Caging experiment: Relationship between mesh size and artifacts

In marine sediments, cages, are widely used to detect effects of predation on infauna. Artifacts due to the use of cages have been, instead, poorly estimated. In this study we have analysed the changes in macrofauna and in sediment composition when cages of different mesh sizes are used to exclude predators. In a shallow micro-tidal flat, the effect of three mesh sizes (2, 6 and 18 mm) was tested on sediment and macrofauna, using cages that excluded predators (EC), partial cages (PC) and natural sediment (un-caged plots, UC). PC allowed the predators to feed on the sediment, but modified the sediment similarly to the complete cages. Changes were measured for the abundance and species composition of macrofauna and for sediment total organic matter (TOM), chlorophyll-a, proteins and water content.