학술논문

Mortalities caused by off-road vehicles (ORVs) to a key member of sandy beach assemblages, the surf clam Donax deltoides.
Document Type
Article
Source
Hydrobiologia. Sep2008, Vol. 610 Issue 1, p345-350. 6p. 1 Chart, 3 Graphs.
Subject
*OFF-road vehicles
*BEACHES
*CLAMS
*DONAX (Bivalves)
*MORTALITY
*ANTHROPOGENIC effects on nature
*ECOLOGICAL disturbances
*RECREATIONAL vehicles
*COASTAL zone management
Language
ISSN
0018-8158
Abstract
Sandy beaches are prime recreational areas, but human use of beaches is not without ecological consequences. Driving of off-road vehicles on beaches for recreational pursuits is perhaps the physically most severe form of direct anthropogenic disturbance on sandy shores. Potential management and conservation interventions lack, however, data on how sensitive beach species are to vehicle impacts. We therefore experimentally quantified the link between beach traffic and lethal damages caused by vehicles to sandy shore invertebrates, using surf clams ( Donax deltoides) as the biological response variable. Although clams had some tolerance against vehicles at low traffic volumes (5 vehicle passes), more than half of them were killed at higher traffic volumes (75 passes) in situations where cars traversed soft sand and turned across the beach face. Overall, both traffic volume and driver behaviour (i.e. straight vs. turning vehicle tracks) determined the incidence of direct crushing of clams under vehicles. Our data demonstrate that recreational use of ORVs is a source of mortality for beach invertebrates, but equally caution against extrapolating impact data from hard-shelled clams to potentially more sensitive soft-bodied species. Robust management interventions that seek to mitigate ecological damage from beach traffic will therefore require information on the functional relationship between the form, intensity and frequency of human disturbance and the biological responses for entire faunal assemblages on sandy shores. [ABSTRACT FROM AUTHOR]