New Guidance Will Support Effective Use of Emerging Marine Protection Tool

As policymakers around the world work toward the ambitious goal of protecting and conserving at least 30% of the ocean by 2030, they are increasingly looking to a marine protection category called other effective area-based conservation measures (OECMs) to help meet that target.

OECMs differ from traditional marine protected areas (MPAs)—MPAs are designed specifically to conserve nature, while many OECMs are established primarily for other reasons, such as restricting access to a culturally important site that also has high biodiversity value. Both can complement each other to protect biodiversity and support Indigenous and local communities that depend on a healthy marine environment. While best practices for MPAs are well defined, policymakers’ understanding how to leverage OECMs as a marine conservation tool is evolving.

Already, though, one thing is clear: If governments want to count marine OECMs toward their conservation goals, those areas must deliver meaningful and long-term benefits to biodiversity, in accordance with internationally agreed definitions. If they do not, research points to the risk that OECMs could be counted toward these targets without making a substantial impact on ocean life.

In 2018, the U.N. Convention on Biological Diversity (CBD) established a definition and criteria for OECMs, yet several key areas of uncertainty have emerged on marine OECMs, particularly around determining effectiveness in conserving biodiversity over the long term. Anticipating the need for greater clarity, CBD invited the International Union for Conservation of Nature (IUCN) to develop scientific and technical advice on OECMs.

Toward that end, IUCN recently published a new technical note focused on the identification and use of OECMs as an effective tool for marine protection. The new guidance seeks to explore perceived ambiguity within the CBD’s criteria. For example, it explores the meaning of “important biodiversity values” in the ocean, where data is often lacking. It also helps to establish the required standard of proof for conservation gains, the difference between recognized and created OECMs, and the meaning of “effective conservation” in marine ecosystems.

The note focuses significant attention on questions regarding fishing and acknowledges that fisheries closures—for example, restrictions on specific gear or species—are one of the main marine management tools being proposed as OECMs. However, closures or other measures aimed at a single species that still allow large-scale fishing for other species or other industrial activities would not be an OECM. According to the IUCN note, fishing within OECMs should have a low ecological impact and be consistent with long-term conservation. 

The note also determines that policymakers should avoid vertical zoning—that is, protecting one area within a water column, like the benthos, while allowing intensive fishing in the waters above. This is because of the potential for active and abundant biological interactions between zones and the challenge of administering and enforcing such areas. However, the note does provide guidance if a “compelling reason” exists for a vertical zoning, including understanding ecological interactions between zones, ensuring that impacts do not unintentionally translate across the water column, and again that the OECM criteria is met. The guidance also confirms that artificial features such as offshore wind farms and human-made reefs can be considered OECMs but reinforces that they must meet the defined criteria.

Such specific advice is critical to the long-term use and success of OECMs for marine conservation. Clear guidance, such as that detailed in this IUCN document, is key as a growing number of countries, local governing authorities, and regional bodies—including Mexico, Argentina, the Baltic Marine Environment Protection Commission, and the North East Atlantic Fisheries Commission—are seeking to identify potential OECMs.

As the world pushes toward its ambitious marine protection targets, recognizing and establishing high-quality OECMs that consistently adhere to robust criteria will be essential for delivering genuine and enduring conservation outcomes in the ocean.

Johnny Briggs works on marine habitat protection at The Pew Charitable Trusts. Emily Klein leads Pew’s work to design research projects that use innovative analytical and modeling tools to improve what we know about marine systems and the human connections to them.