A Brief Introduction to Rocky Shores and their Biota

Submitted by admin on Thu, 09/10/2015 - 15:05
Irish Rocky Shores

Report written by Jennifer Coughlan and Tasman Crowe, School of Biology and Environmental Science, University College Dublin


Image
Tidal rocky shores in Ireland
Image
Cliff shores of Ireland

A rocky shore is an intertidal area of the coastline consisting mainly of solid rock. Rocky shores are very much a boundary zone between terrestrial and marine habitats and therefore represent sharp environmental gradients. This produces an extremely diverse and rich environment which ideal as a field laboratory. Because of ease of access and the abundance of a large range of animals and flora, they have long been the subject of interest, education and industry, spanning seaweed and shellfish harvesters to kids throughout the centuries rock pooling on the shore, to extensive scientific research. Many shores have been central in long term biological monitoring studies of climate change and the testing of many of our basic and ever changing ecological concepts.

Our shores experience a twice daily tidal cycle. The heights of high and low water are determined by the effect of the sun and moon’s gravitational forces. The times of high and low waters vary around the country and can be found in national newspapers or at various websites for the week ahead. For more extensive tidal prediction, you need software or tide table books published by Dublin Port which cover all main coastal stations. Spring tides have the largest range and occur when the gravitational pull of the sun and moon act together on the earth’s oceans. Neap tides have a smaller range and are a result of the sun and moon’s gravitational forces in opposition. Spring and neap tides cycle with an approximately fortnightly pattern: a week of spring tides followed by a week of neap tides.