The oceans are our larder – and our rubbish dump. They have long inspired a range of emotions: fear of their dangers, desire for their riches and admiration for their beauty. Yet despite humanity’s long and intimate relationship with the seas, when it comes to putting interactions on a sustainable footing, we do not have a clearly charted route. The theme for World Oceans Day 2020 on the 8th of June is “Innovation for a Sustainable Ocean” – and innovation is urgently needed. We must move decisively to define desirable outcomes for the world oceans, develop interventions and governance tools that help achieve these outcomes and identify observational requirements that allow us to measure progress along the way.
Defining a desirable outcome is, perhaps surprisingly, not straightforward. Yet without a clear vision of what we would consider successful stewardship, progress is at best unfocussed. In a system as variable, complex and interlinked with the entire Earth system as the global oceans, it is not obvious what level (or rate of change?) in a range of physical, chemical and biological indicators could be considered sustainable: reasons for concern include fish stocks, deep sea biodiversity, acidification, heat and carbon content, oxygen concentrations, plastics pollution, nutrient and pollutant levels, freshwater input from melting glaciers, sea ice cover, sea level and more. Sustainable Development Goal 14 is to “conserve and sustainably use the oceans, seas and marine resources for sustainable development”. If we want to monitor progress, a more quantitative and specific definition of successful stewardship is needed.
Interventions and governance are no easier than defining success. Mutually exclusive interests in how to utilise global oceans - the coastal oceans as well as the high seas – are in competition. The tourism and the shipping industry, pollution control and energy harvesting, preservation of fish stocks and fisheries, seabed species conservation and deep sea mining all have different requirements that are not easy to reconcile. On land, equivalent competing interests are negotiated within the legal frameworks of sovereign states. The matter is vastly more complicated at sea. The United Nations Convention on the Law of the Sea (UNCLOS) of 1982 has brought some governance to the world’s oceans. But it has not led to an internationally agreed action plan for implementing and governing the transition towards sustainable usage of the world’s oceans.
Finally, measuring the state of the oceans is challenging. Satellites usually only chart the ocean surface, the outer skin of the vast deep blue sea; operations at depth are expensive and prone to technical difficulties. Ocean exploration and observation have made great leaps forward, with the Global Ocean Observing System and in particular the Argo array of almost 4,000 measurement floats that are providing systematic data from the ocean interior. But what is still needed is a smart, targeted framework of measurements that quantitatively capture progress towards internationally agreed indicators of sustainability.
The United Nations have declared the years 2021-2030 the Decade of Ocean Science for Sustainable Development, with the motto “The science we need for the ocean we want”. The time for action is now.