The marine biome primarily consists of saltwater environments, including oceans, coral reefs, and estuaries. It does not include freshwater biomes such as rivers, lakes, and ponds. While both types of biomes are essential components of Earth’s ecosystems, they are classified distinctly due to their different salinity levels and the specific organisms that inhabit them.
Saltwater environments, which make up about 71% of the Earth’s surface, support a diverse range of life forms adapted to high salinity levels, including marine fish, mammals, and a variety of invertebrates. On the other hand, freshwater biomes have a much lower concentration of salt and host organisms that are adapted to live in those conditions. Consequently, while the marine and freshwater biomes coexist on our planet, they represent separate ecological communities with unique characteristics and species.