The inflow of nutrients from fertilizers into lakes resulting in the increase of phosphate in lake water and depletion of dissolved oxygen causing the fish to die is called _____

Answer

To solve the question about the inflow of nutrients from fertilizers into lakes, which leads to an increase in phosphate levels and a depletion of dissolved oxygen causing fish deaths, we can break it down into the following steps:

### Step-by-Step Solution:

1. **Understanding Nutrient Inflow**:
- Fertilizers, particularly those high in phosphates, are often washed into lakes from agricultural runoff. This inflow of nutrients significantly alters the water chemistry.

2. **Increase in Phosphate Levels**:
- The introduction of phosphates into the lake water leads to an increase in nutrient levels, which is a critical factor in the growth of aquatic plants, particularly algae.

3. **Algal Bloom Formation**:
- The high concentration of phosphates promotes rapid growth of algae, leading to a phenomenon known as an "algal bloom." This bloom can cover the surface of the water, blocking sunlight from penetrating.

4. **Depletion of Dissolved Oxygen**:
- As the algal bloom grows, it eventually dies off and decomposes. The decomposition process consumes a significant amount of dissolved oxygen in the water, leading to hypoxic (low oxygen) conditions.

5. **Impact on Aquatic Life**:
- The depletion of dissolved oxygen creates an environment where fish and other aquatic organisms cannot survive, leading to fish kills.

6. **Terminology**:
- The entire process described, from nutrient inflow to algal bloom and subsequent fish deaths, is known as **eutrophication**.

### Final Answer:
The process is called **eutrophication**.

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