Mackerel has long been considered a sustainable choice for seafood eaters—but no more. Now, top UK conservationists have taken it off their "fish to eat" list due to overfishing, the Guardian reports. "The total catch is now far in excess of what has been scientifically recommended," says a Marine Conservation Society officer. Scientists say fishermen shouldn't catch more than 542,000 metric tons per year; in 2011, some 930,000 metric tons were caught.
As the MCS explains, Atlantic mackerel populations have moved north toward Iceland and the Faroe Islands, ostensibly in pursuit of their prey. That's led those two countries to bump up their fishing quotas, sparking a three-way feud with the UK over catch allowances. Diners should treat themselves to the omega-3-rich fish only occasionally, the MCS says, and in those cases buy mackerel that is "caught locally using traditional methods—including handlines, ringnets, and drift nets" or from special sustainable suppliers. (Read more mackerel stories.)