Seamounts, submarine canyons, steep banks and reefs, as well as other geologic features with abrupt topographies have similar attributes such as accelerated flows due to impinging currents and exposed hard rock surfaces with coarse grained sediments. Advected and downwelled plankton are an important prey resource in these landscapes.  Major components of their faunas are adapted for intercepting plankton, but the species composition and diversity have a great range.  At the lowest end of the diversity spectrum are Great Lakes reefs with 10s of native species.  For many oceanic features the actual diversity is unknown, but with 100s to 1000s of species and many species yet to be described.  In some cases large suspension feeding invertebrates dominate the macrofaunal component of the invertebrate community.  Fishes use attributes of such features at multiple spatial scales (e.g., rock walls, corals) as shelter from predators and refugia from currents.  For fishes on oceanic structures, their diversity, distribution, and abundance can be described based on trade-offs in shelter requirements and feeding opportunities.  Common strategies include ambush piscivory, ram and suction feeding on drifting zooplankon, and scan and capture of zooplanktors trapped against the substrate.  In contrast, the Great Lakes reefs host a minimalist fish community with post-glacial colonists not adapted for the topographies and currents. 

Results/Conclusions

We propose that a comparison of ecosystem function and services between the diverse oceanic and minimalist Great Lakes will yield important insights into how such communities evolve and function.