The Ballantine scale is a biologically defined scale for measuring the degree of exposure level of wave action on a

rocky shore A rocky shore is an intertidal area of seacoasts where solid rock predominates. Rocky shores are biologically rich environments, and are a useful "natural laboratory" for studying intertidal ecology and other biological processes. Due to th ...

. Devised in 1961 by W. J. Ballantine, then at the zoology department of Queen Mary College,

London London is the Capital city, capital and List of urban areas in the United Kingdom, largest city of both England and the United Kingdom, with a population of in . London metropolitan area, Its wider metropolitan area is the largest in Wester ...

, the scale is based on the observation that where shoreline species are concerned "Different species growing on rocky shores require different degrees of protection from certain aspects of the physical environment, of which wave action is often the most important." The species present in the

littoral zone The littoral zone, also called litoral or nearshore, is the part of a sea, lake, or river that is close to the shore. In coastal ecology, the littoral zone includes the intertidal zone extending from the high water mark (which is rarely flood ...

therefore indicate the degree of the shore's exposure.Ballantine (1961), p. 1.

Summary

An abbreviated summary of the scale is given below. The scale runs from 1) an "extremely exposed" shore, to 8) an "extremely sheltered" shore. The

generally is the zone between low and high tides. The supra-littoral is above the

barnacle Barnacles are arthropods of the subclass (taxonomy), subclass Cirripedia in the subphylum Crustacean, Crustacea. They are related to crabs and lobsters, with similar Nauplius (larva), nauplius larvae. Barnacles are exclusively marine invertebra ...

line.

Modifications to the scale

A modified exposure scale of five stages applying to the shores of the British Isles is given by Lewis (1964): #"Very exposed shores" have a wide Verrucaria zone entirely above the upper tide level, a ''Porphyra'' zone above the barnacle level and '' Lichina pygmaea'' is locally abundant. The eu-littoral zone is dominated by barnacles and

limpet Limpets are a group of aquatic snails with a conical gastropod shell, shell shape (patelliform) and a strong, muscular foot. This general category of conical shell is known as "patelliform" (dish-shaped). Existing within the class Gastropoda, ...

s with a coralline belt in the very low littoral along with other

Rhodophyta Red algae, or Rhodophyta (, ; ), make up one of the oldest groups of eukaryotic algae. The Rhodophyta comprises one of the largest phyla of algae, containing over 7,000 recognized species within over 900 genera amidst ongoing taxonomic revisions. ...

and ''Alaria'' in the upper sub-littoral. #"Exposed shores" show a Verrucaria belt mainly above the high tide, with ''Porphyra'' and ''L. pygmaea''. The mid shore is dominated by barnacles, limpets and some

Fucus ''Fucus'' is a genus of brown algae found in the intertidal zones of rocky seashores almost throughout the world. Description and life cycle The thallus is perennial with an irregular or disc-shaped holdfast or with haptera. The erect portion ...

. Some Rhodophyta . ''Himanthalia'' and some Rhodophyta such as '' Mastocarpus'' and '' Corallina'' are found in the low littoral, with ''Himanthalia'', ''Alaria'' and ''L. digitata'' dominant in the upper sub-littoral. #"Semi-exposed shores" show a Verrucaria belt just above high tide with clear ''

Pelvetia ''Pelvetia canaliculata'', the channelled wrack, is a very common brown alga (Phaeophyceae) found on the rocks of the upper shores of Europe. It is the only species remaining in the monotypic genus ''Pelvetia''. In 1999, the other members of this ...

'' in the upper-littoral and ''F. serratus'' in the lower-littoral. Limpets, barnacles and short ''F. vesiculosus'' mid-shore. ''F. serratus'' with Rhodophyta, (''

Laurencia ''Laurencia'' is a genus of red algae that grow in temperate and tropical shore areas, in Littoral zone, littoral to Littoral zone#Sublittoral zone, sublittoral habitats, at depths up to . Description ''Laurencia'' species have a thallus that ...

'',

Mastocarpus stellatus ''Mastocarpus stellatus'', commonly known as carrageenan moss or false Irish moss, is a species in the Rhodophyceae division, a red algae seaweed division, and the Phyllophoraceae, Phyllophoracea family. ''M. stellatus'' is closely related to Cho ...

, '' Rhodymenia'' and '' Lomentaria''). ''Laminaria'', '' Saccorhiza polyschides'' and small algae are common in the sub-littoral. #"Sheltered shores" show a narrow Verrucaria zone at high water and a full sequence of fucoids: ''Pelvetia'', ''F. serratus'', ''F. spiralis'', ''F. vesiculosus'', '' Ascophyllum nodosum''. ''L. digitata'' is dominant in the upper sublittoral. #"Very sheltered shores" show a very narrow zone of Verrucaria, the dominance of the littoral by a full sequence of the fucoids and ''Ascophyllum'' covering the rocks. '' Laminaria saccharina'', '' Halidrys'', '' Chondrus'' and / or '' Furcellaria''.

Notes

References

* {{physical oceanography Biological literature Marine biology