Benthic Macroinvertebrates in Coastal Plain & Piedmont Parks

Person kneeling in a creek holding a handful of mud and rocks from the creekbed
Staff sampling benthic macroinvertebrates in a creek.

NPS / James Comiskey

Importance and Issues

Benthic macroinvertebrates are a vital component of all healthy stream ecosystems. They are instrumental in nutrient and carbon dynamics and are themselves an important link in stream food webs. Moreover, unlike fish and periphyton (i.e., benthic algae), benthic macroinvertebrate assemblages are both productive and diverse in virtually all undisturbed streams with permanent flow.

This is an important consideration in the Mid-Atlantic Network because many of the smaller tributary streams of component parks have gradients and natural barriers that impede the movement of fish, as well as canopies that restrict light and consequently limit algal productivity. As a result, fish and periphyton assemblages are often represented by very few species even in undisturbed streams.

Other advantages of using benthic macroinvertebrate assemblages to monitor streams include:

  1. They are good indicators of local conditions because most benthic species are either sessile or have limited migration patterns through their aquatic phases.
  2. They exhibit wide variation in tolerance among species and life stages to environmental stresses.
  3. Many species have long life cycles relative to other groups which allows inference regarding temporal trends.
  4. Sampling benthic macroinvertebrate assemblages is relatively easy and inexpensive, and has minimal effects on resident biota.

In addition, because benthic macroinvertebrates have been by far the most commonly used group for biological monitoring of aquatic habitats in North America, a large suite of benthic macroinvertebrate summary metrics have been evaluated with respect to natural variation and responses to numerous sources of degradation.

Monitoring Objectives

  1. Document the status of and trends in the structure and composition of benthic macroinvertebrates.
  2. Determine trends in macroinvertebrate communities in relation to changes in water quality and quantity.
Resource Briefs

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Protocols describe how we monitor. They include a descriptive narrative of what we monitor and why, our field methods, how we analyze and manage our data, and more. All of our protocols are peer reviewed.

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Last updated: October 22, 2018