ABSTRACT
To examine early post-settlement processes, good estimates of both settlement and abundance a few months later are needed. While using artificial collectors can help quantify the supply of settlers, recruitment patterns on collectors are likely to be biased by effects of the collectors on water currents, predators and resources. For example, Harris et al. (1994) found that survival of juvenile sea urchins was greater on plastic turf than on nearby rocks and attributed differences to predator abundance. Therefore, other methods should be sought to determine the number of young recruits. Often this is done by examining settlers on natural substrates by assessing the area within quadrats in situ (e.g. Tomas et al. 2004). However, small individuals (<10 mm) may be overlooked using this method (but see Pearse & Hines 1987, Lamare & Barker
1 INTRODUCTION
Recruitment of most benthic invertebrates, including echinoderms, is dependent on larval supply, settlement and early post-settlement events (Hunt & Scheibling 1997). However, it is hard to observe these processes in the field because juvenile and settler echinoderms are small and often cryptic. To date, various sampling methods have been used to better understand settlement and early post-settlement events.
