Rocky shores, like beaches (or sandy shores) are characterized by the life that lives in the intertidal zone – the area between the high tide and low tide water levels. Life on rocky shores is tough. It is dominated by the need to deal with very high wave energy, regular exposure to the air/sun, and interactions between these two physical stressors and the strong biological pressure applied by voracious intertidal predators.
The rocky shore is one of the best-studied marine ecosystems, and many of the earliest discoveries about marine ecology were made by scientists who study the complex marine communities that live in this system. Early on, some of these researchers discovered vertical zonation in rocky shore communities. Species closer to the high tide mark are often the best at being exposed to air and sunlight without drying out but are some of the worst at avoiding predation by marine predators. Species closer to (and below) the low tide mark are some of the best at avoiding predation but the worst at surviving long periods out of the water. These physical and ecological pressures lead to distinct zones in the community of invertebrates that live on rocky shores. Common rocky shore groups include mussels, barnacles, limpets, sea anemones, and predatory sea stars, each with a different ability to avoid predation or live outside of the water. Though these invertebrates are the most common and abundant species on rocky shores, rocky-reef fishes patrol the shore in search of food, during high tides.
Unlike coral reefs, mangrove forests, and several other marine ecosystems, rocky shores are not directly created by living organisms. Therefore, providing protection for these areas is different than for those other systems. Instead of developing legal protections for species, rocky shores often require area-based protection. Generally speaking, it is necessary to protect entire areas in order to protect the rocky shore ecosystem. In areas where protections are not in place, it is important to ensure that human impacts are minimized, by refraining from littering, removing living organisms, or disturbing the ecosystem in any excessive way.