Blue Planet II: David Attenborough offers stark warning against climate change and pollution during finale

'The future of humanity, and indeed all life on Earth, now depends on us'

Oceans are under threat now as never before in human history, says the veteran broadcaster (PA)

Over the last few weeks, Blue Planet II has been impressing viewers around the country, quickly becoming the most-watched television show of 2017.

Of course, the show wouldn’t exist without fascinating wildlife populating the ocean. Yet, mankind has put the inhabitants of the Big Blue under threat.

During the last episode of the series, David Attenborough issues a warning to viewers, detailing how overfishing, plastic pollution, and climate change are all damaging ocean habitats.

“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,” Attenborough says.

“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.

“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.”

The BBC were reportedly nervous certain viewers would see the series as too politicised by taking a stand, ordering a fact check. “We just couldn’t ignore it – it wouldn’t be a truthful portrayal of the world’s oceans,” producer Mark Brownlow told The Guardian. “We are not out there to campaign. We are just showing it as it is and it is quite shocking.”

Brownlow also revealed that the team saw albatross chicks being killed after eating plastic they mistook for food — they decided the scenes were too upsetting to broadcast.

Blue Planet has issued an article explaining what can be done to help preserve the sea, the first piece of advice — and quickest for those who live by the sea — being to simply pick up litter at the beach. They even call on those who do take part to Instagram and Tweet #2MinuteBeachClean.

Another tip is eating sustainably caught fish — which ensures wildlife and habitats aren’t affected by fishing. The Marine Conservation Society has a handy guide for finding out whether what you’re eating is sustainable.

For those watching Blue Planet II, you’ll be happy to know every piece of plastic the crew came across was removed from the ocean and recycled.

"There would rarely be a dive where I wouldn't find some form of plastic from a thread of plastic fishing line, sweet wrappers or plastic bottles," assistant producer Sarah Conner told BBC Newsbeat.

"When in the open ocean on the boat, if we noticed rubbish while in transit we would do our best to stop and pick it up, just as anyone who cares for the ocean would hopefully do."