A single krill will rest on a human fingertip, its transparent, half-inch long body as fragile as glass.
But the shrimp-like crustacean is an ecological powerhouse, swimming in dense swarms and propagating with a frenzy in all the world's oceans.
Just one species, the Antarctic krill, has an estimated biomass of more than 500 million tons, about twice that of human beings.
Along the California coast, krill feed on microscopic phytoplankton brought from the depths by the upwelling. In turn, krill are fodder for many larger creatures, including fish, seals, birds, humpback whales — and humans.
Scientists monitoring the health of the Farallones waters have found that an abundance of krill coincides with big numbers of finned and feathered animals.
The little crustaceans need to be numerous because a humpback whale, weighing up to 40 tons, consumes up to 1.5 tons of krill and small fish daily.
Krill are also a staple of chinook and coho salmon.
About 200,000 tons of krill are harvested by humans, mostly in the Antarctic Ocean and waters around Japan. They are used for aquaculture and aquarium feeds and sport fishing bait.
In Japan, krill are a food called okiami, with a taste described as salty and stronger than shrimp.
Krill oil is gaining in popularity as a nutritional supplement containing omega-3 fatty acids similar to those of fish oil and astaxanthin, an antioxidant.
The oil is being studied as a natural remedy for high cholesterol, premenstrual syndrome and arthritis inflammation, according to About.com.
— Guy Kovner
UPDATED: Please read and follow our commenting policy: