Zebra Mussels Invasive Species

Invasive species are organisms not native to an environment that cause harm. Invasive species typically disrupt the balance of the ecosystem. This species grows, reproduces, or spreads quickly. If an invasive species is introduced to an environment, then it would result in a trophic cascade because it would disrupt various levels of the food chain.
Zebra mussels are an example of an invasive species. Zebra mussels were first from Eastern Europe and West Russia, but they arose in the Great Lakes in the 1980s. It is believed that they got here in the ballast water of ships. These mussels reproduce in an expedite rate. “In her five-year lifetime, a single zebra mussel will produce about five million eggs, 100,000 of which reach adulthood.” (The National Wildlife Federation) With such a high reproduction rate it’s obvious that “zebra mussels have spread throughout the Great Lakes, parts of the Mississippi River, and other rivers and inland lakes.” (Minnesota Department of Natural Resources)

Zebra mussels filter water by eating plankton.

This may sound beneficial, but not if there is an animal that already does that. Quagga mussels are also an invasive species from Eastern Europe. Since both quagga and zebra mussels both consume plankton this leaves less plankton for other animals to consume. “ In the Great Lakes this had lead to the collapse of amphipod populations that fish rely on for food and the health of fish populations has been severely affected.” (Center for Invasive Species Research) Because of the decrease in plankton, the amphipods population is decreasing. Fish that eat amphipods are also in trouble because now their food source has decreased as

well.
“Quagga mussels are contributing to the dramatic decline of the shrimplike amphipod known as Diporeia, a key food source for a number of native Great Lakes fish at various points in the food web; and they are contributing to the re-emergence of blooms — the toxic algae known as Microcystis — around the lakes.” (Bloch) This toxic algae not only endangers other organisms of the ecosystem but humans, too.
It’s evident that the introduction of these two invasive species, “organism(s) whose introduction causes or is likely to cause harm, ” has caused a trophic cascade. (United States Department of Agriculture) They both deprive the water of plankton, which leads to a lower fish population, and increased amount of toxic algae. Together they harm the ecosystem as a whole. Other organisms, like cane toads, asian carps, and kudzu, yield the same impact on their ecosystem. “Invasive species have contributed directly to the decline of 42% of the threatened and endangered species in the United States.” (The Nature Conservancy) These organisms endanger native organisms and ultimately result in major disruption to the food chain, affecting multiple trophic levels.