Let’s Talk Bugs: an Overview of Benthic Collection and the Benefits of Good Bugs

Let’s talk about bugs! Specifically, aquatic insects, also known as benthic macroinvertebrates. The word benthic refers to anything relating to or occurring at the bottom of a body of water, and that’s exactly where we find these little bugs! These macroinvertebrates are visible to the naked eye and live in a variety of habitats on stream bottoms, like large woody debris, undercut banks, fine root mats, instream structures that promote leaf pack formation, and emergent sticks and rocks within riffles.

But why is it so beneficial to keep track of these bugs? Benthic macroinvertebrates have a wide range of ecological functions, like being the primary processors of organic material and being sensitive to pollution. Depending on their presence and diversity in our streams, it suggests that the water quality of our stream is healthy enough to support a flourishing aquatic community. In other words, if the bugs are present, that’s a great indicator that our streams are healthy.

Wildlands Engineering (Wildlands) established our own biological monitoring program in 2014, and benthic macroinvertebrate collection is a huge part of that. Our mitigation projects are designed to improve biological function and ecological health, which we achieve by alleviating water quality stressors and improving in-stream habitat. These projects have significant impacts, and this monitoring program helps us keep track of their long-term effects. To do this, our scientists collect samples and data from sites over time—from project pre-construction to project close-out—a process that can take upwards of 10 years! The data collected is then analyzed using metrics, like the NCBI, which rates a stream on a scale of “poor” to “excellent” based on a species’ tolerance to pollution. We also use the EPT richness metric—which stands for Ephemeroptera (Mayflies), Plecoptera (Stoneflies), and Trichoptera (Caddisflies)—which indicates the presence of bugs that cannot tolerate pollution. Using this metric, we know that if we are not seeing Mayflies, Stoneflies, and Caddisflies, poor habitat or pollutants are most likely present in our stream ecosystems.

Wildlands recently completed a benthic study on our Candy Creek Mitigation Site, located in Guilford County, NC. Benthic samples were collected beginning in the pre-construction phase [January 2015] through the project closeout phase [March 2024]. The project restored 17,085 linear feet of stream along Candy Creek, and one of the site-specific goals was to improve stream habitat for the bugs! This was accomplished by excluding cattle from the streams and creating stable stream channels, which ultimately reduced pollutants and created habitat for the bugs. Wildlands’ scientists collected benthic samples at four different locations along project streams at Candy Creek during multiple phases of the project: pre-construction, two years post-construction, five years post-construction, and seven years post-construction. At each site visit, the scientists would walk the streams with nets and buckets to collect bugs from rocks, logs, leaf packs, and undercut banks. The bugs were then transferred to a lab where they were identified, and NCBI and EPT metrics were calculated.

What we found in our study on Candy Creek is that benthic communities are sensitive to disturbance and require time to reestablish themselves within our streams as the habitats stabilize and the fine sediments flush out following construction. The NCBI and EPT metrics show that Candy Creek had an immediate decline post-construction, followed by gradual improvement through the closeout phase as the ecosystem reacclimated. At the closeout phase of the project, most streams had an NCBI rating of Good to Excellent and an EPT rating of Fair. While there is still room for improvement for sensitive EPT species, the overall quality of bugs in the streams is improving. Stream restoration and environmental conservation are ever-evolving processes, and our biological monitoring program is one way Wildlands works to keep our restoration projects informed, innovative, and beneficial.

Stewardship Corner | Allelopathy – ‘The Chemicals Between Us’

Ever wonder how a single species can dominate an area and lead to a monoculture, where diverse neighbors are sparse? The answer might lie in allelochemicals.

Allelopathy describes how organisms produce biochemical compounds, known as allelochemicals, that influence the germination, growth, survival, and reproduction of nearby species. This process is essentially a form of chemical competition aimed at boosting the organism’s own survival and reproduction. Without getting too in the weeds, allelopathy is a form of chemical competition.

In allelopathic plants, these compounds can be released through leaves, stems, fruits, or roots. They enter the soil through root exudates, runoff from rain, or decomposing plant matter. Some plants also release allelochemicals into the air, adding another layer to this chemical competition.READ MORE

Urban Growth and Flood Resiliency: Navigating Environmental and Social Challenges in Urban Settings

Wildlands is embarking on a series of Flood Resilience articles that delve into flood-resilient projects’ social and environmental challenges and opportunities. This article specifically focuses on urban landscapes, the backdrop for some of our society’s most pressing challenges and promising opportunities.

With all the benefits of urban development, there are various environmental and infrastructure management challenges, intermingled with social challenges that all present as important considerations in our environmental restoration, recreational, and community enhancement work. They range from increased risk of flooding to impacts on water quality and aquatic habitat degradation and displacement. However, as cities continue to expand and redevelop, the need for effective flood mitigation, water quality, and ecological restoration solutions to manage these development impacts is gaining an increasing amount of recognition. These solutions, when implemented, can bring about a positive change, improving the environment and our quality of life, instilling hope for a more resilient and sustainable future.READ MORE

Stewardship Corner | Mosses, Liverworts, and Lichen

From the Stewardship Corner | Mosses, Liverworts, and Lichen

An often-overshadowed part of the plant kingdom, mosses, liverworts, and hornworts, make up a small world of their own in ecological communities. Often found growing on stones, stumps, and moist shady corners, these organisms play a quiet but vital role in initiating soil formation, slowing water passage, and recycling nutrients. They also provide habitat for macroinvertebrates, and for them, a mossy mat might feel like a fully grown forest. Unlike other plants, these green fuzzy mats do not form vascular systems that can move nutrients and water throughout their bodies, they instead rely on water and nutrients to come to them. This is why you often find them growing in wet, damp, low lying areas where water and moisture can find them.

Like ferns – mosses, liverworts, and hornworts do not produce flowers or seeds, and instead reproduce through spores. Because of their simpler requirements, these plants can grow where nothing else can, and often act as a pioneer species setting the stage for ecological succession. Their spores can travel miles before landing and spread by the millions. They are also a great indicator of air quality due to their sensitive nature, a welcoming sign while on a walk in the woods.

Lichen is another great indicator of air quality, and although they might look similar and grow alongside their counterparts, lichen is a wholly different form of fascinating life. Lichen is the result of a mutualistic relationship between algae and fungi. While they are not a plant, they still perform photosynthesis as a composite organism. Small but mighty, these species are considered to be keystone species in many ecological communities. How many different species of mosses, liverworts, hornworts, and lichen have you come across recently?

Pictured from Wildlands project sites:

1. Tortula Moss (Tortula muralis) – Honey Mill Mitigation Site, Surry County, NC
2. Delicate Fern Moss (Thuidium delicatulum) – Key Mill Mitigation Site, Surry County, NC
3. Star Moss (Syntrichia ruralis) – Alexander Farm Mitigation Site, Alexander County, NC
4. Broom Forkmoss (Dicranum scoparium) – Honey Mill Mitigation Site, Surry County, NC
5. Medusa Moss (Hedwigia ciliata) – Carpenter Bottom Mitigation Site, Gaston County, NC
6. Great Scented Liverwort (Conocephalum conicum) – Carpenter Bottom Mitigation Site, Gaston County, NC
7. Lichen (Parmeliaceae) – Lone Hickory Mitigation Site, Yadkin County, NC

📸 Photos by Dominic Dixon, Stewardship Associate | Charlotte, NC Office

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