Effects of human trampling on an exposed rocky shore

Abstract

The effects of human pedestrian pressure on an exposed rocky shore lying within a newly‐declared marine reserve near Cape Town, South Africa, were investigated. Transects were marked across the intertidal zone of a little‐frequented section of the shore and subjected to trampling up to 500 times per month. Immediate effects of pedestrian impact included the dislodgement of dead barnacles, damage to algae and the crushing of small numbers of amphipods and isopods. Long‐term effects could, however, not be found, and those transects subject to the most intensive pressure did not differ significantly from a control area. A survey of types of footwear used by people walking in the intertidal indicated that over 85 percent used no footwear at all. This lack of protection forces the majority of pedestrians to proceed with caution in order to avoid injury, and sumultaneously minimises the damage they inflict on intertidal biota. It thus appears likely that wave action is of considerably greater importance to intertidal communities than pedestrian pressure on wave‐exposed shores. This paper is a contribution to the current sparse information about the effects of recreational use of rocky sections of shorelines in an age when tourism is one of the largest industries in the world.

Key words:

• Trampling
• intertidal
• rocky shore
• human impact