Allan Kai

Hidden beneath the waters of the Western Indian Ocean lies one of the most enigmatic and endangered marine species: the bowmouth guitarfish (Rhina ancylostoma). Often described as a “living fossil” due to its unique appearance and ancient lineage, this species is now on the precipice of extinction. Recent findings from a vulnerability assessment conducted along Kenya’s coast underscore the dire threats facing this remarkable species and demand urgent action from governments, fisheries, and conservationists.

The bowmouth guitarfish belongs to a group of cartilaginous fish known as elasmobranchs, which includes sharks and rays. While these species often feature prominently in marine conservation discussions, the bowmouth guitarfish remains overshadowed by its more charismatic cousins. Yet its plight is equally, if not more, desperate. The species is currently classified as critically endangered on the IUCN Red List, and the recent study conducted in Kenya’s Exclusive Economic Zone (EEZ) revealed its high vulnerability to multiple fishing practices, particularly prawn trawling and industrial longlining.

A picture of the bowmouth guitarfish (Rhina ancylostoma) stored in the American Museum of Natural History, taken by John E. Randall 

Why is the bowmouth guitarfish so at risk? Its slow growth rate, late maturity, and low reproductive output make it inherently susceptible to overexploitation. These traits, coupled with the non-selective nature of destructive fishing gear, have led to drastic declines in its population. Prawn trawlers, which indiscriminately scoop up marine life as bycatch, are particularly devastating for the bowmouth guitarfish. In Kenya, it has been observed that this species is frequently entangled in these nets, often with fatal consequences.

The loss of the bowmouth guitarfish is more than a biodiversity tragedy; it is a symptom of a broader ecological crisis. As a benthic species, it plays an integral role in maintaining the health of seafloor ecosystems. Its disappearance would disrupt the delicate balance of marine food webs, leading to cascading effects that threaten fisheries and coastal livelihoods.

Protecting the bowmouth guitarfish requires a multifaceted approach, beginning with increased awareness among fishers. Many are unaware of the critical status of this species and its ecological importance. Education campaigns, especially targeting artisanal fishers who often operate in areas frequented by guitarfish, are essential. These efforts can be paired with training on sustainable fishing techniques and bycatch reduction measures, such as the use of turtle excluder devices that also protect other vulnerable species.

Policy interventions are equally critical. The study recommends the development of a Shark and Ray Management Plan (SRMP) tailored to Kenya’s fisheries. For the bowmouth guitarfish, this could include spatial and temporal fishing restrictions in areas where it is known to inhabit, particularly during its breeding seasons. Strict enforcement of bycatch limits and monitoring programs must also be implemented to track population trends and ensure compliance with regulations.

International cooperation is vital, as the bowmouth guitarfish is not confined to Kenya’s waters. It is found throughout the Western Indian Ocean, meaning regional collaboration is necessary to safeguard its habitats. Transboundary initiatives such as the Indian Ocean Tuna Commission (IOTC) must integrate the conservation of species like the bowmouth guitarfish into their agendas, with member countries committing to joint actions.

Above all, we must recognize that the fight to save the bowmouth guitarfish is not just about conserving a single species—it is about preserving the intricate web of life that sustains our oceans. The Western Indian Ocean is home to some of the planet’s richest marine biodiversity, and losing a species as iconic as the bowmouth guitarfish would be an irreversible blow to this natural heritage.

For more on the vulnerability assessment of elasmobranch species to fisheries in coastal Kenya, read >>> https://doi.org/10.1016/j.marpol.2024.106459