This week the journal Science published research by Barbara Block of Stanford University on the trans-oceanic travels of the Atlantic bluefin tuna fish, whose numbers have dwindled since the 1970s due to overfishing. Using electronic tags and satellites to track the tuna,
Block has established that they zigzag across the North Atlantic, moving from feeding grounds to breeding grounds. Commercial fishing of Atlantic tuna is managed on the basis of catch quotas drawn up by the Spain-based ICCAT, the International Commission for the Conservation of Atlantic Tunas. The Commission has established strict quotas for fish harvested in the western Atlantic and more flexible ones for fish caught in the eastern Atlantic and Mediterranean. The Stanford University study has found that large numbers of bluefin tuna cross the regulatory line drawn down the middle of the Atlantic to divide tuna stock management on either side of the ocean, which means that overfishing in the west has an impact on stocks in the east and vice versa. ‘There is serious over-harvest right now occurring in the eastern Atlantic and Mediterranean,’ commented Rolland Schmitten, the US commissioner to ICCAT and director of the US National Marine Fisheries Service’s office of habitat conservation. ‘That has got to be stopped because what this study tells me is that the eastern over-harvest does affect our western stock.’
(Source: Science)
Photo: an Atlantic bluefin tuna fish (http://www.insidesportfishing.com)