Zebra Mussel Monitoring Project (ZMMP)

Sister Grove Creek

River Status

No Texas Parks and Wildlife Status.

USGS Data Collection Activities

River Map

Blue triangles show USGS data-collection locations.

Zebra Mussel Detection Data

Larvae (Veliger) Detections
Most Recent Detection First Date Detected
06/04/2020 Not Detected 04/26/2018

Larvae detection counts are averaged across all sampling sites.

Zebra mussels typically spawn in the spring and autumn as microscopic, free swimming larvae called 'veligers'. The USGS uses fine mesh nets to sample for larvae during the spawning season.

Adult or Juvenile Detections
Most Recent Detection First Date Detected

Adult detection counts are averaged across all sampling sites.

At the end of their larval stage, zebra mussels attach to a substrate and metamorphose into juveniles. The USGS conducts both visual and SCUBA inspections, and deploys artificial substrates as passive samplers, to get a estimate of the juvenile and adult zebra mussel populations.

Water Quality Data

Water-quality monitoring is important for studies of zebra mussel survival, growth, and reproduction. Water-quality data are also important for risk assessments for zebra mussel infestation.