Macroinvertebrates
Benthic macroinvertebrates represent an excellent group of organisms for use in biological monitoring programs. Their varied life spans, ranging from a few months to many years, are long enough to evaluate the full effects of intermittent and continuous pollutants, yet short enough for populations to respond relatively quickly to water quality changes.
The Macroinvertebrate Section at the Patrick Center more than a 50-year history in the bioassessment, biomonitoring, and inventorying of rivers, streams, ponds, and lakes throughout the United States.
Staff | Capabilities | Facilities | Selected Projects | Why Study Macroinvertebrates?
Staff
- Dr. Raymond W. Bouchard, Research Associate
- (215) 299-1114,
- Dr. Bouchard has over 35 years of experience in a range of estuarine and freshwater ecosystems across the United States, Canada, Central America (Belize, Guatemala, and Panama), and South America (Ecuador and Peru). His primary research interests are concerned with the systematics, zoogeography, evolution, and functional morphology of freshwater decapod crustaceans.
Capabilities
- Biological quantitative and qualitative surveys of macroinvertebrates in streams, rivers, lakes, ponds, and estuarine environments
- Multimetric assessments of biotic integrity and ecosystem health
- Quantitative and qualitative mussel surveys, including invasive species
- Studies of the distributions and environmental requirements of endangered species
- Rapid bioassessments of streams and wadeable rivers
- Short- or long-term biomonitoring programs to assess water quality and/or stream health
- Collection of macroinvertebrate taxa for chemical contamination analyses
Facilities
The Macroinvertebrate Section implements a variety of quantitative and qualitative collection methods to sample benthic macroinvertebrate communities. Quantitative field sampling techniques include a variety of active methods [e.g., Hess sampler, PIBS (Portable Invertebrate Box Sampler), quadrats, Surber sampler, plankton nets, Ekman and Ponar dredges, benthic sled, etc.] and passive approaches (inverted cone traps and multiple-plate samplers and other artificial substrates, etc.) as well as a variety of techniques for semi-quantitative and qualitative collections.
Academy certified divers have conducted dive surveys for approximately 25 years employing a wide variety of techniques (e.g., SCUBA, hookah, snorkel) in qualitative and quantitative assessments.
The Section also maintains current meters (i.e., Marsh-McBirney Flo-Mate 2000 current meter and a Gurley 625 pygmy current meter) to measure stream velocities.
Laboratory equipment includes a Zeiss Stemi SV11 stereo-zoom dissecting microscope, a Zeiss Axioscope compound microscope, and two Wild M8 stereo-zoom dissecting microscopes. A large collection of taxonomic literature and identification keys are available in the laboratory as well as synoptic reference collections. In addition, the resources of the Academy's Ewell Sale Stewart Library and the vast Malacology and Entomology collections (including non-mollusc macroinvertebrates) in the Center for Systematic Biology and Evolution are within easy access.
Recent and Ongoing Projects:
- The Ecological Effects of Dam Removal on the Manatawny Creek Watershed. A Pennsylvania Growing Greener project, funded by the Pennsylvania DEP.
- A Watershed-Level Assessment to Guide Restoration Planning and Maximize the Benefits of Riparian Reforestation. A Pennsylvania Growing Greener project, funded by the Pennsylvania DEP and the William Penn Foundation.
- A Risk Assessment Framework for Determining the Potential Ecological Effects of Dam Removal. A Pennsylvania Growing Greener project funded by the Pennsylvania DEP.
- Long-term Biological and Chemical Studies of the Guadalupe River, Texas, 1949 to present. Funded by DuPont-Victoria.
- Sabine River Monitoring Studies. Funded by the Texas Eastman Company
- Long-term Biological and Chemical Monitoring of Water Quality in the Savannah River, Georgia and South Carolina, 1951 to present. funded by the Westinghouse Savannah River Company.
- Riparian Reforestation in an Urbanizing Watershed: Effects of Upland Conditions on Instream Ecological Benefits. Funded by the U.S. EPA.
Why study macroinvertebrates?
Benthic macroinvertebrates represent an excellent group of organisms for use in biological monitoring programs. Their varied life spans, ranging from a few months to many years, are long enough to evaluate the full effects of intermittent and continuous pollutants, yet short enough for populations to respond relatively quickly to water quality changes, producing measurable shifts in abundance and community composition. Moreover, the location of pollution impacts often can be pinpointed using aquatic macroinvertebrates due to their limited individual mobility and thus their inability to escape adverse conditions.
Many specific characteristics of benthic macroinvertebrate assemblages contribute to their value in biomonitoring. This abundant and ecologically diverse group comprises various trophic levels and therefore forms a vital link in the complex food webs of aquatic ecosystems. Shifts in the physical, chemical, and biological quality of their environment can result in changes in the composition and trophic relationships of the aquatic macroinvertebrate community.
The degree of response to specific environmental disturbances and stresses can vary widely, with some macroinvertebrates able to tolerate high levels of disturbance and some sensitive to even minor perturbations. The distribution and abundances of macroinvertebrates can be easily analyzed statistically to ascertain where and when disturbances occur. Community-level summary statistics, such as diversity indices and taxonomic richness, also serve as means to measure the level of disturbance at any particular site. Although each technique is limited in its ability to measure water quality independently, different analyses of aquatic macroinvertebrates collectively can provide a broad, yet detailed, evaluation of water quality conditions.