FreshWater Watchers testing water in Vancouver, Canada
FreshWater Watchers take samples to determine water quality © Earthwatch


In the previous module, you learned about the importance of water to humans and to ecosystems, as well as the challenges of having enough water of suitable quality for people and the planet.

Let’s look more closely at the basics of a freshwater ecosystem.

What is a healthy ecosystem?

In freshwater ecosystems, water, bacteria, plants, aquatic animals, and the animals around the body of water coexist and depend on each other. A healthy ecosystem is often determined by the biodiversity of plants and animals within it. Ecosystems with a more varied and diverse structure will generally be more stable and resilient to extreme events, e.g. drought, flood or pollution event.

To find out more about healthy ecosystems, revisit the Water: a Precious Resource module or refer to the UK Field Studies Council to learn about different freshwater ecosystems.

A healthy freshwater ecosystem
A healthy freshwater ecosystem in the Pantanal of Brazil © WWF

Lives depend on the chemical balance in water. If values fluctuate too much, plants and animals suffer illnesses or die because of their sensitivity to the chemicals they consume. Water quality in different waterbodies varies naturally, with differences in temperature, pH and nutrient levels. But these variations are unlikely to be extreme under natural conditions.

In this module, you can find out which indicators are measured by scientists to determine the health of water. You’ll then learn a little bit more about FreshWater Watch, a global research project investigating the health of freshwater ecosystems, the specific tests FreshWater Watch carries out and why these are important.


Next > Ecosystems & Indicators