The importance of physical scaling factors to benthic marine invertebrate recolonization of laboratory microcosms

Abstract

Five laboratory studies of benthic macroinvertebrate recolonization were conducted for six‐week periods to evaluate the effects of physical scaling factors (i.e. microcosm size, seawater flow rates and sediment depth) on benthic community structure. Design variables included four open‐faced acrylic containers of size‐7, ‐12, ‐20 and ‐32 cm/side; seawater flow rate—approximately 0.7 or 1.6 liters/min; and sediment depth of 2.5 or 5.0 cm. Response variables included: total number of organisms (TNO), and taxa (TNT) and dominant taxa. Effects of seawater flow rates were more apparent than those related to microcosm size and sediment depth. Both TNO and TNT gave significant positive responses to increasing flow. Size effects were non‐linear; size‐20 microcosms tended to average more organisms than size‐32 but effects were often not significant (P>0.05). Size‐20 microcosms averaged higher numbers of taxa than size‐32 and responses were usually significant (P<0.05). Dominant taxa in these experiments were the tu...