What Happens When Invasive Species Are Introduced
Helping students understand the dangers of nonnative species is an important part of ecology and environmental science lessons.
By Lynsey Peterson
It seemed harmless enough when sailors dropped off a few goats on the Galapagos Islands to use as food at a later date. But as the goat populations grew and ate the native vegetation, they destroyed the habitat and competed against native species, such as the giant tortoise. Most species introductions seem harmless. However, many well-adapted plants, animals, and even pathogens can wreak havoc on indigenous species. In fact, invasive species account for a large part of native species extinctions. Because of this, species introduction and its effects are an essential part of a study of ecology and environmental science.
My ecology students learn about the problems of introduced species with the documentary, “Cane Toads.” The film shows how this large Hawaiian toad was introduced to the sugar cane fields of Australia to eat the cane grub pest. The toads did not eat the grubs, but they reproduced expansively and ate everything else in their path, including pet food and small native animals. Their poisonous skin also leaves them with no predator of their own and native species that try to eat them are killed by the poison. While my students laugh at some of the more humorous parts of the film, they also begin to understand the ecological and societal consequences of a nonnative species introduction.
Next, my students research an invasive species of their choice. I have compiled a list of introduced species in our area including fire ants, kudzu, wild pigs, lionfish, and Dutch elm disease. Once students have selected their species, they work to create a “Wanted: Dead, Not Alive” poster to share with the class. They create a criminal name for their species and research its scientific name, area last seen (native range), suspected hideouts (current U.S. distribution), crimes committed on other species and human property. They also determine an ecological reward for elimination of the species. My students do not always realize that some of the species we have become accustomed to are not native and cause harm. This project opens their eyes to the real local effects of introduced species.
In this increasingly globalized society, it is essential for our students to understand that there are real dangers to moving species out of their native range. The following lesson plans will also give you excellent ideas for teaching the far-reaching consequences of species introduction.
Invasive Species Lesson Plans and Activities:
Students discuss the Galapagos Islands, the different animal and plant life native to the Islands, and their significance. Through discussion they examine the possible results of introduced species on endemic species such as endangerment. They research plants and animals that are endemic to their area then plan and create an endemic garden on the school grounds.
Here Today, Gone Tomorrow....?
This lesson helps students understand the effects of an introduced species on the population of native species.
Introduction to Species Interactions w/ Ecosystem
Students learn about how the introduction of alien species into foreign ecosystems affect the ecosystem. They research, in groups, a case scenario in which an introduced species, animal or plant, has caused drastic ecological changes.
Impact of Exotic Species on Lake Ecology
Students examine the effect of foreign species on various habitats. In groups, they identify the population dynamics of the zebra mussel. They calculate averages and graph data from Seneca Lake in New York. They develop hypothesis about how these species affect the food web to end the lesson.
Students assume the role of a laboratory technician working for the Ministry of the Environment or Ministry of Health in Canada. Students analyze an invading species of their choice and report on a course of action to handle the invasion.
