Eutrophication is a threat to biodiversity, is associated withOptions :HUNTINGWATER POLLUTION BY PESTICIDESWATER POLLUTION BY FERTILIZERPOACHING

Understanding Eutrophication

Eutrophication is a process that occurs when bodies of water become overly enriched with nutrients, leading to an increase in plant life, particularly algae. This excessive growth can deplete oxygen in the water, harming aquatic life and disrupting ecosystems, thus posing a threat to biodiversity.

Factors Contributing to Eutrophication

Among the options provided:

1. Hunting: While hunting can affect certain species, it is not directly related to the nutrient load in water bodies.

2. Water Pollution by Pesticides: Pesticides can harm individual species, but they don't contribute significantly to eutrophication.

3. Water Pollution by Fertilizer: This is the direct cause of eutrophication. Fertilizers contain high levels of nitrogen and phosphorus, which when washed into water bodies can lead to excessive algal blooms.

4. Poaching: Similar to hunting, poaching affects species population but does not relate to nutrient loading and eutrophication.

Conclusion

Based on the analysis, the option that is most directly associated with eutrophication is Water Pollution by Fertilizer. This option highlights the nutrient enrichment that leads to the eutrophication process, ultimately threatening biodiversity in aquatic environments.