Save our seas: five ways to recycle and save the ocean

1. Give nature a helping hand by reintroducing species

Some ocean species and habitats struggle to recover on their own and need help. Take sea otters, which were virtually eliminated by the late 19th century from commercial hunting for their super-dense shells.

From the 1960s to the 1990s, some sea otters moved to places where they once lived. Today there are about 150,000 sea otters in the wild, and a third of them are descended from translocated otters.

The US Fish and Wildlife Service is now considering moving more otters to fill the gaps, including along the coast north of San Francisco. The motivation for this is in part because the otter can help keep entire ecosystems healthy.

Without otters to reduce their numbers, sea urchin populations explode and kelp forests graze down to the seabed. When otters returned to Alaska and British Columbia, so did kelp forests.

Efforts are also being made to save other predators of otters. Sunflower starfish are colorful starfish the size of bicycle tires and also have a large appetite for sea urchins. But in 2013, a devastating disease struck the sunflower sea stars, turning them into piles of yawns and their population collapsed.

Some of the remaining healthy sunflower sea stars were moved to labs at the University of Washington, where researchers worked out how to grow them in aquariums. If starfish do not recover on their own in the wild, there is now at least one option to reintroduce the species from captivity.

2. Close the pollutant tap

To save the oceans, humanity must stop the flow of pollutants pouring into it. More people than ever care about the threat of pollution in our waterways and seas, from Britain’s sewage-polluted rivers to the plastic bags that dig up the guts of whales.

A step towards the change that is needed is building, with negotiations on a global plastic treaty continuing at the United Nations. Those who want to limit plastic production are battling those who claim we can recycle our way out of trouble, although global recycling rates have stalled at around 10%.

The problem of “chemicals forever” is also more widely recognized. These pollutants are used in all kinds of everyday goods, including furniture, food containers, non-stick cookware and school uniforms.

Virtually indestructible, traces of these highly dangerous chemicals remain in wildlife, water and human bodies. Small amounts increase the risk of cancer and are linked to a long list of serious health problems, from liver damage to birth defects, while adding stress to seals, sea lions, dolphins and whales.

So far, few chemicals have been permanently banned, and only after lengthy legal battles. Now, calls are growing for an outright ban, in part to stop the chemical industry from pulling its old trick of substituting one harmful substance for another.

3. Limit overfishing

One obvious way to save many ocean species is to stop catching and killing so many of them.

By the mid-20th century, commercial whaling had killed more than 99% of the Antarctic subspecies of blue whales. The largest animals known to exist disappeared for decades even after the global ban on industrial whaling, but in recent years scientists have spotted them again around South Georgia Island. Their songs, recorded on hydrophones across the Southern Ocean, herald the return of the whales.

Species can also be recovered while still being hunted. Fishing regulations, if well designed and properly enforced, can protect populations from overexploitation and revive depleted species. After disappearing for decades, bluefin tuna are returning to British seas after Atlantic catch limits were reduced.

In the Cayman Islands, fishing for Nassau groupers is now strictly controlled. It is illegal to catch or sell fish half a meter long during the winter spawning months. The rest of the year there is a daily catch limit of five fish per boat. Gradually, groupers are visiting the spawning grounds in greater numbers.

More fisheries need to be effectively managed and their damage limited, especially industrial fishing.

4. Keep sea areas off limits

A tried and tested method of encouraging marine life is to leave parts of the oceans completely alone, with no fishing or extraction at all. A shocking number of marine protected areas (MPAs) are still being fished, often legally and using highly destructive methods. In 2023, industrial bottom fishermen spent 196 weeks hauling heavy nets along the seabed within British MPAs.

A small part of the global ocean is under strict protection, but these reserves are reaping phenomenal benefits. One of the largest is Papahanaumokuākea Marine National Monument, which covers more than 1.5 square meters (580,000 square miles) of the Pacific Ocean around the northwestern Hawaiian Islands. Studies have shown that schools of tuna migrating through the surrounding seas have increased, possibly because their spawning grounds are now protected.

Much of the ocean needs similar protection, such as thousands of deep seamounts adorned with rich coral and sponge forests. Existing marine parks need to be better protected and regulations tightened in order to have a meaningful impact on ocean life. Protection of coastal areas is best done in close consultation with local communities; careful planning ensures the benefit of nature and people.

5. Prohibition of deep sea mining

The future of the ocean depends in part on whether a new destructive industry is allowed to begin mining the deep seabed for rare minerals.

The rich mix of life on the sea floor—from “barbie pig” sea cucumbers to white ghost octopuses—occurs nowhere else and plays a vital role in ocean health that scientists are only just beginning to understand. All of this could be at risk if the mine goes ahead.

Miners would use machinery like combine harvesters the size of a house to scrape and suck seabed rock from plateaus miles below the surface and across vast areas of the seabed every year, over and over again, for decades to come. Early targets will probably include a central Pacific region roughly the size of the United States.

The big unknown is not whether deep-sea mining could affect the ocean, but how bad those effects would be. At least a decade of coordinated and well-funded research is needed to properly answer this question. But mining companies, backed by governments, want to start within the next year.

This year is critical for the future of deep sea mining. Negotiations continue at the International Seabed Authority – the industry’s watchdog – including the first formal discussions of a proposed 10-year moratorium.

What the wild sea can be: The future of the world’s oceans published by GrovePress –Atlantic Books on June 6