Re: NANFA-- carp vs. waterfowl

Pete Liptrot (coelacanth_at_btinternet.com)
Sun, 1 Dec 2002 22:29:43 -0000

> > The Carp have destroyed a lot of the vegetation which Dabbling Ducks
> >favor and depend upon for nutrition during migration.

Just out of interest (or not!), I've read a study done on a complex of
artificial lakes over here, which showed a direct link between fish numbers
(particularly Cyprinids) and the numbers of both resident and migratory
water fowl.
Particularly impacted were diving ducks (our Tufted Duck is very similar to
your Ring-neck), but most species were heavily affected, with breeding
successes greatly reduced. Obviously the opposite effect was observed with
piscivorous bird species, but even this would only have been temporary as
whole year-classes of fish were missing due to lack of suitable spawning
sites and refuges for the fry. Where heavy fish stocks existed impaired
biodiversity was seen right across the board, and where Carp were present
these effects were at their most extreme.
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