Question on: JAMB Biology - 1990

The salinity of a brackish environment is the salt content of the water. * **Brackish water** is a mixture of saltwater and freshwater. * **Rain** dilutes the water, thus reducing the salinity. Therefore, option A is incorrect. * **Micro-organisms** can affect water chemistry, but their direct impact on salinity is less significant than rainfall or evaporation. Therefore, option C is incorrect. * The **dry season** leads to evaporation, which would increase the salinity as the water becomes more concentrated with salt. However, the question is looking for the most immediate effect. Therefore, option D is not the best choice. * After the rainy season, the influx of freshwater slows down and the water becomes more saline compared to during the rainy season. Therefore, option B