Unit A Lesson A11 How Humans Damage Ecosystems
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Lesson A11: How Humans Damage Ecosystems
Video Lesson
Humans have done and are doing amazing things to promote the ease of our lives. However, even as we try to make our lives better, we damage ecosystems – which will be disadvantageous to us in the long term
Lesson A11: How Humans Damage Ecosystems
Preventing Ecosystem Damage
Ecological damage can be difficult to identify and measure. For example, a single industrial operation can harm a wide range of organisms. The damage can be difficult to see. Careful scientific monitoring is required to understand human effects.
Effects can seem small at first, but they can increase over time. When an ecosystem experiences many effects from many sources, damage is multiplied. When this happens, the system’s natural balance can be overwhelmed. Taking action before that happens is essential.
Ecological damage can be difficult to identify and measure. For example, a single industrial operation can harm a wide range of organisms. The damage can be difficult to see. Careful scientific monitoring is required to understand human effects.
Effects can seem small at first, but they can increase over time. When an ecosystem experiences many effects from many sources, damage is multiplied. When this happens, the system’s natural balance can be overwhelmed. Taking action before that happens is essential.
Reading and Materials for This Lesson
Science in Action 7
Materials:
Science in Action 7
Reading: Pages 20–23
Materials:
No other materials are needed for this lesson.
Figure A.4.11.1 – Pristine glacial meltwater feeds the Athabasca River.
Figure A.4.11.2 – Many species, such as moose, live in the Athabasca River basin.
Human Effects on the Athabasca River Basin
The Athabasca River is one of Alberta’s major rivers. It is a vital resource for plants, animals, and people in northern Alberta. The river basin contains lake, river, stream, and wetland aquatic habitats.
This ecosystem evolved in an ever-changing environment. Beavers influence the river basin by building lodges and dams. The dams produce wetlands by flooding rivers and streams. The water flow slows and the river deposits its nutrient-rich sediment. The beavers are a keystone species in the river basin because their presence affects many other species in the food web.
Human activities also change the Athabasca River basin. They affect it in many ways. OIl sands operations, uranium mines, pulp and paper mills, discharges from towns and cities, and runoff from grain and livestock farms all cause wide-ranging changes. The river basin ecosystem cannot always handle these man-made changes.
The Athabasca River is one of Alberta’s major rivers. It is a vital resource for plants, animals, and people in northern Alberta. The river basin contains lake, river, stream, and wetland aquatic habitats.
This ecosystem evolved in an ever-changing environment. Beavers influence the river basin by building lodges and dams. The dams produce wetlands by flooding rivers and streams. The water flow slows and the river deposits its nutrient-rich sediment. The beavers are a keystone species in the river basin because their presence affects many other species in the food web.
Human activities also change the Athabasca River basin. They affect it in many ways. OIl sands operations, uranium mines, pulp and paper mills, discharges from towns and cities, and runoff from grain and livestock farms all cause wide-ranging changes. The river basin ecosystem cannot always handle these man-made changes.
Figure A.4.11.3 – A beaver dam can slow down the flow of water in a river.
Chemicals Damage Ecosystems
Many industrial activities leak harmful chemicals that wash into the aquatic ecosystem. Some of the chemicals are consumed by microorganisms. The chemicals become more concentrated as they move up the food chain. Poisonous heavy metals such as mercury accumulate in fish. They are concentrated further in the birds that eat them. Some studies of the Athabasca River show that the fish are unsafe for humans to eat.
Other substances disrupt the development and growth of aquatic organisms. Pesticide runoff and chemicals in town and city discharges can harm developing fish and impair the ability of fish to reproduce.
Oil sands operations and pulp mills emit gases and fine particles into the air. These settle in the water nearby. Some of the gases make the water more acidic. Increasing acidity can affect many plant and animal species.
Many industrial activities leak harmful chemicals that wash into the aquatic ecosystem. Some of the chemicals are consumed by microorganisms. The chemicals become more concentrated as they move up the food chain. Poisonous heavy metals such as mercury accumulate in fish. They are concentrated further in the birds that eat them. Some studies of the Athabasca River show that the fish are unsafe for humans to eat.
Other substances disrupt the development and growth of aquatic organisms. Pesticide runoff and chemicals in town and city discharges can harm developing fish and impair the ability of fish to reproduce.
Oil sands operations and pulp mills emit gases and fine particles into the air. These settle in the water nearby. Some of the gases make the water more acidic. Increasing acidity can affect many plant and animal species.
Figure A.4.11.4 – Many species, such as moose, live in the Athabasca River basin.
Figure A.4.11.5 – This oil refinery has drastically changed the look of Athabasca River.
Climate Change and an Alberta Ecosystem
Human-caused climate change also affects the Athabasca River. The Athabasca Glacier in the Columbia Icefield feeds the Athabasca River. It is receding at a rate of 5 metres per year. The river’s water source is disappearing. Earlier spring melting and increased evaporation also decrease the water level in the river basin. Oil sands operations also use a great amount of water from the river. As areas dry out, organisms might not adapt in time to survive. Warmer summer water temperatures can kill trout and other fish.
Some human effects on the Athabasca River basin are well known. Others require further monitoring. This river basin is an essential source of fresh water and food for many people in Alberta, and clearly this resource is under threat.
Human-caused climate change also affects the Athabasca River. The Athabasca Glacier in the Columbia Icefield feeds the Athabasca River. It is receding at a rate of 5 metres per year. The river’s water source is disappearing. Earlier spring melting and increased evaporation also decrease the water level in the river basin. Oil sands operations also use a great amount of water from the river. As areas dry out, organisms might not adapt in time to survive. Warmer summer water temperatures can kill trout and other fish.
Some human effects on the Athabasca River basin are well known. Others require further monitoring. This river basin is an essential source of fresh water and food for many people in Alberta, and clearly this resource is under threat.
Figure A.4.11.6 – A scientist tests the water quality of a river.
Figure A.4.11.7 – First Nations people have a long, proud history in the Athabasca River basin.
Saving the Athabasca River Basin with the Help of First Nations Knowledge
The full effect of human activity on the Athabasca River basin is not yet known. Many influences occur at the same time. Protecting the river basin is a complex and difficult problem.
To understand the situation well, the river basin must be studied, or assessed. This requires the knowledge of people who have a long history with the ecosystem. First Nations people live in the basin. They fish from the waters and hunt on the lands nearby. They interact closely with the ecosystem. First Nations people often are the first to notice effects. People conducting assessment are encouraged to include the traditional knowledge of First Nations people.
Traditional knowledge and scientific study together provide the most complete understanding of this ecosystem. Here are some ways that traditional knowledge helps:
The full effect of human activity on the Athabasca River basin is not yet known. Many influences occur at the same time. Protecting the river basin is a complex and difficult problem.
To understand the situation well, the river basin must be studied, or assessed. This requires the knowledge of people who have a long history with the ecosystem. First Nations people live in the basin. They fish from the waters and hunt on the lands nearby. They interact closely with the ecosystem. First Nations people often are the first to notice effects. People conducting assessment are encouraged to include the traditional knowledge of First Nations people.
Traditional knowledge and scientific study together provide the most complete understanding of this ecosystem. Here are some ways that traditional knowledge helps:
Figure A.4.11.8 – The Athabasca River basin has long been home to First Nations people.
- It provides historical information about the area.
- It often is the first to recognize possible environmental effects of human activities.
- It helps improve the design of restoration projects.
- It leads to a fuller understanding of the ecosystem and, therefore, better decisions on its behalf.
- It helps non-native scientists understand and consider traditional approaches to ecosystems that they might not have otherwise considered.
In many ways, First Nation people are the experts on the Athabasca River basin. They have lived in the basin for thousands of years. They were there long before fur traders arrived in the late 1700s. They know what the basin ecosystem was like before industrial development began.
Assessment is only the first step. After this comes action. When information is gathered, people must decide on safe limits for various activities. Those restrictions on development and usage must be enforced. Not everyone will be happy with those restrictions. To protect the Athabasca River basin ecosystem, everyone must be involved.
Figure A.4.11.9 – First Nations play a large role in Athabasca River environmental issues. Photo by
Tavis Ford.
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guide your learning.
Unit A Lesson 11 Self-Check
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This ecosystem evolved with natural changes such as beaver dams and seasonal flooding. Its organisms are adapted to cope with those changes. Those organisms are not adapted to cope with man-made changes such as the presence of heavy metals,
rapid climate change, fertilizer runoff, and water acidification. When organisms cannot adapt to change, they die, and the ecosystem loses its biodiversity. The ecosystem weakens and is even more vulnerable to continuing man-made changes.
The Athabasca River basin contains river, stream, lake, and wetland aquatic habitats. Those habitats support a tremendous variety of native organisms. Many of those organisms, such as the whooping crane, are endangered. The river basin also
supports almost all the people who live in northern Alberta. It is their fresh water source and it is a food source, either through fishing, hunting, or agriculture. Therefore, keeping this ecosystem healthy is essential.
Individual effects, especially from chemicals, can be difficult to see. Because these often start small and build over time, careful monitoring is required. Some changes are difficult to measure. Tiny concentrations of certain chemicals can
cause great damage. Many effects are occurring at the same time. This makes them especially difficult to monitor.
Consulting First Natives is significant for two main reasons.
- First Nations people have lived closely connected to the ecosystem there for a very long time. They know what the ecosystem was like before it was developed industrially. They have seen the changes. Because they live close to nature, they can identify effects before others know about them.
- The second reason was not covered in this lesson, but it is equally important. First Nations have a critical stake in the region. Many of these people rely directly on plants, fish, and animals for their livelihoods. Therefore, to respect their relationship with the ecosystem is important.
The Alberta government has the very difficult question of satisfying the various interests within the Athabasca River basin. It must consult with all the interests, from industry to First Nations to residents, about what they want. It must consult
with the scientists and First Nations people who assess the region. Those people must help decide what actions must be taken to protect the ecosystem. The government must construct a plan that protects the ecosystem and meets as many needs
as possible.