Oceans under greatest threat in history

David Attenborough                   Guardian/UK             5 December 2017

The world’s oceans are under the greatest threat in history, according to Sir David Attenborough. The seas are a vital part of the global ecosystem, leaving the future of all life on Earth dependent on humanity’s actions, he says.

Attenborough will issue the warning in the final episode of the Blue Planet 2 series, which details the damage being wreaked in seas around the globe by climate change, plastic pollution, overfishing and even noise.

Previous BBC nature series presented by Attenborough have sometimes been criticised for treading too lightly around humanity’s damage to the planet. But the final episode of the latest series is entirely dedicated to the issue.

“For years we thought the oceans were so vast and the inhabitants so infinitely numerous that nothing we could do could have an effect upon them. But now we know that was wrong,” says Attenborough. “It is now clear our actions are having a significant impact on the world’s oceans. [They] are under threat now as never before in human history. Many people believe the oceans have reached a crisis point.” His sequel to The Blue Planet will focus not only on the marvels of sea life but also the threats to it. The naturalist explains why plastic pollution, climate change and overpopulation are problems too urgent to be left to ecologists

Attenborough says: “Surely we have a responsibility to care for our blue planet. The future of humanity, and indeed all life on Earth, now depends on us.” Brownlow said much of the footage shot of albatross chicks being killed by the plastic they mistake for food were too upsetting to broadcast. The programme also filmed on the Great Barrier Reef in 2016, witnessing the worst bleaching event in its history.

Climate change is causing ocean temperatures to rise, bleaching the corals vital as nurseries for ocean life, and waters are warming rapidly in Antarctica too. Jon Copley, from the University of Southampton and one of many scientists appearing in the final episode, says. “What shocks me about what all the data shows is how fast things are changing here [in Antarctica]. We’re headed into uncharted territory”

The noise from shipping, tourism, and fossil fuel exploration is also revealed as harming sea life. Steve Simpson, at the University of Exeter, who works on coral reefs in southeast Asia, says: “There is a whole language underwater that we are only just getting a handle on. They use sound to attract a mate, to scare away a predator. You hear pops and grunts and gurgles and snaps.” He shows the noise of motorboats distracting saddleback clownfishes from warning against a predator attack.

The Blue Planet 2 team found plastic everywhere they filmed, even in the most remote locations such as South Georgia Island, an important breeding site for wandering albatrosses. There, Lucy Quinn from the British Antarctic Survey says many chicks are killed by plastic fed to them by their parents, including one young bird whose stomach was punctured by a plastic toothpick.

Overfishing, which remains prevalent around the world, is also addressed. “Every night thousands of miles of fishing lines laden with hooks are set – there is enough, it is said, to wrap twice around the world,” says Attenborough. But the programme also highlights some success stories, such as the revival of sperm whales off Sri Lanka and herring stocks off Norway after bans or restrictions were put in place.

Attenborough also visits Trinidad, where the conservationist Len Peters has transformed the prospects of the giant leatherback turtles who come to the island to lay their eggs and whose numbers have fallen catastrophically in recent decades. “I grew up in a house where turtle meat was normal,” says Peters. But his work to end turtle hunting and encourage tourism has seen numbers rise from 30-40 to more than 500.

Daniel Pauly, who leads the Sea Around Us programme at the University of British Columbia in Canada, and was not involved in Blue Planet 2, endorsed its stark conclusion. He said vast, subsidised fishing fleets were scraping the bottom of the barrel and that ocean acidification could be terminal for many species. [Abridged]

https://www.theguardian.com/environment/2017/dec/05