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