![Rhodoliths at Emerald Bay, Catalina](https://mlml.sjsu.edu/student-life/wp-content/uploads/sites/75/2011/01/pict0003.jpg)
Imagine tubleweeds spread across the ocean floor. If you make them purple/pink and living, then you have a rhodolith bed. Rhodoliths are hard calcareous algae which have broken from the ground and formed a bed with other individuals. Many invertebrates and algae species associate with this habitat. Rhodoliths are a hot study subject in Europe, where they are used as a soil conditioner.
![White Urchin Baby](https://mlml.sjsu.edu/student-life/wp-content/uploads/sites/75/2011/01/pict0056.jpg)