Protected areas and benthic characteristics influence the distribution of the Vulnerable bumphead parrotfish Bolbometopon muricatum in the Andaman and Nicobar Islands, India V ARDHAN P ATANKAR,TANMAY W AGH and A NIRUDDHA M ARATHE Abstract TheVulnerablebumpheadparrotfishBolbometopon ; Hughes et al., ; Burkepile & Hay, ) and muricatum, a highly prized fishery resource worldwide, has piscivory (Jennings & Polunin, ; Boaden & Kingsford, experienced population declines throughout its geographical ). Conservation of such fish groups is a key priority range. There is limited knowledge of the distribution and for ecosystem managers (Nyström, ; Bellwood et al., abundance of, and threats to, this fish in Indian waters, par- ). One such fish that is also of conservation concern ticularly for the Andaman and Nicobar Islands. To assess the is the bumphead parrotfish Bolbometopon muricatum, the species’ distribution and conservation status we conducted largest herbivorous and corallivorous fish, categorized as underwater surveys across sites around islands and Vulnerable on the IUCN Red List (Chan et al., ). An interviewed fishers across the Andaman and Nicobar individual can consume up to t of structural reef carbonate archipelago. We recorded a total of individual B. murica- per year (Bellwood et al., ), and the species promotes tum across nine sites from the northernmost island in the coral growth and recruitment by balancing coral erosion Andamans (Landfall Island) to the southernmost island in and calcification, preventing macroalgal growth and main- the Nicobars (Great Nicobar Island). Interviews revealed taining sediment flow in the reef ecosystem (Bellwood et al., that most fishers (% in Nicobar, % in Middle Anda- , ; Kobayashi et al., ; McCauley et al., ; man, % in South Andaman) had seen B. muricatum, Roff et al., ). and knowledge of the species is highest amongst spear- A large body size, aggregating behavior and limited fishers. Generalized linear models indicated that presence activity at night make B. muricatum an easy target for spear- of marine protected areas and high live coral cover influ- fishers (Bellwood et al., ; Donaldson & Dulvy, ; enced the abundance and distribution of B. muricatum. Kobayashi et al., ; Chan et al., ; Munoz et al., The species’ density seems to be naturally low in the archipel- ; Hamilton et al., ). Combined with slow growth ago. We discuss our findings in the light of protecting rare and low replacement rates, this has resulted in population and threatened species, and recommend strengthening the declines across the Indo-Pacific and Red Sea (Kobayashi existing marine protected areas in these islands. et al., ; Chan et al., ; Andrews et al., ). These declines have been particularly marked in the Solomon Keywords Andaman and Nicobar Islands, Bolbometopon Islands, Papua New Guinea, Samoa, Guam, the Marshall muricatum, bumphead parrotfish, coral reefs, India, marine Islands and parts of Malaysia and Fiji (Bellwood et al., protected area ; Aswani & Hamilton, ; Dulvy & Polunin, ). Supplementary material for this article is available at Many countries have implemented conservation measures https://doi.org/./S for the species, including establishment of marine protected areas and restrictions on spearfishing (Dulvy & Polunin, ; Weeks et al., ). Introduction In India B. muricatum occurs from the Gulf of Mannar in Tamil Nadu state (Varghese et al., ), to the Lakshadweep ertain fish groups have important functional roles in archipelago (Rohan Arthur, pers. comm.) and the Andaman Cstructuring coral reef ecosystems, including corallivory and Nicobar Islands (Rajan et al., ). Little is known (Cole et al., ), herbivory (Diaz-Pulido & McCook, about the species’ distribution and conservation status around the Andaman and Nicobar Islands. In the recent VARDHAN PATANKAR* (Corresponding author, orcid.org/0000-0002-9088- 4537) and TANMAY WAGH* Wildlife Conservation Society, 551, 7th Main past the islands have been affected by a series of coral Road, Rajiv Gandhi Nagar, 2nd Phase, Kodigehalli, Bengaluru, India bleaching events (in , , and ) and the E-mail [email protected] Tsunami of , which may have disturbed the species’ ANIRUDDHA MARATHE Ashoka Trust for Research in Ecology and the Environment (ATREE), Bengaluru, India habitat (Jeyabaskaran and Rao ; Patankar et al., ; Mondal et al., ). *Also at: National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru, India For species that are rare, threatened or Data Deficient, Received July . Revision requested October . local ecological knowledge has been used to examine popula- Accepted February . tion trends (Aswani & Hamilton, ;Lavidesetal.,; Oryx, Page 1 of 8 © 2019 Fauna & Flora International doi:10.1017/S0030605318000376 Downloaded from https://www.cambridge.org/core. IP address: 182.73.193.33, on 19 Mar 2019 at 07:14:56, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1017/S0030605318000376 2 V. Patankar et al. Lavides et al., ; Pan et al., ). Studies that have com- November –April . At each site we counted B. bined ecological data from underwater surveys with infor- muricatum along five random × m transects ( m ) mation from fishers have shown that both sources can delineated with a m fiberglass tape. Identification of provide reliable information (Iniesta-Arandia et al., ; B. muricatum is relatively straightforward because of its Zappes et al., ). In addition, the inclusion of local eco- large size and the presence of a unique bulbous bump on logical knowledge in conservation research can increase the the head. On sighting, we counted the number of individuals involvement of local stakeholders in conservation activities and visually estimated their size. A prior calibration was (Drew, ). We therefore used a combination of surveys conducted to refine the accuracy and precision of our and interviews to assess the abundance, distribution and underwater size estimates until they were within %of conservation status of B. muricatum across the Andaman actual lengths. and Nicobar Islands. Using generalized linear models, we test whether abundance is influenced by a combination of benthic variables and the presence of marine protected Benthic cover areas, and discuss our findings in the light of developing con- We quantified the benthic cover (live coral cover, turf algae, servation strategies for B. muricatum around these islands. macroalgae, sand, rubble, soft coral and others) at each tran- sect by photographing five × m quadrats, one at each m Study area along the m transect, using an underwater camera with- out flash. Per cent benthic cover categories were measured The Andaman and Nicobar archipelago of India is part of using Adobe Photoshop . (Adobe Systems, San Jose, USA). the Indo-Myanmar and Sundaland biodiversity hotspots in the south-eastern Bay of Bengal (Davidar et al., ; Roberts et al., ). The archipelago comprises islands Documentation of local knowledge and a land area of , km , with a total coastline of , km. It includes the Andaman group (. islands, To investigate the awareness and perception of B. murica- inhabited, , km ) and the Nicobar group ( islands, tum by fishers we conducted a total of semi-structured – inhabited, , km ), separated from each other by the interviews (Huntington, ) during January May Ten-degree Channel. The Andaman Islands have pro- , in three villages in South Andaman (Wandoor, in- tected areas ( national parks and wild sanctuaries), all terviews; Junglighat, ; Mohanpura, ), two villages in of which encompass coast and surrounding waters, and Mayabunder in Middle Andaman ( ) and five villages in the Nicobar Islands have seven community-protected mar- the Nicobars (Tapong, ; Hitui, ; Ramjav, ; Masala ine areas, with restrictions on fishing and other resource use Tapu, ; Kakana, ). These are the major fishing villages activities (Patankar et al., ). The islands are influenced in the archipelago. All respondents were male, as fishing by both the south-west and north-east monsoons (May– activities are predominantly carried out by men in this re- December). gion. The number of interviews in each region was based on the intensity of fishing, the ethnic heterogeneity of the fishing community and the diversity of fishing gear used. Methods Thus, there were interviews in South Andaman, which has the highest number of fishing vessels, several ethnic We surveyed sites across the archipelago, to account for groups (Telugu, Bengali, Malayali and Tamil) and a high variability in coastal morphology, oceanographic condi- diversity of fishing gear (gillnets, trawls, long lines, hook tions, geography and reef resources. In total we surveyed and lines, cast nets, and hand-held wooden spears and six sites at Camorta Island, four at Great Nicobar Island harpoons), and in Middle Andaman and in Central and Nancowry Island, two at Aves, Katchal, Little Nicobar, where spearfishing and hook-and-line are the Nicobar, Interview, Twins, Cinque, Sister, Rutland and common fishing methods used, by Karen and Nicobari Eastern Reef islands, and one site at all other locations. communities. We used the snowball sampling method to se- The number of sites around each island were selected lect the interviewees in each village (Kvale, ). Interviews based on the size of the island, aspect, and location and were conducted in Hindi in South Andaman, and in in accessibility of the reef (Fig. ). Karen and Nicobari in