Sea

Sea describes a smaller section of the global ocean that is partly surrounded by land or separated by underwater ridges and currents. Examples include the Mediterranean Sea nestled between europe and africa, the Caribbean Sea bordered by island chains, and the South china Sea dotted with reefs and shoals. Even inland seas like the Caspian are salty lakes formed in low basins.

Seas often have their own circulation patterns, salinity levels, and climate influences. The Mediterranean stays saltier than the Atlantic because evaporation exceeds rainfall, while the Baltic Sea remains brackish due to large river inflows. These differences shape which plants, animals, and corals thrive.

Human history centers on seas. Ancient traders sailed the Aegean and Red Seas, Caribbean ports fueled the spice and sugar trades, and coastal communities still depend on fishing, tourism, and shipping lanes. Strategic straits like Gibraltar or Malacca connect seas to open oceans and are carefully monitored for navigation safety.

Seas also face environmental challenges. Overfishing, oil spills, invasive species, and warming waters threaten food webs. Algal blooms in semi-enclosed seas can deplete oxygen and create "dead zones" where few organisms survive. Regional organizations and neighboring countries often work together to manage resources and reduce pollution.

Exploring a sea teaches local geography and culture. Mapping coastlines, studying tides, testing water quality, and learning about maritime history help students appreciate how seas support life and commerce. Responsible recreation—respecting marine protected areas, reducing litter, and using reef-safe sunscreen—keeps seas vibrant for future generations.