Sunday, 22 July 2012

In all the debate about the environment, one doesn’t hear much about ...

In all the debate about the environment, one doesn’t hear much about the oceans; it’s mainly about the atmosphere.

Well, here’s some fascinating stuff I’ve been learning from the documentary, ‘Sharkwater’ (DVD – 2008).

Sharks are being fished to exhaustion (‘long-line’ fishing). This is because shark-fin is very lucrative.

The reasons for the unopposed, though illegal, fishing-to-exhaustion include: there are no campaigns to save the shark, like, say, the panda, partly (largely?) because people aren’t bothered about sharks because they have a bad reputation – ‘man-eaters’, which, in fact, is the diametric opposite of reality. (But I understand that Steven ‘Jaws’ Spielberg has a habit of making trite films, e.g. ‘E.T.’, ‘War Horse’.)

All life came from the oceans.

Sharks are amongst the oldest animals on the planet – 400 million years old, essentially unchanged in all that time (whereas innumerable other species have evolved a great deal).

Shark-fin consumption is very popular because there is another myth (in addition to the ‘man-eating’ one) about sharks: they hardly ever get ill. The ‘logic’ goes: since sharks are very healthy animals, then by consuming shark-fin, that good health can transfer to the consumer. The reality, though, is that sharks are not especially healthy: they too are susceptible to the cancer that results from the toxins that we dump into the sea. Moreover, since they are at the top of the food-chain, these toxins are particularly concentrated in them. Thus, ironically, by consuming shark, one is more likely to contract, rather than stave off, cancer.

They are top predators, making them crucial in the balance of the oceans’ (and therefore earth’s) ecosystem.

The oceans, through plankton, are a major source of CO2 absorption (and CO2 is a principal global-warming gas).

Sharks feed on plankton-feeders. Without sharks, the plankton-feeder population explodes. This reduces the ocean’s capacity to absorb CO2.

Thus, saving sharks would help us to save ourselves.

(You might like to watch this documentary if you’re not already familiar with this stuff; or you might like to watch it anyway for the great photography.)

Oh, and another interesting fact is that sharks have always been top predators.

This is the first time - in just the last 100 years of their 400 million years on the planet - that they have become prey (of man).

(That's of the order 10^-7 of their period of existence - a vanishingly small fraction.)

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