The effects of within-shore water movement on growth of the intertidal mussel Perna perna: An experimental field test of bottom-up control at centimetre scales

摘要: Abstract Top-down effects on intertidal communities concern species interactions such as competition and predation, occur small-scales. In contrast, bottom-up factors the supply of resources food recruits. These are generally understood to be large-scale that oceanographically controlled. Here we examined small-scale growth mussels test hypothesis can also operate small (cm m) spatial scales. L-shaped aluminium baffles were used reduce flow around very (cm) scales in before/after experiments run at different sites 2004 2006. Each experiment had two phases, each phase lasting approximately 100 days. At start one, individually marked growing edge shell 10 control treatment patches before applying treatment. 2, same individuals again new placed patches. After there was no significant difference rates between treatments either year. both years, reduced by 30% compared Condition index end showed reverse lower for mussels. Untreated a temporal effect (i.e. differences phases) during but not The results clearly show associated with food-supply small, within-shore scales, strongly influencing possibly competitive abilities. They indicate top-down interact across multiple