Wednesday, October 13, 2010

BBC Oceans: Atlantic Ocean

Oceans: Atlantic Ocean
BBC’s underwater science program Oceans takes us to the Atlantic this time. First, marine biologist Pooni Mahti brings us to the Bahamas’ “Black Hole,” an isolated column of water mimicking chemically toxic conditions similar to the seas of three and a half billion years ago. After diving eighteen meters (60ft) deep through emerald green water, suddenly the temperature spikes by six degree centigrade (10F) and the water turns a cloudy shade of purple. The cause is a purple sulfur bacteria that traps the sunlight through photosynthesis, thus heating the water, and producing hydrogen sulfide. Below the purple cloud the water turns pitch black and the oxygen level is practically nil. The divers’ skin starts itching and they need to return to the surface out of safety precautions. From this “Black Hole” on the island of South Andros, we travel to Lee Stocking Island to investigate one of the oldest surviving life-forms on Earth. Stromatolites are almost lifeless seeming rocks formed by cyanobacteria that produce oxygen through photosynthesis. Their existence has made it possible for more complex life to develop.

Lucayan remains of Grand BahamaMaritime Archaeologist Lucy Blue searches for clues of the lost civilization of the Lucayans, the pre-Columbian people inhabiting the Bahamas. (The arrival of the Europeans obliterated them by the tens of thousands.) In an underwater cave system she finds a neatly deposited skull that may be identified as Lucayan due to its flattened forehead. On another dive she finds the remains of the HMS Southampton, possibly the first true frigate, that was wrecked off Conception Island during the War of 1812 between the British Empire and the recently independent United States of America.

Quite naturally environmentalist Philippe Cousteau wishes to gauge the effects human activity has on the second largest water mass on the planet. He shows us the bad-guy poster-child of invasive species: the beautiful lionfish (popular in aquariums), which belongs in the Pacific Ocean, not in the Bahamas. This ornate creature has neurotoxic venomous glands on its fin’s spines, but more problematically, without a natural predator around, it is free to prey and wipe out the native fish stock, spreading fast from the Caribbean all the way north to Rhodes Island. Additionally, commercial fishing has practically annihilated some species of fish by 95%, most significantly endangered is the shark. (Anywhere between seventy to a hundred million sharks are caught per year – mostly as accidental by-catch!) The team participates in several experiments to test shark repellents that may save the oceans’ shark population from extinction.

Maybe because I’m getting used to the formula, maybe because I’m getting to know the individuals better, maybe because my expectations were so low about the Atlantic Ocean, I have to say there were some pretty interesting moments in this episode.

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