Project type: Shark tagging expedition
Date: October-November 2014
Location: Guadalupe Island, Mexico
Project target: To place acoustic tags on great white sharks and take biopsy samples of great white sharks.
Lead scientists: Dr. Mauricio Hoyos, Dr. Yannis Papastamatiou
Tagging team: William Winram & Fred Buyle, assisted by Lukas Mueller
Supportive team: Ismaehl (el Capitan), Edgar Becerril
Collaboration: Islander Charters, IUCN
*** Please Note that any diving without a cage at Guadalupe Island is only legal with special government and biosphere permits for scientific field work. This applies as well for setting foot on the island. Our team was granted all permits for their scientific work during the expedition. ***
Isla Guadalupe: 29°1′51″N, 118°16′48″W
The sight of Guadalupe Island at sunrise is priceless. The volcanic ridges and cliffs give the impression to hover over the Islander as the boat anchored a few hundred meters offshore.
A home away from home
In previous years we waited for sharks to approach the boat, started observing their behavior before getting in the water and beginning to place tags. This time around we packed our gear, loaded everything on Dr. Mauricio Hoyos’ boat and following some warm handshakes landed at the rocky beach of the north east cove and set up camp. Ahead laid 4 weeks of living and working on and around the island of white sharks – Isla de Guadalupe.
The old fishing house that Dr. Hoyos cleaned and improved over the years served as our base camp and provided shelter for gear and equipment. Camp life included no running water or electricity. Our diet consisted of hot tea, dry food, some apples and lemons throughout our stay – all cooked on a propane stove. Sometimes this was complemented by dinners on some of the cage diving boats that visited the bay.
Sharks and El Niño
In the beginning phase, working conditions in the water were very poor. The visibility was just over 10 meters with lots of particles in the water. In addition water temperature was a lot warmer than usual and caused sharks to stay deep. Once they arrived at the surface, most of them circled the boat a couple of times and disappeared again. The reason for these difficult conditions is the El Nino event that has been affecting many ecosystems along the Californian coast this year. Adapting to the poor conditions our freedivers had to stay very close to Dr. Hoyos’ boat and constantly look for sharks to not miss an opportunity to tag one.
More that meets the eye
But at a productive ecosystem like Guadalupe there is always something to see and explore. Amongst other things we got to see blue whales cruising through the bay, huge yellow fin tuna jumping in a feeding frenzy and dolphins keeping our sharks away from the boat. Guadalupe is probably the best place in the world to observe the elusive beaked whale. We got to see them on a daily basis in pods of 5-6 animals. Dr. Hoyos has had the chance of seeing them underwater and documented white shark bite marks on them. From our top water observations this season we can clearly say that Guadalupe isn’t just about the white sharks. This was further proven to us when we explored the coastline in order to find sharks that were searching for prey in the shallower waters around the island. It was an impressive sight to fin through the water, right under the volcanic cliffs, constantly keeping a look out for white sharks. Of course we had our tagging gun, biopsy gun, camera, and tags with us in case we encountered a good candidate for an acoustic tag.
During these explorations we saw turtles on every single dive, big yellowtails, california sea lions, guadalupe fur seals, groupers, lots of reef fish, bat rays and horn sharks. It is such a diverse and productive ecosystem with an incredible scenery. When diving at a ridge to the north of the bay we crossed a 12-meter deep canyon when one of us spotted a 5-meter female Great White Shark cruising in on the bottom from behind us, passing under us and swimming away, with the gigantic caudal fin generating a powerful thrust against the current. It was an amazing sight to see a great white shark swim in between the rocky canyons and pinnacles close to shore and perfectly camouflaged to the sea floor.
After finishing our work in the water and returning to camp we got to enjoy the company of elephant seals and Guadalupe fur seals at the beach. Being based on land and spending as much time on sight was a perfect opportunity for us to observe the pinnipeds’ behavior and their role in the ecosystem of the white sharks. Surprisingly, the most common cause of death in the Guadalupe fur seal population is not white shark predation but falling rocks. At several occasions we heard loud growls howling from hundreds of meters away when huge rocks crash down onto the shoreline or into the water. At first, the little fur seals were scared of us but over the course of the expedition they accepted us at the beach and became so confident as to sniff our feet and bark at us from a couple of feet away.
To engage people that are passionate about the ocean we gave presentations about our work at the cage diving boats that visited the area to show their clients the great white sharks of Guadalupe. Together with Dr. Hoyos who explained key aspects and findings of his research, we showed people that great white sharks can be interacted with and tagged by freedivers without a cage, but that these animals are still big ocean predators and have to be treated as such – with respect.
We are grateful for the many passionate questions and talks after our presentations and how much interest the people we encountered expressed towards ocean conservation and our work. We were extremely lucky to meet Dr. Sylvia Earle and spend an exceptional evening with her, friends and colleagues. It was one of the strangest feelings to ride a small zodiac through the dark waters around the cliffs of Guadalupe back to the camp with the only light being the stars – after having had lots of good company and a nice dinner.
Exploring Guadalupe Island without fins
Being based on the island also gave our team the rare opportunity to explore the island on foot. We prepared our backpacks and put our shoes on for the first time during our stay to find our path up an old dirt road. It didn’t take us long to understand how treacherous this terrain is. Rocks falling down the steep ridges and remains of vehicles from past accidents definitely left their impression on us. The island was unusually green in comparison to past expeditions. This was due to the many storms and hurricanes in 2014 which caused so much rain that it (in the right light) reminded us of the Azores. Cactus plants were to be found everywhere and penetrated our soles from time to time. When reaching the viewpoint from where you look across the entire bay, the sight was breathtaking. The contrast between the dark blue water, green murky patches in shore and the grey-red-orange walls of the island has something special. We spotted sea lions, elephant seals and beaked whales from up there. Once more, our team got to get a more lateral picture of the ecosystem and the role of the white shark at Guadalupe.
Over the course of the expedition conditions improved and even came back to “Guadalupe standards” by the end of the last week. During the last days of the expedition we placed more acoustic tags than in the weeks before because conditions went back to normal with 25-meter visibility, water cooled down and fewer particles. In total our team placed 15 acoustic tags and took 7 biopsy samples. Dr. Hoyos and Dr. Papastamatiou are excited about the outcome of the expedition given the extremely difficult circumstances under which our team operated this year. In addition to the usual acoustic tags we place on white sharks for Dr. Hoyos we placed new acoustic tags that have the potential to uncover interactions between Great White Sharks from Guadalupe and sharks from California.
When conditions improved the white sharks became more confident and moreover arrived at the surface again to check us out. Dr. Hoyos believes that the sharks at Guadalupe stay below the thermocline most of the time. The warm water of this year’s season pushed the thermocline deeper and therefore we were seeing sharks much less frequently at the surface. When in the water with the amazing predators in order to tag them, sometimes sharks that are already tagged come back right after or a couple of days later. This is a great opportunity to capture photos for identification purposes and the respectful interactions professional freedivers can have with great white sharks.
Some of the females that were quite confident this season and displayed their presence in the water towards our Watermen were: Emma, Giana and Faye – according to the white shark photo ID book of Guadalupe
We are already looking forward to our 2015 expedition to find out what data our tagging efforts produced and to continue supporting White Shark research in the pacific.
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