Ecological Associates, Inc. | EAI Environmental Services


March 8, 2019

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Stream mapping and biological assessments are crucial elements for environmental impact assessments and stream restoration efforts.  EAI staff are trained, audited, and registered by the Florida Department of Environmental Protection for Habitat Assessment (HA) and Stream Condition Index (SCI) sampling.  The taxonomic lab at EAI is well-equipped to process and identify SCI macroinvertebrates for SCI stream scoring. Our senior taxonomist has trained with world experts in several insect groups, and holds a certification from the Society for Freshwater Science for genus-level eastern Ephemeroptera, Plecoptera, & Trichoptera.  Macroinvertebrate samples can be collected by EAI field staff, or shipped by clients to EAI’s lab from registered SCI biologists for processing, identification, and index calculations. Take a look at the photos below for a glimpse into the sampling process.

Conducting Habitat Assessments in a Florida stream involves a series of qualitative and quantitative observations.  EAI Biologist Keith Dawson is measuring out and tagging the 100-meter section of stream for Habitat Assessment (HA) and Stream Condition Index (SCI) sampling.
After the in-stream assessment, EAI Biologist Keith Dawson completes the stream habitat assessment sketch and grades the habitat components to calculate the stream’s Habitat Assessment score.
Fine roots less than thumb-size in diameter are productive aquatic habitat.  The percent of productive habitat (e.g., fine roots, decaying wood, dead leaves, submerged rocks, & aquatic macrophytes) is an important criteria used for assessing a stream’s health, and is a sampling area for SCI macroinvertebrates.
EAI Senior Taxonomist, Dr. Matt Scripter, holds a sample vial and sweep net while collecting aquatic insects above Whitewater Falls, NC.  Matt was attending a training session at Highlands Biological Research Station with Dr. John Morse (Clemson) and received his Society for Freshwater Science genus-level certification for eastern Ephemeroptera, Plecoptera & Trichoptera.
EAI Biologist Liz Ranalli and Lab Manager Erica Oliva process a Stream Condition Index (SCI) sample.  The randomization process prior to sorting for macroinvertebrates is designed to provide an unbiased sample and allow the calculation of a reliable final score.
Aquatic caddisfly larvae are an important indicator species for SCI assessment due to their sensitivity to water pollution. The microcaddisfly genus Oxyethira is the 2nd most speciose (19 species) in Florida, but they are small and many larvae cannot be linked with known adult species. Oxyethira microcaddisflies spin silk into a clear, bottle-like case, and feed by puncturing aquatic plants and drinking the cytoplasm that oozes out.
This Chironomidae larvae and case is attached to a caddisfly case in a common and fascinating incident of phoresy – one organism living on another without being a parasite. Chironomids resemble mosquitos as adults, but are in fact so harmless that they are known as the “non-biting midges.”  Chironomidae midges are highly diverse and many genera within this family have a known range of environmental tolerances, so the various genera are used in the SCI as indicators of good or bad water quality.