Let’s get to know the Mobula Project Indonesia! Part Two

May 2021

Last month we were introduced to the incredible team that makes up Mobula Project Indonesia. If you missed it, do go back and give it a read here. Carrying on from that article…

What does Mobula Project Indonesia actually do?

In order to achieve our goals, we conduct applied research to identify specific measures to be implemented in fisheries management:

1. We’re assessing whether releasing mobulid rays alive from gillnets could be implemented as a management & policy measure in Indonesia.

To do this, we are deploying survival tags that assess whether and for how long manta and devil rays can survive after being released from nets set by fishermen during ‘normal’ fishing trips. We have boarded many fishing boats off Muncar and deployed tags on 2 devil ray species up to now, the spinetail devil ray (Mobula mobular) and the bentfin devil ray (Mobula thurstoni), and we hope to also release any Chilean devil rays captured as bycatch by fishermen (Mobula tarapacana). Soon, we will be doing the same off East Flores by releasing oceanic manta rays (Mobula birostris) captured by fishermen as bycatch, with a survival tag. We download data that has been transmitted from the tag to a satellite after it has detached from the ray and popped up to the surface. This happens either due to the death of the animal or once the animal has survived for the maximum deployment timespan of 60 days.

Although manta and devil rays are often still alive when fishermen pull the gillnets back onboard, it takes time to free them from the net and they can die from lack of oxygen due to having spent multiple hours trapped in the net. Indeed, manta and devil rays rely on water circulating through their gills to breathe. So, the longer they are trapped in a net, the more difficult it may be to recover, and the animal may die a few hours or days afterwards despite having been released. We want to figure out what measures can minimize this post-release mortality, such as the net soaking duration for example. This will provide a basis to suggest informed management policies at a local and national level.

Our team releasing a devil ray from a gillnet with a survival tag on a fishing boat from Muncar.

2. We’re identifying hotspots for managing the overlap of mobulid ray habitats with fishing activities. To do this, we record daily all the elasmobranch species landed in Muncar. We also gather other types of data that can help us better understand devil ray populations such as biological information. Additionally, interviews with fishermen help us understand socio-economic aspects of the fisheries, and the value of sharks and rays to local communities. This provides insight into trends in fisheries, socio-economic value, detailed fishery practices, and fishing grounds- so we have a clear view of what we can do to reduce fishing impacts.

Activity_Devil Ray Measurement 2_Mobula Project Indonesia.jpg — Here, our team is measuring a devil ray pup that was still inside of its mother when she was trapped in a gillnet and landed at Muncar fishing port.

Here, our team is measuring a devil ray pup that was still inside of its mother when she was trapped in a gillnet and landed at Muncar fishing port.

3. We’re raising awareness regarding elasmobranch conservation so that it is taken seriously by all stakeholders. We are especially focusing on organizing workshops at regional levels this year so that local stakeholders can learn more about these issues. Encouragingly, Muncar Fishing Port (PPP) has become a priority for shark and ray monitoring by the Ministry of Marine Affairs and Fisheries. In October 2020, we supported efforts to organize management and conservation resources in the region, facilitated capacity building related to shark & ray identification, and raised awareness about species’ conservation status. It is an important basis for further supporting the implementation of protection and management measures of sharks and rays at a local scale, also ensuring that Indonesia meets its obligations for more comprehensive data reporting. This is important to ensure conservation measures are carried out in an efficient, appropriate, and effective manner.

Our team at one of the local workshops we organised to train local officials in shark and ray identification and to raise awareness of their conservation status.

4. Our efforts also aim at reaching other groups of people through education awareness. We conduct events with students, in local primary schools or for high schools and undergraduates. For example, last year we organised an online educational outreach event for the Vocational School of Fisheries in Banyuwangi, where 92 students learned about the biology and ecology of sharks and rays, as well as conservation concerns and current government regulatory frameworks, to build awareness.

Education outreach event we hosted last year.

We believe education and awareness need to reach the grassroots level, so we joined in a discussion among artisanal fisheries community groups in Muncar. There, we discussed mobulid ray and shark regulations in Indonesia, including species’ protection levels, and how to identify species included on the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) Appendices. Since both manta and devil rays get caught as bycatch during fishing operations, it is crucial to keep reminding fishermen of the need to implement conservation efforts, for example by releasing manta rays back into the ocean if they accidentally catch one. Some of them allow us to board their boats and to release devil rays with a survival tag, despite this not being legally required of them. We also inform them about the decreasing population trends observed for devil rays in Indonesia, and why we are exploring ways to reduce their mortality. In 2014, Indonesia took serious action by giving full protection to oceanic manta rays (Mobula birostris) and reef manta rays (Mobula alfredi) following their listings on CITES Appendix II in 2013. Any use of the animal body part is illegal in Indonesia, including when the ray is caught accidentally. All devil ray species were also listed on CITES Appendix II in 2016, but while their international trade is regulated, fishing them inside the country is still authorized, despite worrying population declines. We hope the government of Indonesia will take action to ensure manta and devil ray populations do not become extinct.

Activity_Fishermen awareness_Mobula Project Indonesia.jpg

Importantly, as a team of young emerging conservationists, we are taking on key roles in the project that will help us take on the important responsibility of conserving, together, our tremendous biodiversity. We are gaining invaluable knowledge of the intricacies of working in marine conservation, from being at the forefront of the action in the field to attempting to fuel policy change at regional and national levels.

Here is what Firman has to say about this experience:

‘It’s a really exciting experience for me! I am taking an interest in understanding fishermen's perceptions related to devil ray fisheries and we know that the devil rays in Muncar are mostly caught as bycatch. As I gain deeper insight from conversations with the local fishermen, they generally don’t intend to benefit from this by selling the devil ray, it only happens because of the need for economic fulfilment, and the habitual landing of any fish that is caught in the nets. Therefore, I am keen to get the fishermen to be more actively involved in devil ray conservation through continuous education awareness from both a conservation and fisheries perspective, to find alternative solutions to devil ray fisheries. In this way, conservation can thrive, and we can also strive for the well-being of fishermen and their families.’ Firman, Mobula Poject Indonesia.