Learning About Oceans, Unit 7

Overview

How to Use This Guide

Key Messages

Learning Outcomes

Curriculum Connections

Teacher's Notes

Lesson Plans

Resource Sheets

Overview

The theme of this learning module is "Canada Is an Ocean Community." As we all know, humans rely on communities — including families, friends, teachers, farmers, fishers, shopkeepers, doctors, and others — to survive. If we take a closer look, we see that we depend not only on human communities but also on natural communities, particularly oceans and the plethora of life they hold.

In fact, human communities and ocean communities are inseparable. We are connected to the ocean by way of waterways and the atmosphere, not to mention ocean products commonly found on supermarket and pharmacy shelves. The many marine species, such as whooping cranes and harlequin ducks, that migrate through our communities en route to summer breeding areas or wintering habitats are further examples of the infinite ways in which ocean life enriches us. Even our cultural heritage connects us to the sea. And yet, we continue to place marine communities at risk through actions that destroy or pollute them.

In recognition of our link with the ocean and the urgent need to conserve this connection, we have created this learning module. It will help your students discover how their survival depends on healthy seas, how they are part of an ocean community, and how they can take hands-on action to protect the watery wonders that give them life.

Work through lessons 1 to 6 to deepen your students' understanding of key concepts and issues. Complete each lesson by discussing main points (outlined in each "Procedure" section) highlighting important learning objectives, linking the various lessons to the overall theme, and building up to responsible actions described in lessons 7 to 12.

Finish the unit by selecting one or more of lessons 7 to 12, which enable students to take action beneficial to ocean communities. Lessons 7 to 11 focus on actions relating to pollution, litter, habitat enhancement, and biodiversity. Lesson 12 heightens students' awareness of ocean conservation issues in general.

• All organisms, including humans, inhabit communities that include other life forms with which they interact and on which they depend. (Activity 1)
• All living things, including humans, depend on specific habitats that include clean water and suitable space.  (Activity 2)
• Important ocean habitats, such as coastal areas, beaches, salt-marshes, and estuaries, are also destroyed by human activity. (Activity 2)
• People depend on ocean communities to survive; ocean health is vital to us. (Activity 3)
• We are physically connected to ocean communities through watersheds and the atmosphere. (Activity 4)
• Human communities are a major source of dangerous contaminants, which enter oceans through watersheds and the atmosphere. (Activity 5)
• Contaminants can bioaccumulate to lethal levels in some organisms, disrupting and endangering ocean communities, including the people that depend on them. (Activity 6)
• Human communities share responsibility for the health of ocean communities and can benefit them through action projects. (Activities 7-11)
• We can raise awareness about oceans and encourage others to conserve them by publicizing our positive actions. (Activity 12)

• understand that all species, including humans, inhabit communities that include other life forms;
• recognize that all living things depend on specific habitats that include clean water and suitable space;
• identify ways in which people depend on ocean communities;
• describe their community's connection to the ocean and trace their physical link to the sea;
• identify community-based sources of pollution that enter oceans through watersheds and the atmosphere;
• understand how the bioaccumulation of contaminants threatens ocean communities, including humans;
• describe how human activities can threaten marine habitats;
• identify ways in which human communities can benefit ocean communities through action projects;
• demonstrate stewardship of ocean communities through action projects; and
• raise awareness about oceans and encourage others to conserve them by publicizing positive actions.

• Needs and characteristics of living things
• Air and water in the environment

• Habitats and communities
• Diversity of life

• Interactions within ecosystems
• Water systems on Earth

• Sustainability of ecosystems
• Interactions among living things
• Earth systems

Biodiversity

Biodiversity means "biological diversity," or the variety of living things. Biodiversity is usually described at three levels: genetic, species, and ecosystem. Genetic diversity occurs within each species or population. A genetically diverse species or population will have members that exhibit a broad range of characteristics. Broad genetic diversity is what allows a species to adapt to changing conditions over time. Species diversity refers to the variety of species that occur in a particular area. It allows for more complex food webs and, therefore, more resilient ecosystems, since creatures may have several alternate food sources. Ecosystem diversity refers to the variety of ecosystems on Earth. The greater the variety of living spaces, the greater the variety of life forms that can inhabit them.

Ecosystems

Ecosystems include the living and non-living components of an area, along with interactions among them. The living parts of an ecosystem consist of micro-organisms, plants, and animals (including humans). Non-living elements include minerals, soil, water, and so on. Vital processes, such as the carbon cycle, water cycle, and energy cycle, also occur within healthy ecosystems. Ecosystems can be any size, from microscopic to enormous. Larger ecosystems contain smaller ones. For example, we might consider the world's oceans to be one giant, interconnected ecosystem, and the Pacific, Atlantic, and Arctic oceans to be smaller ecosystems within it. We might also consider each reef, estuary, salt-marsh, and beach to be a separate ecosystem.

Natural communities

Natural communities are collections of living things that share the same space. The plants, animals, and micro-organisms that inhabit natural communities tend to depend on one another either directly or indirectly. For instance, polar bears depend directly on seals that make up the main part of their diet and indirectly on the fish that feed the seals. Polar bears, seals, and fish form part of an Arctic ocean community.

Watersheds and drainage basins

All land is drained by systems called watersheds, which include creeks, lakes, wetlands, and rivers that eventually empty into the ocean. Smaller, local watersheds flow together and can be considered as larger units on a regional level. Canada's watersheds are organized into five main drainage basins, the boundaries of which are determined by the ocean bodies they flow into: the Pacific, Atlantic, Arctic, Hudson Bay, and Gulf of Mexico.

Bioaccumulation in food chains

Some toxic chemicals "bioaccumulate" in wildlife. Scientists discovered this phenomenon when they noticed that the levels of certain chemicals in some animals' bodies were significantly higher than those in the surrounding environment. These levels were highest at the top of food chains. The more links in a food chain, the higher the levels of toxic chemicals. Many types of chemicals are stored in fat tissues and eliminated by animals far more slowly than they are consumed. Over its lifetime, an animal will gather and store toxic chemicals at levels far above those in its environment. This bioaccumulation happens at each successive level of a food chain. Predators, such as polar bears, eagles, and people, are at the top of long food chains and sometimes accumulate concentrations of toxic chemicals in their bodies hundreds of times greater than those in the surrounding environment. Bioaccumulation can lead to serious health risks, including cancer.

Untreated or partially treated sewage from domestic waste-water often ends up in waterways. Its main threat to humans is the bacterial and viral contamination of shellfish, which can turn seafood into a lethal meal and lead to the closure of economically important fisheries.

Persistent organic pollutants (POPs) are a class of chemicals that accumulate in food chains and cause tumours, deformities, loss of reproductive ability, and even death in plants and animals, including humans. Some examples are DDT, PCBs, and dioxins. POPs enter the environment through pesticides sprayed on lawns and crops and industrial chemicals that leak from landfills. They are transported long distances by waterways, ocean currents, and the atmosphere. POPs affect ocean wildlife, such as beluga whales, fish, seals, and even arctic species like polar bears.

Heavy metals, such as mercury and cadmium, cause problems similar to those caused by POPs. They enter the environment through mining and smelting operations, the burning of coal for electrical generation, and pulp and paper industrial processes.

Oil is toxic to aquatic life if ingested or absorbed through the skin. It also fouls the fur and feathers of wildlife and smothers aquatic habitats and beaches. Oil finds its way into the ocean through marine oil spills and land-based sources like domestic storm sewers. Urban communities introduce an estimated 30 million litres of oil into aquatic ecosystems each year, as people carelessly pour waste oil down the drain.

Marine debris, particularly plastic litter, chokes and entangles wildlife, such as sea turtles, whales, dolphins, and seals. Litter gets into the marine environment through direct dumping from ships and by entering waterways from poorly managed waste-disposal sites.