substrate substratethe surface or medium on which an organism lives or grows, or the material on the bottom of the ocean. Related Articles: Glossary: essential fish habitat (EFH)How do marine invertebrates produce sounds?Pile drivingSea Urchin (Kina)Marine invertebrate communicationMedia BackgrounderHow do marine invertebrates detect sounds?Tutorial: Can Animals Sense These Sounds Part IIWind TurbineTutorial: Wind Turbine Chris Knowlton2019-09-10T09:41:25-05:00