Great white tagging program off N.S. stirs debate over treatment of sharks – CFJC Today Kamloops

Posted: October 14, 2019 at 5:50 pm

A black cloth was placed over thesharkseyes,a tube pumped water through the gillsandsix scientists descended to the platform, allowing themselves15 fast-paced minutes to take blood, parasite, muscle, fecaland semen samples.

Veterinarian Mike Hyatt of the New York Aquariumcut the shining whitebellyto install an acoustic tag,as University of Windsor research associate Dan Madigan drilled thesatellitepositioning tag referred to as a SPOT tag to the dorsal fin. Its this tag which will allows thousands of peoplewhove downloaded an app to follow the sharks movements online.

But behind the excitement, an unresolvedscientific debate has bubbled away over how sharks, notoriously sensitive to handling, are impacted.

During a briefing, Hyatt saidblood tests taken at the beginning and end of such intense captures show the animals stress levels dont rise.Whats quite astonishing is working with them out of the water their stress levels stay the same and sometimes actually improve, heexplained.

However,while marine biologists interviewed by The Canadian Press concur withHyatts view ofthe sharks short-term reaction,they wonder what will happen to internal organs and reproductive systems in the months and years to come. Some shark researchers refuse to use the method.

At the federal Bedford Institute of Oceanography in Halifax, Heather Bowlby, the research lead at the federal Canadian Atlantic Shark Research Laboratory, has shifted away fromsystems that involves hooking sharks or bringing them aboard ships.

This season, her teamused a lureto attract a four-metre female and then a harpoon torapidly attach a pop-up archival tagnear its dorsal fin.

Therecording devicewill later detach and float to the surface and provide light, temperature and depth data that will helpBowlby study its habitat and habits.

Theres been a general shift in the shark research community to move away from bringing sharks on board a boat, she said in an interview. All of their muscle is concentrated in their back and it does press down. They dont have a rib cage.Theyre not designed to be out of the water, and thats why we have moved to tagging inside the water.

Gregory Skomal, wholeads a Massachusetts Division of Marine Fisheries study group off Cape Cod, says he uses a spotter plane and harpoon methods like Bowlbys to minimize invasive handling.

Hesaid he has questions aboutthe impact of Ocearchs method. It could be creating long-term problems for the future reproductive success of the animal . Its an area that people arevery worried about.

Chris Lowe, a veteran shark researcher with the University of California at Long Beach,says he observed the impact on a younger shark after hebolted a SPOT tagto it, and the fin bent over and deformed over time.

At that point I elected not to use them any more due to damage to the fin . I dont think weve developed a good enough tag design thats designed to come off or to minimize damage, he said.

Still, Lowe says this may not hold true of more mature sharks, and there are tradeoffs for scientists who dontuse the Ocearch methods.

He saysthe pop-up tags he harpoons onto sharks are less accurate in tracking the sharks precise journeys and he cant collect thevolume of data on blood, genetics and parasites.

Meanwhile, Ocearchs method cancombine the positioning provided by the SPOT tags withthe archival depth and temperature information from the pop-off tags.Its a practicethe grouphasused for females the last two years, providing a potentially rich source of data.

Chris Fischer, the expedition leader and founder of Ocearch, firmly disagrees with criticsand sayshes gatheringa whole suite of valuableinformationwidely available for scientists to examine and whichwill lead to improved fisheries management.

These will be the most comprehensively studied individual white sharks in history here in Canada, he said during an interview after the expedition ended its work, which ranfrom Sept. 13 to Oct. 4 off Cape Breton and Lunenburg.

The precision of his taggingmethodscould help researchers locate the holy grail of the nursery where mature females reproduce and give birth, he said aboard his research ship.

Meanwhile, Robert Hueter, the chief scientist with Ocearch, says photos of great whites tagged in the eastern Pacific that were observed years later after the SPOT tagscame off show no significant effect on the shark or its dorsal fin.

The shark biologist at Floridas Mote Marine Laboratorysayscriticisms about unknown, long-term impactsarespeculation without data,and he notes that during the operation, their team does ultrasound imaging of internal organs and has found no evidence of damage.

Finally, we put the resulting movements of our sharks on the Ocearch Tracker for all the world to see; clearly our sharks are moving as we know white sharks to do, south in winter and north in summer, with key stops along the way, he wrote in an email.

Still, Aaron MacNeil, the Canada Research Council chair in fisheries conservation at Dalhousie University,has become a critic ofthe scientific methodologies.

Herecently raised theissue ofthe vesselfishing for sharksnear waters where Nova Scotians surf and dive, saying hes concerned it could draw the animals closer to people.

In my view, the federal Fisheries Department still needs to establish a safe distance for shark-fishing to occur relative to recreational users and exclude shark-fishing within this zone, he said.

Fischercontends that it is not that simple to alter shark behaviour.

A federal Fisheries Department spokeswoman said great white sharks are normally found in waters around Nova Scotia this time of year and in close proximity to coastal areas, and therefore, it is considered that these research activities are unlikely to significantly increase risks.

Meanwhile, as the season wrapped up, Fischer said he intends tocontinue his relationship with the federal Fisheries Department, which has granted him permits under the Species At Risk Act anda foreignvessel license.

He says under the conditions of its permit, Ocearch will provide the federalauthorities with its tracking information, along with blood, semen, diet, genetic and other valuable information.

The question for DFO is Where do you need us to go next for you?'said Fischer, noting he would like to return to Cape Breton next year to validate this years findings.

Alain Vezina, the Maritimes region director of science at the federal Fisheries Department, declined a request for an interview. In written responses, thedepartment said Ocearchis required to provide it with an outline ofits activities and the tagging data they collect, and that the organization is to submit a report by the end of this year.

The methods are intended to minimize any potential impacts to these sharks. Monitoring will be undertaken to ensure compliance with the permit conditions, the email from the communications department said..

This report by The Canadian Press was first published Oct. 14, 2019.

Michael Tutton, The Canadian Press

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Great white tagging program off N.S. stirs debate over treatment of sharks - CFJC Today Kamloops

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