Sampling methods

Two principle methodologies were used to perform the habitat assessment:

  1. A sonar survey, to profile the bottom contour and
    2. general substrate type (hard or soft)

  2. A semi-quantitative assessment of substrate
    3. composition and zebra mussel presence/abundance along transects set at regular intervals throughout the study reach using a petite Ponar dredge.

Water quality sampling for selected parameters was performed in conjunction with the Ponar sampling.

Scuba divers sampled zebra mussels along transects set within each habitat zone with a minimum of three transects sampled in each zone. At each transect, three samples were collected, one about mid-channel and one about midway between each marker buoy and the corresponding shore. At each sampling location, the diver randomly placed a 10-inch diameter (0.051 m²) open center ring on the bottom. All substrate, including zebra mussels, within the ring was carefully removed and placed into a macroinvertebrate wash bucket fitted with a 583-µ mesh bottom. All zebra mussels were placed into labeled plastic bags and transported to Beak's biological laboratory in Lancaster, NY for further processing.