Bioerosion

Bioerosion describes the breakdown of hard ocean substrates – and less often terrestrial substrates – by living organisms. Marine bioerosion can be caused by mollusks, polychaete worms, phoronids, sponges, crustaceans, echinoids, gastropods and fish; it can occur on coastlines, on coral reefs, and on ships; its mechanisms include biotic boring, drilling, rasping, and scraping. Overall, the species that cause this phenomena are highly diverse coming from several kingdoms of life. On dry land, bioerosion is typically performed by trees, pioneer plants, or plant-like organisms such as lichen. Terrestrial bioerosion is performed by either chemical (e.g. by acidic secretions on limestone) or mechanical processes (e.g. by roots growing into cracks). In marine systems bioerosion occurs on nearly all coastlines, and all reef systems.

Bioerosion by endolithic organisms is also well known in the fossil record on shells and hardgrounds, with traces of this activity stretching back well into the Precambrian (see gallery). Macrobioerosion, which produces borings visible to the naked eye, shows two distinct evolutionary radiations. One was in the Middle Ordovician (the Ordovician Bioerosion Revolution) and the other in the Jurassic. Microbioerosion also has a long fossil record and its own radiations.