Pearce Creek Tidal Monitoring

Maryland Environmental Service and the Maryland Port Administration (MPA) established a long-term exterior monitoring program for the Pearce Creek Dredged Material Containment Facility (DMCF), located in Cecil County, Maryland. The exterior monitoring program includes samples collected for sediment quality, water quality, benthic community composition, and benthic toxicity.  MES and the MPA are conducting this program to establish baseline environmental conditions in the environment around the DMCF prior to the placement of dredged material and the discharge of water from spillways as a result of dewatering activities at the site. 

Coastal Resources, Inc. (CRI) is a subconsultant on this multi-year contract with MES, providing support for collection, processing, and identification of tidal benthic macroinvertebrate samples, as well as data analysis and reporting, including calculation of the Chesapeake Bay Benthic Index of Biotic Integrity (BIBI).  Field sampling occurs biannually, including sediment sampling, water sampling, and benthic community sampling from a total of 12 locations – 8 locations in Pearce Creek Lake and 4 locations in the Elk River. Triplicate benthic samples are taken from each of the 12 locations for a total of 36 benthic community samples per event.  Undisturbed surface sediments are collected from the sediment-water interface down to a depth of 6 inches using a Ponar grab sampler. Samples are sent to a laboratory for analysis of metals, grain size, moisture content, total organic carbon (TOC), nitrogen, sulfur, and specific gravity.  Surface water samples are also collected from each location from the mid-depth of the water column and are analyzed for metals. Physical parameters, including temperature, dissolved oxygen (DO), pH and salinity, are also collected using a Quanta Hydrolab. 

Triplicate benthic macroinvertebrate samples are collected by CRI at each of the 12 locations in the vicinity of the Pearce Creek DMCF using a standard Ponar grab to characterize the benthic community in the project area.  Samples collected in the field are sieved, stored in laboratory-provided sample containers, and preserved with formalin and rose bengal.  All benthic samples are processed and identified by CRI laboratory personnel. In the laboratory, organisms are removed from the sample material and identified to species or the lowest practical taxonomic level. Benthic macroinvertebrate data are used to calculate the Chesapeake Bay BIBI, which uses several metrics to assess and characterize the benthic community conditions.  These metrics include total species abundance, Shannon-Wiener diversity index, abundance of pollution-indicative taxa, abundance of pollution-sensitive taxa, abundance of carnivore and omnivore taxa, tolerance, evenness, species richness, and Simpson’s dominance index.  


Cecil County, MD


Maryland Environmental Service (MES)

Key Services:

  • Estuarine Benthic Macroinvertebrate Monitoring
  • Chesapeake Bay Benthic Index of Biotic Integrity
  • Quality Assurance/Quality Control
  • Data Analysis and Reporting