The Blue Planet is a BBC nature documentary series narrated by David Attenborough. Described as "the first ever comprehensive series on the natural history of the world's oceans", each of the eight 50-minute episodes examines a different aspect of marine life. 'Seasonal Seas' surveys the effects of the seasons on the world's temperate seas — the most productive on Earth. Sable Island near Nova Scotia boasts the largest colony of grey seals, which breed there when the weather is at its worst ...