Blue Planet II finale was a celebration of ocean conservation that resonated deeper than a reprimand: episode seven review

The most entrancing and revelatory television series of 2017 was never going to be an entirely guilt-free pleasure. Blue Planet II (BBC One) held millions of us in thrall each week with the incandescent beauty, variety and, often, previously unrealised intelligence of our ocean creatures. But there were constant hints at the degree to which humanity and our polluting ways are spoiling it.

Attenborough laid it out straight: “The oceans are under threat now as never before in human history,” he insisted.

It is a mark of his genius as a communicator that he left us with a message of hope and encouragement, rather than one of doom and despair. Nudging us towards positive action, rather than whacking us over the head with a cudgel of blame.

There were shocking moments. In particular those relating to the impact of the estimated eight million tons of plastic that we dump in the sea every year. Which not only ends up in the stomachs of albatross chicks in Antarctica but also breaks down into a toxic soup that pollutes marine life in every corner of the globe.

Yet the episode was primarily a celebration of conservation heroes and success stories – a practical demonstration of how the oceans can and will recover if only we would mend our ways. We saw how overfished herring stocks and orca numbers have recovered off Norway through strict management. How whale populations have increased globally since the Eighties hunting ban.

We learnt how, in Trinidad, giant leatherback turtles were saved from the brink of extinction through education and tourism; an exquisite Attenborough moment coming when this 91-year-old lay down in the sand alongside a nesting turtle to enable us to see how truly “giant” she was.

Blue Planet II: The spectacular BBC natural history series, in pictures

Ultimately, Attenborough’s own embodiment of enlightened humanity is the inspirational, and aspirational, image we were left with.

“Surely, we have a responsibility to care for our blue planet?” he prompted, in closing. A quiet call to action that resonated deeper than any reprimand.