Wednesday, August 6, 2008 - 10:50 AM

COS 53-9: Multi-scale relationships between eastern Lake Michigan nearshore fish and anthropogenic shoreline factors

Reuben R. Goforth, Purdue Universtiy

Background/Question/Methods

The multiscale nature of streams, rivers, and inland lakes is well documented, although relationships between the ecology of Great Lakes nearshore areas and shoreline processes are generally poorly understood.  Given the high levels of development pressure currently exerted on Great Lakes shorelines, I sought to determine whether patterns exist between measures of shoreline development quantified at multiple spatial scales and nearshore fish communities.  I expected that shorelines would act similarly to riparian zones of streams and rivers, with intact shorelines providing buffers to anthropogenic activity and modified shorelines providing little to no protection from human land uses.  Moreover, I expected anthropogenic shoreline factors to act cumulatively in combination with prevailing currents to influence downdrift nearshore areas.

Results/Conclusions

The study results offer some evidence to indicate that at least some elements of nearshore fish communities exhibit patterns that may be attributable to shoreline characteristics at both local and larger spatial scales.  For example, total shallow water (i.e., < 1.0m water depth) and nearshore (i.e., <4.0m water depth) piscivorous fish catch per unit effort measures were both positively related to the extent of urban-residential land use within shoreline buffers 5-10 km updrift of study sites.  These results, among others, indicate that there is critical need for alternative and multiscale management strategies for shorelines that will enhance the long-term viability of Great Lakes nearshore ecosystems while at the same time meeting the rising demands for urban, residential, and recreational uses of these coastal areas.