A rocky shore is an intertidal area of seacoasts where solid rock predominates. Rocky shore

Shore

A shore or shoreline is the fringe of land at the edge of a large body of water, such as an ocean, sea, or lake. In Physical Oceanography a shore is the wider fringe that is geologically modified by the action of the body of water past and present, while the beach is at the edge of the shore,...

s are biologically rich environments, and make the ideal natural laboratory for studying intertidal ecology

Intertidal ecology

Intertidal ecology is the study of intertidal ecosystems, where organisms live between the low and high tide lines. At low tide, the intertidal is exposed whereas at high tide, the intertidal is underwater...

 and other biological processes. Because they are so accessible, they have been studied for a long time and their species are well known.

Marine life

There are a large number of factors that favor the survival of life on rocky shores. Temperate coastal waters are mixed by waves and convection maintaining adequate availability of nutrients. Also, with the effect of the tides, the sea brings plankton and broken organic matter in with each tide. The high availability of light and nutrient levels means that primary productivity of seaweeds and algae

Algae

Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...

 can be very high. Human actions can benefit rocky shores with nutrient runoff

Surface runoff

Surface runoff is the water flow that occurs when soil is infiltrated to full capacity and excess water from rain, meltwater, or other sources flows over the land. This is a major component of the water cycle. Runoff that occurs on surfaces before reaching a channel is also called a nonpoint source...

.

Regardless of the factors that favour life on rocky shores, there are a number of challenges that marine organisms which use them as their habitat must face. Generally, the distribution of its benthic species is limited by salinity, wave exposure, temperature, desiccation and general stress.The constant threat of desiccation

Desiccation

Desiccation is the state of extreme dryness, or the process of extreme drying. A desiccant is a hygroscopic substance that induces or sustains such a state in its local vicinity in a moderately sealed container.-Science:...

 during exposure at low tide can result in dehydration which many creatures have developed strong adaptations to prevent such as production of mucous layers and shells. Many species use shells and holdfast

Holdfast

A holdfast is a root-like structure that anchors aquatic sessile organisms, such as seaweed, other sessile algae, stalked crinoids, benthic cnidarians, and sponges, to the substrate. ...

s to provide stability against strong wave actions. There are also a variety of other issues such as varying temperature fluctuations due tidal flow, changes in salinity and various ranges of illumination which can make life very difficult for rocky shore organisms. This can be coupled with predation from birds and from other marine creatures and also the vast effects of pollution

Pollution

Pollution is the introduction of contaminants into a natural environment that causes instability, disorder, harm or discomfort to the ecosystem i.e. physical systems or living organisms. Pollution can take the form of chemical substances or energy, such as noise, heat or light...

.

Pollution

Rocky shores are exposed to many forms of pollution, in particular pollution related to oil spills. Prominent spills are the Torrey Canyon spill, The Amoco Cadiz spill outside the Brittany coast in France and the Exxon

Exxon

Exxon is a chain of gas stations as well as a brand of motor fuel and related products by ExxonMobil. From 1972 to 1999, Exxon was the corporate name of the company previously known as Standard Oil Company of New Jersey or Jersey Standard....

 Valdez spill in Prince William Sound, Alaska, USA. Garbage such as plastics and medals being left behind by people is also a problem among many rocky coastlines that attract tourists.

Further reading

• Cruz-Motta J. J., Miloslavich P., Palomo G., Iken K., Konar B., et al. (2010). "Patterns of Spatial Variation of Assemblages Associated with Intertidal Rocky Shores: A Global Perspective". PLoS ONE
  PLoS ONE
  PLoS ONE is an open access peer-reviewed scientific journal published by the Public Library of Science since 2006. It covers primary research from any discipline within science and medicine. All submissions go through an internal and external pre-publication peer review but are not excluded on the...
  
  5(12): e14354. doi:10.1371/journal.pone.0014354.