Wave Shock as a Factor in Littoral Ecology
Edward Flanders Ricketts
Unpublished Essay but Reprinted Here From the Living Edge by Joel Hedgpeth
1938 Photo of Ed Ricketts

Compiled by
Robert 'Roy' J. van de Hoek
Field Biologist & Geographer
Sierra Club, Wetlands Action Network, National Audubon Society

Ed Ricketts Essay Excerpts:
"Increasingly it seems to me evident that wave shock, working often indirectly through its allies physiography and type of bottom is the most significant distribution factor for the Pacific coast littoral, lacking here as we do any effective temperature differential from Pt. Conception clear into Alaska. Wave shock, currents, type of bottom and shore physiography are tied up together in mutual cause-effect circles, so that while any one of these factors can be defined exclusive of the others, the causes and effects of one cannot be considered, sometimes cannot even be differentiated, except in their mutual reactions and relations. Stone or boulders, unless they be very large, cannot occur in the face of heavy surf; the only shore that bears up under continual wave impact is cliffy wall, solid reef or solid terrace. The type, slope and exposure of the shore are functions remotely of geology, but immediately of physiography. A good many forces act from outside. The steady wind piles up the ground swell offshore, temperature and barometer variations in other parts of the world induce currents, the lay of the land is in part due to remote earth movements. But within a given region all act and react together and mutually. Together they produce a result which conditions the environment of the animal communities." (Ricketts, 1932, p.42,43).

Reference: Hedgpeth, Joel. 1976. The Living Edge. Geoscience and Man, Volume 14, June 1, 1976, Page 17-51, 20 Figures.

Joel Hedgpeth had two title quotes that prefaced his article, The Living Edge. One quote was by Henry David Thoreau (1864,p71) and the other by Carl O. Sauer (1962). They are presented here as background information for undertanding the linkages of Ricketts, Hedgpeth, Thoreau, and Sauer.

Before the land rose out of the ocean, and became dry land, chaos reigned; and between high and low water mark, where she is partially disrobed and rising, a sort of chaos reigns still, which only anomalous creatures can inhabit.

Henry David Thoreau (1864,p.71)
Cape Cod
1951 Edition
W.W. Norton, New York

To primitive collector and modern naturalist alike, the borders of the sea are richly rewarding. Between high and low tide a wide assemblage of life forms useful to man is to be had for the taking. These differ from place to place according to the bottom, whether it is sand, silt or rock, according to the qualities and motions of the water, and by extent of daily exposure above the water. In warm oceans sea turtles visit sandy beaches to deposit their eggs. From back beach to sea cliff a different and varied fauna and flora yield edible shoots, fruits, eggs, and nestlings. The shallow sea holds yet another assemblage.
. . . We still like to go beachcombing, returning for the moment to primitive act and mood. When all the lands will be filled with people and machines, perhaps the last need and observance of man still will be, as it was at his beginning, to come down to experience the sea.

Carl O. Sauer (1962, p.45,46),
Seashore-primitive home of man?
American Philosophical Society Proceedings,
Volume 106, page 41-47