MONITORING AQUATIC ENVIRONMENTS
Aquatic communities and the habitat that supports them are fundamental sensors that respond to stress affecting the aquatic ecosystem. As such, they can be assessed as indicators of the overall health of the aquatic ecosystem.
LPRCA's Healthy Watershed Services Program monitors key aquatic indicators including stream temperature and benthic macroinvertebrates.
Benthic macroinvertebrates are small aquatic ‘bugs’ that live in lakes, rivers, streams and wetlands. These bottom-dwelling organisms are good indicators of water quality because different species have different levels of tolerance to pollution making them excellent water quality indicators. The presence, or absence, and abundance of certain benthos species can be related to the quality of the water.
Long Point Region Conservation Authority staff collect and identify these aquatic ‘bugs’ on an annual basis. Samples are collected at 15 locations, once a year in the fall, using a standard “kick and sweep method” with a D-net. The samples are collected in support of the Ontario Benthos Biomonitoring Network (OBBN), a program of the Ontario Ministry of the Environment.
Through collecting and analyzing benthic organisms, LPRCA can assess, over time, changes in surface water quality. Although benthic samples have been collected in the Long Point Region watershed since 2003, it is still a relatively new and evolving program. This biological monitoring complements the LPRCA’s surface water quality monitoring programs.
Stream temperature is an aspect of water quality that affects every aquatic organism. The rates of biological and chemical processes depend on temperature. Aquatic organisms from microbes to fish are dependent on certain temperature ranges for their optimal health. If temperatures are outside this optimal range for a prolonged period of time, organisms become stressed and die.
LPRCA conducts surface water temperature studies throughout the watershed. Data is collected using a network of more than 25 digital temperature loggers. These data loggers are installed in area streams in the spring and removed in the fall. They are used throughout the watershed to assess stream temperature to identify cold, cool and warm water streams for fish habitat as well as measure the benefits of stream rehabilitation projects. LPRCA staff also uses the information gathered to create watercourse temperature profiles.
Fish Community and Habitat
LPRCA conducts project-specific biological surveys to document existing aquatic species. Fish species are a convenient measure of the health of an aquatic system since they are easy to sample and identify, and they are relatively well understood in terms of ecological requirements. Species numbers and distribution can provide a good measure of aquatic ecological condition, and the presence/absence of species over time, or changes in the numbers and locations of sensitive species, provide an indirect measure of aquatic health and an indication of broader environmental change.