Rohan Arthur

Scientist, Oceans and Coasts

Rohan 20credit 20vishnu 20som

Ph.D.

My research interests concern issues of conservation, particularly the implications of climate change for marine ecosystems, the rational management of marine systems and fisheries in India, and the interface between policy, traditional practices, and ecosystem management. I have worked in several reef systems around India, and along the Kenyan coast. My chief concerns are in furthering the fledgling tradition of good field ecological research in marine environments in India, and in helping fill some of the significant gaps in the very basic knowledge we require to manage them. A long-held fascination for their aesthetic irresponsibility, together with generous helpings of inertia and serendipity, has drawn me to marine ecosystems and their conservation. I obtained my Master's degree in Wildlife Science from the Wildlife Institute of India in 1995. For my master's research I worked on coral community composition and its response to human disturbance in the intertidal reefs of the Gulf of Kutch in Northwest India. I am one of NCF's founder-trustees, and direct its reef program. I continue to be interested in reef community dynamics and disturbance, and my doctoral research focuses on the consequences of temperature-induced mass-mortality of coral on the reef systems of the Lakshadweep atoll reefs, Western India.

Projects

Grouper faceoff

Aggregating groupers

Documenting and protecting spawning aggregations in the Lakshadweep

Trawlers

Chickenfeed

The economics of trawl fishing along the Coromandel coast

Dugong 201 20neil 20island photo vardhan 20patankar

Conserving an extinct species

Tracking changes in dugong populations in the Andaman and Nicobar archipelago

Agatti 20rubble

Coping with catastrophe

Documenting patterns and processes of resilience in the Lakshadweep reefs

Dscn6646

Kitchen Stories

Understanding how Nicobar communities share resources in the wake of the tsunami

Img 0012

Mainstreaming resilience principles

Understanding and managing the buffer capacity of the Andaman and Nicobar reefs

Irrawaddy 20breaching

Net Gains

Understanding coexistence between Irrawaddy dolphins and fishers in Chilika

Grouper

Reef fish responses to climate change

Understanding how fish communities in the Lakshadweep cope with change 

Traditional 20management 20project 20

Traditional management and change

Marine resource management in the Nicobar archipelago

Boat 20and 20turtle

Turf Wars

Understanding turtle-fisher conflicts in Lakshadweep seagrass meadows

Publications

  • Popular Article
    2016
    Living with change: local responses to global impacts
    Rohan Arthur, Naveen Namboothri, Vardhan Patankar
    Current Conservation, issue 10.2 http://www.currentconservation.org/?q=issue/10.2
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    PDF, 290 KB

  • Journal Article
    2016
    For traditional island communities in the Nicobar archipelago, complete no-go areas are the most effective form of marine managementFor traditional island communities, no-go areas are the most effective form of management
    Ocean & Coastal Management 133, 53-63 http://dx.doi.org/10.1016/j.ocecoaman.2016.09.003
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    PDF, 1.16 MB

    For traditional island communities in the Nicobar archipelago, complete no-go areas are the most effective form of marine management

    The ability of local communities to sustainably manage natural resource harvests in coral reefs ecosystem depends heavily on the strength of traditional institutions. Coastal communities have evolved a suite of restrictive practices to control marine offtake and there is considerable recent evidence of their effec- tiveness in protecting and enhancing resource stocks. However, traditionally imposed restrictions can vary considerably in their complexity and in their functional effectiveness. The indigenous communities of the Nicobar Islands are dependent on marine resources for sustenance, managing them with a range of traditionally imposed restrictions. These include limited entry to certain locations, closed seasons and areas, and restrictions on species, size-classes of fish and fishing methods. We tested the relative effectiveness of protection in areas managed under different traditional control regimes by comparing the abundance and biomass of targeted fish groups in managed and unmanaged areas. Our results indicate that reef sites with the strictest form of restriction e essentially no-go areas e had significantly higher abundance and biomass values of most functional groups of fishes compared with partially protected and control locations. In contrast, targeted food fish stocks did not differ from control locations in partially protected sites managed with even complex forms of traditional management. Ensuring that traditional harvest rules are complied is critical to the success of any management system, and our re- sults suggest that they can be most strictly enforced in traditional no-go areas. Our work highlights the importance of critically evaluating the factors influencing traditional management systems to strengthen their ability to protect these reefs from unsustainable overharvest.

  • Journal Article
    2016
    "Choice" and destiny: The substrate composition and mechanical stability of settlement structures can mediate coral recruit fate in post-bleached reefs
    Coral Reefs. 35: 211-222

    Increasingly frequent and intense ocean warming events seriously test the buffer and recovery capacities of tropical coral reefs. Post-disturbance, available settlement structures on a reef (often dead coral skeletons) vary considerably in their mechanical stability and substrate composition, critically influencing coral recruit settlement choice and fate. In the wake of a coral mass mortality in the Lakshadweep archipelago, we examine (1) the relative availability of recruit settlement structures (from stable to unstable: reef platform, dead massive coral, consolidated rubble, dead corymbose coral, dead tabular coral, and unconsolidated rubble) in 12 recovering reefs across three atolls in the archipelago, (2) the substrate composition [crustose coralline algae (CCA), mixed turf, macroalgae] of these structural forms, and (3) whether the choice and fate of young coral are mediated by the substrate and stability of different structural forms. For this, we measured the abundance and distribution of recruit (<1cm), juvenile (1–5 cm), and young adult (5–10) corals of 24 common coral genera. Four years after the mass mortality, reefs differed considerably in composition of settlement structures. The structures themselves varied significantly in substrate cover with dead tables largely covered in CCA [60 ± 6.05 % (SE)] and dead corymbose coral dominated by mixed turf (61.83 ± 3.8 %). The youngest visible recruits (<1 cm) clearly preferred CCA-rich structures such as dead massives and tables. However, older size classes were rarely found on unstable structures (strongly ‘‘avoiding’’ tables, Ivlev’s electivity index, E = -0.5). Our results indicate that while substrate cover might mediate coral choice, the mechanical stability of settlement structures is critical in determining post-settlement coral survival. The composition and availability of settlement structures on a reef may serve as a characteristic signature of its recovery potential, aiding in assessments of reef resilience.

  • Dataset
    2016
    Long-lived groupers require structurally stable reefs in the face of repeated climate change disturbances.
    Karkarey R, Kelkar N, Lobo AS, Alcoverro T, Arthur R (2014) Data from: Long-lived groupers require structurally stable reefs in the face of repeated climate change disturbances. Dryad Digital Repository. http://dx.doi.org/10.5061/dryad.d7j02
  • Poster
    2015
    What are coral reefs?
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    PDF, 12.5 MB

  • Poster
    2015
    What makes a healthy reef?
    Download

    PDF, 7.61 MB

  • Popular Article
    2015
    Eats shoots and doesn't leave: Dugong herbivory and movement patterns in the seagrasses of the Andaman and Nicobar Islands
    EcoLogic: The NCF Blog

    Link: http://blog.ncf-india.org/2015/11/23/eats-shoots-and-doesnt-leave/

  • Journal Article
    2015
    Sharing mechanisms in corporate groups may be more resilient to natural disasters than kin groups in the Nicobar Islands
    Human Ecology. 43:709-720

    It has been suggested that kin groups are better predisposed to cooperatively manage essential natural resources than non-kin groups because of inclusive fitness gains. Whether these long-term genetic pay-offs sufficiently offset the immediate costs of cooperation in periods of scarcity is uncertain. We compared patterns of resource sharing across three island communities in the Nicobar Archipelago affected by the 2004 tsunami. While sharing mechanisms were similar across regions, group composition varied: Central and Southern Nicobar were organised along kinship lines, while Chowra was organised as corporate alliances of unrelated households. We documented post-tsunami losses and conflicts emerging in resource sharing after the event. While kin groups showed considerable breakdown in resource sharing arrangements, corporate communities in Chowra were much more resilient to change. Our results suggest that the more immediate reciprocity of corporate alliances may outweigh the potential benefits of inclusive fitness when faced with conditions of extreme resource scarcity.

  • Journal Article
    2015
    Seagrass Herbivory Levels Sustain Site-Fidelity in a Remnant Dugong PopulationSeagrass Herbivory Levels Sustain Site- Fidelity in a Remnant Dugong Population
    PLoS ONE 10(10): e0141224. doi:10.1371/journal.pone.0141224
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    PDF, 624 KB

    Seagrass Herbivory Levels Sustain Site-Fidelity in a Remnant Dugong Population

    Herds of dugong, a largely tropical marine megaherbivore, are known to undertake long-dis- tance movements, sequentially overgrazing seagrass meadows in their path. Given their drastic declines in many regions, it is unclear whether at lower densities, their grazing is less intense, reducing their need to travel between meadows. We studied the effect of the feeding behaviour of a small dugong population in the Andaman and Nicobar archipelago, India to understand how small isolated populations graze seagrasses. In the seven years of our observation, all recorded dugongs travelled either solitarily or in pairs, and their use of seagrasses was limited to 8 meadows, some of which were persistently grazed. These meadows were relatively large, contiguous and dominated by short-lived seagrasses spe- cies. Dugongs consumed approximately 15% of meadow primary production, but there was a large variation (3–40% of total meadow production) in consumption patterns between meadows. The impact of herbivory was relatively high, with shoot densities c. 50% higher inside herbivore exclosures than in areas exposed to repeated grazing. Our results indicate that dugongs in the study area repeatedly graze the same meadows probably because the proportion of primary production consumed reduces shoot density to levels that are still above values that can trigger meadow abandonment. This ability of seagrasses to cope per- haps explains the long-term site fidelity shown by individual dugongs in these meadows. The fact that seagrass meadows in the archipelago are able to support dugong foraging requirements allows us to clearly identify locations where this remnant population persists, and where urgent management efforts can be directed.

  • Book
    2015
    Common Marine Life of Lakshadweep
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    PDF, 10.2 MB

    A pocket guide to Lakshadweep's common marine creatures.

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