Consider the following pairs regarding salinity trends in different seas: 1. Baltic Sea : Low salinity due to river influx 2. Mediterranean Sea :…

The correct Answer is

Only three pairs

Explanation

Ocean salinity is a measure of the salt content in water, primarily influenced by evaporation, precipitation, river runoff, and ocean currents. Variations in these factors lead to distinct salinity patterns in different seas and oceans.

Statement-wise Analysis

1. Baltic Sea: Low salinity due to river influx
   Correct. The Baltic Sea is characterized by low salinity. This is primarily due to a large influx of fresh water from numerous rivers draining into it and limited exchange with the highly saline North Sea.
2. Mediterranean Sea: High salinity due to high evaporation
   Correct. The Mediterranean Sea exhibits high salinity. This is attributed to high rates of evaporation in its warm climate and limited freshwater input from rivers, leading to a concentration of salts.
3. Black Sea: Very low salinity due to fresh water influx
   Correct. The Black Sea has significantly lower salinity compared to oceanic waters. This is due to a substantial inflow of fresh water from major rivers like the Danube, Dnieper, and Don, coupled with restricted exchange with the more saline Mediterranean Sea.
4. Bay of Bengal: High salinity due to low fresh water influx
   Incorrect. The Bay of Bengal generally exhibits lower salinity compared to the Arabian Sea. This is primarily due to a large influx of fresh water from major rivers such as the Ganga, Brahmaputra, Mahanadi, Godavari, Krishna, and Kaveri. The statement incorrectly attributes high salinity to low freshwater influx.

Key Takeaway

Salinity in enclosed or semi-enclosed seas is primarily determined by the balance between freshwater input (from rivers and precipitation) and water loss through evaporation.