If you've been watching Doctor Who at all this season (and you should, if only for Catherine Tate), you'll know that the show has been laying subtle ground for giant Earth doom that somehow relates to the recent real-life phenomenon of disappearing bees. In fact, it's worse than even Who producer Russell T Davies knows: Fish are checking out, too.

Moises Velasquez-Manoff, of the Christian Science Monitor, reports on one analysis estimating that every fishery in the world will be empty by the middle of this century:

Until relatively recently, fishermen, fishery managers, and scientists alike thought the sea was so vast, so teeming with life, that human activity simply couldn't diminish it, Mr. Pauly says.

Until the advent of modern fishing technology in the 20th century, it couldn't.

"The sea was very large compared to the means we had to exploit it," Pauly says. But beginning with steam-powered trawlers more than 100 years ago, and ending with today's global-positioning navigational systems, technology has improved fishermen's reach and efficiency. "We essentially deployed our industrial armada against fish, and obviously we would win: It's a war against fish," says Pauly.

As in the case of the disappearing bees (technically known as the widespread Colony Collapse Disorder), it's clear that human decimation of the ecosystem is beginning to have incredibly severe consequences. If the sharp decline of the honey bee population has us worried, we should be panicked by this report: A normal fishery should be able to sustain itself, providing a certain amount of fish to humans and then replenishing its population within a year, but 25% of all fisheries in the world are now unable to restore their populations — and still 50% more have been fished to capacity. But we must, of course, find a way to turn that panic into productivity.

In the US, all quarters are pushing to develop solutions before the problem becomes unfixable. Fishermen and fishery managers are rethinking management to encourage stewardship. Scientists now say that fish stocks can't be viewed in isolation; they must be managed in the context of the greater ecosystem. Many, even some fishermen begrudgingly, realize the importance of having some areas completely off-limits to fishing in order to keep ecosystems healthy. And increasingly, a new argument is heard in the debate over fisheries: Marine ecosystems should be preserved not just for their economic value, but also because, like the wilderness preserved in the national forest system, they are part of humankind's natural heritage.

Perhaps these oceanic inhabitants, like the dolphins in Douglas Adams's A Hitchhiker's Guide to the Galaxy, are simply leaving the planet in short order before Earth is destroyed by an alien ship planning to build a hyperspace bypass. I'd say keep an eye overhead for Vogon constructor fleets, and just in case, don't fish over the limit.

Image by Curt Degler from californiafish.org

Where Have All the Fish Gone? [Alternet.org via Christian Science Monitor]