Thursday, April 24, 2008

Mercury from fish to spiders to songbirds

OK this is just too weird. Songbirds are contaminated with mercury near a river in Virgina where the fish are too mercury-contaminated to eat. But the birds don't eat from the river. What gives?

Oh, it's the spiders. The mercury-laden songbirds are getting it from mercury-contaminated spiders. Nobody knows yet how how the spiders are getting the mercury. Unless the spiders are eating the mercury-contaminated fish. What a tangled web of pollution, and the first known instance of mercury from fish infiltrating a purely land-based ecosystem (spiders and songbirds).

3 comments:

Max said...

I don't know that it's that hard to think of plausible explanation for how the mercury is getting out of the water. For instance: what do spiders eat? Insects. What's probably the biggest conveyor belt of biomass from the water to the land? Insects. It seems like the most cryptic part of the equation was finding out that the mercury is getting to the birds via the spiders, but they already figured that part out :)

Anonymous said...

I had the same idea as Max, that the spiders probably got the mercury via their prey (insects that spend the beginning of their lives in water)...

Mark Powell said...

Good ideas, I think you're right that spiders are eating insects that live in the river as larvae, then fly out onto bushes to mate.