In September, OCEARCH, a non-profit that travels the globe studying marine animals, launched a short-term project called Expedition Nantucket in federal waters, between Cape Cod and the island of Nantucket.

A battle is brewing on the high seas off Cape Cod between two groups of researchers trying to tag and track the growing population of great white sharks.

A replica of a great white shark’s jaws and teeth were on display at the Atlantic White Shark Conservancy’s Chatham Shark Center in May.

But biologists from the state Division of Marine Fisheries, who are in the third year of a five-year study of the oceangoing predators, say OCEARCH’s vessel has come close to state waters, where they are conducting their own research. The state experts fear that OCEARCH’s methods of attracting and capturing sharks could alter the animals’ natural behavior, jeopardizing their work.


“We’re scared to death of introducing any bias into [our own research], so we are being very cautious,” said state biologist Greg Skomal, lead researcher of the shark population study, which is being funded by the non-profit Atlantic White Shark Conservancy.

The state first notified OCEARCH about its concerns back in December, when the group expressed interest in tagging white sharks off Cape Cod. The group had previously worked with Skomal in 2012 and 2013.

State officials, however, denied OCEARCH’s request this time, citing its use of chum — a mixture of fish parts tossed into the ocean — and seal decoys to entice sharks.

The state said “chumming” could interfere with its approach of tagging and filming the sharks in the water as they explore the region naturally, hunting for gray seals.

“While the multi-year, mark-recapture study is ongoing, we will not permit chumming for white sharks for any researchers,” said David Pierce, director of the Division of Marine Fisheries, in the first of three letters sent to OCEARCH founder Chris Fischer.

The OCEARCH activities, which include using a lift to pull sharks out of the water to tag them, have the “potential to alter the natural behavior and distribution of white sharks in the area,” Pierce said.


He said the use of the lift could cause the sharks to flee Cape waters once they’re released.

“I’m convinced your proposed work would compromise our research by jeopardizing our study’s validity,” he wrote.

But in mid-September, the OCEARCH team turned up, having obtained a federal — rather than state — permit during the summer.

The permit was granted by the National Oceanic and Atmospheric Administration’s Fisheries Highly Migratory Species Management Division. It allows OCEARCH to tag sharks near Nantucket and Cape Cod so long as the group remains outside the 3-mile limit of state waters.

Fischer and OCEARCH officials did not respond to requests for comment. But a spokeswoman for the group told the Cape Cod Times that they’ve yet to hear “science-based” arguments that their work would conflict with the state’s.

While OCEARCH is operating legally, its research vessel, at times, has come close to state waters, ship-tracking websites show.

Experts believe the state’s concerns about OCEARCH using chum are “spot on.”

“The fact of the matter is, chumming is an attractant activity by all definitions,” said George H. Burgess, director of the Florida Program for Shark Research at the Florida Museum of Natural History.

Burgess said it’s possible that chum could steer great whites away from the state’s population study area. Or, he said, it could lure more sharks to it.

“Any way you look at it, it’s a modification,” he said. “The reality is, once an established researcher or team has a project underway, and it’s known, standard operating procedure is to not intrude.”


Burgess, who is not affiliated with either group, called it a “gentlemen’s agreement” that OCEARCH seems to be ignoring.

“It’s not good form,” he added. “This is a violation of scientific trust.”

Members of the Atlantic White Shark Conservancy have directly addressed Fischer and OCEARCH on Twitter.

“You are working 0.5 miles off state waters,” near Chatham, the group said in a tweet to Fischer on Sunday.

The tweet included a picture of the OCEARCH vessel’s position on a map, based on coordinates picked up by a vessel-tracking website.

“I know it seems high drama, and it’s an unfortunate position to be in, but it really is just about the timing of the study right now,” said Cynthia Wigren, president of the conservancy. “It’s not a matter of not wanting to work together, it’s a matter of doing what we can to protect the integrity of the study.”

At least one great white tagged by OCEARCH during its current expedition, which the group named Miss Costa, seems to have left the Cape area after being caught. Miss Costa last pinged on Oct. 3, near North Carolina.

The shark had been previously identified and documented by the state as part of its own study, and called “Island Girl,” according to Wigren.

In 2012 and 2013, when OCEARCH was working with the state, three other sharks left local waters almost immediately after release, state officials say.

Burgess, of the Florida shark research program, was not surprised.


“Oftentimes what we see is, after an animal is tagged, it boogies,” he said. “It has clearly come to the conclusion that, ‘This is not a good area for me, because look what happened to me.’”

Steve Annear can be reached at steve.annear@globe.com. Follow him on Twitter @steveannear.