Pilot studies for designs of surveys of human disturbance of intertidal habitats in NSW

Abstract

Data are presented from pilot studies as the first step in the design of large-scale surveys of the effects of human recreational activities on intertidal habitats in New South Wales. People visiting the seashore were counted and interviewed. Numbers of organisms removed for food or bait were determined, as were the numbers of fishermen and scavengers frequenting the shore. Data from pilot studies using these methods assessed the various effects of human recreation during school terms or holidays, on week-days or week-ends and on sunny or overcast days. Pilot sampling at different locations provided estimates of the variability from place to place within 30 km. Sampling was in a fully orthogonal design which allowed tests of various factors and their interactions. More people affected the shore during school holidays than during term-time, but there were no differences between week-ends and week-days. There were significant effects due to weather, with more potential impact occurring on sunny than on overcast days. There were also substantial differences in effects at different places. Other potential sources of variation which should be considered in designing surveys of the effects of human recreation are briefly considered. These include variability due to time of day, the state of the tide, prevailing weather and various spatial and temporal scales. Such pilot sampling enables the efficient design of the large-scale, long-term surveys that are a necessary prerequisite to determining the magnitude and effects of human disturbances and their eventual management.