New Study Says We Could Return Our Oceans to Health In A Generation
A wide-ranging plan to restore the health of our oceans over the next 30 years was published this week by a team of experts from universities from around the world.
Ravaged by climate change, pollution, unsustainable fisheries and habitat destruction, our seas are at a tipping point. But the report published in Nature argues that if we act decisively we could within a generation rebuild the marine world and cites numerous examples which prove what is possible.
Headed by Carlos Duarte from King Abdullah University in Saudia Arabia, the 15 leading scientists across a range of disciplines including the UK's coral reef expert Callum Roberts and Australia's Terry Hughes, who a leading light in the battle to save the Great Barrier Reef, make a powerful plea that it is possible to restore our oceans but we have only one chance.
A TIMELINE OF MARINE THREATS
The report - Rebuilding Marine Life - states: 'In addition to this being a necessary goal, substantially rebuilding marine life within a human generation is largely achievable, if the required actions—including, notably, the mitigation of climate change—are deployed at scale.'
Professor Roberts, the head of Marine Conservation at the University of York, says: 'Overfishing and climate change are tightening their grip, but there is hope in the science of restoration. One of the overarching messages of the review is, if you stop killing sea life and protect it, then it does come back. We can turn the oceans around and we know it makes sense economically, for human wellbeing and, of course, for the environment.'
The review presents evidence of what has been achieved in recent years and the authors point out a series of successes in marine conservation and advances in our knowledge which are often overlooked in the welter of negative news reports about the growing threats to the world's oceans.
It reports that while the abundance of marine animals and their habitats has substantially shrunk in the past 200 years, there is evidence that it can bounce back. Currently, a third of fish stocks are overfished and up to half of vulnerable marine habitats have already been lost. Nevertheless, biodiversity losses in our seas are significantly less than they have been on land. It also notes the dramatic rebound fish stocks made during both the First and Second World Wars when fishing pressure was reduced and points out that the coral reefs around the Marshall Islands in the Pacific even returned after nuclear testing in the region.
The Convention on International Trade on Endangered Species (CITES) and the global moratorium on commercial whaling in 1982 have had significant impacts on protecting marine life.
It acknowledges it would be impossible to return the ocean to some concept of past glories - not least because we don't have robust enough baselines as a reference point, but it suggests a useful target would be to make sure the complex marine ecosystems can sustainably supply the growing needs of an additional 2 to 3 billion people expected by 2050. It broadly defines a 'complete' recovery of fish stocks and habitats would be anything more than 90 per cent of known previous stocks.
'Some large marine species have exhibited particularly notable rebounds, even from the brink of extinction,' it states. 'Humpback whales migrating from Antarctica to eastern Australia have been increasing at 10 per cent to 13 per cent per year, from a few hundred animals in 1968 to more than 40,000 currently.'
While sea turtles are still endangered it points out that most populations are now starting to grow. Green turtle nesting populations are increasing by 4 to 14 per cent a year.
Using a comprehensive fish stock database, the team discovered, that fish stocks with available scientific assessments are increasingly managed sustainably and that globally it is believed there is a slowing down of the depletion of all fish stocks. It argues that managing fish stocks is an urgent worldwide need and the successes apparent when this does happen shows what could be done.
There have been crucial successes in habitat restoration such as the vast programme to bring back mangrove forests in the Mekong Delta with 1,500 square kilometres established. The review says global mangrove loss has now been slowed to 0.11 per cent per year with stable coverage now reported along the Pacific coasts of Colombia, Costa Rica and Panama and increasing populations in the Red Sea, the Arabian Gulf and China.
There have been numerous examples where we have managed to combat marine pollution. The total ban in 2008 of the antifouling chemical tributyltin (TBT) has led to rapid declines of female gastropods developing male sexual organs. There has been a 14-fold reduction in large oil spills from tankers 24.7 events per year in 1970 to 1.7 events in 2010-2019. Improved coastal water quality has resulted in the recovery of seagrass meadows in the US, Europe, the Baltic Sea and Japan.
The team identified a number of what is calls 'recovery wedges'. Of particular importance was the establishment of marine protection areas (MPAs). Twenty years ago less than one per cent of the ocean was protected. Today that sits at 7.5 per cent. However, not all are full implemented. There is growing support for reaching a target of 30 per cent by 2030.
THE GROWTH IN PROTECTION
The review doesn't shy away from the many challenges we face from plastics to new pollutants; from political inertia to finding the resources to implement what is known to be best practice; the difficulties in building global cooperation to struggling with impacts of destructive past behaviours.
And it focuses on the biggest threat of all - climate change. 'Climate change is the critical backdrop against which all future rebuilding efforts will play out,' it argues.
The major roadblock to restoring our oceans will be if we fail to curb the warming of our planet. The review states: 'Current trajectories of greenhouse gas emissions lead to warming by 2100 of 2.6 to 4.5ºC above preindustrial levels, far exceeding the long-term goal of the Paris Agreement (holding the increase in global average temperature to well below 2ºC above preindustrial levels). Much stronger efforts to reduce emissions are needed to reduce the gap between target emissions and projected emissions.'
Professor Duarte says: 'We have a narrow window of opportunity to deliver a healthy ocean to our grandchildren, and we have the knowledge and tools to do so. Failing to embrace this challenge, and in so doing condemning our grandchildren to a broken ocean unable to support good livelihoods is not an option.'
The report looks at the speed in which current evidence suggests our oceans could bounce back. It concludes: 'Based on the data reviewed here, we conclude that substantial rebuilding across many components of marine life by 2050 is an achievable Grand Challenge for science and society. Meeting this challenge requires immediate action to reduce relevant pressures, including climate change, safeguarding places of remaining abundance, and recovering depleted populations, habitats and ecosystems elsewhere.'