Unit E: Fresh and Saltwater Systems

Key Ideas     Unit Checklist

Pre-assessment: What do you know?


Figure E.P.1 โ€“ Canada has over 200,000 km of ocean coastline.

Figure E.P.2 โ€“70 percent of the earth is covered in water.


Figure E.P.3 โ€“ Many of Albertaโ€™s rivers flow from the Rocky Mountains.
Water is one of the most common substances on Earth. Water is located in Earthโ€™s oceans, rivers, and atmosphere. The movement of water affects landscapes and climate around the world.

Water is one of the most important substances on Earth because all living things need to consume water to survive. Living cells consist mostly of water. It is important for humans to make sure that we maintain enough clean and safe water sources for us and the other living things that our survival depends upon.

How do you use water everyday? Where does your tap water come from? How can we keep water clean and safe to drink?

To learn more about how humans can manage and protect our water use, we must first understand fresh and saltwater systems, and how water affects living things and their environments.


Figure E.P.4 โ€“ People need clean drinking water to stay alive.

Figure E.P.5 โ€“ Polluted water negatively affects the environment.

Pre-assessment Questions & Hints

Step 1: The Questions


This short pre-assessment is to find out what you might already know about the topic of fresh and saltwater systems. Below are four questions. Think about them! If you need a hint, click on the question.

Optional: If you would like a place to write your answers, download this document.

Step 2: The Answers

Click each of the suggested answers below โ€“ how do they compare to your thoughts and answers?
  • Fresh water is found in glaciers. Glaciers are large sheets of frozen water which are found at Earthโ€™s poles and in high mountains. Glaciers form in cold places where snow falls and does not melt.
  • Fresh water is found in rivers. Some rivers start from an underground spring, and some rivers flow from melting glaciers. Rivers collect water and carry it to the ocean.
  • Fresh water is found in the ground. Groundwater collects in spaces between rocks, when rain and snow water percolate down through soil and rock.
  • Moving liquid water applies force to and erodes away at rocks, forming landscapes over many years. For example, flowing rivers erode rock into valleys. Ocean tides erode rock into jagged coastlines.
  • Glaciers, which contain frozen water, also shape landscapes. When glaciers slowly grow and melt over time, they erode rocks, move rocks, and deposit rocks. This process leaves behind distinct landscapes.
One example of an organism that lives in water is the salmon fish. Salmon have gills as an adaptation to breathe underwater. Salmon have scales surrounding their body as a protective layer.

Humans test drinking water sources for harmful pollutants from industry and harmful microorganisms like E coli bacteria. In developed countries, drinking water for urban areas is cleaned in large water treatment plants. In places where large water treatment plants are not available, people use filters and disinfectants to remove any harmful substances from water before drinking it.

Step 3: Check In With Your Teacher

The start of a new unit is a great time to touch base with your teacher! Here are just a few reasons to consider contacting your teacher:

  1. Perhaps you found this pre-assessment quiz very easy because you have studied this material before, such as at another school. If so, it's important to tell your teacher.

  2. It's very good for your teacher to know you are starting a new unit; it will give them a good idea of your progress. It doesn't have to be a long message, just a "I'm starting Unit E; just thought you might want to know!"

  3. Your teacher may have special tips and suggestions for the unit you are starting.

  4. Just to say hi โ€“ your teacher always enjoys hearing from you!

To contact your teacher, post in the Course Questions Forum, send your teacher an email, or call on the phone if you like. Whatever way you choose, it's always a good idea to get in touch with your teacher โ€“ make sure you do it frequently.