Research  |  Marine

Marine Research at ANET involves a variety of different projects spear headed multiple researchers and institutions.

Ongoing Projects

Long-term Ecological Observatories (LTEO) Programme


Human-induced climate change is now globally recognised as one of the primary drivers for ecosystem decline. Understanding how natural systems respond to constantly altering environmental conditions is thus key to mitigate the impacts of climate change, especially in highly resource-dependent countries like India. However, long term impacts of climatic and other anthropogenic pressures on natural systems and consequently human societies remain poorly understood. Towards this, the Ministry of Environment Forests and Climate Change (MOEF&CC) initiated the Long Term Ecological Observatories (LTEO) Programme, a multi-institutional and inter disciplinary initiative that aims to understand the impacts of climate change and other anthropogenic disturbances on select ecosystems and taxa.

The Marine component of the LTEO programme is based out of the Andaman and Nicobar Islands and involves monitoring of coral reefs, seagrass meadows, sea turtles, reef fish and other abiotic parameters, to understand their responses to climatic as well as anthropogenic disturbances including overfishing, marine pollution and coastal development. The Marine LTEO project is a consortium, headed by Dakshin Foundation in collaboration with the Nature Conservation Foundation (NCF); Indian Institute of Science (IISc) and the Pondicherry University.

Along with marine research, ANET is recognised as the primary field station for all the LTEO Programme activities in the Andaman Islands and will facilitate both marine and terrestrial research in the islands.

To find out more about the lteo project, please visit:

Coral Reefs

Deploying Autonomous Reef Monitoring Structures (ARMS)

This collaborative project brings together ANET/Dakshin, Hong Kong University, and the Indian Institute of Science (IISc.), Bangalore. Its primary objective is to monitor marine biodiversity in the A&N islands and assess its vulnerability to anthropogenic stressors. The project employs standardized census methods and the latest molecular technologies. It involves deploying Autonomous Reef Monitoring Structures (ARMS), collecting marine sediment, and conducting in situ ecosystem function assays. ARMS structures provide a standardized approach to observing and characterizing biodiversity, especially organisms that are visually challenging to study. While ARMS have been used globally, this project marks its first deployment in the Andaman Islands, connecting the region to a broader network of sites and datasets. It also establishes a baseline for understanding marine biodiversity in the context of climate change in the Indian subcontinent.

The project involves Prof. Kartik Shanker from ANET/Dakshin and IISc, Dr. Tejal Vijapure from IISc, Dr. Archana Anand from Hong Kong University and Dr. Naveen Namboothri, from ANET/Dakshin. Its specific objectives are to:

  1. Determine the cryptic biodiversity of A&N islands’ marine environments and discover new species.
  2. Understand how water quality influences marine biodiversity.
  3. Inventory and quantify major ecosystem functions across spatial gradients and seasonal changes in reefs.
  4. Assign value to foundational species based on their contribution to biodiversity and ecosystem function.
  5. Assess the uniqueness of the site and study its biogeographic connections between the Indian subcontinent and Southeast Asia.

As of 2022, ten units of ARMS have been deployed, retrieved, and are currently being processed in Prof. Kartik Shanker’s lab at IISc, Bangalore.

Through the application of monitoring techniques and comprehensive analysis, the project aims to enhance our understanding of marine biodiversity, especially cryptic biodiversity that is challenging to sample in the A&N islands. This knowledge will contribute to conservation and management efforts in the region, supporting the long-term sustainability of marine ecosystems.

Past researchers: Mahima Jaini, Tanmay Wagh, Diya Das, and Harshal Patil.

Current researchers: Tejal Vijapure, Akshata Joshi, Titus Immanuel, Naveen Namboothri and Kartik Shanker.

Field and lab support:  Anne Theo, Bharat Ahuja, Divyashri Varadharajan, Shawn Dsouza, Adhith Swaminathan (field); Aditi Shankar, Mudra Deshpande, Vidisha Kulkarni, Shree Varsha VK (lab).

Collaborators:  Archana Anand, David Baker and Goutham Bharathi.

Vulnerability and resilience of coral reef ecosystems to anthropogenic disturbance and predicted alterations due to climate change in the Andaman and Nicobar Islands

The collaborative research project, titled “Vulnerability and Resilience of Coral Reef Ecosystems to Anthropogenic Disturbance and Predicted Alterations due to Climate Change in the Andaman and Nicobar Islands,” brings together the Indian Institute of Science, Bangalore, and the Laboratoire d’écogéochimie des environnements benthiques, Centre National de Recherche Scientifique (CNRS), Observatoire Oceanologique de Banyuls-sur-Mer, France. It is conducted under the CEFIPRA Scientific Collaborative Research Programme, complementing the ongoing marine ecology research within the Long Term Ecological Observatories project supported by the Ministry of Environment, Forest & Climate Change, Government of India.

This project takes a comprehensive approach to address the significant threats faced by coastal ecosystems, particularly in the nearshore zone, due to climate change-induced alterations, with a specific focus on highly vulnerable coral reef systems. Sampling methods through SCUBA diving, are employed to study long-term coral reef ecosystem processes. Additionally, novel techniques such as autonomous reef monitoring systems (ARMS) are integrated to enhance our understanding of these processes. By utilizing baited remote underwater video systems (BRUVS), the project investigates the impact of anthropogenic disturbances on marine trophic dynamics, particularly apex predators in reef ecosystems. Furthermore, through oceanographic modelling, insights are gained into the larval dispersal of key scleractinian coral species, improving our understanding of reef connectivity, resilience, and vulnerability to disturbances related to global changes. The collaboration involves Prof. Kartik Shanker, Dr. Titus Immanuel, and Ms. Akshta Joshi from IISc, India, and Dr. Katell Guizien, Dr. Stephane Hourdez, and Dr. Lorenzo Bramanti from CNRS, France.

By partnering with Dakshin Foundation and ANET, which maintain a permanent field station and research facility in the Andaman Islands, the project aims to establish a platform for collaboration among local stakeholders, including the fisher community and boat owners. This collaboration aims to improve the monitoring of local reef fishery and promote the conservation of reef fish.

Do fishes fear the reaper?

Anthropogenic fear in coral reefs of the Andaman islands

Humans have been hunter-gatherers for most of their evolutionary history and may fill the niche of predators in many ecosystems. Many indigenous communities still rely on hunting and fishing as a primary source of nutrition. Hunters and fishers are more lethal and efficient than other predators in most ecosystems. Human predators kill more prey than all predators combined across terrestrial and marine ecosystems. The greater lethality and pervasive nature of human predation may result in greater perceived risk by prey species. 

Historic overfishing has led to the loss of top predators in nearshore marine ecosystems. The reduced predation pressure has had ecosystem wide consequences such as mesopredator release and in some cases has led to the collapse of fisheries. As predators have been fished out, fisheries have had to expand in spatial scale and effort while also targeting lower trophic levels. The loss of predators from coral reefs has been shown to change the distribution of seagrass which are vital for blue carbon sequestration. 

The loss of predators due to human activities such as fishing may reduce the local intensity of and homogenise the spatial distribution of risk experienced by prey. Prey can implement behavioural anti-predator strategies to mitigate risk. Changes in prey behaviour due to altered risk can alter the abundance, distribution, and composition of plants. This phenomenon is known as a behaviourally mediated trophic cascade. This can affect key ecosystem processes such as carbon sequestration and nutrient cycling. 

This study examines the behaviorally mediated effects of increased fishing pressure on coral reefs in the Andaman Islands, including the response of herbivores to human and non-human predators and the effect of fishing boats on predator abundance and behaviour. The study will also test whether the effects of human predators vary in areas with high and low fishing pressure. The study uses a combination of observational and experimental methods to answer our questions. The methods include remote underwater video surveys and predator model experiments.

This study will help gain a better understanding of the behaviorally mediated effects of human predators on coral reefs. In summary, this study tests whether humans fishing in the Andaman Islands fill the role of a super-predator for targeted species such as groupers, elasmobranchs, and roving carangids. These species occupy trophic levels higher up the food chain and we expect behaviourally mediated trophic cascades to result in higher foraging rates and lower vigilance in herbivorous fish due to predator removal. The consequence of such herbivory has potential impacts on reef trophodynamics, coral recovery, carbon sequestration and nutrient cycling. In experiments within the Marine National Parks which are no-take reserves, the study expects a higher relative abundance of apex predators, owing to the lack of fishing pressure. The apex predators here should still instill a landscape of fear in their prey species, which will be captured in experiments that account for foraging rates, vigilance behaviour and latency to feed in the herbivorous prey species. The insights from this study will be used to inform better management of coral reefs for biodiversity and livelihoods. This knowledge can inform the development of conservation and management strategies that seek to protect and preserve these vital ecosystems.

The project is led by Shawn Dsouza. Titus Immanuel, Bharat Ahuja and Akshta Joshi are part of the project team. Prof. Kartik Shanker is the project supervisor.

Swimming with the fishes

An integrated approach to assess reef fish populations and behaviour in the Andaman islands

Fisheries in the Andaman Islands are primarily small-scale and predator-targeting. There is a limited understanding of the top-down effects of fisheries on reef ecosystems. Selective overfishing has been identified as a key factor in influencing the distribution and abundance of predators such as sharks, rays and groupers. The loss of these species can lead to trophic downgrading and have cascading impacts on local fish populations as well as coastal communities that depend on marine resources. Through this project, the aim is to examine key top-down processes (such as commercial fishing) that are influencing reef community dynamics and vulnerable species in the ANI by using an integrated approach with a view to promote conservation, inform local management and impact island policies.

The project will also aim to quantify changes in the grouping and foraging behaviour of herbivorous reef fish. Specifically, monitoring of ephemeral mixed-species groups that are formed by surgeonfish, parrotfish, and their allies will be carried out. In tropical reef ecosystems, such groups have the potential to alter local species distribution patterns and increase diversity of participating species. The formation of such groups can potentially impact reef trophodynamics owing to increased rates of herbivory. 

External drivers for the formation of such mixed-species groups in reef fish include the presence of key resources such as food and the extent of predation pressure. In the case of herbivorous reef fish, foraging for food and guarding against predators can be strongly interrelated activities. The project hopes to understand the drivers for such shoaling behaviour for these species in the fringing reefs of the Andaman Islands by covering a range of sites across the archipelago that differ in fundamental aspects such as fishery intensity (predation pressure) and resource availability.

The project aims to do this by employing a combination of methods such as Baited Remote Underwater Video Stations (BRUVS) and Underwater Visual Census (UVC) by SCUBA diving to quantify the abundance of species of interest and their behaviour(s). By comparing our findings within and outside Marine Protected Areas (MPAs), the aim is to determine the efficacy of current management regimes and develop better management recommendations for preserving coral reefs and reef-associated fauna in the Andaman Islands.

The project is led by Bharat Ahuja and the team includes Titus Immanuel, Shawn Dsouza, and Akshta Joshi. Dr. Kartik Shanker is the project supervisor.

REEF LOG: Citizen science

Given that professional researcher-based ecological monitoring is often highly expensive, logistically demanding and patchy in space and time, Dakshin Foundation in association with ANET recently launched an underwater citizen science programme called REEF LOG. Starting with its Andaman chapter, primarily based at the leading dive shops on Havelock Island, REEF LOG consists of two surveys; one for fish and another for invertebrates. REEF LOG also helps generate data on rare species and phenomenon. In the near future REEF LOG also hopes to launch websites and mobile applications for easier engagement, information dissemination and data sharing. The idea for REEF LOG is backgrounded by the need for initiatives that combine long-term monitoring goals and strategies that aid the public understanding of science and action. REEF LOG was conceptualised by Mahima Jaini, ANET/Dakshin’s Marine Research Officer as well as Dr. Naveen Namboothri and Dr. Kartik Shanker. Given that professional researcher-based ecological monitoring is often highly expensive, logistically demanding and patchy in space and time, Dakshin Foundation in association with ANET recently launched an underwater citizen science programme called REEF LOG. Starting with its Andaman chapter, primarily based at the leading dive shops on Havelock Island, REEF LOG consists of two surveys; one for fish and another for invertebrates. REEF LOG also helps generate data on rare species and phenomenon. In the near future, REEF LOG also hopes to launch websites and mobile applications for easier engagement, information dissemination and data sharing. The idea for REEF LOG stems from the need for initiatives that combine long-term monitoring goals and strategies that aid the public understanding of science and action. REEF LOG was conceptualised and led by Ms. Mahima Jaini, Dr. Naveen Namboothri, and Dr. Kartik Shanker. The project is led by Mahima Jaini, ANET/Dakshin’s Marine Research Officer.

Sea Turtles

Leatherback Turtles

ANET/ Dakshin leads a multi-institutional team that is involved in a long-term monitoring and conservation programme for sea turtles of the Andaman and Nicobar Islands, in particular for leatherback turtles. The leatherback monitoring programme involves tagging of nesting turtles as well as satellite telemetry of individuals to understand the population dynamics and movement patterns of Indian Ocean leatherbacks. The project also involves regular archipelago-wide surveys. A major objective of these surveys are to monitor post-tsunami leatherback nesting recovery and other ecological factors (for more details, visit:

Regular monitoring of nesting sites of the leatherback turtles was initiated at the Galathea nesting site in Great Nicobar in the early 2000s. However, the turtle camp at this site was destroyed in the 2004 tsunami. In 2008, new monitoring sites were established in South Bay and West Bay on Little Andaman, and monitoring has been continuing till date. Every nesting season, between December and March, a team of six field staff set up temporary monitoring camps at the two nesting sites, South and West Bay, in Little Andaman Island. As of February 2019, over 250 leatherback nests were encountered in West Bay and South Bay, the highest recorded since the initiation of the project in 2008. The programme also has a strong focus on developing networks for conservation in the region and a long-term education and outreach programme to sensitise government authorities and local communities on conserving sea turtles and their habitats.

This project is led by Dakshin and is carried out in collaboration with the Andaman and Nicobar Forest Department, the Centre for Ecological Sciences, Indian Institute of Science, Bangalore and ANET. The project team includes Dr. Kartik Shanker, Adhith Swaminathan, Saw Thesorow, Saw Momong, Sushil Lakra, and Vipin Tirkey.

Harnessing agent-based models to mitigate marine conservation conflict involving saltwater crocodiles in the South Andamans and Rutland


Marine ecosystems around the world often experience serious conflict between a wide variety of individual and institution-level stakeholders, as conservation decisions taken to preserve these ecosystems are often characterised by inherent trade-offs and conflicts within the environment sector itself, as well as links to a range of other social and developmental stressors impacting human communities in marginal coastal spaces.

As an example, in the Andaman islands, we consider the case of the saltwater crocodile (Crocodylus porosus), a large predator known for attacking people and livestock. Our strategic goal is to harness agent based modelling (ABM) approaches to develop an intelligent decision support system (IDSS) for resolution of conservation conflict around salt- water crocodiles in the Andaman Islands. This modelling exercise will serve as a workable template for similar conservation situations involving problematic wildlife across the country and will also serve as a policy discovery tool. This project is supported by Google India under the GoogleAI for Social Good initiative.

Past Projects

Dugongs & Seagrass Beds

Ecology and conservation of dugongs

Dr. Elrika D’Souza from the Nature Conservation Foundation, has been studying the ecology and conservation of Dugongs (Dugong dugon) in the Andaman and Nicobar archipelago for several years. Recently, Elrika and her team combined historical and current data from the archipelago to estimate long term dugong occupancy trends. The results showed a 60% decline in numbers in the last 20 years. Surprisingly, they found that remaining dugong populations, now scattered and restricted to a few sheltered bays and channels, were not limited by the availability of seagrass, their primary food, but due to anthropogenic factors such as hunting, and strangulation in fishing gill-nets. By prioritising sea grass meadow sites based on their use and occupancy by dugongs, D’Souza and team monitored sites to aid the Department of Environment and Forests in conserving the remaining population. Building on this work, Dr. D’Souza is currently studying the carbon dynamics of sea grass meadows; the impact of sedimentation, sea grass species and herbivory on carbon sequestration.

Reefs of the Andaman and Nicobar Islands are most diverse in India and considered a biodiversity hotspot. A multiple series of catastrophic disturbances (including repeated mass bleaching and a tsunami) have impacted these reefs, seriously testing their buffer capacity.

Coral Reef Resilience

Climate change is considered the greatest long-term threat to the coral reefs. Managers must, therefore, focus on supporting the natural resilience of reefs. Factors contributing to resilience are multidimensional and contingent on local conditions. Identifying these factors at managerially-relevant scales is important if resilience principles have to be included in rational reef conservation efforts. Reefs of the Andaman and Nicobar Islands are most diverse in India and considered a biodiversity hotspot. A multiple series of catastrophic disturbances (including repeated mass bleaching and a tsunami) have impacted these reefs, seriously testing their buffer capacity. In the face of these disturbances, Dr. Vardhan Patankar, a DST-INSPIRE Faculty Fellow, who is affiliated to the Wildlife Conservation Society (WCS), India and the Tata Institute of Fundamental Research, National Centre for Biological Sciences, Bangalore is working towards understanding what factors makes certain reef resilient and plan to incorporate resilience principles in the prevailing reef management of the Andaman Islands.

As a part of this long-term research programme, the processes by which herbivory acts as a top-down force in controlling algal overgrowth and maintaining the coral-algal balance on the coral reefs is also being examined. The findings from this research will help in understanding how local processes influence post-disturbance reef recovery and thus aid in the existing reef conservation and management efforts in the Andaman Islands.

Integrating microscopy and satellite oceanography to understand the dynamics of planktonic communities around the Andaman Islands

A project proposal led by Mahima Jaini, Marine Research Officer at ANET/ Dakshin was successful in securing a grant to use Foldscopes in marine research in the Andamans. This project has been funded by India’s Department of Biotechnology (DBT) to promote the use of low-cost instruments such as foldscopes in research. A foldscope ( is an ultra-affordable, paper microscope, which is designed to be extremely portable, durable, and to give optical quality similar to conventional research microscopes. The use of such instruments is likely to revolutionise research and action in various fields.

This project aims to understand the diurnal and seasonal dynamics of marine plankton and ground-truth satellite-derived ocean surface metrics. The zooplankton sampling component of this project is underway and identification is carried out using foldscopes. Sampling is conducted at day and night during the flooding tide for new moon, first quarter, full moon and last quarter phases of the lunar cycle, for the inshore station (Lohabarrack Sanctuary). Our initial surveys are revealing stark differences in zooplankton diversity and abundance at day and night, new moon and full moon and spring and neap tides. By focusing our effort on distinct meroplankton families we hope to establish a baseline for inshore larval diversity and abundance. In addition to baseline data collection, this project aims to establish efficient and cost effective protocols that can be used to create a long term plankton monitoring initiative here at ANET.

Sharks and Rays

Since the first record of its existence in 1966–67, elasmobranch fisheries in the Andaman Islands have been largely unregulated and unmonitored. Basic fisheries monitoring provides collective information on harvested catch but species-wise information is greatly lacking. While threatened species like the hammerheads, thresher sharks, mantas and devil rays are being exploited, the information on their ecology and biology remains scarce. In order to sustainably utilise resources, it is important to assess species over time. Lead by Zoya Tyabji of the MCBT, this CLP and Ruffordfunded project helps establish baseline data on shark and ray demographics through researcher-lead monitoring surveys. Interactions with local stakeholders are aimed to understand the issues of threatening elasmobranch populations in the Andamans Islands. The results will be targeted towards filling knowledge gaps to improve sustainable management practices.

The Andaman and Nicobar archipelago encompass an ongoing targeted shark fishery with rays, guitarfish and skates caught as bycatch in commercial and artisanal fishing gears. In order to manage their sustainably, it is imperative to know the driving force behind this catch, trade and demand-supply chain. With this in mind, Zoya Tyabji and team aims to conduct semi-structured interviews with fishermen, traders/middlemen and cold storage centre owners in the archipelago. Our interviews aim to examine trends in species composition, sizes and abundance; trends in gear use and perceptions and knowledge of fishermen towards elasmobranchs and its fisheries. The project will help gain insights into the social, motivational and economic drivers behind the fishery aiding us to formulate long-term and effective conservation and management plans for these species.

Human Wildlife Conflict

Cetacean-Fisheries Interactions

A recently completed project by Sachin Vaishampayan of the MCBT aimed to create baseline information on interactions between the fisheries sector and cetaceans present in the Andaman waters. The study has helped identify areas of high cetacean presence through fisher interviews. Sightings of whales seem to be rare and mostly in the deeper ocean. Intimidated by their size, fishermen try avoiding whales and have very less knowledge about them. Dolphin sightings, on the other hand, are frequent, with fishermen describing two to three different species. Some types of fishing gear such as gill nets tend to be involved in more encounters with cetaceans as compared to others such as hook and lines. Though instances of depredation and damage to gear occur, they do not significantly affect the catch or profits of most of the fisherfolk. If the presence of dolphins is detected in water, fishermen either avoid putting their nets in or pull them out if already deployed, hence mitigating their losses. Interestingly, dolphins are perceived positively by majority of fishermen in the area, given their behavioural traits like bow riding and a widespread belief that they rescue fishermen. Most of the fisherfolk are aware of the protected status of the dolphins, and there seems to be no instance of them hunting dolphins for meat and oil in the past or present.

Human-Saltwater Crocodile Conflict

A recent study funded by the In Laks Foundation aims to identify potential areas of risk (based on crocodile attacks on humans and livestock), to classify them on the basis of severity, to understand factors influencing them, to understand people’s perceptions about crocodiles, identify key factors influencing these perceptions and to obtain people’s viewpoint on mitigation measures and post-attack management interventions by the administration. Lead by Sachin Vaishampayan of the MCBT, this study aims to develop better insights into human-crocodile relationship in the Andamans and hopes to help streamline current efforts to mitigate the conflict.

Marine Protected Areas

Managing tourism in and around MPAs

​The unique ecosystems of the Andaman and Nicobar Islands serve as important resource bases for local communities, as well as attract lakhs of tourists every year. Important tourist destinations such as Swaraj Dweep (formerly Havelock Island), Smith and Ross Islands, are within or proximate Marine Protected Areas (MPAs) and have received renewed attention from central government schemes, which aim to further promote this archipelago as a global tourism destination. However, this is filled with challenges as the design of MPAs are based on concepts borrowed from terrestrial ecosystems and there is a lack of consensus among government institutions on even basic aspects such as the legal definition, boundaries, and total number of MPAs in these islands. Dr. Madhuri Ramesh, Ms. Deepika Sharma and Ms. Shimul Bijoor from ANET/ Dakshin Foundation initiated this project in 2018 to understand their management and tourism in the Andaman Islands. This project was initiated with assistance from WWF-India.

The project is divided in two phases: during the first phase, researchers examined the existing management challenges in two PAs which significant marine components, i.e. the Rani Jhansi Marine National Park, and Smith and Ross Islands. In the second phase, a preliminary assessment of the engagement of different stakeholders involved in tourism around these MPAs as well as the state of related public infrastructure, was carried out. Some key findings from this study are as follows: many well-educated islanders are interested in investing and working in the tourism sector because it offers them comparatively high-paying jobs, hence, there is a scope for capacity building to engage more islanders in tourism. But at present only high-ranking officials and businessmen are involved in the planning and implementation of tourism-related projects. There is also a considerable lack of public infrastructure and services in the islands, and with the rise in tourism this gap between requirement and availability is expected to widen.