Grade 8 Unit E: Curriculum Links | Print |

Unit E: Fresh and Saltwater Systems
(emphasis on Social and Environmental context)

Earth is sometimes described as the water planet: over two-thirds of Earth's surface is covered by oceans and freshwater features. By exploring examples of aquatic systems, students come to appreciate their dynamic nature and learn about the interactions of these systems with climate, the biosphere and Earth's landscape. In the process, students become aware of conditions which have led to the development of aquatic systems, as they investigate factors that affect their characteristics and quality as part of a life-supporting environment.

Focusing Questions:

What are the characteristics and dynamics of fresh and saltwater systems?

How do these systems interact with the atmosphere and Earth, and with the actions of humans?

Key Concepts

  • water quality
  • stream characteristics
  • water-borne materials
  • continental drainage systems
  • erosion and deposition
  • climate
  • ocean basins
  • glaciers and ice caps
  • adaptations to aquatic ecosystems
  • human impact

STS and Knowledge Outcomes
Students will: Describe the distribution and characteristics of water in local and global environments and identity the significance of water supply and quality to the needs of humans and other living things
describe, in general terms, the distribution of water in Alberta, Canada and the world and interpret information about its characteristics (e.g., identify glaciers, snow, polar-ice caps, groundwater and oceans as components of the Earth's water, interpret graphical information on the availability of potable water)
recognize that fresh and salt water contain varying amounts of dissolved materials, particulates and biological components; and interpret information on these component materials
identify major factors used in determming if water is potable, and describe and demonstrate tests of water quality (e.g., investigate and describe the physical characteristics of a sample of water such as clarity, salinity and hardness; investigate biological tests)
describe in general terms methods for generating fresh water from salt water based on evaporation, distillation, and reverse osmosis

Students will:
Investigate and interpret linkages between landforms, water and climate

describe processes of erosion and deposition resulting from wave action and water flow
identify dissolved solids and sediment loads, and identify sources and endpoints for these materials
describe how waves and tides are generated, and how they interact with shorelines
investigate and describe stream characteristics (e.g., describe the slope, flow rate and stream profile characteristics of a model stream on a stream table)
describe processes leading to the development of ocean basins and continental drainage systems (e.g., describe the formation ofgeologicalfeatures on the ocean floor such as continental shelves and trenches)
  identify evidence of glacial action, and analyze factors affecting the growth and attrition of glaciers and polar icecaps (e.g., identifyfactors which affecting the size of polar ice sheets and the Columbia ice fields)

Students will:
Analyze factors affecting productivity and species distribution in marine and fresh water environments

investigate the diversity of life forms found in fresh and salt water, and interpret the adaptive value of some common characteristics (e.g., investigate fish and invertebrate species found in a local freshwater environment, and do research on comparable species found in a marine environment)
analyze factors that contribute to the development of adaptations in species found in salt and fresh water environments
describe, in general terms, populations found in fresh and saltwater environments and interpret examples of seasonal, short-term and long-term change (e.g., algal blooms, changes infish populations in local lakes and streams, cod and salmon stock depletion)
analyze relationships between water quality and living things, and infer the quality of water based on the diversity of life supported within it

Students will:
Analyze human impacts on aquatic systems and identify roles of science and technology in addressing related questions, problems and issues

analyze human water uses and identify the nature and scope of impacts resulting from different uses (e.g., identify pollutants in groundwater and suiface water systems resulting from domestic and industrial use; analyze the effects of agriculture and forestry practices on stream flow and water quality)
identify current practices and technologies that affect water quality, evaluate environmental costs and benefits, and identify and evaluate alternatives (e.g., research and analyze alternatives for ensuring safe supplies of po table water; research, analyze and debate alternatives for a specific water quality issue such as the location and design of a landfill, the protection of a natural waterway, the use of secondary and tertiary waste water treatment, the salinization of soils due to irrigation, the eutrophication of ponds and streams due to excess phasphate fertilizer use, or a proposal to export water resources)
illustrate the role of scientific research in monitoring environments and supporting development of appropriate environmental technologies (e.g, describe a local example of aquatic monitoring, and describe how this research contributes to watershed management)
provide examples of problems that cannot be solved using scientific and technological knowledge alone (e.g., provide examples such as the need to prevent pollutants from entering aquatic environments, the need to avoid damage from ice sheets and icebergs)