Final answer:
The three types of aquatic biomes are freshwater, marine, and estuaries. Freshwater biomes have less than 1% salt content, while marine biomes have a higher salt content. Estuaries are transitional habitats between freshwater and marine environments.
Step-by-step explanation:
The three types of aquatic biomes are freshwater, marine, and estuaries. Freshwater biomes, such as ponds, lakes, streams, and wetlands, have less than 1% salt content. Marine biomes, including oceans and coral reefs, have a higher salt content. Estuaries, where freshwater and saltwater mix, are found along coastlines.
Approximately 2.5% of the Earth's surface is covered by freshwater biomes, while marine biomes cover about 71% of the Earth's surface. Estuaries cover a smaller percentage, but play a vital role as transitional habitat between freshwater and marine environments.