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LAKE NEWS
George Knoecklein is the
limnologist, our lake management consultant, on whom we rely for Copake
Lake care. Please read his explanation of the appearance of dead fish
this spring. This is his explanation.
COPAKE LAKE CONSERVATION SOCIETY
INFORMATION FROM THE EDUCATION COMMITTEE
WHY ARE WE SEEING SO MANY DEAD FISH THIS SPRING?
RESPONSE FROM GEORGE KNOCKLEIN, LAKE SPECIALIST:
“The term that is used for dead fish during the spring is Post Spawning
Mortality. It is common to lakes and is for the most part,
unpreventable.
Fish die at this time of year because as they try to spawn in the
shallow water that same water experiences extreme shifts in temperature,
oxygen, pH, and ammonia between day and night. Because the spawning fish
need to stay at their nest they must endure these shifting conditions.
Fish can go into the spawning period stressed from winter conditions so
that they are unable to cope with the additional stress of spawning
combined with the environmental fluctuations.
It is my understanding that fisheries biologists at the state level
don't get concerned by up to several hundred dead fish in lake the size
of Copake, especially if they are mixed species mostly pan fish; perch,
crappie, and sunfish (bluegills, pumpkinseeds, sunfish), there may even
be a few bass included. These kills are an example of natural selection
by which the weaker individuals are removed from the population. The
time to be concerned is when all the dead fish are the same species and
when the numbers are in the thousands.
It is probably very likely that Copake contains tens of thousands if not
several hundred thousand fish. During my June survey last year I noted
many, many more fish nests than prior years suggesting that there could
be an increase in fish numbers.”
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