Artificial seagrass: How useful is it for field experiments on fish and macroinvertebrates?

Twenty-four artificial seagrass units (ASUs), each of 7 m², were submerged near Zostera capricorni Aschers, beds for 6 wk. Fish, decapods and cephalopods associated with ASUs and with comparable areas within adjacent Zostera beds were then collected. ASUs yielded significantly fewer species than Zostera areas but there was no significant difference in number of individuals. Relative abundances of species were similar in samples from ASUs and Zostera, and there were few significant differences in abundances of the seven major faunal groups. Our interpretation of these data is that artificial seagrass attracts vague macrofauna typical of real seagrass, that ASUs had fewer species than Zostera only because they had less time to accumulate species, and that ASUs should prove a valuable tool in field experiments on macrofaunal assemblages.