Protecting Ocean Life on the High Seas

Protecting Ocean Life on the High Seas

View the October 2015 fact sheet update.


From majestic shark species to charismatic whales to little understood creatures of the deep, the high seas are home to some of the ocean’s most interesting and valuable life. But for all of the beauty and wonder they hold, the high seas are highly vulnerable. The rules and regulations that should protect them are a patchwork inadequate to the task. This ocean ecosystem is at risk of becoming a classic “tragedy of the commons,” a resource used freely by all but owned and protected by no one.

Recognizing this plight, leaders at the 2012 United Nations Conference on Sustainable Development (the Rio+20 Summit) committed to decide by September 2015 whether to begin negotiations on a new agreement to conserve and protect marine life in the high seas.1 These waters need modern management tools, particularly legally mandated and globally respected marine protected areas and reserves,2 if their future is to be secured.

Only a new agreement can deliver on this imperative. The Pew Charitable Trusts is working with governments to secure a decision to launch negotiations at the United Nations on this new international legal instrument to safeguard life on the high seas.

What are the high seas?

The high seas, or ocean areas beyond national jurisdiction, fall outside countries’ exclusive economic zones and cover nearly two-thirds (64 percent) of the ocean’s surface. That amounts to 43 percent of the Earth’s surface.

These seas comprise 80 percent of the world’s living space. These areas are not governed by any one country, but are part of a global commons overseen collectively by all nations.

Once thought to be largely barren with limited life, the high seas are now known to be among the largest reservoirs of biodiversity on the planet. Many marine species, such as whales, tuna, and sharks, spend much of their lives in these waters, migrating along routes through great ocean basins from feeding to spawning grounds and back again. Others spend their entire lives in the high seas, living and breeding along submerged mountain ranges. Today, scientific discoveries made in ancient, deep-sea coral fields and on seamounts teeming with life yield potentially lifesaving medicines and enhance our understanding of global biodiversity.

High seas biodiversity also brings great economic benefits. Despite their distance from coastal communities, these waters provide important ecosystem services—from fisheries to climate regulation to recreation, among others. High seas fisheries account for up to US$16 billion annually in gross catch.3 In addition, estimates of the economic value of carbon storage by the high seas range from US$74 billion to US$222 billion a year. These examples represent just a small part of the total benefits and economic value the high seas provide.4

Bubblegum Coral© National Oceanic and Atmospheric Administration

Bubblegum coral

Threats to the high seas

The high seas are increasingly under threat from human activities, including pollution, overfishing, mining, geoengineering, and climate change. Currents carry tons of plastics and other waste thousands of kilometres from shore into the open ocean. Globally, 90 percent of fished species are either depleted or fully exploited, and fishing vessels are venturing farther and farther out to sea and fishing deeper and deeper, accelerating the exploitation of these species as well as increasing bycatch and habitat disruption.5 New technologies for deep-sea bottom trawling and fish aggregating devices enable further degradation of habitat, as well as overexploitation of commercial fish and other species caught incidentally. Climate change and emerging ocean uses, such as deep-sea oil and gas exploration and extraction and seabed mining, also pose risks.

Unfortunately, no international framework is in place that can fully protect the high seas from these and other threats.

The need for a new international agreement

Today, the high seas are governed by a patchwork of international, regional, and sectoral agreements and treaties. In some areas, these overlap and create complicated jurisdictional issues. Elsewhere, there are gaps where no one has full authority to act. For example, some regional seas conventions can establish marine protected areas, but those designations do not include limits on activities such as fishing or seabed mining because other organizations are responsible for managing them. As a result, these protected areas cannot exclude activities that pose some of the most significant risks to marine life. With the exception of the international commission that governs the Southern Ocean surrounding Antarctica, no mechanism exists to establish fully protected marine reserves in the high seas.

Discussion about the need for a legal instrument to provide more comprehensive protections for marine life in the high seas has been ongoing at the United Nations since 2003. In 2011, a special working group recommended that the General Assembly initiate a process to identify policy gaps and ways forward for the conservation and sustainable use of biological diversity in these areas beyond national jurisdiction. That included consideration of a new international instrument under the United Nations Convention on the Law of the Sea (UNCLOS).6 The working group outlined the topics that the process would address:

  • Marine genetic resources, including the sharing of benefits.
  • Area-based management tools, including marine protected areas.
  • Environmental impact assessments.
  • Building capacity to enable sustainable and equitable development.
  • The transfer of marine technology.

Time for action

At the Rio+20 Summit in 2012, leaders affirmed the importance and urgency of conserving and sustainably managing marine biodiversity on the high seas. They committed to making a decision on whether to develop a new international instrument under UNCLOS, known as an implementing agreement, by the close of the 69th session of the United Nations General Assembly in September 2015.

Launching negotiations is the next step toward protecting the great diversity of life in the high seas and ensuring that comprehensive action can be taken to conserve these waters within the next 10 years. Without a new agreement, human activities will continue to jeopardize the ocean and the planet. By instituting one, we can put the high seas on a path to recovery and secure our common future.


1 United Nations Conference on Sustainable Development, Rio+20, “The Future We Want” (June 2012), para. 162,

2 Ibid., para. 177.

3 A.D. Rogers et al., “The High Seas and Us: Understanding the Value of High-Seas Ecosystems,” Global Ocean Commission (2014),

4 Ibid.

5 Food and Agriculture Organization, The State of World Fisheries and Aquaculture. Opportunities and Challenges (2014),

6 United Nations General Assembly, “Letter Dated 30 June 2011 From the Co-Chairs of the Ad Hoc Open-Ended Informal Working Group to the President of the General Assembly” (June 2011),