Invasive Species - Sharon Fletcher | Biblioteka

Instrukcije

Use the diagram and the passage to help you answer the questions.

Invasive Species Part 1

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This aquatic food pyramid illustrates energy transfer and relative biomass (defined below) in an aquatic ecosystem. Producers make up the greatest biomass in the system, and support all other life forms. Producers convert light energy from the sun into food energy. This food energy is transferred through the levels of the food pyramid, or trophic levels, as one organism consumes another. At each level in the food pyramid, energy is transferred to the surrounding environment as heat as the organisms use food energy to feed, respire, grow, and reproduce. For this reason, each trophic level can only support or provide energy for a smaller biomass of organisms. Energy is also lost as heat on each level as organisms eat, move, grow, and reproduce. The sun continually replaces the energy in the system. Because energy is lost at each level, most food pyramids contain, at most, four trophic levels.

2

Using the aquatic food pyramid above, where does the energy for the producers come from?

The water

The sun

The producers

The decomposers

2

If a primary consumer was introduced into the food chain, with no natural predator to control its population, what level of the pyramid would be directly affected?

Tertiary Level

Secondary Level

Primary Level

Producer Level

Invasive Species Part 2

There are four species of Asian carp in the United States and in Tennessee. All are from the Yangtze and Amur River systems in China. They were imported into the United States for various purposes back as early as 1970. They were unintentionally introduced into the waters of our country in the late 1980s and early 1990s when they escaped from ponds in the delta areas of the Mississippi River during extreme floods.

All four Asian carp species were first found in the Mississippi River, where they are still abundant, and they migrated into Tennessee waters via locks at Kentucky and Barkley dams. Carp are also known to have entered Reelfoot Lake during high flows through its spillway. All four Asian carp species can affect fish and aquatic life in numerous ways.

Asian Carp have the capacity to deplete and alter the current food web of the reservoirs that support natural resources, including highly-valued recreational and commercial fisheries. Silver and Bighead Carp are both filter feeders that feed on microscopic plankton. This plankton is a vital food for some species of fish, and young fish of all species. By out-competing native fish for a limited resource, the silver and bighead carp have the ability to reduce the growth rates of native fish or displace them almost completely. The black Carp pose a risk to Tennessee’s diverse and already threatened mussel population.

2

After reading the passage above, choose TWO answers that explain how the Asian carp have affected Tennessee waterways.

Served as a food source for other biotic organisms.

As filter feeders they have depleted the current food web by eating microscopic plankton.

Outcompeted native fish for limited resources.

Asian Carp are bigger than other biotic organisms in the lake

They have improved the biodiversity of the Tennessee waterways.

2

Common and Grass carps are able to do a lot of damage to wetlands and other water habitats by destroying a lot of plant life that is necessary for other native species that depend on it for food, shelter, and reproducing. They only digest half of the plant material they eat and let the rest expel into the water. This causes more algae in the water, makes the water murky, and lowers the oxygen levels. In addition, grass carps sometimes carry parasites and diseases.
The picture below shows how waterways have changed over the course of three years in the part of a lake that has a vast amount of Asian Carp. What might be a cause for the change in the water clarity?

The sun has increased the water temperatures and it’s too warm for plants to grow.

Various species of carp consume vegetation at a rate faster than it can reproduce and grow.

The mussels found in the water way eat the vegetation.

The water does not carry enough nutrition to support the growth of vegetation.

2

Analyze the bar graph above. What will likely happen to the populations of native fish if the population of the carp are not controlled?

The Smallmouth Bass will increase in population.

The Walleye population will outnumber the Gizzard Shad.

The Silver carp will cause all other species of fish to become extinct.

The Bighead carp will become a predator to the Silver Carp.