Prey Fish Biomass In Lake Michigan Falls By 50% In One Year - 2nd All-Time Record Low Total

[hatrack]

The quantity of fish food in Lake Michigan hit a record low for the second straight year in 2007, a trend that could be disastrous for the salmon fishery if it continues. The volume of all prey fish in the lake -- alewife, bloaters and other small fish eaten by salmon, lake trout and whitefish -- dropped by half, from 61 kilotons in 2006 to 30 kilotons in 2007, according to data compiled by the U.S. Geological Survey's Great Lakes Science Center.

That's the lowest volume recorded since the government began tracking prey fish densities in 1973. Prey fish abundance last year was 92 percent below the record volume of 400 kilotons recorded in 1989, said Chuck Madenjian, a USGS research fishery biologist.

At the same time prey fish numbers are plummeting, the volume of foreign dreissenid mussels in Lake Michigan -- quagga and zebra mussels -- increased 13 percent in 2007, according to USGS data. There were 245 kilotons of quagga and zebra mussels in the lakes, eight times the volume of all prey fish; quaggas account for 98 percent of the mussels in the lake, according to government data.

"Most of the stuff we bring up in our bottom trawl now is quagga mussels," Madenjian said. "Their population has just exploded in the lake in the last five years." The divergent trends of more mussels and fewer prey fish doesn't bode well for the Lake Michigan ecosystem or the sport and commercial fisheries.

EDIT

http://blog.mlive.com/chronicle/2008/01/big_lakes_fish_population_plum.html

[GliderGuider]

1. Wait a second! Prey fish biomass is down by 92% in just 18 years? Down 50% in one year?

Wow, the Great Lakes fish are beating the ocean fish to extinction.

We do all realize this is the end, right?

[phantom power]

2. It's the end of the beginning!

...of the end.

[pscot]

3. The advert for extreme walleye fishing

at the bottom of this thread is cognitive disonance at its finest. Is it possible to die from an overdose of irony?

[malakai2]

4. So, how does zebra mussel taste?

Because if that's where the biomass is, I really don't see how it will end up back in the various fish species. Between that, the spiny water flea, ruffe, various gobies, several carp species, and a few particularly nasty exotic diseases, the loss of much of the shoreline marsh around the lower lakes and the southern parts of the upper lakes, and infestations of purple loosestrife in the marshes that remain, it probably wouldn't matter if we could eliminate the mussels. Those fish are gone. Hooray for unregulated international shipping.

[hatrack]

5. Zebra & Quagga mussels apparently both taste like shit

Not that I've tried them myself, but that's the word - both inedible.

[Nihil]

6. Time to start spreading a rumour ...

... that they do wonders for the manly prowess of middle-aged men
and you could start shipping them back to China ...

Hmmm ... probably have to declare them a protected species first though
to get their full attention ... and Sod's Law suggests that this would
be the first and only time that they paid any attention to such a category
so you'd end up with tons of protected invasive mussels that taste like shit
and even the Chinese refuse to eat ... you're SOL!

[malakai2]

7. I've seen Andrew Zimmern on the Travel Channel

If people are willing to eat the stuff I've seen on that show...but then again the mercury and PCBs and such would probably make eating zebes not such a good idea.