Jack Bowling wrote:
SNIP...
>And
>many more
>scoters now overwinter on the lakes than before the mussels took hold.
>Question:
>are the scoters now experiencing higher levels of dissolved metals, etc.
>from
>eating the mussels?

The explosion of zebra mussels in the Great Lakes has led to a
dramatic increase in the wintering of several sepcies of diving ducks,
including Oldsquaw, scoters, and scaup, all of which feed on the mussels.
There may be a downside, however. A couple of papers in the past year or
two have reported that the mussels provide negative nutritional benefit
because there is so little meat in relation to the shell and that the
energy consumed in grinding up the shells in the gizzard exceeds the energy
gained. Birds feeding exclusively on zebra mussels are reported to lose
weight and to suffer reproductive failure at much higher rates. The
research is very limited at this point, but several Oldsquaw were examined
and had as many as 500 mussels in their gullets at the time of death.

Rick (long-range lurker on this lovely list)

"A great many people now reading and writing would be better employed
keeping rabbits." Edith Sitwell


Rick Blom
rblom at blazie.com
4318 Cowan Place
Belcamp, Maryland 21017
(410)575-6086