CERC Branch: Aquatic Macroinvertebrates

For aquatic ecology group

USGS Science for a changing world

 

Aquatic macroinvertebrates are ecologically important as a food source for fish and wildlife, and for processing of organic matter. This aquatic community includes both benthic (bottom-dwelling) and pelagic (free-swimming in the water column or surface film) species.  Aquatic macroinvertebrates include:

1) insects in their larval stages of development such as mayflies, stoneflies, caddisflies, dragonflies, beetles, and flies such as midges, and 2) a variety of non-insect invertebrates including snails, clams, scuds, crayfish, water mites, and aquatic worms. Abundance and composition of aquatic macroinvertebrates inhabiting aquatic systems reflect past and present environmental conditions, making them sensitive indicators that are valuable for evaluating the biological and ecological health of streams, rivers, lakes, and wetlands.

Aquatic macroinvertebrates are the most commonly used biotic component of the aquatic community for Bioassessment studies.  Bioassessments (or, biosurveys) utilize resident biota to evaluate the quality or health of water bodies, and are commonly incorporated into research studies conducted in these systems.  Aquatic macroinvertebrates are also important in the diets of fish and other vertebrates, making them an important component for studying the food habits of threatened or endangered species that are insectivorous during part of their life cycles (i.e. Pallid Sturgeon).