We only have 20 years to save the oceans
By Jeremy Jackson, senior scientist emeritus at the Smithsonian Institution and professor emeritus at the Scripps Institution of Oceanography
The oceans are alarmingly unhealthy and getting sicker fast. At first, crises were localised, as in the collapse of Newfoundland cod and the lifeless dead zone in the Baltic Sea due to runoff of agricultural waste. Now the problems are global.
Ocean fisheries have been pushed past the limit for the 1 billion people who have no readily available protein substitute, and worldwide there are now more than 400 marine dead zones - areas starved of oxygen – up from 49 in the 1960s. Global piracy, modern slavery, and a lawless supply chain are disguising the source, species, and healthiness of one fifth of global seafood. In 2012, almost three in five of 81 retail outlets sampled in New York City were found to be selling flagrantly mislabelled fish.
Rapidly warming and rising seas are powering stronger hurricanes and storm surges, eating away at our coastal lands and cities, presenting the ominous prospect of hundreds of millions of climate refugees within the next few decades. The UN’s sustainable development goals for the environment, biodiversity, and human wellbeing will be impossible to achieve – with severe consequences for people and the global commons – unless we turn things around very fast.
Fisheries present the most obvious solutions. Over 80% of the global fleet make zero or negative profit, and is propped up by about $35bn (£27bn) in annual subsidies. Removing subsidies would dramatically decrease fishing fleets by roughly 60%; stocks would immediately rebound. Surprisingly few jobs would be lost because most are in small-scale fisheries with few, if any, subsidies. Fish catches in developing countries would stay closer to home, where people need them most, instead of being siphoned off to the US, Europe, and Japan.
Rebuilding depleted fisheries involves eliminating harmful fishing practices and establishing large marine protected areas to provide refuges. There have been important breakthroughs, including the 1990s United Nations ban on high seas drift nets to reduce the harmful bycatch of sea turtles and dolphins, though law-breaking remains a major threat. The UN also nearly passed a global ban on deep-sea trawling in 2006 and, despite this initial failure, the movement is still very much alive. In 2016, the European parliament banned all trawling below 800 metres in EU waters, as well as fishing in areas with vulnerable ecosystems.
The US, Australia, and the UK have established huge marine protected areas in the Indo-Pacific, and the international Commission for the Conservation of Antarctic Marine Living Resources designated the Ross Sea as the world’s largest marine protected area (MPA) in 2016. The total proportion of the oceans in MPAs still hovers around 3%, with only 1% closed to fishing – but they provide critically important refuges for an enormous variety of species and the trends are moving in the right direction.
Closing the high seas to fishing would make financial as well as conservation sense. Bordering countries would make up for lost income from spillover into their national exclusive economic zones: more than 99% of high seas fisheries exploit species also caught in them. Only the half dozen wealthy countries that dominate the high seas fishery would lose out. Developing countries, which lack the resources to participate in high seas fisheries that reduce their stocks, would benefit and global income inequality from fisheries would halve.
Individual countries have begun to rebuild depleted stocks. The US has made progress under the 1996 revised Magnuson-Stevens Fishery and Conservation Act that mandates rebuilding overfished stocks within a decade. An independent assessment in 2013 showed that 70% of its stocks with well-developed recovery plans were no longer overfished: government statistics now suggest that just 16% of 233 stocks are overexploited. But the status of New England groundfish has worsened, raising questions about how nimble federal policies are in adapting to local circumstances. The locally regulated lobster fishery in the Gulf of Maine, however, is booming through effective management.
Coastal pollution and dead zones continue to increase because governments have failed to regulate destructive industrial farming practices and sewage discharges that send topsoil and excess nutrients downstream. The nutrients also poison groundwater and reservoirs: in Iowa, it costs $1,000 per person annually to make drinking water safe.
The irony is that green farming is booming, turning dramatically larger profits than the poison-addicted crops of genetically modified corn and soya beans that cause the problems. Eliminating the US ethanol mandate would tip the scales dramatically in its favour, with enormous environmental benefits. We know reforms can make a difference: coordinated efforts to clean up pollution in Tampa Bay, Florida, enabled seagrasses – critical habitat for shrimp and juvenile fish – to recover to 1950s levels.
The recent explosion in renewable energy may help curb the threat of ocean acidification that impedes reef corals and commercially important shellfish in building their skeletons. Ocean surfaces and the atmosphere are closely coupled, so reductions in carbon dioxide emissions should be rapidly reflected in surface water pH.
Increasing temperatures will have much longer-lasting effects and it is increasingly evident that global sea levels will rise one to two metres by 2100. Coupled with stronger storms and storm surges, that’s bad news for the roughly 6% of global population living less than five metres above sea level.
Engineered barriers, as in the Netherlands and the mouth of the Thames, could buy perhaps a century of protection for well-situated cities that can afford them, such as New York. But there are few, if any, practical solutions for Miami and New Orleans, the coastal megacities of Asia and Latin America, or the low lying island nations of the Indo-Pacific. We need to prepare for massive human population displacements.
We are making progress on mostly local problems, but its pace is dangerously slow. We have failed to wake up to the deadly implications of climate change for coastal populations worldwide. Real progress will require a more realistic assessment of the risks – and a revolution in thinking that places the common good above selfish interests defending the status quo. We have at most 20 years to act.