On March 10th, 2014 a tagged great white shark known as Lydia was recorded roughly 1,000 miles from the coast of the United Kingdom. Research organization Ocearch originally tagged the shark in Jacksonville, Florida almost a year ago, in a process that took 15 minutes to complete. The team first chums the water to attract sharks to the boat, where the animals are maneuvered onto a custom-built hydraulic platform to facilitate blood analysis and ultrasounds. Researchers also attach two types of tags to the animal’s dorsal fin; the first provides data on the depths at which the sharks swim, and the levels of light at those depths, for example. These tags detach from the sharks after a certain time period, and then float to the surface for collection. Lydia’s second tag transmits data via GPS whenever she surfaces, providing long-term insight into migration patterns — if she continues on her current heading she’ll become the first recorded great white to make the transatlantic crossing. Since being tagged, Lydia’s movements have provided valuable insight into great-white migration patterns. White sharks have been thought to favor warm water, which precluded them from appearing in colder climes like those around the U.K. Lydia has, however, proven that great whites do visit colder waters, both here and in Nova Scotia in Canada. Why Lydia crossed the Atlantic in the first place is unclear, although Ocearch founder Chris Fischer recently hypothesized that she may be pregnant and heading for warmer waters in which to pup around the Mediterranean.
A non-profit organization, Ocearch combines several international initiatives to form the world’s largest white-shark research project, as well as studying other marine apex predators. Since the project’s inception, Ocearch has collaborated with more than 50 researchers from worldwide institutions; renowned marine biologist Greg Skomal was a part of the team that tagged Lydia last March.
Although the research value of Ocearch’s data is undeniable, the program has generated a lot of controversy. Conservationists and several other scientific bodies have criticized the logistics of the data collection, asserting that the method used to tag the sharks causes them unnecessary trauma and physical damage. Photographs of sharks tagged by Ocearch show the degradation caused to the shark’s dorsal fin by the tagging devices, which are bolted through fragile cartilage. In several cases, the damage has been so severe as to leave the fin ragged and incomplete, potentially affecting its role as the shark’s rudder. Many scientists argue that there are less invasive ways to attach tags to sharks; some organizations insert the devices beneath the animal’s skin, while others attach tags beneath the dorsal fin, resulting in less drag and, therefore, less damage. Other impacts of Ocearch’s methods include trauma, internal injuries and damage to the shark’s jaw as a result of the hook used to bring them onto the hydraulic platform. In 2010, a shark named Junior suffered horrific injuries to his mouth after this hook could not be removed; it had to be left in place after his release. Once out of the water, sharks are susceptible to internal injuries that can lead to later death, since their cartilaginous skeletons are not strong enough to support their weight on land. Ocearch has been responsible for the death of at least one shark in this way.
Criticism has also been leveled at Ocearch from a human perspective. In 2012, the organization was blamed for the death of surfer David Lilienfeld in False Bay, South Africa. Immediately before the tragedy, shark expert Dr. Dirk Schmidt maintained that the baiting and tagging of white sharks by Ocearch in the area heightened the risk of attack, due to the animals’ altered behavior as a result of trauma. After the attack though, GPS locations of the tagged sharks in the area at the time confirmed that none of the Ocearch animals were responsible for the attack. The organization’s research permit was nevertheless pulled shortly thereafter. Fischer’s previous career as the star of the History Channel’s “Shark Wranglers” is also the source of much of the controversy, with critics claiming that his methods are unnecessarily invasive in an effort to improve ratings and therefore funding opportunities. Fischer responds by saying he “is not a TV guy who decided to get in the ocean. [He] is an ocean guy who tries to use TV to do good for the ocean.” While Ocearch’s data has not contributed thus far to any major progress on international white-shark conservation, the value of possibly changing public perception for the better could affect future conservation efforts around the world.
And as exciting as the new data is, Lydia is not the first shark to undertake such a lengthy journey. In 2013 a short-fin mako named Carol covered 8,265 miles over the course of six months, and blue sharks regularly cross the Atlantic. There are also several documented cases of great whites traversing the Indian Ocean between South Africa and Western Australia. A female white shark named Nicole made the journey twice in one year, swimming 12,400 miles. While Lydia may not be the first nomad shark, if she reaches the shores of the U.K., she will be the first confirmed white shark to reach those waters, despite much anecdotal evidence for previous visits by her species. There have been almost 100 reports of white sharks in British waters over the last 18 years, 10 of which have been deemed credible by Shark Trust chairman Richard Peirce. Despite the hysteria generated by local media upon the news of Lydia’s proximity, there have only been five shark attacks in the U.K. since 1785 — none of which involved great whites. The growing insight into these magnificent creatures’ lives, generated by Ocearch and other organizations, may lead one day to a welcome for sharks to new shores, instead unfounded fear.