what kind of algae are seaweeds that most often occur in warm marine waters
1 Although red algae are found in all oceans, they are most common in warm-temperate and tropical climates, where they may occur at greater depths than any other photosynthetic organisms. 2  Most of the coralline algae, which secrete calcium carbonate and play a major role in building reefs, belong here. Most of the world's seaweeds belong to this group. 2  Although red algae are found in all oceans, they are most common in warm-temperate and tropical climates, where they may occur at greater depths than any other photosynthetic organisms.