Communication about an incident of a white shark in Guadalupe Island, Mexico

Last Thursday, December 5th 2019, Arturo Islas Allende broadcasted a video in social media about a cage diving incident with a white shark in Guadalupe Island, Mexico, which made a big impression in many of us because the integrity of the animal was severely affected. In sharks, the area of ​​the gills is highly irrigated, which means that there are many veins and arteries that allows to obtain oxygen from the water, as well as controlling their internal temperature.

We deeply regret this incident and wish it never happens again.

We want to share with you some information about white sharks and the recreational activities with this species in Guadalupe Island:

The white shark is a nationally and internationally protected species. We are fortunate that it spends much of its biological cycle in Mexican waters, using them as a breeding and feeding areas.

Guadalupe Island is considered the best place in the world for white shark observation due to the excellent visibility of its waters, and the number of sharks that can be observed in one single day (up to 34 individuals). In addition, this site is the farthest in the world from the coast to observe them (230 km away). Only this year, 113 individuals were recorded, of which 40% were new records or recruits.The white shark season in Guadalupe is from July to February, where they take advantage of the great abundance of prey, such as fish and rays in the case of juveniles, and seals and sea lions in the case of adults. At the beginning of the season, usually young male individuals arrive to the island, and as the season moves on, mature females arrive, which can reach more than 6 meters as Deep Blue.

Due to the recent arrival of juveniles (individuals under 3 m) and adults (3-6 m), and the importance of Guadalupe Island for the life cycle of the white shark, an adequate regulation and good practices is essential in order to perform all observation activities in a controlled manner, and to guarantee the safety of divers and sharks at all times. It is important to consider the diameter of their body in relation to its stage. Therefore, it is critical that rules are followed and adjustments to cages are made for tourism activities in Guadalupe.

After a similar incident in 2016, Pelagios Kakunjá and ECOCIMATI participated as scientific advisors in meetings with CONANP (National Commission of Natural Protected Areas) to analyze the characteristics of the cages to try to avoid new incidents. Hence, we carried out the following activities in 2017:

  • Modifications to the Management Plan of the Guadalupe Island Biosphere Reserve (GIBR), where all the rules for white shark observation activities in the Reserve were adapted and updated.
  • Recommendation of a new cage design used for the observation of white sharks in GIBR: the new cages should be of a single piece, made of stainless steel or high density aluminum, bars should be polished with a 35cm of space between them, no balconies or chains, they should include two emergency exits, floats inside the cage, mesh on the bottom, emergency compressed air, and all corners smoothen to avoid hurting sharks.

We urge the Mexican government to review this unfortunate event and proceed with the necessary actions to protect and conserve this emblematic species of the Mexican Pacific. We are willing to continue supporting the CONANP and the GIBR with scientific information, in particular on the behavior of white sharks and their interaction with tourists in Guadalupe Island. All of this in order to improve and ensure the safety of divers and sharks.


Ph.D. Mauricio Hoyos, General Director, Pelagios Kakunjá, A.C. — Ph.D. James Ketchum, Director of Marine Conservation, Pelagios Kakunjá, A.C. — M. in Sc. Omar Santana, Director of Marine Projects, ECOCIMATI, A.C.