- Investigate population ecology
- Identify migration patterns
- Assess Indonesian manta fishery
Project Start Date:
To undertake a long-term, comprehensive study of Indonesia’s manta rays that will simultaneously increase our understanding of the species and their threats, help towards the successful implementation of conservation goals, raise awareness and provide sustainable economic benefits for local communities.
Why this is important:
Increased demand for manta gills used in Chinese medicine is changing what was previously a limited scale subsistence fishery in Indonesia into an expanding commercial fishery, with the number of mantas caught each year rising dramatically. Due to their life history (slow growth, late age of sexual maturation and low fecundity) manta rays have a limited capacity to recover from overfishing and population declines have already been observed in certain areas of Indonesia where fishing pressure is high.
Research on Indonesian manta populations to date has been limited in scope, however, growing fishing pressure and habitat disturbances have underlined the critical importance of further research to evaluate the impact of these threats and develop appropriate conservation plans.
The Republic of Indonesia is the most expansive archipelago in the world and consists of 17,508 islands and a diverse range of marine habitats, a diversity that has led to one of the richest elasmobranch (sharks, skates and rays) assemblages in the world. Worryingly, Indonesia also has the largest elasmobranch fishery in the world and the overall abundance of sharks and rays in Indonesia is thought to be in decline.
Both reef and oceanic manta rays occur in Indonesia and although commonly seen and dived with in several areas where they aggregate, such as Komodo National Park and Nusa Penida in Bali, very little is known about their ecology, biology and movements; factors that need to be understood in order to properly assess the impact of threats and to successfully achieve conservation goals.
Through multi-faceted research The Indonesian Manta Project and Manta Trust are working to shed light on Indonesia’s manta populations and the threats that are impacting them. Using photo-identification methods and field observations we are building a comprehensive database of individual manta rays which allows us to map the species distribution throughout Indonesia. Over time, this data enables us to make an estimation of population size and can highlight trends in behaviour, movements, life history and identify areas of critical habitat use.
Knowledge of movements and migration patterns is of particular importance for conservation and management, as a result acoustic and satellite tagging methods will be used alongside photo-identification to help detect finer-scale movements and large-scale migrations. Genetic analysis will also be undertaken in order to determine the relatedness of manta populations within Indonesia and further afield throughout the world.
Investigating the manta ray fishery in Indonesia is an equally important aspect of the project’s research. Currently it is unclear where mantas are being targeted and on what scale. Through fish market surveys, interviewing fishermen and investigating reported population declines we are working to uncover the true extent and impact of this threat in Indonesia.
Through our research we will work closely with and engage local communities, the dive tourism industry, conservation organisations and media to help raise awareness on the ecological and economical importance of protecting manta rays and their habitat with the fundamental goal to create value for living manta rays as a sustainable natural resource for the tourism industry.
- Identify and map manta ray distribution throughout Indonesia.
- Research into the ecology and biology of Indonesia’s manta populations.
- Survey of Indonesia’s manta fishery.
- Local community education, awareness raising and support of alternative, sustainable incomes.
- Research into mantas’ current and potential contribution to eco-tourism in Indonesia.
- Expand our network of divers throughout Indonesia to assist with the collection of photo-ID data and to help locate other areas that mantas frequent.
Visit the new Bird’s Head Seascape Manta ID Database: find your manta, share your images!
Partners & Sponsors:
Without the generous support and sponsorship we receive we would not be able to achieve our work in Indonesia. We are very grateful to the Save Our Seas Foundation for their support.