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Collection of Benthic Macro Invertebrates (Water Bugs)
•wide variety of species that exhibit a range of responses to independent and interactive environmental stressors •sedentary in nature and have a long life cycles (weeks to years) allowing temporal changes in characteristics such as abundance and age structure to be examined •the
abundance of invertebrates, sampling equipment and the availability
of easy-to-use keys for identification. Macro
Benthic Invertebrates
Sampling Protocol used in Severn Sound The TEHMP assesses eight sub-watersheds within Severn Sound: Avon (1 site), Coldwater (3), Copeland (1), Hog (4), North (1), Silver (5), Sturgeon (3), and Wye River (3). Additional sites are monitored seasonally depending on projects within the watershed. Each monitoring station is evaluated once a season between the months of July/August. Two sampling protocols are used for the collection of invertebrates. The first sampling protocol is a qualitative sampling method. This involves using a hand sieve and forceps to collect invertebrates on all available habitats within a fifteen-meter stream reach. Habitats included sand, silt, gravel, rip-rap, large rocks, logs and vegetation. The second protocol is a quantitative method using a t-sampler within the riffle area of a stream because it has the highest diversity of all habitat. This protocol is used because the density of invertebrates can be calculated within a set area through the cylinder of the t-sampler. It provides valid comparisons between samples, by relative abundance and will show any species and density changes at a station. The open end of the sampler is placed into the current and the substrate inside the t-sampler is agitated for one minute and allowed too clear. The flow of the water through the t-sampler will carry any invertebrates through the net and into the catch bottle. All specimens are placed in a labeled specimen jar with seventy percent alcohol as a preservative and taken back to the lab for identification. After identification the invertebrates are stored for later reference. To correspond with the sampling protocols, Tidbit Temperature loggers and monthly chemistry is completed/installed at each site. The loggers are launched to record water temperature every thirty minutes from the middle of June to the end of September. The data is stored on the logger and retrieved by staff monthly. The data retrieved from the loggers is excellent for determining the thermal stability of the stream. The average water temperature at a stream is of vital importance to the survival of the stream inhabitants. Different species (invertebrate and fish) within a system require different temperatures for survival. For instance brook trout and brown trout require constant coldwater temperatures within a stream where sunfish/minnows can thrive in fluctuating warm water conditions. Chemistry sampling is completed through the Provincial Water Quality Monitoring Network by the Ministry of the Environment, Environmental Monitoring and Reporting Branch. The program involves collecting samples eight times within the ice-free period (monthly). The
samples are analyzed for chloride, dissolved nutrients, ions,
metals, pH, alkalinity, conductivity, suspended solids, total
nutrients and turbidity. Temperature loggers and chemistry
sampling will give SSEA staff additional tools to help
evaluate the monitoring stations that have a low species
diversity but the habitat and flow are excellent. For more information about the Tributary Ecosystem Health Monitoring Program, contact Paula Madill, Ecosystem Technologist at 705-527-5166 or by email pmadill@town.midland.on.ca
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