A variety of seashore organisms, including mollusks, sponges, and sea urchins, can destroy rocks by physically boring into them. Their effectiveness is influenced by rock type: most sedimentary rocks being much more susceptible than igneous rocks, for example. The relative importance of biological erosion is much greater along coasts characterized by low wave energies because here abrasion and quarrying operate at only moderate or low intensities.

Many organisms are either directly or indirectly responsible for the construction of some coastal landforms. The most spectacular example of direct construction is by corals and other carbonate-secreting organisms that form coral reefs. These structures can attain immense sizes, as in the case of the Great Barrier Reef, which