An international fisheries panel agreed Friday to adjust catch restrictions on bluefin tuna in the northern Pacific, based on surveys of parent fish numbers, Japan's Fisheries Agency said Friday, amid concerns that stocks are dwindling due to overfishing.

Wrapping up a five-day meeting through Friday in Busan, South Korea, the Western and Central Pacific Fisheries Commission reached the deal after toughening a Japanese-proposed flexible cap on catch sizes. The new catch limit is likely to be implemented in 2019.

Due to overfishing, the population of parent fish in the Pacific fell to about 17,000 tons in 2014, hitting a near record-low.