Student Instructions In this lab, you will determine how an invasive species—the zebra and quagga mussel—affects other species in the freshwater lake. Use the animation to help you come up with an answer to the following: Why do you see increases and decreases in the invasive species population? What are the implications associated with these alterations to the ecosystem as a whole? The Effects of Zebra and Quagga Mussels Introduced into a Freshwater Lake As you have learned, population dynamics are caused by the biotic potential of the population and the effects of environmental resistance. When there is minimal environmental resistance impacting a population, it will exhibit a population explosion. One reason for minimal resistance could be factors that no longer regulate a population (e.g., predator decline or resource increases). Another reason for a population explosion is the introduction of an invasive species. Invasive species are species foreign to an ecosystem and are not immediately regulated by the environmental restraints of the particular ecosystem that they invade. This in turn allows their populations to grow seemingly uncontrolled and to displace other indigenous populations. Examples of such an invasive species into North America are dreissenid mussels, commonly known as zebra and quagga mussels. Their introduction into the Great Lakes has caused economic hardship and a reorganization of the ecosystem. This has led, in part, to pollution-causing effects that can be linked to an alga known as Cladophora . Ecosystems are webs of intricately balanced interactions, what happens when a new species is introduced that uses a disproportionate share of the ecosystem’s resources? Using the M.U.S.E. link, review the background information and animation to complete your report. Use the Lab 5 worksheet for assignment instructions and data collection. Hi Everyone, For your lab report this week, you will investigate the impact and spread of invasive species. One of these described in your MUSE lab activity is the Zebra Mussel.  Just as you have done for the previous assignments, you will first review the background information, then collect the data. Your study will involve measurements showing how the mussels have spread and how they have impacted native species in an aquatic environment. You will find that the number of mussels increases for 13 years and then begins to decrease. You are asked to explain this in your report. Why do you see increases and decreases in the invasive species population? What are the implications associated with these alterations to the ecosystem as a whole? Use the notes in the animation to review the food chain in this ecosystem.  It will be very important to be able to describe which species are native and which are invasive. And to describe how even a native species, such as cladophora (algae) can result in ecological damage.  Next, review Chapter 4 of your eBook and refresh your memory on h.

1. Student Instructions
In this lab, you will determine how an invasive species—the
zebra and quagga mussel—affects other species in the
freshwater lake. Use the animation to help you come up with an
answer to the following:
Why do you see increases and decreases in the invasive species
population?
What are the implications associated with these alterations to
the ecosystem as a whole?
The Effects of Zebra and Quagga Mussels Introduced into a
Freshwater Lake
As you have learned, population dynamics are caused by the
biotic potential of the population and the effects of
environmental resistance. When there is minimal environmental
resistance impacting a population, it will exhibit a population
explosion. One reason for minimal resistance could be factors
that no longer regulate a population (e.g., predator decline or
resource increases). Another reason for a population explosion
is the introduction of an invasive species.
Invasive species
are species foreign to an ecosystem and are not immediately
regulated by the environmental restraints of the particular
ecosystem that they invade. This in turn allows their
populations to grow seemingly uncontrolled and to displace
other indigenous populations. Examples of such an invasive
species into North America are dreissenid mussels, commonly
known as zebra and quagga mussels. Their introduction into the
Great Lakes has caused economic hardship and a reorganization
of the ecosystem. This has led, in part, to pollution-causing
effects that can be linked to an alga known as
Cladophora
.
Ecosystems are webs of intricately balanced interactions, what

2. happens when a new species is introduced that uses a
disproportionate share of the ecosystem’s resources?
Using the M.U.S.E. link, review the background information
and animation to complete your report.
Use the
Lab 5 worksheet
for assignment instructions and data collection.
Hi Everyone,
For your lab report this week, you will investigate the impact
and spread of invasive species.
One of these described in your MUSE lab activity is the Zebra
Mussel.
Just as you have done for the previous assignments, you will
first review the background information, then collect the data.
Your study will involve measurements showing how the mussels
have spread and how they have impacted native species in an
aquatic environment.
You will find that the number of mussels increases for 13 years
and then begins to decrease. You are asked to explain this in
your report.
Why do you see increases and decreases in the invasive species
population?
What are the implications associated with these alterations to
the ecosystem as a whole?
Use the notes in the animation to review the food chain in this
ecosystem.
It will be very important to be able to describe which species
are native and which are invasive. And to describe how even a
native species, such as cladophora (algae) can result in
ecological damage.
Next, review Chapter 4 of your eBook and refresh your memory
on how the members of an ecosystem interact and the upper

3. limit of organisms that an ecosystem can support, known as the
carrying capacity.
As you collect your data consider how the cladophora
increases along with the mussels. This happens because the
mussels filter the water making it clearer. More sunlight reaches
into the water's depths allowing for better growth of these
autotrophs. At year 13 we see a peak in both populations. I
expect you will find that the huge number of mussels and the
high level of cladophora deplete the Great Lakes ecosystem of
nutrients.
Note that after 13 years the numbers of these detrimental
organisms decreases, allowing the native populations to
rebound.
If you would like a little more background information on the
Zebra Mussel, this site has a good description with clear
pictures:
http://www.protectyourwaters.net/hitchhikers/mollusks_zebra_
mussel.php
Please use this outline to help you craft your report:
Purpose
State the purpose of the lab. This will be a sentence or two
about assessing the impact of zebra mussels on the native
populations of species in the Great Lakes.
Introduction
Include information on zebra mussels; where they come from;

4. how they got to the US; what effect they have on native species.
Hypothesis/Predicted Outcome
A hypothesis is an educated guess. It needs to be a
single statement that can be shown to be true or false through
the results gleaned from this investigation.
It could be that zebra mussels will grow out of control.
It could be that zebra mussels will grow until they reach the
carrying capacity of the ecosystem and then their population
will crash.
Methods
Imagine you are the investigator. You will have to go to the
Great Lakes and take samples to determine the population of all
the species for which data has been collected.
For zebra mussels, they actually go diving to count and collect
mussels. For fish species, they would perform a catch and
release survey. Microscopic organisms would be analyzed
through determining concentrations spectroscopically, etc.
Results/Outcome
Include the table. No further analysis is necessary.
Discussion/Analysis
In this section,
1)
Summarize your results
2)
Relate your results back to your hypothesis, either accepting or
rejecting your prediction with an explanation of why you did so.
3)
Explain the increase and decrease in population. Present an

5. explanation of why the zebra mussels and cladophora increased
and then suddenly decreased. Be sure to answer these questions:
Why do you see increases and decreases in the invasive species
population?
What are the implications associated with these alterations to
the ecosystem as a whole?
Deliverable Length:
1 page
Name:
Date:
Instructor’s Name:
Assignment: SCIE211 Phase 5 Lab Report
Title: Identifying Environmental Hazards
Instructions:
You will write a 1-page lab report using the scientific method to
answer the following questions:
·
Why do you see increases and decreases in the invasive species
population?
·

6. What are the implications associated with these alterations to
the ecosystem as a whole?
When your lab report is complete, post it in Submitted
Assignment files.
Part I:
Using the lab animation, fill in the data table below to help you
generate your hypothesis, outcomes, and analysis
.
Years
Zebra and Quagga Mussel (density/m2)
Phytoplankton (µg/ml)
Zooplankton (µg/ml)
Cladophora
Biomass (g/m2)
Foraging Fish (kilotons)
Lake Trout (kilotons)
0
100
3
2
10
150
15
4
1000
2.5
1
100
100
10
7
2500
2

7. 0.5
200
80
8
10
7500
1.5
0.25
600
50
5
13
15,000
1
0.1
700
25
2.5
15
7500
1.5
0.2
243
40
4
20
5000
1.75
0.4
136
60
6
Part II:
Write a 1-page lab report using the following scientific method
sections:

8. Purpose
State the purpose of the lab.
Introduction
This is an investigation of what is currently known about the
question being asked. Use background information from
credible references to write a short summary about concepts in
the lab. List and cite references in APA style.
Hypothesis/Predicted Outcome
A
hypothesis
is an educated guess. Based on what you have learned and
written about in the Introduction, state what you expect to be
the results of the lab procedures.
Methods
Summarize the procedures that you used in the lab. The
Methods section should also state clearly how data (numbers)
were collected during the lab; this will be reported in the
Results/Outcome section.
Results/Outcome
Provide here any results or data that were generated while doing
the lab procedure.
Discussion/Analysis
In this section, state clearly whether you obtained the expected
results, and if the outcome was as expected.
Note: You can use the lab data to help you discuss the results
and what you learned.
Provide references in APA format. This includes a reference list
and in-text citations for references used in the Introduction
section.
Give your paper a title and number, and identify each section as
specified above. Although the hypothesis will be a 1-sentence
answer, the other sections will need to be paragraphs to
adequately explain your experiment.
When your lab report is complete, post it in Submitted
Assignment files.