More of the Southern Ocean Must Be Protected to Safeguard Marine Biodiversity

Lead author of new study says CCAMLR should expand conservation to include full range of habitats

More of the Southern Ocean Must Be Protected to Safeguard Marine Biodiversity
John B. Weller
A new study says Southern Ocean marine protections should represent all life in the region’s ecosystems (such as sea stars at the bottom of the Ross Sea) in order to be most effective.
John B. Weller

The Southern Ocean surrounding Antarctica has a cold and foreboding appearance yet is home to an extraordinary diversity of wildlife—species that can have a long and successful future if they are safeguarded in marine protected areas (MPAs). Studies show that effectively designed and implemented MPAs convey benefits such as improving outcomes for fished species and helping ecosystems to build resilience to climate change.

Cassandra Brooks
Cassandra Brooks

But new research published on Earth Day—April 22—in PLOS ONE reveals that the existing network of MPAs in the Southern Ocean is not meeting the ecosystem “representation” goal set by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) in 2011, meaning that not all the species are reaping the same benefits from the protections. The study analyzed MPA coverage of two large-scale ecosystem types: the seafloor (benthic) and open ocean waters (pelagic).

The Pew Charitable Trusts spoke with Cassandra Brooks, an assistant professor in the environmental studies program at the University of Colorado, Boulder, and lead author of the new study, for insights on what’s needed to make Antarctic MPAs the most effective. This interview has been edited for clarity and length.

Q: What does your new research tell us about marine protections and the Southern Ocean?

A: There is a global push for marine protected areas to safeguard biodiversity, with many targets set by world leaders calling for between 10 and 30% protection globally by 2020. The Southern Ocean, largely comprised of international waters, is critically important to Earth systems but imminently threatened by climate change and fishing. In recent years, we have made progress in protecting the Southern Ocean, including when governments made history by adopting the world’s largest marine protected area in the Ross Sea. In fact, almost 12% of the Southern Ocean is encompassed in protected areas. This implies that governments have met at least minimum international targets in the Southern Ocean. However, as our recent research shows, this is not enough.

Q: What does it mean for a network of MPAs to be “representative”?

A:  In short, the ocean is full of a huge variety of animals, and all require specific habitat types to survive. Some animals, like seabirds, depend on the surface of the water; some feed in open water, like whales, seals and fish; and others thrive on or near the seafloor, like long-lived deep-water corals, glass sponges, and giant Antarctic sea spiders.  For a marine protected area to be considered representative, and thus be effective at conserving marine life, the full range of habitat types need to receive the same level of protection.

Q: The study suggests that Southern Ocean MPAs lack sufficient protections for benthic and pelagic regions. Why is it important to include those regions in MPAs?

A: We used existing bioregionalizations to examine if existing Southern Ocean protected areas were representative of biodiversity. In the Southern Ocean, we know there are 23 distinct benthic regions and 19 pelagic regions. Each of these supports a potentially different array of life. Thus, to protect biodiversity in full, marine protected areas in the Southern Ocean should encompass all of the different benthic and pelagic regions. Encompassing both ensures the greatest chance of protecting at least a portion of all Southern Ocean life.

Land-based predators that feed in pelagic waters, such as Adélie penguins, would benefit if current and future marine protections in the Southern Ocean were representative, meaning they provide better protections for all species in the region.
John B Weller

Q:  What actions are needed to ensure that the Southern Ocean remains healthy?

A: Our research shows that current Antarctic MPAs are not representative of the full range of benthic and pelagic ecoregions, meaning that, in their current form, protected areas are not adequate at protecting Antarctic marine biodiversity. Further, we show that more than half of the Southern Ocean marine protected areas include multiuse areas, allowing for fishing. Research suggests that protected areas need to have large, strict no-fishing areas to effectively conserve biodiversity. The Southern Ocean supports international commercial fisheries for toothfish (sold as Chilean sea bass) and krill. Fishing pressure on these species has increased in recent years and is likely to continue, and at the same time, climate change pressures on Southern Ocean ecosystems are also increasing.

Increasing numbers of studies show that MPAs, especially no-take marine reserves, can be a proactive and precautionary tool to enhance resilience to climate change and warming. Importantly, the MPAs need to be well designed, with representation being one of many elements. The urgency of threats and the need for protection is more critical than ever before. The Southern Ocean is largely governed by the multinational CCAMLR. These governments need to act quickly. CCAMLR needs to adopt further MPAs as soon as possible and ensure they include large no-take areas and are representative of all life living in the Southern Ocean. If they do, we will give the Southern Ocean and all the creatures living there the greatest chance of thriving into the future.