Benthic Macroinvertebrate Monitoring Protocol

Vital Sign: Aquatic Benthic Macroinvertebrates
Protocol will be implemented: all ERMN parks

Justification/Issue being addressed:
There are approximately 211 miles of river and more than 425 miles of stream throughout the ERMN. The importance of water resources is reflected by the network’s ranking of benthic macroinvertebrates (BMI), river and stream hydrology, and chemical/physical water quality as 3 of the top 4 vital signs. 

Benthic macroinvertebrates are aquatic invertebrate animals larger than microscopic size that live on or within the stream bottom (benthos), and because they are a vital component of all functioning stream ecosystems, they are often used as indicators of ecosystem integrity.  In addition to being instrumental to nutrient and carbon dynamics, BMI are an important link between basal resources (e.g., algae and detritus) and higher trophic levels (e.g., fish and birds) in stream food webs.  Because BMI have been by far the most commonly used group for biological monitoring of aquatic ecosystems (Carter and Resh 2001), many metrics have been evaluated with respect to natural variation and responses to various sources of human-induced degradation.  Given the proven ability to derive ecosystem integrity based on measures of BMI assemblage structure and composition, combined with the relatively low cost to sample, BMI are almost certainly the single best biological group to assess and monitor the ecological integrity of small and mid-sized streams.

Monitoring objectives:

1. Determine the status and trends of BMI assemblages throughout a subset of ERMN streams by way of diversity, abundance, and community metrics,
2. Determine the status and trends of habitat condition (both instream and streamside) and water quality by way of reach-wide rapid habitat assessments and point-in-time measurement of core water quality parameters (i.e., dissolved oxygen, temperature, pH, conductivity),
3. Relate condition of BMI communities in ERMN streams to water quality and habitat condition with regionally developed multi-metric indices, and
4. Assess effects of key stressors on BMI.

Principal investigators and NPS lead: Drs. Ferreri and Tzilkowski, Pennsylvania State University, are developed the macroinvertebrate monitoring protocol for the ERMN. Caleb Tzilkowski, ERMN Aquatic Ecologist, is the lead NPS contact.