PLANET EARTH: BLUE PLANET II
BBC America, 9:00 p.m. ET
Tonight’s installment, no less breathtaking than the ones before it in this fabulous series, is called “Green Seas.” It explores the patches of water where algae and seaweed and living reefs give way to an amazing abundance of life. Watch for sea otters. And moulted crabs. And Technicolor cuttlefish (pictured). And so, so much more…