast 37 Alias bin man., Assessment of coral reef fish population coast of India. Current Science., 85(12) (2003) 1787- at pulau payar Marine Park and adjacent waters. Thesis 1793. submitted in fulfillment of the requirements for the 19 Asta lakshmi, S. and Sundaramanickam, A., degree of Doctor of Philosophy May., (2008) 151-156. Biodiversity of Reef Icthyofaun in Cuddalore coast, 38 Thomas Wernberg, E., Mathew, A., Vanderklift Jason Southeast coast of India, Internationl Journal of How. and Paul S Lavery., Export of detached Environmental Sciences., 1(2011) 7. macroalgae from reefs to adjacent seagrass beds 20 English, S., Wilkinson, C. and Baker, V., Survey Oecologia., 147 (2006) 692–701. manual for tropical Marine resources. Australian 39 Mumby, P J., Edwards, A J., Ernesto Arias-Gonzalez, J Institute of Marine Science, Townsville Australia., E.and Linde- man, P G., Mangroves enhance the bio- (1997) 390. mass of coral reef fish communities in the Caribbean. 21 Froese, R. and Pauly, D., (eds.) Fish Base. World Nature., 427(2004) 533–536. Wide Web electronic publication.WWW.fishbase.org, 40 Parrish, J D., Fish communities of interacting shallow- version (2005). water habitats in tropical oceanic regions, Mar. Ecol. 22 Gerald, A., Roger, S., Paul, H. and Ned De, L. Reef Fish Prog. Ser., 58(1989) 143–160. Identification, Tropical Pacific, New World 41 Baelde, P., Differences in the structure of fish assem- Publications, Florida, USA & Odyssey Publishing, blages in Thalassia testudinum beds in Guadeloupe, California, USA (2003). French West Indies, and their ecological significance. 23 Allen, G R., FAO species catalogue. Vol. 6. Snappers Mar Biol., 105 (1990) 163–173. of the world. An annotated and illustrated catalogue of 42 Blaber, S J M., Tropical estuarine fishes: ecology, Lutjanidae species known to date. FAO Fisheries exploitation and conservation. Blackwell Science, Synopsis., 125 (1985) 208. Oxford., (2000). 24 Myers, R F., Micronesian reef fishes. Coral Graphics, 43 Beck, M W., Heck, K L., Able, K W., Childers, D L., Guam., (1989) 298. Eggleston, D B., Gillanders, B M., Halpern, B., Hays, C 25 Russ, G., Distribution and abundance of coral reef fishes G., Hoshino, K., Minello, T J., Orth, R J., Sheridan, P F. in the Sumilon Island Reserve, central Philippines, after and Weinstein M P., The identification, conservation, nine years of protection from fishing. Asian Marine and management of estuarine and marine nurseries for Biology., 6(1989) 59-71. fish and invertebrates. Bioscience., 51 (2001) 633–641. 26 Hiatt, R W. and Strasburg, D W., Ecological 44 Mathews, G., Diraviya Raj, K., Thinesh, T., Rajesh, S., relationships of the fish fauna on coral reefs of the Jamila Patterson and Patterson Edward, J K., Marshall Islands. Ecol. Monogr., 30 (1960) 65-127. Preliminary baseline data on marine flora and fauna of 27 Hobson, E S., Feeding relationships of Teleostean fishes Kudankulam coast, Gulf of Mannar, Southeastern India, on coral reefs in Kon, Hii. Fish bull. 72(1974) 915-931. South Indian Coastal and Marine Bulletin., 2(1) (2010) 28 Harmelin-Vivien, M L., Ichtyofaune des récifs 1-5. coralliens de Tuléar (Madagascar): Ecologie relations trophiques. Thèse d’Etat, Univ. Aix- Marseille II., (1979) 165.

MATHEWS et al.: UNDER WATER VISUAL CENSUS OF REEF FISHES 1597

45 Ragupathy Venkatachalam., CCS research internship 60 Thinesh, T. and Patterson, J K., Observation and papers 2004, Centre for Civil Society., (2004). Outbreak of coral diseases in the Gulf of Mannar and 46 FAO, Trends in world fisheries and their resources: Palk Bay of Mandapam area, Coral reefs in India – 1974–1999, In: The State of World Fisheries and status, threats and conservation measures IUCN., (2012) Aquaculture., (2000) 98–104. 247-256. 47 Soekarno, R., Comparative Studies on the Status of 61 Edward, J.K.P., Mathews, G., Raj, K.D., Thinesh, T., Indonesian Coral Reefs. Netherlands Journal of Sea Patterson, J., Tamelander, J. and Wilhelmsson, D., Coral Research., 23(1989) 215-222. reefs of Gulf of Mannar, India - signs of resilience, 48 Samoilys, M A., Abundance and species richness of Proceedings of the 12th International Coral Reef coral reef fish on the Kenyan coast: The effects of Symposium, Cairns, Australia.,(2012) 9-13. protective management and fishing. Proc, 6th Int, Coral reef symp., 2(1988) 261-266. 49 Harmelin-Vivien, M L., Impact of human activities on coral reef fish communities in French Polynesia. Cybium., 16(1992) : 279-289. 50 Mathews, G., Deepak Samuel, V. and Patterson Edward, J K., Status of ornamental reef fishes of the Gulf of Mannar Marine National Park, Southeastern India, Coral reefs in India –status, threats and conservation measures IUCN., (2012) 155-163. 51 Samuel, D V., Patterson, J. and Patterson Edward, J K., Destructive fishing in the reef and mangrove areas of Tuticorin coastal waters, SDMRI Res. Publn., 2(2002) 98–103. 52 Qasim, S Z., Images and realities. New Delhi: Oxford and IBH Publishing Co, The Indian Ocean., (1999) 1167-1172. 53 Ramanujam, N. and Sudarsan R., A study of coastal transformation at Tuticorin as a result of emerged and submerged natural break waters of Van island, Gulf of Mannar, Environment Geology.,43(5) (2003) 521-525. 54 Patterson Edward, J K., Mathews, G., Jamila Patterson., Ram Kumar, R., Dan Wilhelmsson, Jerker Tamelander. and Olof Linden., Status of coral reefs of the Gulf of Mannar, Southeastern India, Obura DO, Tamelander J & Linden O, Ten years after bleaching - facing the consequences of climate change in the Indian Ocean. CORDIO Status Report 2008. Coastal Oceans Research and Development in the Indian Ocean/Sida-SAREC, Mombasa., (2008) 45-60. 55 Diraviya Raj, K., Mathews, G. and Patterson Edward, J K., Macro algal assemblage structure on the reefs of Tuticorin groups of islands in the Gulf of Mannar, Journal of Marine Biological Association of India., 48(2) (2006) 166-172. 56 Chandrasekaran, S., Arun nagendran, N., Pandiraja, D., Krishnakutty, N. and Kamalakannan B., Bioinvasion of Kappaphycus alvarezii on corals in the Gulf of Mannar, India, Current science., 94(2008). 57 Patterson Edward, J K. and Bhatt, J R., Impacts of cultivation of Kappaphycus alvarezii on coral reef environs of the Gulf of Mannar and Palk Bay, Southeastern India. In: Invasive Alian Plants: An Ecological Appraisal for the Indian Subcontinent (eds. J.R. Bhatt, J.S., Singh, S T Singh., R.S. Tripathi., and R.K. Kohli). CAB International., (2012) 89-98. 58 Thinesh, T., Mathews, G. and Patterson Edward, J K., Coral disease prevalence in Mandapam group of Islands, Gulf of Mannar, Southeastern India, Indian journal of Marine Science., 38 (4) (2009) 444-450. 59 Thinesh, T., Mathews, G. and Patterson Edward, J K., Coral disease prevalence in Palk Bay Southeastern India- with special emphasis to black band, Indian Journal of Geo Marine Science., 40(6) (2011) 813-820.