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Edinboro Lake - Zebra Mussel Update On November 8 and 9, 2000 DEP conducted a Zebra Mussel study on Edinboro Lake
to determine the extent of the population. Approximately forty sample
locations were utilized to determine the population at various depths in the
lake. The results indicate that the highest concentration of mussels is at
the 1'-2' depth. The average density per square meter is 290 mussels. The
0-1' range and the 2'-3' range are have similar densities of 273 and 271.6
respectively. Between 3'-4' the density drops to 174 per square meter, and
at 4'-5' the average density is 55 per square meter. Below 5' the population
the samples resulted in zero zebra mussels captured. (The study does report
that it is recognized that zebra mussels are present at depths of up to 8'+
on selected hard substrates. However, these organisms were not collected
during quantitative sampling, and are not included in this estimate. Taking
these figures in to account the total lake population is estimated to be
greater that 37.3 (37,273,524) million mussels. The US Army Corps of Engineers published a study in July 1992 which concluded
that Zebra Mussels can be effectively controlled by winter dewatering and
exposure to subfreezing temperatures. The time required for 100 percent
mortality ranged from approximately 1/2 hour at 20 degrees F to greater than
48 hours at 32 degrees. Using the population density information from DEP, and information from US
Army Corps of Engineers, Edinboro Borough (with assistance from DEP) has
requested a Draw Down Permit through the Pennsylvania Fish and Boat
Commission. On December 5, 2000 a meeting was held at the Borough Hall to
discuss the permit request and logistics of such a draw down. The meeting
concluded in agreement to a lake draw down of 5' to 5.5' in depth for no more
than three days. Upon final approval signatures of the permit, the draw down
will begin immediately. Please listen to local news media for the exact date
of the draw down. Please note, that although the Fish and Boat Commission is very concerned
about possible long term effects to populations of native aquatic species, it
has been determined that no significant impact should be noted. Edinboro
Lake has gone through many lake draw downs over the years, and no negative
impact has been observed or documented by studies.
The Fish and Boat Commission is concerned also for the safety of ice
fisherman during this draw down period. It is difficult to determine how the
draw down will effect the thin layer of ice that has begun to form. It is
therefore recommended that all ice anglers, cross country skiers, and skaters
take extra caution during this draw down period. WCO Ann Caretto
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