BBC The Blue Planet Disc 3: Seasonal Seas (2002)

Index

An eight-tonne basking shark filters 1,000 tonnes of seawater through its gills every hour to sieve out plankton, and large numbers are attracted to plankton blooms. On the seafloor, seaweed stretches towards the sunlight, and off the coast of California, underwater forests of giant kelp grow up to 100 metres high. Massive schools of fish shelter here and sea otters snooze at the surface winding strands of kelp around themselves as anchors.

By July, the seasonal seas are warming up fast. On the coast of Nova Scotia large female lobsters are marching 150km from cold, deep waters where they spent the winter, to warm shallows where they can incubate their eggs. In August, pacific salmon return to the coast of Alaska and are hunted down by huge salmon sharks.

By early autumn, Pacific white-sided dolphin are turning up in British Columbia in great numbers. Rather than fish for herring they like to play - engaging in a dolphin's version of tag, as they pass a strand of seaweed from flipper to flipper.

As fast as winter approaches in the north, spring is coming back at the opposite end of the world. Strange handfish walk across the bottom of the sea using their fins like hands. There is also a beautiful courtship ballet performed by Australian squid that change colour as they dance. A male leafy seadragon is a devoted parent, carrying dozens of eggs on his belly and relying on his perfect leafy camouflage to hide them from other hungry fish.

Peter's DVD rating: Great scenes in this portrait of the seas through the seasons include huge swarms of jellyfish, a Herring bait ball being hunted to the last individual in a feeding frenzy from several predator species, and the hilarious Handfish. The Sea Slug chase scene shows clearly how Navanax follows the slime trail left by Janulus. The only weak segments are the Sea Otter and the Pacific Salmon (which species?), which should go a bit more in depth on the ecology of these animals.

2:50	Gray Seal pup in winter (Sable Island, Nova Scotia)	4:50	Phytoplankton: Volvox, Diatoms (Scotland)	5:55	Jellyfish medusae budding from polyps
6:55	Copepod leaves feeding trails	8:00	Sea Nettle (up to 30 kg) and Moon Jelly (Common Jellyfish) feed on Copepods	11:25	Basking Shark filters plankton
12:10	Anemones, Sea Squirts, Gorgonians on the sea floor	13:25	Bull Kelp (British Columbia)	14:10	Giant Kelp (California)
15:10	Blacksmith Fish feed on plankton in Kelp forest	15:45	Californian Sea Otter feeds on shellfish and are guardians of the kelp forest	17:20	Garibaldi Fish feed on Bryozoans
18:00	Bryozoans open at night to feed	18:25	Amphipod mother produce silk to form nest in kelp	19:45	Harbor Seal males establish dominance in Eelgrass
21:50	Bat Ray digs in sand to feed	22:45	Kelp Bass stealing scraps	23:15	Fan-tailed Sole hunts Manta Shrimp
23:55	Sea Slug Navanax? stalks Janulus by following trail of slime	25:20	Atlantic Lobsters migrate 150 km to spawning ground, fight for nest site (Nova Scotia)	28:40	Baby Crab feeds on Sea Lettuce , sensors in feet of adult
29:55	Common Octopus preys on crab	30:50	Pacific Salmon feed on Mysid Shrimp (Alaska)	31:50	Salmon Shark preys on Pacific Salmon by sensing electrical signals
32:40	Vancouver Island: Atlantic Herring? bait ball decimated by Gulls, Auklets, Murres, and Yellow-tailed Rockfish	35:40	Pacific White-sided Dolphin playing "pass the seaweed" (British Columbia)	36:45	Dogfish embryo develops from spring to autumn
38:00	Hooded Sea Slug swims and feeds on plankton (British Columbia)	40:00	Handfish walking among Kelp (Tasmania)	41:10	Australian Squid ? mating by passing sperm packet
42:40	Australian Squid ? baby swimming	43:10	Leafy Sea Dragon male carrying eggs	44:20	Killer Whale hunt North Atlantic Herring (5 billion individuals) by echolocation and stun the fish with their tails (Norway)

2:50 Gray Seal pup	5:55 Jellyfish	6:55 Copepod
8:00 Sea Nettle	8:00 Moon Jelly	11:25 Basking Shark
13:25 Bull Kelp	14:10 Giant Kelp	15:10 Blacksmith Fish
15:45 Californian Sea Otter	17:20 Garibaldi Fish	18:00 Bryozoans
18:25 Amphipod	19:45 Harbor Seal males	19:45 Eelgrass
21:50 Bat Ray	22:45 Kelp Bass	23:15 Fan-tailed Sole
23:15 Manta Shrimp	23:55 Navanax?	23:55 Janulus
25:20 Atlantic Lobsters	28:40 Crab	28:40 Sea Lettuce
29:55 Common Octopus	30:50 Pacific Salmon	30:50 Mysid Shrimp
31:50 Salmon Shark	32:40 Atlantic Herring?	32:40 Yellow-tailed Rockfish
35:40 Pacific White-sided Dolphin	36:45 Dogfish	38:00 Hooded Sea Slug
40:00 Handfish	41:10 Squid ?	42:40 Squid ?
43:10 Leafy Sea Dragon male	44:20 Killer Whale	44:20 Atlantic Herring

Index	Dec 24, 2005	Peter Chen