The Canary Islands have long been a hot spot for Angelsharks with regular sightings by divers and fishers. Once abundant in European coastal waters, Angelsharks are now listed as a critically endangered species on the IUCN Red List of Threatened Species. It’s important for decision makers to plan for conservation initiatives in order to further protect the species; however, without important ecological information, the impact of conservation measures can’t be accurately assessed.
“Limited understanding of adult Angelshark habitat use, movement and site fidelity is a major factor preventing effective species protection in the Canary Island stronghold,” says David Jacoby, Research Fellow at the Institute of Zoology in the UK.
Threats to Angelsharks come from incidental fishing (bycatch) in the Canary Islands’ commercial and recreational fisheries, habitat degradation from pollution, coastal and marine infrastructure development, and disturbance by divers and beachgoers. To overcome this, the Angel Shark Project (ASP; angelsharkproject.com) in collaboration with Jacoby, designed the first acoustic tagging study in La Graciosa Marine Reserve, which will be used to understand fine-scale (precise) habitat use and residency of adult Angelsharks.
Forming a solution
A workshop hosted in 2017 by The Zoological Society of London (ZSL) identified external electronic tagging as the most minimally invasive way to monitor Angelsharks. After taking into consideration Angelsharks’ biological makeup, the most suitable tag attachment would be a fin puncture modified with a cattle tag at the base of the first dorsal fin. Using this type of attachment provides the ability to modify it in order to take genetic sampling while also providing good retention.
The first tagging expedition was successfully completed in July 2018 in the La Graciosa Marine Reserve with a team of research staff from ZSL, The University of Las Palmas de Gran Canaria (ULPGC) and the Zoological Research Museum Alexander Koenig (ZFMK). The team applied the new tagging methodology for the first time on freely swimming Angelsharks.
Seven acoustic receivers were deployed around the Island; six were loaned from OTN that’s global database will feed the detections into other global databases. During the expedition, nine adult Angelsharks were fitted with Vemco V9 acoustic tags. Genetic samples were also successfully taken from six individuals.
“Though the project is still in its infancy, it has provided invaluable information on refining the technique of external tagging … as well as increasing the knowledge of residency patterns of Angelsharks in the shallow waters of the Canary Islands,” says Jacoby.
Future collaborative efforts
The project received support from Oceanário de Lisboa, National Geographic, and the Arribada Initiative in addition to OTN. It’s hoped managers will move forward with improved decision making for the protection of Angelsharks by providing new ecological and movement data to the Canary Islands and Spanish governments.
A follow up to the initial tagging effort is underway. Jacoby is set to lead the analysis of results with project updates in 2019.
For more information on the Angel Shark Project visit their website.
This project is being delivered by the Angel Shark Project team (ULPGC, ZFMK, ZSL), IRNAS, Arribada Initiative and Centre for Environment Fisheries and Aquaculture Science. It has received permits from the Canary Island and Spanish governments.