Biomagnification of DDT in an aquatic food chain starting from water having a concentration of 0.003 ppb may go, in fish eating birds, upto:

Options

A. 2 ppm
B. 25 ppm
C. 50 ppm
D. 100 ppm

Answer

To solve the question regarding the biomagnification of DDT in an aquatic food chain, we can follow these steps:

### Step 1: Understand Biomagnification
Biomagnification refers to the process where the concentration of a substance, such as a pesticide, increases in organisms at each successive trophic level of a food chain. In this case, we are looking at DDT (dichlorodiphenyltrichloroethane) in an aquatic ecosystem.

**Hint:** Remember that biomagnification occurs as you move up the food chain, with each level accumulating more of the substance.

### Step 2: Identify the Starting Concentration
The starting concentration of DDT in water is given as 0.003 ppb (parts per billion).

**Hint:** Always note the initial concentration as it is crucial for calculating the subsequent levels.

### Step 3: Determine the Concentration at Each Trophic Level
We will follow the food chain from the water to the fish-eating birds, noting the concentration of DDT at each level:

1. **Water:** 0.003 ppb
2. **Zooplankton:** The concentration increases to 0.04 ppb.
3. **Small Fish:** The concentration increases to 0.5 ppb.
4. **Large Fish:** The concentration increases to 2 ppb.
5. **Fish-eating Birds:** The concentration reaches 0.25 ppm (which is equivalent to 250 ppb).

**Hint:** Keep track of how the concentration changes at each level; it typically increases significantly.

### Step 4: Final Concentration in Fish-Eating Birds
After calculating the concentrations through the food chain, we find that the concentration of DDT in fish-eating birds is 0.25 ppm, which is equal to 250 ppb.

**Hint:** Converting units can be helpful; remember that 1 ppm = 1000 ppb.

### Conclusion
The concentration of DDT in fish-eating birds, starting from an initial concentration of 0.003 ppb in water, can go up to 250 ppb.

**Final Answer:** 250 ppb in fish-eating birds.