Understanding the role of local communities in the conservation of critically endangered rhino rays

Rhino rays form a distinct and important group of elasmobranchii, a subclass of cartilaginous fish that comprises rays and sharks. However, there is limited information on rhino rays, and 15 of the 17 known species of rhino rays are categorised as critically endangered, as per the International Union for the Conservation of Nature (IUCN) Red List.

The 2019 annual report by the Central Marine Fisheries Research Institute (CMFRI), found that 43,741 tonnes of landed elasmobranchs were recorded, making India one of the top three countries in the world that fish elasmobranchs.

A recent study by scientists from Ashoka University, India and the University of Oxford, U.K. published in January this year examines the socio-ecological status of rhino rays using local ecological knowledge (LEK) of fishing communities in the coastal state of Goa.

Current status of rhino rays

According to study author Divya Karnad, who is also a co-founder of InSeason Fish, “Guitarfish and wedge fish, which together form rhino rays, are a group of species that the public was not concerned with until recently. A few years ago, the IUCN did Red List assessments on these species and found that the status of many had changed to critically endangered. This was strange because guitarfish in India are not considered particularly commercially important.”

Karnad adds that prior to the amendment of the Wildlife Protection Act, several experts had urged that these species be granted strict protection under Schedule I. While some suggestions were accepted, the new amendment has not been released yet.

The aim of this study was two-fold. First, the authors attempted to gain information on habitat use and seasonality of rhino rays and understand their relationship with local fisheries and fishing practices. Second, they sought to evaluate the local ecological knowledge and perspectives of fishers of these species.

The study authors noted limitations of data available on elasmobranch landings in the country, making it difficult to discern patterns of the fish. Trisha Gupta, lead author and a doctoral student at the University of Oxford says, “In India, there are initiatives by the government and NGOs like the CMFRI that conduct species-level monitoring. This is not in the case in Goa where they are broadly categorised into sharks or elasmobranchs and even then, it is an underestimation.”  To cover gaps in information, Gupta planned to carry out catch and landing surveys in south Goa.

Interviewing fisherfolk in Goa

Interviews with 66 individuals that were part of the study comprised questions on habitat use, breeding, behaviour and seasonality of rhino rays. The interviews also helped identify fishing gear, catch rates, and notes on how they were used after capture. Twenty-two individuals with immense fishing experience were chosen for more extensive interviews.

Almost all (97%) respondents were able to identify rhino rays and confirmed habitat use patterns as seen in literature. Details from respondents like breeding near the shore, especially around the mouth of rivers during and after the monsoon rains are particularly interesting to note.

Local ecological knowledge can help fill in gaps in literature, especially in the case of behaviour that is not recorded as a part of routine assessments. For instance, Karnad recalls observing rhino rays rise to the surface and seemingly ‘gulp air’, a behaviour that a study reviewer had also noted in guitarfish in other parts of the world. “Detailed observations like this should be tapped into and this is what we plan to do in the next stage,” she says.

While rhino rays are currently only caught as bycatch, some interviews revealed that that they were once targeted, primarily for their fins. But the declining numbers now have made the fin trade less viable. Karnad compares their status to that of sawfishes, whose large fins were highly coveted. “However, there aren’t many of them left. Similarly, for wedge fish, some of them can grow to be quite large, but because there are so few left, they are no longer targeted as it is not worthwhile for traders to invest all this time and effort for something they may not be able to find.”

Incentivisation to release bycatch

According to reported numbers, bycatch rates appear higher in South Goa and in September and October, following the monsoon.

After capture, the rhino rays are either sold in local markets, consumed or discarded, depending on the region. Individuals interviewed in the study were of the opinion that with north Goa catering to more tourists, market value of rhino rays were decided by what was in demand there. Larger sized captures were more likely to be sold or consumed in the north. In south Goa, size was not the defining factor and almost all captures were sold or consumed.

Presently, there is no compensation offered to fishers for releasing protected species caught as bycatch. While the majority of respondents did not feel compensation was required, some believed incentivisation would encourage them to release them.

Karnad uses the example of experiments with incentivisation in Brazil to explain how this could work. Initially offered financial incentive, now fisherfolk are awarded community recognition instead. However, fisherfolk were mostly motivated by the convenience of releasing bycatch.  “It would depend on the size of the animal — if they are small (less than a metre long), most fishermen would be willing to release them. The effort of going to release many small ones is high, which makes them less willing to do so. If it is a large individual, a financial incentive may come into play.” Karnad noted that the incentivisation model used for whale sharks showed success. Fisherfolk who released them would be recognised with plaques or photos in the newspaper or social media features. “It worked very well to incentivise them, and perhaps this is a model we could explore for guitarfish.”

Through their interviews, the team also learnt about shark fisheries and their targeted fishing. Gupta plans to further investigate this area during her PhD. “I want to investigate what [which species] they are catching, what drives them to catch them, and why are they so valuable. I am hoping to tie all of this up with what kind of conservation initiatives might work,” she told Mongabay-India.

Further research on rhino rays

The team plans to continue investigating their findings from this study in August 2023, soon after the monsoon ends. According to Karnad, “Right now, we have a broad understanding of where these species are found and through this work, we have been able to identify individuals who have a wide knowledge base. We plan to sit down with these individuals and gather more details on types of behaviour, feeding habits, and where they can be found.”

The new project, funded by Save Our Seas Foundation, will utilise ecological methods such as underwater cameras and transect lines to further investigate the potential nursery sites identified through interviews.

Gupta says, “this ecological work could allow for identification of these nurseries and aggregation sites, to help design area-based conservation measures.”

“The IUCN Species Survival Commission’s (SSC) Shark Specialists Group has come up with a classification called Important Shark and Ray Areas (ISRA), and we could potentially get them declared as ISRAs which would then pave the way for the government to take notice and possibly declare them as community reserves,” adds Karnad.

According to one of the interviewees, fishers would be more likely to release bycatch rhino rays if they better understood the ecological importance of these species. As a part of her ongoing doctoral studies, Gupta has plans to conduct outreach workshops. “I would like to give back to the community and figure out a way to share some of my findings. I would also like to do some workshops, particularly for guitarfish, as I see a lot of potential to do something on ground.”

“The LEK gave us a really good base for these species, and ecological methods will help us fill in the limitations. Places like Goa are unique in that people (including the fishing communities) have a higher educational knowledge and high awareness when it comes to conservation issues. They are a relatively easier group to talk to as they are open to conversation with researchers and are open to sharing their data and knowledge and I think there is a possibility to continue work alongside them,” she concludes.

Banner image: Release of a juvenile widenose guitarfish captured in a shore seine net. Photo by Trisha Gupta.