Ocearch hopes for future expeditions off N.S.
“Excluding young-of-theyear pups, this is the greatest number of white sharks Ocearch has tagged on any expedition in the northwest Atlantic.”
Harley Newton chief scientist
The recently wrapped up expedition to catch and tag great white sharks off Nova Scotia was so successful, the research organization hopes to return in the future.
Ocearch, a U.S.-based group focused on gathering data on the apex ocean predators, caught 11 white sharks in Nova Scotia waters in late September and early October.
They began their 2019 expedition at Scaterie Island off Cape Breton and then moved to the location near West Ironbound Island in the Lunenburg-LaHave area where they had success last fall.
Ocearch likes to name the sharks it tags and creates social media profiles that have captured the attention of Nova Scotians and other shark fans. This year’s collection included Sydney, Bluenose, Vimy, Teazer, Ironbound, Murdoch, Shaw, Scotia, Caper, Ferg and Unama’ki.
According to a news release from Ocearch, there were 18 different projects involved, including fecal and sperm analysis and — a first for scientists -— ultrasound recordings of their hearts.
Seal fur was spotted in the fecal samples, confirming that the sharks are preying on the mammals, and the sperm of large adult male sharks were found to be motile.
Scientists are also looking for evidence of microplastics, heavy metals and toxins in the food chain.
Another project sought to collect bacteria samples from the sharks’ mouths and teeth, offering a chance to provide advance guidance on possible antibiotic treatment options should the unthinkable occur and a person be bitten in Nova Scotia waters. Infection can be the cause of some of the worst effects of a bite.
“Excluding young-of-theyear pups, this is the greatest number of white sharks Ocearch has tagged on any expedition in the northwest Atlantic,” Harley Newton, head of aquatic health at the Wildlife Conservation Society’s New York Aquarium and Expedition Nova Scotia's chief scientist for the first half of the trip, said in the release. “Sample size is critical to all of our research and each sample is invaluable. Nova Scotia has proven to be an important location to advance white shark research and I hope we can return.”
The carnivores are caught on baited lines and taken to the main Ocearch boat, a former crabbing vessel, where they are guided into a lift that is suspended over the side and can be raised and lowered into and out of the water using a crane. Once the sharks are raised out of the sea, a team of researchers spring into action to collect samples, perform examinations and attach a variety of tracking devices to the subjects. One of those devices is attached to the dorsal fin and is equipped with satellite tracking capabilities, which enables the sharks to be located whenever the hardware, called a SPOT tag, breaks the surface of the water long enough to make a connection.
The batteries are designed to last five years and the tags eventually drop off.
Other devices record depth and range data and pop off after one year.
Two of the sharks tagged during last year’s expedition, Nova and Luna, had these tags pop off this fall, while they were in Nova Scotia waters.
Department of Fisheries and Oceans scientists retrieved the devices for Ocearch to recover the data.