The introduction of zebra mussels (ZM) into the Great Lakes and subsequently waters of the Ohio and Mississippi River Valleys, and numerous other waters has caused countless environmental, biological, and economic problems. Although an isolated sighting

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NATURAL AND HUMAN-MEDIATED DISPERSAL OF ZEBRA
MUSSELS FROM EATON BROOK RESERVOIR, MADISON
COUNTY, NY M.S. Gray1, T.G. Horvath1, S.
Ingmire2 1Biology Department, SUNY Oneonta,
Oneonta, NY Biological Field Station,
Cooperstown, NY. 2Madison County Planning
Department, Wampsville, NY.
Introduction
Natural Dispersal
Human-Mediated Dispersal
Boater Survey Results
Total estimated summer boat trips at the Eaton
Brook Reservoir in the summer 2003.

• Recreational boaters are a known vector of ZM
  dispersal. A boater survey was conducted in the
  summer of 2003 to estimate ZM dispersal examine
  boater habits at Eaton Brook Reservoir boat
  launch.
• Boaters surveyed twice during the week with an
  equal proportion of weekend days sampled.
• Boaters surveyed from either 0700-1400 or
  1400-2100 hours. AM/PM sampling ratio was equal.
• Sampling dates/times were randomly chosen.

The introduction of zebra mussels (ZM) into the
Great Lakes and subsequently waters of the Ohio
and Mississippi River Valleys, and numerous other
waters has caused countless environmental,
biological, and economic problems. Although an
isolated sighting of zebra mussels occurred in
the Susquehanna River in 1991, it was later
determined that the populations had not taken
hold and no further sightings were reported. The
first confirmed population in the Susquehanna
Watershed of zebra mussels was reported from
Eaton Brook Reservoir (EBR) in Madison County,
NY. Based on dispersal patterns from other
watersheds, this population can be a source for
further dispersal within the Susquehanna
Watershed via natural and human-mediated
pathways. Although all the potential impacts are
unknown, the mussels will undoubtedly have
numerous detrimental effects throughout the
Chesapeake Bay Watershed.
Weekday 852
Weekend 783
Total Trips 1635

• 98 of boaters have heard of ZM.
• 32 of boaters dont know how to
• minimize the dispersal of ZM (i.e. by washing
  boats).
• 33 of boaters dont wash their boats.

Boaters Interviewed 126
Boaters Counted (not interviewed) 98
Total 224
Mean veliger densities at six sites on Eaton
Brook based on weekly sampling (numbers above
points are densities). 80 L of water were
bucketed through a 63-µm-mesh plankton net during
the summer of 2003.

• Veligers made it through Eaton Brook into the
  Chenango River (a Susquehanna River tributary)
  several weeks over the summer.
• Based on nominal transport time in Eaton Brook,
  estimated from a dye tracer release, it takes an
  average of 33 hours at a discharge of 0.28 m3s-1
  for a ZM veliger to travel from EBR to the
  Chenango River (25km).
• The mean summer discharge for Eaton Brook was
  0.30 m3s-1.

• Applying the 6 (actual ZM observations) to the
  total estimated number (N 1635) of boater trips
  at the EBR boat launch, 98 boaters are carrying
  live ZM from EBR in June, July, August, from
  just one small reservoir!!!

Passive veliger drift from EBR is a potential
dispersal mechanism of veligers throughout the
connected waterways (Eaton Brook, Chenango River,
Susquehanna River).
Dispersal To From Eaton Brook Reservoir
Location of sampling sites along Eaton Brook and
the Chenango River. Samples also were collected
from Eaton Brook Reservoir (EBR).
Dispersal routes from EBR to other lakes are red
arrows and dispersal into EBR are yellow arrows.
Data are boater movements within 1 wk of boating
on EBR. Line width is relative to number of
boaters.
Funding for this project provided through the
National Fish Wildlife Foundation EPA
Chesapeake Bay Small Watershed Grant Program
(Project 2002-03686-000)