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Intertidal Zonation References

Clean Oceans

Created by Anica Vranic © 1998 a student of Southern Cross University Humanities, Media and Asian Studies

The coastal zone is an important part of the bigger picture - Our World.  

Our coastal zone includes our catchment areas, the rivers that run into the oceans and the oceans themselves. In the coastal zone you will find the beaches that we use, the rocky shores and the estuaries. It's important to remember that all these areas are connected, along with the plants and animals we depend on it to be clean and healthy for our survival. To find out more about these different areas click on the map or choose an area from the list .

Intertidal Collections

The intertidal zone, lying between the extreme high and low water marks, is at the interface between land and the ocean. This zone yields some of the most interesting algal collections, especially on temperate coasts or in areas with high tidal amplitude where species distribution limits determined by biological and physical factors are evident.

The varied intertidal micro-habitats (rock, sand, tidepools, attached organisms) and differing degrees of exposure to the elements (wave surge, sand scouring, freezing, desiccation, etc.) account for the high species diversity found here. In the earlier days of phycology, most specimens were collected from this zone, and even today the intertidal zone is an important collecting habitat.

Algae - An Introduction

National Museum of Natural HistorySmithsonian Institution

Algae are photosynthetic organisms that occur in most habitats, ranging from marine and freshwater to desert sands and from hot boiling springs to snow and ice. They vary from small, single-celled forms to complex multicellular forms, such as the giant kelps of the eastern Pacific that grow to more than 60 metres in length and form dense marine forests. Algae are found in the fossil record dating back to approximately 3 billion years in the Precambrian. They exhibit a wide range of reproductive strategies, from simple, asexual cell division to complex forms of sexual reproduction.

Algae are important as primary producers of organic matter at the base of the food chain. They also provide oxygen for other aquatic life. Algae may contribute to mass mortality of other organisms, in cases of algal blooms, but they also contribute to economic well- being in the form of food, medicine and other products. In tropical regions, coralline algae can be as important as corals in the formation of reefs.

Common Intertidal Invertebrates of California

The first page lists the various phyla, which link to genera pages, and then to individual species pages with a clear photograph and description of each species.

Phylum Porifera
Phylum Cnidaria
Phylum Annelida
Phylum Echiura
Phylum Arthropoda
Phylum Mollusca
Phylum Echinodermata
Phylum Chordata

Dorset Coastlink: Sharing the Secrets of the Sea.

By visiting this site we hope you will be amazed by the range of innovative and exciting projects that are on offer along the Dorset coast. We hope you enjoy your visit and leave knowing a little bit more about Dorset's splendid coastal environment and why it is so special - you will be amazed at the richness and diversity of the relatively unknown marine environment.

The Dorset coast is an exceptional resource worthy of protection; it attracts a wide variety of interest groups to enjoy its coastal landscape, beaches and scenery, geology, coastal ecology, wildlife, cultural and heritage features. After visiting this web site you will know where to find out more about underwater acoustics and dolphins, where to see live pictures from the seabed or the cliff top, where to go on guided fossil hunts, as well as a host of other exciting opportunities to learn more about Dorset's spectacular marine and coastal environment.

InterTidal Times

published by the Essex Elementary School

Reports by children from the Essex Elementary School about an excursion to the seashore.

Grafton Online: Intertidal Marine LifeAround
Sandon Headland and Plover Island

A well illustrated single page on some of the intertidal creatures you will find on a rocky shore in eastern Australia.

The drawings are by Sue Hardman.
Reference: W.K. Dakin's classic study "Australian Seashores".
Original Pamphlet: by Louise Hardman as a DEET-jobskills Placement.

Intertidal zone

The shallow water habitats are made up of mixture of mud, rocks, and gravel. Animals that filter the water for food like oysters, clams and mussels find abundant food in this habitat. They feed on microscopic animals and plants called "plankton". They spend their whole lives in the same place so their habitat is extremely important for shelter and feeding. Human developments along our coasts, poorly designed wastewater treatment systems, sewage outfalls and infilling of marshes and bays can all have a very bad effects in these areas. The filter feeding animals living in these areas are very sensitive to changes in their habitats such as a lack of oxygen, increases in temperatures or being buried by mud.

By the Sea: Fisheries and Oceans Canada

Introduction Page

Have you ever walked along our shorelines wishing you knew what we can find in these environments? "By the sea" was created to answer your questions. This guide is about 11 ecosystems within the coastal zone of Eastern Canada. While consulting this guide, you will learn who are the inhabitants of our shores, why these environments are so important to our economy and well-being and what part we can play in preserving these habitats. This web site contains a short summary of the eleven modules, parts of the introduction module and five activities from module 13.

Rocky Shores

Rocky shores are dominated by rocky substrate and all show, to a greater or a lesser extent, some form of zonation of banding. One of the most striking features of a rocky shore is its pattern of zonation. Zonation refers to the regular appearance of specific plants and animals at specific places along an intertidal area, the area that lies between the low and the high tide mark. They display bands of colors, depending on where they're located in relationship to the rising and falling tides.

Introducing the South African Seashore

© 1997, Derek Keats


When you have completed this web resource you should:

Understand the nature and causes of tides.

Be able to solve problems relating to the tides. Understand the concept of zonation as it relates to the intertidal zone.

Know how tides affect the physical conditions experienced by plants and animals at different levels (zones) on rocky shores.

Be aware of the names applied to the different levels on the seashore.

Intertidal Marine Projects

University of Exeter, Department of Psychology

Extending from the high water mark on Lundy to a distance of one kilometre offshore is the area of a Marine Nature Reserve administered by the English Conservation Council. Within this area there is a wealth of protected marine habitats of intertidal species. Although the majority of these habitats are inaccessible from the land side, there are some which are accessible. These latter are found in the South East corner of the island around the Landing Bay and Rat Island. Most of Lundy is composed of granite but the South East is mainly slate which has allowed the formation of many rock pools and at low tide these are exposed. If you are interested in following a line of investigation into marine behaviour please remember that you will be working within a Marine Nature Reserve and that nothing should be disturbed. If you raise a rock or any of the seaweed wracks, they must be replaced as you found them. Neither should any species be removed from the pools - Please take your books to the shore, not the shore to the books.

Western Cape Schools Network: Marine Ecology

Western Cape, South Africa

Home Page

Index to Intertidal Ecology

This page is maintained by Tony White

The WCSN is a dynamic, independent schools networking organization which provides a range of Internet services, training and resources. It is founded, funded and led by schools, and is dedicated to bringing Internet access to all schools in the Western Cape, South Africa.

Close encounters in biodiversity

NSW National Parks and Wildlife Service - Science & Research

Biodiversity on the rocky sea shoreRocky sea shores are great places to explore. Many forms of life which are not commonly seen on land can be seen on rock platforms and tidal pools. We have highlighted a very few of the animals and plants that you might see along the shores of New South Wales.

This page has links to various intertidal species.

Rocky Shores

In the study of community structure, larval recruitment, and physiology, rocky shores have proven to be the most versatile habitats, owing to their accessibility to observation and to the strong physiological gradient, ranging from fully marine to terrestrial habitats. The physiological gradient makes it relatively easy to see the interactions of physiological performance and interspecies interactions.

Ecological processes such as competition and predation are strongly modulated by the time organisms are exposed to air and such effects cause vertical gradients in the importance of, for example, predation. Many carnivores can only move about and seize prey when covered with water, which limits the time that intense predation can occur in the high intertidal.

Our understanding of these environments has been informed especially by field experiments. Removal or addition of hypothetical predators and prey has been crucial in understanding ecological interactions. The experiments performed by Joseph Connell and Robert T. Paine and their followers set the standard for ecological field work both in the marine and other environments.

Rocky Shore Monitoring Program

Monterey Bay National Marine Sanctuary

The MBNMS includes 220 kilometres of rocky shore coastline between San Francisco and Cambria. Important management issues related to this habitat include understanding natural changes to assess sanctuary health, preparation for natural resource damage assessment after small ship groundings (which occur roughly once per month) or potential large oil spills, and human impacts from trampling and collecting (DeVogelaere 1996 ). The MBNMS Scientific Research Plan, indicates that monitoring the rocky shore habitat is a necessary component of managing the resource (MBNMS Research Advisory Committee 1993). The north-east pacific shoreline has received extensive attention by rocky shore ecologists (reviews by Foster et al. 1988, 1991, Ricketts et al. 1988) and some regional monitoring efforts have detected interesting results (Druehl et al.1988, Barry et al. 1995).The Sanctuary is currently in the process of compiling regional data sets from previous studies, establishing several long term monitoring sites, and continuing past monitoring work. Species lists and quantitative surveys of intertidal organisms generated through this monitoring program will provide a valuable resource management tool for the rocky shores within MBNMS and other areas.

Kindergarten- 1st Grade - Rocky Seashore

During Oceans Week at Rancho Santa Fe School, the kindergarten and first grade classes studied the rocky seashore. The classes learned about this unique marine habitat through hands-on experiences including: hermit crab and crayfish (simulating lobsters) labs, creating 3 dimensional models of a tidepool, making shoebox dioramas, playing "Seashore Charades", going on a "Sculpin Hunt", and many other activities that helped make the rocky intertidal zone come alive! These classes now have a greater understanding of the rocky seashore habitat and a new respect for the animals that inhabit this wondrous place.

Scientific Research and the Rocky Shore Strategy

A White Paper prepared for the Oregon Ocean Policy Advisory Council March 21, 1997 by Robert Bailey, Department of Land Conservation and Development, Jim Golden and Dave Fox, Department of Fish and Wildlife Marine Region.

The Rocky Shores Strategy in the Territorial Sea Plan resulted from a process that began with public concerns in the late 1960s and early 1970s that, without proper planning and management, the natural resources and aesthetic values of the Oregon coast would fall victim to population growth, land-use development, misuse and overuse. The Oregon Coastal Conservation and Development Commission, created by the 1971 Legislature, developed planning policies for all aspects of coastal resource protection and development, including policies on continental shelf and ocean resources. These policies became the basis for the four coastal planning goals: Goal 16, Estuarine Resources; Goal 17, Coastal Shorelands; Goal 18, Beaches and Dunes; and Goal 19, Ocean Resources. The goals were adopted by the Land Conservation and Development Commission in 1976 and approved by the federal government as the part of Oregon's Coastal Management Program.

The Rocky Shore

Created and maintained by: Jocelyn Collins, South Africa

The rocky shore is one of the most fascinating of all ecosystems. It is packed with a wide variety of marine life. The shore is covered by the sea and pounded by the waves at high tide in the intertidal zone. Low tide means exposure to drying air and heat. Plants and animals living here must be able to live both in air and water; they must be able to survive the loss of almost 70 % of their body water during dry periods, and, in addition, be able to cope with freshwater rain when exposed and salty seawater when submerged.

The Rocky Shore

The Rocky Shore is a CD-ROM package which combines photographic images, illustrations, detailed texts and video to provide an interesting and detailed insight into the fauna and flora of the North-East coast of England. Surveying techniques such as the use of quadrats are presented together with species and classification lists. The information is backed up with both video footage and paper resources. The pack contains :- CD-ROM. Associated paper resources. and associated video material.

The Rocky Shore

Nova Scotia's rocky seashores are wonderfully varied. Some are steep cliffs exposed to the pounding ocean waves, like Cape Split. Others have a gentler slope, with a greater area of potential living space for seashore plants and animals. Some shores are solid bedrock, while others are "cobble beaches" of rounded stones which make rattling noises as the salt water washes over them. These sounds are made as rocks tumble against each other—a precarious habitat for soft-bodied creatures.

You will find some living things on all rocky shores, but plants and animals thrive best on shores of large solid rocks or bedrock, with lots of crevices and tidepools for shelter.

The seashore habitat is created by the tides. Twice each day, tides cause the ocean's edge to advance and retreat. The best time to explore rocky shores is within one hour of low tide. The times of high and low tide become about one hour later each day.

As you walk toward the water's edge at low tide, both the abundance and diversity of seashore life increase. There are both many more creatures and more kinds of them, the closer you go to the sea. Ecologists divide the rocky shore into three bands or zones, according to height above low tide and also the most common creatures: the Upper Shore, the Middle Shore (or Rockweed Zone) and the Lower Shore (or Kelp Zone).

Galapagos Islands - Intertidal Life

TerraQuest 1996.

This is a very well done site, with excellent infrmation and photographs.

Though the intertidal zone is but a strip around all the islands, the total area has been estimated as about 40 square kilometres, or two thirds the size of Espa-ola Island. Organisms here must adapt to spending part of their time submerged and part above water, resisting the incessant action of waves. Only a few of the intertidal creatures, like the marine iguana and Sally Lightfoot crab, will be familiar to most visitors, but if you take a close look at life on the tidal rocks and in the tide pools, you will discover an ecosystem every bit as complex as that on land.

The Intertidal Zone

Melissa S. & Adam G

Two high school students havecreated this educational web site..

  • To start FREE TOUR of intertidal zone
  • Geography and Weather cycles
  • Survey of Organisms
  • Animals of the Intertidal Zone
  • Adaptation Page
  • Endangered Species
  • Myth of the Intertidal Zone
  • Systems Comparison
  • Symbiosis Page
  • Quest Page
  • Bibliography

If you know of any other sites that should be linked to this list of Marine WebSite Resources please contact me at the email address below.

Thank you,

Keith Davey

Home Page
Rocky Shores
Tidal Levels
Intertidal Zonation
Environmental Factors
Biological Factors
Feeding Relationships


photo of Keith DaveyLife on Australian Seashores
by Keith Davey (C) 2000

Learning Consultant - Media
The University of Newcastle

email at

Scientific Consultant: Phil Colman
site created 01.01.98 : updated 01.04.2000