The industrialisation and overuse of the high seas jeopardises the natural wealth of their ecosystems and the services they provide to people. Fishing and shipping continue to inflict harm on high-seas ecosystems. Mining for minerals and new sources of fossil fuels will likely increase the industrial use of the high seas and will further damage their ecosystems. At the same time, the governance of the high seas is fragmented, with different international institutions focusing on specific industrial activities, places, or even different parts of the ecosystems. For instance, weak fisheries governance in the high seas has led to ad hoc regulation that varies from place to place. The result has been widespread overfishing.
There is growing evidence that the ecosystem services provided by the high seas are of high social and economic value. The evidence also is clear that poor management of human activities on the high seas has eroded the natural wealth and productivity of high-seas ecosystems with negative economic and social consequences for all of us.
We examine 15 important ecosystem services provided by the high seas. These fall into the categories of provisioning services (seafood; raw materials; genetic resources; medicinal resources; ornamental resources), regulating services (air purification; climate regulation; waste treatment; biological control) habitat services (lifecycle maintenance; gene pool protection) and cultural services (recreation and leisure; aesthetic information; information for culture, art, design and for cognitive development). The quantity and quality of ecosystem services depend directly on both the living (e.g. animals, algae, microorganisms) and non-living (e.g. the shape and structure of the seabed) components of the marine ecosystems of the high seas.
To understand the potential value of high-seas ecosystem services, we describe and quantify, when possible, the provision and general nature of values provided by these 15 types of ecosystem services. We put these values in the context of the costs of improved governance and management of human activities in the high seas with a particular focus on improved marine protection.
Few ecosystem services in the high seas can be accurately valued given currently available information. We lack scientific information about the provision and use of most high-seas ecosystem services and their quantity and nature, and even lack knowledge regarding how and where, precisely, they are produced. The high seas support economically important species that may swim, migrate or drift well beyond the physical boundaries of the high seas. This makes it difficult to disentangle the contribution of high-seas ecosystems to the services that are produced in the high seas but are enjoyed elsewhere – sometimes thousands of kilometres away. Many high-seas ecosystem services are not enjoyed directly in all contexts. Instead, in some contexts, many play an intermediate role in the creation of ecosystem services elsewhere (e.g. high-seas ecosystems support prey that are consumed by commercially important fish species which are harvested elsewhere). Clearly, there is the need for more and better science on the provision and value of high-seas ecosystem services.
We provide estimates of the economic value of two important high-seas ecosystem services: carbon storage and fisheries. Carbon is stored by high-seas ecosystems as part of naturally occurring processes in which marine organisms convert sunlight and carbon dioxide into energy and biological production. We estimate that high-seas ecosystems are responsible for nearly half of the biological productivity of the global ocean. While the science of carbon sequestration in the high seas is still evolving, we estimate that nearly half a billion tonnes of carbon, the equivalent of over 1.5 billion tonnes of carbon dioxide, are captured and stored by high-seas ecosystems annually. Based on current estimates of the economic cost of additional carbon in the atmosphere (i.e. the social cost of carbon), we find that the value of carbon storage by high-seas ecosystems ranges between US$74 billion and US$222 billion annually.