The role of sinking phytodetritus in structuring shallow-water benthic communities

摘要: Abstract Sinking phytodetritus from surface waters represents a prime source of high-quality food supply for marine benthic organisms. Despite its obvious relevance, the structuring role it plays in shallow sedimentary communities is surprisingly poorly studied. In this article we review contribution natural sources organic to abundance, composition, and diversity shallow-water macrobenthic communities. We then present case study that tests how addition spring bloom-levels diatom 20-m deep habitat contributes variation community structure coastal Newfoundland. situ patches otherwise undisturbed sediment were enriched by syringing high low concentrations onto their surface. After one week five weeks, macrofauna sampled compared with ambient sediments where no was added. The experiment conducted during summer repeated fall order evaluate seasonal colonizers might influence infaunal response. significant temporal changes macrofaunal abundance composition within between experiments, only response could be attributed rapid first experiment. Multiple measures (species richness, rarefaction, Margalef's index) indicated reduced addition. These responses did not persist through weeks observed experiment, suggesting effect short term strongly dependent on timing. both material largely undetectable even after week. utilization phytodetrital environments, concert higher background levels flux, may represent key difference deep-sea