Sport fish use of an artificial reef in nearshore Lake Michigan during 2000-2006

In November 1999, an artificial reef composed of granite rubble was built in southwestern Lake Michigan near Chicago to attract smallmouth bass and create angler opportunities. Adult fish communities were sampled at the artificial reef site and a nearby reference site before (1999) and after reef construction (2000-2006) via 180 total gill nets sets and 76 SCUBA dive transects. Total number of fish and species diversity observed during SCUBA dive transects was higher at the artificial reef than at the reference site during 2000-2006. Both dive and gill net data showed higher numbers of smallmouth bass and rock bass at the reef compared to the reference area. However,mean annual total gill net CPUE did not differ at the two sites after reef construction indicating the reef only attracted species that prefer rocky, complex habitats. For example, freshwater drum and salmonines exhibited clear responses to temperature rather than site specific preferences. Although anglers were aware of the artificial reef, fishing effort and success were low, in part because few anglers targeted bass. In addition to attracting desirable sport fish, the Lake Michigan artificial reef also attracted large numbers of invasive round goby. The structure of the artificial reef has remained intact and not buried as of summer 2012. Keywords:Habitats, Smallmouth bass, Lake Michigan, Fishing.