Water hyacinth is an aquatic plant native to South America. This species has been introduced into aquatic ecosystems as an omamental plant in many areas of the United States due to the attractive purple flowers that the plants produce when they bloom. Water hyacinth can reproduce much more quickly than most other aquatic plants. Additionally, the lack of native animal species that feed on water hyacinth in the United States allows it to spread rapidly once introduced into an area. In fact, it can completely cover a small water body within just a few years. The image below shows a water body that has been covered by water hyacinth.

Question

Suppose water hyacinth is introduced into a lake ecosystem in the southeastem United States where it was not previously located Which of the following best predicts how this will impact the ecosystem over time?

A. The biodiversity of plant species in the lake will decrease.

B. There will be an increase in nutrients available in the lake.

C. There will be an increase in oxygen available in the lake.

D. The number of individual plants living in the lake will decrease.

Answer 1

The best prediction of how the introduction of water hyacinth into a lake ecosystem will impact the ecosystem over time is:

A. The biodiversity of plant species in the lake will decrease.

Water hyacinth is highly invasive and can rapidly dominate aquatic environments, outcompeting native plant species for resources such as light and nutrients. This competition can lead to a reduction in plant biodiversity in the lake. The other options are less likely; for example, the presence of water hyacinth can actually lead to lower oxygen levels in the water due to decomposition processes and reduced overall light penetration, negatively affecting the ecosystem.