It's a shark-eat-shark world, and not just in the ocean. Scientific American reports that state and private researchers are feuding over access to great whites off Cape Cod, with Massachusetts scientists alleging that the activities of a nonprofit research group may be compromising their studies.

The state's research was recently covered in a National Geographic magazine story that documents the return of great whites to the coast of New England, where they had largely vanished over recent decades. The shark recovery was due to a return of seals—favorite prey for the sharks—and strong legal protections.

Massachusetts shark biologist Greg Skomal told Scientific American that the activities of nonprofit group Ocearch have been "extremely egregious." Ocearch has reportedly been chumming waters just outside of Skomal's study area, in an effort to attract and then tag sharks.

But Skomal alleges those activities may alter the sharks' natural behavior and interfere with his research. On at least one occasion, one of Skomal's research subjects has even been caught by Ocearch. (Learn more about the rise in sharks off Cape Cod.)

How I Got the Shot: Photographing Great White Sharks off Cape Cod

Ocearch reportedly does not have a permit to operate in state waters but has paperwork for its activities in nearby federal waters. Given the close proximity, Skomal has requested that Ocearch cease its activities in the region until his study completes in a few years.

An Ocearch spokesperson responded to Scientific American that "our scientists have asked for but have not been provided any details or evidence that the claim that Ocearch activities in federal waters in Massachusetts would disrupt any studies in state waters."

National Geographic has also covered the work of Ocearch in the past, which has been catching and tagging sharks for several years. The group is perhaps most famous for chronicling the long voyages of Mary Lee, a female great white with her own Twitter following that has become a minor celebrity. Skomal had helped the group tag the big fish in 2012 and 2013.

The disagreements among the scientists underscores the difficulties and sensitivities involved in studying large marine animals. Just last week, federal scientists announced that they were suspending tracking programs of orcas, after one was killed in the Pacific Northwest after a botched darting attempt.

During a press conference last week, scientists said they need tracking data to better understand where large sea creatures go—and how we can better protect them from human impacts like pollution, ship collisions, and bycatch in fisheries. Yet at the same time, the scientists said they were committed to minimizing harm to individual animals.

It's a tough balance that requires further study, they said.