In the results of the water survey last fall, we learned from watershed residents that healthy rivers and aquatic ecosystems are very important to their quality of life.
But what exactly do we mean when we say “healthy” aquatic ecosystems?
Survey respondents had a lot to say about aquatic ecosystems, for instance stating that we should “maintain natural environments – for fish, wildlife, vegetation” and preserve “quality for all living organisms.”
The term “health” or “healthy” appeared over 90 times in survey results and was often associated with habitat, ecosystems, or water quality.
Health was also implied in a number of statements.
According to one respondent, “Changing water patterns, chemical usage and drainage disrupt the natural habitat. We are taking our precious water, fish and animals for granted and should have … more respect.”
In the “What we heard” report (kettleriver.ca/what-we-heard), we summarized statements about healthy aquatic ecosystems into three components that support native biodiversity and aquatic life: adequate flows and water levels; good water quality and high habitat quality in wetlands, riparian areas and associated uplands. But the phrase “healthy aquatic ecosystem” needs a bit more explanation.
An ecosystem is a community of living things (including people) interacting with each other and their physical environment (soil, water, climate) as a system.
The parts of the system are interlinked through nutrient cycles and energy flows. It is a scientific concept that can be applied to scales as great as the envelope of life around the earth’s surface (the biosphere) to areas as small as a single wetland and its surrounding upland.
An aquatic ecosystem is simply an ecosystem that is associated with water bodies (rivers, streams, lakes, wetlands, springs). It is a special place where organisms have evolved to spend part or all of their life in and around water.
The idea of health is more difficult to define, as it is subjective. People refer to an ecosystem as “healthy” when it meets our expectations in terms of species composition, values and services.
One aspect of health is biodiversity. Does the ecosystem support the variety and abundance of life forms traditionally found there?
For instance, a lake with fewer species of fish and invertebrates than in the 1800s, and more non-native organisms, would be considered unhealthy in terms of biodiversity.
Healthy ecosystems also demonstrate stability and resilience – they tend to be similar over time, and return to the same communities of plants and animals after disturbances like fires and floods, instead of weedy or non-native species.
Of course ecosystems are dynamic and also evolve in response to changes in climate, disturbances, or management.
Society also expects ecosystems and watersheds to provide us with certain “services” and values: clean and safe water, good recreational opportunities, food and economically valuable materials, and aesthetically pleasing views and characteristics.
We alter ecosystems to provide more of these services, often without due consideration for biodiversity or other people.
Changing an ecosystem to meet our preferences, such as landscaping to the shoreline or allowing heavy grazing, can seriously impact wildlife and fish habitat as well as downstream water users.
Do you have more to say about healthy ecosystems or your vision for the Kettle River watershed? Go to kettleriver.ca/what-we-heard and complete the short follow-up survey by April 22.
– Contact Graham Watt (firstname.lastname@example.org) about this or any other watershed questions. Watt is Kettle Watershed Management Plan project
co-ordinator for the RDKB