Monday, February 21, 2011

Big fish disappearing from the ocean

We're eating most of the big fish from the ocean and replacing them with sardines. So says a new study:
"predators like tuna, cod and swordfish have seen their numbers drop by two-thirds over the past century, while small prey fish such as herring, caplin and anchovies have doubled."
This produces a "while the cat's away, the mice will play" scenario, where the nasty, hungry big tuna and swordfish have mostly been caught, and so little fish like sardines get to play in a much more hospitable ocean

This study says "yes" in the scientific debate over whether or not people have been fishing down food webs in the ocean--catching the big fish first and producing an ocean full of small fish. There is a "no" side to this debate, with strong evidence against the idea that we're everywhere fishing down food webs.

What's a fish lover to do? It's simple really, let's let the scientists duke it out over who's right and see who's left standing. The real challenge is getting people to behave better and not catch too many of the big fish or the little fish.

Friday, February 18, 2011

Fishery science turned upside down

Keep the little ones? That's heresy for most fishery scientists. Don't worry about bycatch? Crazy advice.

But there's an argument to be made for catching fish in proportion to their abundance in the ocean. This goes against the dogma that says selective fishing is best.

A new study says some non-regulated African fisheries are operating in a useful way by failing to select certain fish for catch. The result is a more productive ecosystem despite intense fishing pressure:

"(in some)...specific artisanal and rather unmanaged fisheries of Africa, the use of a wide range of versatile fishing methods and mesh sizes, each of which selects specific sections of a fish community, resulting in a very broad distribution of the fishing pressure on the ecosystem components, leads to high yields while maintaining the ecosystem structure, i.e., the proportions between the abundance of the different size groups. Such “unregulated”, broadly targeted adaptive fishing patterns appear to be far more effective in conserving the ecosystem than single-species management theory predicts. This pattern of development appears to be the result of strong competition between fishers and low individual catch rates, and could be considered analogous to natural predator niche specialization and co-evolution. This requires, obviously, that fishing pressure (using “low tech” gears) remains at levels compatible with the ecosystem productivity."

Wednesday, February 16, 2011

What's in Clorox products?

Clorox is coming clean. They're the first mainstream manufacturer of cleaning products to reveal all the ingredients in all of their products.

This means if you want to know what's in Pine-Sol before you use it in your house, you can find out. This is good green news.

Save the bluefin internet campaign

Watch the video, click on the website, donate useful objects for the campaign(?) Strong story, a bit light on facts, but very provocative and interesting.

Japan's whale hunt suspended

Sea Shepherd harassed Japan's whale hunters, and the whale hunt is now suspended. I wonder what comes next?

Shrimp artificial insemination

In case you've ever wondered how it's done...

Monday, February 14, 2011

Sunday, February 13, 2011

Flamboyant new squid worm

It's a squid. No, it's a worm. It's a squid worm.

Scientists diving deep off the Philippines in 2007 found the Star Wars-looking squid worm. According to National Geographic:

"Relatively long, at nearly four inches (nine centimeters), the new annelid worm earned its moniker with a head that looks as if it's covered

in tentacles.

Its front end bristles with eight arms used for breathing—each as long as the worm's entire body—and two long, loosely coiled appendages employed for feeding.

As if that weren't enough hardware, six pairs of feathery sensory organs—the squid worm's collective "nose"—protrude from the new species' head. And along the length of its body, the worm has iridescent "paddles" for propulsion."

Just another day in paradise--the deep sea.

Saturday, February 12, 2011

Flood runoff a murky soup

Ever wonder what happens when a flooding river hits the ocean? The ocean turns into a murky soup.

Check out this amazing satellite image of an Australian flood plume (right) as muddy water heads for the Great Barrier Reef.

Up close, the water looked like this (below left).

What are the effects of muddy water on the ocean? Floods are natural, and ocean ecosystems can tolerate high sediment loads now and then.

But bad things can happen when floodwaters dump too much freshwater on coral reefs, when runoff is contaminated with toxic chemicals, or when ocean ecosystems are stressed from high nutrient loads and routine sediment loading, death of vulnerable organisms like coral can be a result. Floods don't do this dirty work alone, but they can play a role.

This muddying of the ocean is not unique to massive floods like in Australia,a more modest flood near Seattle also turned the ocean into a murky brown soup (right).

Secchi disk measurements of the Seattle Bay showed 8 inches of visibility, way below average for winter, when visibility can approach 30 feet--see my Swim Around Bainbridge Island for some photos.