When are invertebrates considered a pest?

Invertebrates are considered a pest when they create health and safety hazards. This can occur when certain species proliferate to the point where they pose risks to human health, such as contributing to waterborne diseases, causing allergic reactions, or creating unsafe recreational environments. For example, large populations of certain invertebrates, like mosquitoes or invasive species, can lead to increased nuisance conditions or health risks, prompting management actions to mitigate their impact.

In contrast, the other options describe positive interactions between invertebrates and aquatic ecosystems. Invertebrates can enhance aquatic ecosystems by serving as a food source for various organisms, which contributes to the food web. They also promote biodiversity, playing crucial roles in nutrient cycling and habitat structure. Additionally, by supporting recreational fishing through their role in the aquatic food chain, they enhance the enjoyment of these activities for anglers.