The second series of Blue Planet has given us some phenomenal views of previously unseen animal behavior the ocean. It's been a joy to watch, but it's also been completely horrifying to learn how much humans are affecting life in our oceans.
The episodes so far have tended to follow the same structure. The episodes show you amazing creatures, followed by a blunt explanation of exactly how humans are killing those creatures, through destroying their environment. It has been an extremely effective at getting across its message.
The latest episode is no exception and is possibly the most devastating of the whole series so far. After a fascinating look at the Portuguese man o' war and an adorable story about albatrosses, the episode told an extremely sad story of a family of whales, torn apart by human action. It's left everyone who saw it heartbroken.
In a truly distressing segment, Attenborough explained how a young short-finned whale may have been killed by its own mother's milk, as a result of the trillions of tonnes of plastic we have put into the oceans.
"[Short-finned whales] live together in what perhaps may be the most closely-knit families in the whole ocean," Attenborough narrated. "Today, they have to share the ocean with plastic."
"A mother is holding her new-born young. It's dead."
"It's possible her calf may have been poisoned by her own contaminated milk," he says.
"In top predators like these, industrial chemicals can build up to lethal levels. And plastic could be part of the problem. As plastic breaks down it combines with these other pollutants that are consumed by vast numbers of marine creatures."
Attenborough went on to explain that pilot whales are smart animals, capable of experiencing emotions such as grief, as demonstrated here.
The episode also showed fish living amongst plastic-filled parts of the ocean, and has left many people who watched it both devastated, and determined to do more to help our environment.
People online, and a number of high-profile celebrities in the UK – where the series is currently being aired – spoke about how saddened they were by the death of the whale, as well as how much they hate humanity right now for it.
There was also a lot of praise from viewers for mentioning plastic at all.
The episode has had the desired effect, with people online swapping tips on how you can help the oceans in your own way.
And just to end on a positive note, if you were worried about the turtle trapped in plastic towards the end of the episode, BBC Earth revealed that they rescued it from its trap.