Could Climate Change Impact the Mosquito-Human Disease Ecosystem?
Scientists are concerned that climate change could cause the spread of mosquito populations that carry diseases like malaria, West Nile virus, Zika virus, and dengue fever. In this lesson plan, your students will access real-world data on mosquitoes at different locations throughout the United States, and examine the effects of temperature on mosquito populations.
Remote learning adaptation: This lesson plan can be conducted remotely. Students can work independently on the Explore section of the lesson plan using the Student Worksheet as a guide. The Engage and Reflect sections can either be dropped entirely, done in writing remotely, or be conducted over a video chat.
- Develop a research-based hypothesis about the effect of climate on mosquito populations.
- Analyze data and determine whether it supports the hypothesis.
NGSS AlignmentThis lesson helps students prepare for these Next Generation Science Standards Performance Expectations:
- MS-LS2-4. Construct an argument supported by empirical evidence that changes to physical or biological components of an ecosystem affect populations.
- HS-LS2-1. Use mathematical and/or computational representations of phenomena or design solutions to support explanations of factors that affect carrying capacity of ecosystems at different scales.
|Science & Engineering Practices||Disciplinary Core Ideas||Crosscutting Concepts|
|Science & Engineering Practices||Analyzing and Interpreting Data.
Analyze and interpret data to provide evidence for phenomena.
Using Mathematics and Computational Thinking. Use mathematical and/or computational representations of phenomena or design solutions to support explanations.
|Disciplinary Core Ideas||LS2.C: Ecosystem Dynamics, Functioning, and Resilience.
Ecosystems are dynamic in nature; their characteristics can vary over time. Disruptions to any physical or biological component of an ecosystem can lead to shifts in all its populations.
LS2.A: Interdependent Relationships in Ecosystem. Ecosystems have carrying capacities, which are limits to the numbers of organisms and populations they can support. These limits result from such factors as the availability of living and nonliving resources and from such challenges such as predation, competition, and disease. Organisms would have the capacity to produce populations of great size were it not for the fact that environments and resources are finite. This fundamental tension affects the abundance (number of individuals) of species in any given ecosystem.
|Crosscutting Concepts||Cause and Effect.
Small changes in one part of a system might cause large changes in another part.
Scale, Proportion, and Quantity. The significance of a phenomenon is dependent on the scale, proportion, and quantity at which it occurs.
- Computer with internet access
- Spreadsheet program
Background Information for TeachersThis section contains a quick review for teachers of the science and concepts covered in this lesson.
Mosquitoes thrive in warm, wet habitats. Because of this, scientists are worried that as global temperatures rise due to climate change, mosquitoes will expand to new regions that were previously too cold. This poses a threat to human health since mosquitoes can carry diseases like malaria, West Nile virus, and Zika virus. The resources in the Additional Background section contain more information about mosquitoes, their habitat, and the potential effects of climate change.
In this lesson, your students will access data from the National Ecological Observatory Network (NEON). NEON consists of a network of sites around the U.S. where a wide variety of ecological data is recorded, including counts of different mosquito species found in traps set by scientists. This will allow your students to explore the effects of weather on mosquito populations. For example, Figure 1 plots total mosquito count and average monthly temperature on a dual-y-axis graph for a single location. From this graph, you can see that mosquito populations are highest in the warmer summer months. Figure 2 shows a scatter plot of the same data with mosquito count on the y-axis and average monthly temperature on the x-axis. Table 1 shows mosquito species (and the diseases they carry) that were found in a cold, northern location and a warm, southern location over a span of several years.
It is very important to remember when looking at all this data that correlation does not imply causation. In other words, just because two variables appear to be related, it does not mean that a change in one causes a change in the other. There can be many other variables not present in this data that could affect mosquito populations. For example, governments may enact mosquito control programs that include spraying pesticides or other mitigation efforts. A flood, hurricane, or other natural disaster could result in unusually high amounts of standing water—prime breeding ground for mosquito larvae. In this project, your students will not be doing a controlled experiment where they breed their own mosquitoes. However, they can certainly do background research on relevant topics, and present a scientific explanation for why they do or do not think there is a causal link between two variables.
A graph with total mosquito count on the left y-axis, average monthly temperature on the right y-axis, and month on the x axis. Total mosquito count goes to zero at the beginning and end of the year, and peaks at about 110,000 in August. Temperature peaks at nearly 80 degrees F in July and is a minimum of about 50 degrees F in December.
Figure 1. Total mosquito count and average monthly temperature for Lenoir Landing, Alabama in 2017. Note how there are more mosquitoes during the warmer months.
Figure 2. Scatter plot of total monthly mosquito count and average monthly temperature for Lenoir Landing, AL over a 3-year period. Note the positive correlation between mosquito count and temperature.
|Mosquito Species||Human Disease(s) Carried||Treehaven, WI||Lenoir Landing, AL|
|Aedes albopictus||Zika, chikungunya, dengue||X|
|Culex quinquefasciatus||West Nile virus||X|