Salinity tolerance refers to the ability of organisms, such as plants and animals, to survive and thrive in environments with varying salt concentrations. This trait is crucial for species living in coastal areas, estuaries, and salt marshes, where salinity levels can fluctuate due to factors like tides and rainfall. Organisms with high salinity tolerance can maintain their internal balance of salts and water, allowing them to function effectively in these challenging conditions. Different species exhibit varying degrees of salinity tolerance, which can influence their distribution and ecological roles. For example, halophytes are plants specifically adapted to grow in salty environments, while some fish species can tolerate brackish water. Understanding salinity tolerance is essential for conservation efforts and managing ecosystems affected by climate change and human activities.