Better protection for scalloped bonnetheads
Scientists have discovered a population of the Critically Endangered scalloped bonnethead in Colombia. With a small home range and being highly resident and vulnerable to bycatch, this shark is at risk of local extinction. Maria has collaborated with local communities to secure a 10-square-kilometre (3.86-square-mile) no-take zone around a unique high-occurrence area. She will delineate the new no-take zone using moorings with marker buoys and track the fine-scale movements of the sharks to evaluate their level of protection. Maria will also gather mark-recapture data to estimate the number of sharks using the proposed no-take zone and she will develop educational activities in village primary schools to promote shark conservation.
Maria Alejandra Herrera
My passion for the ocean began at an early age. I remember my parents going on diving trips and as soon as I was big enough to carry the scuba tank I began to learn to dive. I got my licence when I was 12 and, as a good Caleña (born and raised in Cali, Colombia), I did my first dives in the Pacific Ocean. I never thought that it would become a career until I attended a symposium on marine mammals and listened to a presentation about bottlenose dolphins. Until then I had taken part in research...
Found and Protected: Implementation and monitoring of the first conservation site for Critically Endangered hammerheads
This project aims to improve the effectiveness of a newly established no-take zone, as well as determine the degree of protection the zone is providing to the local sub-population of scalloped bonnetheads.
Our discovery of a population of Critically Endangered scalloped bonnetheads in Colombia presents a unique conservation opportunity. This shark, with the smallest home range, is highly resident and vulnerable to bycatch, risking local extinction. Urgent action is needed due to inadequate management and enforcement. This project will provide essential data to determine the best protective measures and foster a conservation culture among local communities, ensuring the species’ survival.
Hammerhead sharks are among the most iconic and most threatened shark species. While many research projects have focused on the large species (scalloped, smooth and great hammerheads) very little research has been conducted on their smaller counterparts (scoophead and scalloped bonnethead sharks). One of the least studied hammerheads is the scalloped bonnethead Sphyrna corona, a gold-coloured species endemic to the Eastern Tropical Pacific, from the Gulf of California to Peru. This is the smallest of the nine recognised hammerhead species, with both sexes reaching sexual maturity at about 57 centimetres (22 inches) total length. There is intense fishing pressure throughout the scalloped bonnethead’s range, resulting in bycatch in commercial and artisanal longline, gill-net and trawl fisheries. As a result, there have been sharp declines in scalloped bonnethead populations over the past two decades, including their possible extirpation in Mexico and the Gulf of California. These population declines and range contractions have led to the scalloped bonnethead’s current assessment on the IUCN Red List as Critically Endangered. To date, the only known area where this species is still frequently captured by artisanal fishers is the southern region of the Colombian Pacific coast. However, no recovery programmes, systematic monitoring schemes or management plans are in place.
The lack of ecological knowledge about small hammerhead shark species hampers conservation efforts as time runs short for these animals. Our recent discovery of an abundant population in Colombia offers a vital chance for protection. This shark’s high residence and small home range suggest that even a spatially limited no-take zone in the national natural park is likely to benefit its conservation. However, many questions still need to be answered in order to determine the effectiveness and degree of protection the recently proposed 10-square-kilometre (3.86-square-mile) no-take zone would provide to the sub-population.
Collaborating with local communities, we have secured a 10-square-kilometre no-take zone devoid of fishing around a unique high-occurrence area. Therefore, the proposed project aims to
- Delineate the new no-take zone by deploying moorings with marker buoys.
- Study the fine-scale movements of scalloped bonnetheads within the no-take zone to evaluate the level of protection it provides for this Critically Endangered shark.
- Estimate the number of sharks using the proposed no-take zone through mark-recapture data.
- Develop educational activities in the primary schools of the villages to promote the conservation of sharks and key ecosystems.