If the G7 can be perceived as the powerhouse of global politics, then the ocean and its biodiversity are definitely the powerhouse of global sustainability. As such, the ocean should be respected, secured and nurtured.
Our oceans are an integral part of life support on the planet. They are crucial to the very air we all breathe and play a key role in defending us from climate change.
The biodiversity of the ocean and its intricate food web provides food security for billions of people worldwide, particularly in countries where seafood from wild capture and aquaculture is the only accessible source of dietary protein.
At the coastal interface of sea and land, marine plants and animals provide a natural and free coastal defence against floods and storms. For example, coral and shellfish reefs, mangroves and saltmarshes protect cities, rural towns and villages, and farmland by acting as giant barriers and sponges, absorbing and deflecting excessive water flows and waves.
Across the world the ocean supports people’s physical and mental health and wellbeing. All of us can recall moments of tranquil calm and spiritual awe from watching smooth seas, or crashing waves. Yet we are demanding more of our oceans. They are the transport lifeline for globalised trade, and our global refuse bin absorbing human waste – most obviously carbon emissions from fossil fuels and plastics.
We are increasing our exploitation of marine resources, through fisheries and metal mining which is now also occurring in open ocean areas beyond the jurisdiction of national governments. And our oceans are the new frontier for providing energy security by harnessing renewable energy from wind, wave and tides.
These increasing demands are challenging the biodiversity and natural habitats in the oceans, their so-called natural capital, and the life support systems they provide through the ecosystem services and benefits that they deliver.
Both now, and for future generations, we must manage our activities in the ocean globally and locally to safeguard the natural capital that underpins economic and social sustainability.
The first pressure to address is climate change, a key focus of the G7 leaders.
Associated ocean warming, acidification, and de-oxygenation are already affecting marine natural capital and its functioning worldwide. We can reduce global greenhouse gas emissions, and governments are aware from many sources of the needs and the innovations to do this, but addressing climate change has to be integrated with addressing the parallel global biodiversity crisis.
As we look to the ocean to provide renewable, carbon-neutral energy we are rapidly urbanising the seas and coasts in pursuit of energy with a proliferation of built infrastructure and cables.
Considering the interface of ocean and society, that may not always necessarily be a bad thing, but we should acknowledge what we are doing. This transformation is not too dissimilar from how we have modified natural habitats on land, but that has taken place over thousands of years, through farming, forestry and urbanisation, and there has been a co-evolution to habitats that, by and large, most people like.
Our transformation of the ocean is much more rapid. It also includes opencast mining of precious metals from the deep sea to support our technological innovations; the largescale harvesting of open ocean species (from fish to squid to Antarctic plankton) that have never been harvested before; and the introduction of noise from the building works associated with renewable energy development, and from the increased shipping that supports global trade and services this new coastal infrastructure.
We urgently need interdisciplinary research – from environmental, economic, social, health and wellbeing, and governance perspectives (to name a few) – to understand and explain the impacts on natural capital, ecosystem services and the functioning of the ocean.
We also need to know how these impacts will promulgate to affect economies and societies, who will be the winners and losers, what the trade-offs could be, and to identify solutions that create equitable and sustainable outcomes globally from our use of the ocean and its natural resources.
Engineers, researchers and industry can work together to develop approaches and strategies that will minimise associated environmental damage, especially at the seabed.
They also need to focus on producing offshore renewable energy structures that can both maximise safe, secure and durable energy production, and enable the enhancement of marine biodiversity and associated sustainable production of food from aquaculture of shellfish, and even leisure and recreation via tourism, wildlife watching and sea angling.
Careful design of artificial structures can create habitats that enhance the type of biodiversity naturally found in rocky and reef habitats, including climate regulating species such as kelp, providing nature-based solutions to the climate crisis. These habitats will be artificial, but so are the generally admired semi-natural grasslands and woodlands that have been carefully cultivated over thousands of years on land.
Alongside our encroachment into, and transformation of, the ocean we need to ensure that we have genuine and well-managed marine protected areas to enhance biodiversity and maintain ocean resilience in the face of change.
The evidence base concerning our transformative use of the oceans is just developing but needs to grow as rapidly as the blue economy that is driving it.
The G7 leaders and other local and global policy makers, in addition to business and industry, and environmental managers, can only make decisions based on best understanding and consideration of all of the trade-offs. Interdisciplinary approaches are the only way to ensure that our global ocean can remain the powerhouse of global sustainability.