Research | Marine
Marine Research at ANET involves a variety of different projects spear headed multiple researchers and institutions.
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: https://lteo.iisc.ac.in
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:
- Determine the cryptic biodiversity of A&N islands’ marine environments and discover new species.
- Understand how water quality influences marine biodiversity.
- Inventory and quantify major ecosystem functions across spatial gradients and seasonal changes in reefs.
- Assign value to foundational species based on their contribution to biodiversity and ecosystem function.
- 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
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
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
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: https://www.seaturtlesofindia.org).
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
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.
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
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
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
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
Human-Saltwater Crocodile Conflict
Marine Protected Areas
Managing tourism in and around MPAs
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.