What does "biodegradable" mean in relation to aquatic pesticides?

The term "biodegradable" specifically refers to a substance that can be broken down by microorganisms such as bacteria and fungi into simpler, non-toxic substances. In the context of aquatic pesticides, this means that the pesticide can be decomposed naturally in the environment, reducing its potential impact over time. When a pesticide is biodegradable, it can break down into harmless components, thereby mitigating long-term environmental concerns and promoting healthier ecosystems.

In contrast, the other choices suggest incorrect interpretations of the term. Instantaneous degradation is not a requirement for a substance to be considered biodegradable, as degradation may take time depending on various environmental factors. Option that implies no change in the environment contradicts the principle of biodegradability, where a substance is expected to transform into different components. Lastly, the notion that a pesticide is harmful to aquatic life does not align with the definition of biodegradability, as many biodegradable substances are designed to minimize toxicity to aquatic organisms. Thus, the focus remains on the natural decomposition process that occurs when microorganisms actively break down the pesticide into less harmful or benign substances.