As a former newspaper editor, I know that the media finds it extremely hard to deal with complex, multifaceted stories. When they arise, if they’re big enough it might be a week of stories, with each day focused on a different angle. But mostly, one angle will dominate and come to be THE story.

So it is with our oceans. David Attenborough’s Blue Planet II did a good job, over the expanse of hours of television, of setting out many of the issues affecting the oceans, two-thirds of our planet. But most of the follow-up has come down to one issue: plastics.

On one level, that’s worked well. After massive public pressure, the government has finally agreed to introduce a bottle deposit scheme. Pub and café chains are rushing to promise to get rid of plastic straws, and there’s now some decent discounts on coffee in some places if you bring your own cup.

Crucial corals

But at the television series made clear, plastics are just one of the issues threatening the environment that produces half of the air we breathe, stores massive quantities of carbon, that is crucial to the food security of at least 50 million people and the jobs of 350 million, and to the future ecological balance of our fragile planet.

It’s not going too far to say that our oceans are suffocating. ‘Dead zones’ – where lack of oxygen, often the result of nutrient pollution particularly from farming and the meat industry more generally kills almost everything – have multiplied enormously, now covering an area the size of the entire European Union.

The level of oxygen overall has fallen by two percent since 1950 – in part because of ocean warming. Warmer water holds less oxygen. And our seas are being poisoned in multiple ways.

We’ve used them as a dumping ground – for toxic chemicals and nuclear materials – so that even the Mariana trench, the most inaccessible place on the planet – has been shown to be heavily contaminated.

The rising levels of carbon dioxide, absorbed by the ocean, are leading to acidification. The building of crucial corals is impaired or stopped, threatening crucial, rich breeding grounds, and phytoplankton and zooplankton, , threatening the future of the foundation of the food chain.

Combined assault

Going even further, we’re reaching deep into the oceans to destroy everything we can with the immensely destructive practice of bottom trawling, now common down to 2,000 metres.

More than 30 percent of stocks are overfished, nearly 60 percent are fully fished – a vital food source is right on the edge.

Creating fully protected areas is generally agreed to be crucial, but only two percent of the ocean is effectively protected today.

This is a combined assault that can’t be split into separate silos of issues to be treated in isolation.

It might be taken as a case study for the way in which we need to change our thinking, and our policy, towards what the jargon calls “systems thinking” – looking at the overall impact of our actions or inactions.

Industrial-scale

The Sustainable Development Goals – globally agreed to replace the millennium development goals – provides one way of doing this. SDG14 directly addresses the oceans, saying we must “conserve and sustainably use the oceans, seas and marine resources.”

But the SDG framework also crucially acknowledges that this can’t be at the expense of other environments, or vulnerable human beings.

We can’t stop hoovering protein from the oceans only to cut down even more of the Amazon for soy-growing.

We need to allow small-scale, poor fishers more access and opportunity for harvesting the food crucial to their health, while fast reining in the industrial-scale harvests.

Edge of disaster

All of this needs to be developed and worked through by experts – and that means educating a great many more people to a very high level: at the Bonn climate talks I heard an academic from the Vienna Institute of Applied Systems Analysis, one of the leaders in the field, say we needed 100 times the number of expertly trained people that we have now.

And we need far better understanding among the public – and politicians.

Single issue stories, single ‘simple’ solutions are no answers at all. We’ve created a fragile, complex, overstretched world in which many economic, social and environmental systems are on the edge of disaster.

Getting our thinking – and actions – about the oceans right could be a model for other areas. We need to demand that thought and action from our media, from our bureaucracies, and our political leaders.

This Author

Natalie Bennett is a member of Sheffield Green Party and the former Green Party leader.