New science released by the international body that manages Atlantic bluefin tuna suggests a theory about why there have been so many tuna in the Gulf of St. Lawrence in recent years.

Katie Schleit, senior marine campaign coordinator for the Ecology Action Centre, said science released by the International Commission for the Conservation of Tuna (ICCAT) found a large number of the tuna caught in Gulf waters are from the Mediterranean region.

"Previously it was believed there were two independent stocks, the western stock on which Canada fishes, which spawns in the Gulf of Mexico, and then an eastern stock which spawns in the Mediterranean," said Schleit.

Katie Schleit

Katie Schleit is concerned about an increase in bluefin tuna quotas. (CBC)

"More and more what they've been finding is that the two are mixing. Recent studies have shown that 59 per cent of the tuna caught in the Gulf [of St. Lawrence] are actually from the eastern stock."

Schleit said that might mean the western stock isn't growing as much as was previously believed.

The Ecology Action Centre will be one of the observer groups at quota meetings to be held in Morocco by ICCAT next week.

Schleit is concerned the count of fish in the Gulf of St. Lawrence may lead to higher quotas being set at the meetings in Morocco.