AttenboroughSir Richard Attenborough usually gets closer to his subject matter than he is able to in “Planet Earth: Blue Planet II” (BBC America, 9 p.m.). Concentrating on the 3/4 of the planet that is ocean, it finds a lot of sea creatures so obscure you might think they may be making it up after a while.

With a soundtrack by Hans Zimmer and Radiohead, an filmed over four years, on 125 expeditions, in 39 countries , on every continent and across every ocean, it’s visual splendor at its heights — sure fodder to sell hi-def sets or set off young people on drug-enhanced reveries. At its heart, though, is science.

And whether he can be down there or not, Attenborough, the grand tour guide to natural world wonders for decades, can appreciate it while keeping in mind the threats to the ocean.

“I think we have an obligation to show it as it is and with all the excitements and beauties that it is,” he told reporters via satellite at the TV Critics Association winter press tour. “But also the perils that are currently facing it, which are very considerable.”

“The last program deals in some detail with the threats that are currently facing the ocean, which are very considerable and, of course, are manmade,” Attenborough says.

Of the natural wonder in the film, the nature maven could pick one, from tonight’s initial episode, of the giant, ugly trevally fish jumping out of the water in the Seychelles to grab a bypassing flying tern.

“Those trevally, calculating the speed of a bird which is in the air,” he mused on the screen from London. “They’re in the water. It’s got to be refractive index, whether it bends the light as it comes out of the water. They’re going to have to calculate where it’s going to be, when they’re going to have to take off in order to catch it. I mean, it would take a bank of computers to do that, and yet that’s what the trevally does. And you see it. It comes out of the water and, wallop, it gets that bird. It’s quite extraordinary.”

One of a number of wonders in “Planet Earth: Blue Planet II.” Besides BBC America, it shows tonight on its sister cable networks, AMC, Sundance and WeTV.