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

Answer

To solve the problem of biomagnification of DDT in an aquatic food chain, we will follow these steps:

### Step 1: Understand the Concept of Biomagnification
Biomagnification refers to the process where the concentration of a substance, such as a pesticide like DDT, increases in the tissues of organisms at each successive level of the food chain. This occurs because organisms at higher trophic levels consume multiple organisms from lower levels, leading to an accumulation of the substance.

**Hint:** Remember that biomagnification leads to higher concentrations of pollutants at higher trophic levels.

### Step 2: Identify the Initial Concentration of DDT
The initial concentration of DDT in the water is given as 0.003 parts per billion (ppb). We need to convert this concentration into parts per million (ppm) for easier calculations.

**Hint:** Recall that 1 ppm is equivalent to 1000 ppb.

### Step 3: Convert ppb to ppm
To convert 0.003 ppb to ppm:
\[ 0.003 \, \text{ppb} = \frac{0.003}{1000} \, \text{ppm} = 0.000003 \, \text{ppm} \]

**Hint:** Use the conversion factor to switch between ppb and ppm.

### Step 4: Determine Concentrations at Each Trophic Level
Now we will outline the concentration of DDT at different trophic levels based on the information provided:
- **Producers (e.g., phytoplankton):** 0.003 ppb (or 0.000003 ppm)
- **Primary consumers (e.g., zooplankton):** 0.04 ppm
- **Secondary consumers (e.g., small fish):** 0.5 ppm
- **Tertiary consumers (e.g., large fish):** 2 ppm
- **Quaternary consumers (e.g., fish-eating birds):** 25 ppm

**Hint:** Keep track of how the concentration increases at each level.

### Step 5: Identify the Final Concentration in Fish-Eating Birds
From the data, we see that the concentration of DDT in fish-eating birds is 25 ppm. This is the final concentration we are looking for.

**Hint:** Look for the highest concentration in the food chain as it relates to the question.

### Step 6: Conclusion
The concentration of DDT in fish-eating birds, starting from an initial concentration of 0.003 ppb in water, can go up to **25 ppm**.

**Final Answer:** 25 ppm