SNC1P: Science, Grade 9, Applied
Unit 1: Biology- Sustainable Ecosystems and Human Activity
Activity 4: Human Impact on Ecosystems
Overview | Expectations | Content | Assignment
Overview
In this activity you will explore how humans impact ecosystems. First you will gain an
understanding of some of the factors related to human impact. Next you will learn about
biodiversity and how it is decreased in an ecosystem. Finally you will be planning and
conducting an investigation on the effect of pesticides on ecosystems.
Overview | Expectations | Content | Assignment
SNC1P: Science, Grade 9, Applied
Expectations
Overall Expectations:
SIV.01 demonstrate scientific investigation skills (related to both inquiry and research) in
the four areas of skills (initiating and planning, performing and recording, analysing and
interpreting, and communicating);
BIV.02 investigate some factors related to human activity that affect terrestrial and/or
aquatic ecosystems, and describe the consequences that these factors have for the
sustainability of these ecosystems;
BIV.03 demonstrate an understanding of characteristics of terrestrial and aquatic
ecosystems, the interdependence within and between ecosystems, and the impact
humans have on the sustainability of these ecosystems.
Specific Expectations:
SI1.01 formulate scientific questions about observed relationships, ideas, problems,
and/or issues, make predictions, and/or formulate hypothesis to focus inquiries or
research;
SI1.02 select appropriate instruments (e.g., soil sampling instruments, pneumatic trough
and test tubes, magnifying glasses, electroscope) and materials (ebonite rods, star
charts, oxygen testing splints, pH paper) for particular inquiries;
SI1.05 conduct inquiries, controlling some variables, adapting or extending procedures
as required, and using standard equipment and materials safely, accurately, and
effectively, to collect observations and data;
SI1.06 gather data from laboratory and other sources, and organize and record the data
using appropriate formats, including tables, flowcharts, graphs, and/or diagrams;
SI1.08 analyse and interpret qualitative and/or quantitative data to determine whether
the evidence supports or refutes the initial prediction or hypothesis, identifying possible
sources of error, bias, or uncertainty;
SI1.10 draw conclusions based on inquiry results and research findings, and justify their
conclusions;
SI1.11 communicates ideas, plans, procedures, results, and conclusions orally, in
writing, and/or in electronic presentations, using appropriate language and a variety of
formats (e.g., data tables, laboratory reports, presentations, debates, simulations,
models);
BI2.03 compile and graph data (both qualitative and quantitative) on biodiversity within
an undisturbed and disturbed ecosystems (terrestrial or aquatic);
BI2.04 plan and conduct an inquiry into how a factor related to human activity affects
terrestrial or aquatic ecosystems (e.g. how changes to soil composition from the use of
different compostable materials or organic or inorganic fertilizers affect the types of
plants that can be grown; how lower water levels resulting from water diversion affect
waterfowl nesting areas and fish reproduction), and describe the consequences that this
factor has for the sustainability of the ecosystem;
BI2.05 analyse the effect of factors related to human activity on terrestrial and/or
aquatic ecosystems by interpreting data and generating graphs (e.g., data on the
concentration in water of chemicals from fertilizer runoff and their effect on the growth of
algae);
BI3.05 identify some factors related to human activity that have an impact on
ecosystems (e.g., use of fertilizers and pesticides; organic and conventional farming;
urban sprawl), and explain how these factors affect the equilibrium and survival of
populations in terrestrial and aquatic ecosystems (e.g., fertilizers affect the fertility of
soil, affecting what types of plants can grow in it; pesticides leach into water systems,
affecting water quality and aquatic life; urban sprawl wipes out fields and woods,
destroying wildlife habitats).
Overview | Expectations| Content | Assignment
Content
There are many ways that humans affect the ecosystem in which they live. Some of
these effects are outlined below.
Pesticides
Pesticides are intended to kill pests, but they kill
organisms other than the targeted pests. For
example, pesticides can kill bees that are needed to
pollinate crops. Some pesticides have also been
shown to be harmful to humans.
Spraying pesticides over a field.
Fertilizers
Fertilizers entering aquatic ecosystems can have several
effects. Fertilizers contain nitrates and phosphates,
which increase algae growth in aquatic ecosystems. The
algae at the top of the water block the sunlight causing
plants deeper in the water to die. Decomposers
(bacteria) break down the dead plant matter and dying
algae, using up the oxygen in the water. As a result, fish
and other aquatic animals that require high oxygen levels
will die.
Algal bloom produced in a river.
In a terrestrial ecosystem, the extra fertilizer in the soil can damage tree roots, cause
needles on trees to yellow, and stunt tree growth.
Did you know?
That too much fertilizer entering an aquatic environment can
cause population explosion of algae? This is called an algal
bloom.
Pollution from the Burning of Fossil Fuels
The gases emitted from industrial smokestacks,
vehicle exhaust, and power plants can produce acid
precipitation (acid rain) when they combine with
water in the atmosphere. The acid precipitation
entering aquatic ecosystems has killed fish, birds,
amphibians, and other organisms. Scientists
believe sugar maple trees are also damaged by
acid precipitation.
Pollution produced from an industry
burning fossil fuels.
Did you know?
That the only solution to acid rain at the present time is to dump
large quantities of powdered limestone into the water to
neutralize the acid?
Next
Content
Effects on Species
The human impact on ecosystems is causing a decreased number of species on Earth.
The variety of species on Earth or in an ecosystem is called biodiversity.
Biodiversity is reduced by extreme
conditions such as areas that:

are very hot or very cold;

have a high acidity level;


are very wet or dry;
have high nutrient levels.
Biodiversity is seen in
the Polynesian rainforest.
For example, high acidity in lakes has decreased biodiversity. Although fish will vary in
their sensitivity to acid concentrations, Canadian lakes affected by acid precipitation
show less biodiversity than the past.
Check Your Understanding
Answer the following questions in your notebook. Complete the questions in sentence
form where appropriate. Check your answers for each question.
1. Define the term biodiversity.
Answer
2. Pesticides can prevent _______ from pollinating crops.
Answer
3. List two effects that fertilizers have on an aquatic ecosystem.
Answer
4. Use the resource sites below as a guide for this question. Why is over-fishing a
problem for aquatic ecosystems?
Answer
5. What are some of the causes of acid precipitation?
Answer
Resources
To learn more about this topic you may wish to visit the following sites:
Human Activities and their Impacts
http://canadianbiodiversity.mcgill.ca/english/conservation/activities.htm
This is a disclaimer. External Resources will open in a new window. Not responsible for external content.
Unless otherwise indicated, all images in this Activity are from the public domain or are © clipart.com or
Microsoft clipart and are used with permission.
Assignment: Choose one of the following areas where human activity impacts ecosystems:




Fishing, Forestry
Urbanization and Development
Agriculture
Industry
Write three paragraphs focusing on the following with regards to your human activity



Species
Protecting Ecosystems
Deciding what gets protected