The world will soon have a new largest protected area, marine or terrestrial. In October, member states of the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) agreed by consensus to designate a 1.55 million-km2 MPA in the remote and relatively pristine Ross Sea. The purpose is to protect benthic biodiversity, populations of commercially valuable toothfish, and critical habitat for penguins, seals, and other predators.

The Ross Sea MPA will come into force on 1 December 2017. In a concession to CCAMLR members concerned about a permanent MPA, the designation is set to expire in 35 years — the year 2052 — at which point it will be up for renegotiation.

The agreement, which occurred at CCAMLR’s annual meeting in Hobart, Australia, capped several years of negotiations on the Ross Sea within CCAMLR. These negotiations are detailed in the following perspective piece in this issue. Under CCAMLR regulations, the decision on designation had to be made by consensus of the Commission’s 25 members. Holdouts by particular CCAMLR member nations over the years, especially Russia, resulted in several changes to the proposal over time, including reducing its size and adding the 35-year duration.

The new MPA — more than twice the size of France — will include most of the Ross Sea shelf, eastern slope, waters around the Balleny Islands, and seamounts to the north. A map of the MPA, provided by, is here. Approximately three quarters will be closed to all commercial fishing (General Protection Zones). The remaining quarter will allow limited research fishing that is strictly controlled by CCAMLR under advice from the Commission’s Scientific Committee, and which must be approved by consensus.

The current record holder for largest protected area is Papahānaumokuākea Marine National Monument in the US’s Northwestern Hawaiian Islands. Papahānaumokuākea was expanded to 1.51 million km2 in late August of this year.

For more information on the Ross Sea MPA: