Lakes and ponds that are rich in nutrients and high in productivity are called

Options

A. Eutrophic
B. Oligotrophic
C. Secondary producers
D. both 1 and 2

Answer

To answer the question, "Lakes and ponds that are rich in nutrients and high in productivity are called," we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Question**: We need to identify the term used for lakes and ponds that are nutrient-rich and have high productivity.

2. **Analyzing the Options**: The options given are:
- Eutropic
- Oligotropic
- Secondary producers
- Both first and second

3. **Defining Eutropic Lakes**:
- Eutropic lakes are characterized by high nutrient levels, particularly nitrogen and phosphorus.
- These nutrients lead to increased fertility, which stimulates the growth of aquatic plants and algae.

4. **Effects of High Nutrients**:
- With increased plant growth, there is a rise in organic matter in the water.
- However, as organic matter decomposes, it consumes dissolved oxygen, which can lead to lower oxygen levels in the water.

5. **Defining Oligotropic Lakes**:
- Oligotropic lakes, in contrast, have low nutrient levels and low primary productivity.
- They are less fertile and support fewer aquatic plants.

6. **Understanding Secondary Producers**:
- Secondary producers refer to organisms that consume primary producers (like plants) for energy. This term does not apply to the classification of lakes.

7. **Conclusion**: Based on the definitions and characteristics discussed, the correct term for lakes and ponds that are rich in nutrients and high in productivity is **Eutropic**.

### Final Answer:
Lakes and ponds that are rich in nutrients and high in productivity are called **Eutropic**.

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