A clean lake surrounded by trees.
Because of their sensitivity to changes in environmental quality, monitoring macroinvertebrates is a vital part of every bioassessment and biomonitoring program.

Our team at HANA Resources consists of skilled aquatic biologists and entomologists who utilize various methods to collect benthic macroinvertebrates from their aquatic habitats. We use qualitative, quantitative, and semi-quantitative techniques depending on your project’s requirements.

Related: The Best Types of Remote Sensing for Your Environmental Project

Benthic Macroinvertebrates: What They Are & Why They Matter

A macroinvertebrate is an organism without a backbone that is visible to the naked eye. Aquatic macroinvertebrates live around, under, and on sediment and rocks found on the bottoms of streams, lakes, and rivers.

Due to their habitat choice, we refer to most macroinvertebrates as “benthos,” which means that they live in, on, or near the bottom of bodies of water.

Some examples of benthic macroinvertebrates include immature stages of invertebrates like flies, mayflies, stoneflies, caddisflies, dragonflies, snails, leeches, aquatic worms, and both immature and adult beetles.

How We Use Benthic Macroinvertebrates in Bioassessments

Benthic macroinvertebrates, specifically aquatic insects, represent a vital group of organisms frequently used in biological monitoring programs. Macroinvertebrates in the same system can have been residents for a few months to several years, depending on their particular lifespan.

Therefore, macroinvertebrate communities often reside in aquatic systems long enough for us to see the chronic effects of various pollutants. In addition, they live short enough lives that we can also see their responses to acute changes in the water quality.

Unlike the fish population, these organisms are mostly immobile, which means they are almost constantly exposed to various constituents of the water they inhabit. Due to their inability to get out of adverse conditions and limited mobility, benthic macroinvertebrates can help pinpoint the location of pollution sources. We do this by comparing the different communities of the organisms in a body of water.

How Does It Work?

Benthic macroinvertebrates exhibit different responses to changes in water quality, chemistry, and their physical habitat. Each of these responses produces measurable shifts in composition and abundance at the community level—and it’s often predictable.

Individually, we can use macroinvertebrates to find sublethal effects, like mouthpart deformities in aquatic fly larvae. Specifically, we use chironomids and benthic macroinvertebrates as bioindicators for different stressors in an aquatic ecosystem. Invertebrate deformities often get used as ecotoxicological endpoints in determining environmental issues.

Related: The Benefits of Drone Mapping & Land Surveying

A scuba diver taking a water sample.
A scuba diver taking a water sample.

The Sampling of Benthic Macroinvertebrates

Many environmental monitoring programs look at biological indicators in addition to physical and chemical tests.

Due to their sensitivity to various degrees of water pollution, the shifts in macroinvertebrate communities can help us identify two things:

  1. The impact of the specific pollution, and
  2. The effectiveness of any pollution control activities in effect.

And, per the Clean Water Act, states must report waters that don’t support their designated uses. We use biological surveys to examine the aquatic communities and find any stressors affecting them. Therefore, we can determine whether a body of water’s designated aquatic life uses are being supported.

Over time, we can study macroinvertebrates to identify water quality trends as a particular site over years or even decades.

By surveying aquatic insect communities, we can also identify causes of concern within rivers and streams. Those communities can reflect the presence of certain conditions that other measurements can miss.

Using habitat assessments along with aquatic surveys allows us to determine whether shifts in the macroinvertebrate communities are caused by habitat limitations, like siltation and bank erosion.

When evaluating catastrophic environmental events, we can track the various acute and chronic effects of an ecosystem’s recovery over time.

Benthic Macroinvertebrate Surveys As a Part of Other Studies

In addition to the use cases listed above, benthic macroinvertebrate bioassessments are a critical part of other studies to comply with requirements within:

  • Aquatic Resource Permitting;
  • Threatened and endangered habitat surveys;
  • Watershed inventories;
  • TMDL (Total Maximum Daily Load) Studies;
  • Environmental management;
  • Environmental incident management;
  • Hydrologic determination;
  • NARS;
  • Stream monitoring;
  • NRDA (Natural Resource Damage Assessment);
  • NPDES (National Pollution Discharge Elimination System);
  • Satisfy US EPA requirements as part of RCRA or CERCLA;
  • Site inventory;
  • Construction, development, and
  • Wetlands – emergency permitting, restoration, HHEI

Need Help With Your Environmental Project?

At HANA Resources, our experts can provide a variety of biological resource services, including benthic macroinvertebrate bioassessments. Our range of services includes biological resource surveys, wetland restoration, pre- and post-construction surveys, construction monitoring, and more for projects in the western US.

Whether you need monitoring or surveying for biological resources, migratory or nesting birds, threatened or endangered species, ecological evaluations, or help to identify environmentally sensitive areas, we can help. Our experts have the expertise required to ensure all of the resources are protected per the approved environmental documents.

Our Biological Studies, Monitoring, and Management team have extensive experience and expertise in the following areas:

  • Special-Status Species Permits and Surveys;
  • Botanical Services and Surveys;
  • Avoidance & Minimization Recommendations;
  • Bat Surveys;
  • Fisheries and Aquatic Assessments;
  • Preconstruction Surveys;
  • Benthic Macroinvertebrate Bioassessments;
  • Environmental Permitting;
  • Habitat Restoration;
  • Mitigation;
  • Construction Monitoring;
  • Documentation & Reporting;
  • CEQA/NEPA Analysis;
  • Incidental Take Permit / MSHCP Compliance;
  • Wildlife Recovery & Relocation;
  • California Rapid Assessment Method (CRAM);
  • Wetland Assessment and Delineation;
  • Marine Sciences, and
  • Water Resources

Related: Learn More About Our Biological Resource Services

Sun shining through tree branches and leaves.
Sun shining through tree branches and leaves.

Choose HANA Resources for Your Benthic Macroinvertebrate Bioassessments and Other Environmental Projects

Our team has been applying innovation and initiative to natural resource management since 1995 as a premier environmental consulting firm.

We’re WOSB, SB-PW, WBE, and Federal SBE certified and work continuously to simplify the environmental industry.

Using cutting-edge technology, we aim to produce for our clients an objective, reproducible, and process-driven methodology. We remove all of the subjective components to provide proven data supported by transparency, science, and standards.

View our projects and see how we’re changing the environmental industry. Or learn more about how to ensure the success of your environmental projects with our free resources. And, as always, feel free to reach out to us with any questions about our services!

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