Reconceptualizing community structure and dynamics in light of consumer mobility

Background/Question/Methods

Ecologists lack a clear model for how to incorporate information on consumer mobility into investigations of how communities are structured and how they operate. This deficiency is becoming increasingly apparent as new technologies broaden our insight into the dynamics of consumer mobility. Classically, ecologists draw interpretative boundary lines around discrete habitats and search for spatially endemic explanations for patterns of community construction and function within these boundaries. Such an approach is problematized by the transience of functionally important consumers that interact intermittently with this ecological space. We engage some of these complications by empirically investigating how the mobility of putatively site-attached coral reef consumers (e.g. sharks, snapper) challenges the interpretations that we make of the architecture of reef fish communities. We used stable isotopes, biologging, and community surveys to inform these inquiries.

Results/Conclusions

Results revealed variable and unanticipated patterns in the degree of energetic reliance on reefs of dominant mobile consumers previously believed to be entirely linked to reef communities. Conclusions about patterns of ecological connectedness of principal mobile consumers in this system were congruent in both isotopic and tracking data. Incorporation of this new insight provides a means for making more thermodynamically parsimonious interpretations of the trophic architecture and biomass distributions of these particular reefs under study. Conclusions from this case study illustrate both the necessity for better incorporating emerging information about the ecology of mobile consumers into our foundational interpretive frameworks in community ecology and illuminates potential pathways by which such integrations may be achieved.