CORAL REEFS IN CRISIS: THE RELIABILITY OF DEEP-TIME FOOD WEB RECONSTRUCTIONS AS ANALOGS FOR THE PRESENT

Ongoing anthropogenic alterations of the biosphere have shifted emphasis in conservation biology from individual species to entire ecosystems. Measures of modern ecosystem change, however, lack the temporal scales necessary to forecast future change under increasingly stressful and non-analogue environmental conditions. Accordingly, the assessment and reconstruction of ecosystem dynamics during previous intervals of environmental stress in deep time has garnered increasing attention and significance. The nature of the fossil record, though, raises questions about the difficulty and reliability of reconstructing paleocommunity and paleoecosystem-level dynamics. In this study, we assess the reliability of such reconstructions by simulating the fossilization of a highly threatened and disturbed modern Caribbean coral reef. Using a high-resolution Jamaican coral reef food web, we compare system properties of the modern and simulated fossil reefs, including guild richness and evenness, trophic level distribution, predator dietary breadth, food chain lengths, and modularity. Simulated fossilization resulted in loss of species (295 of 728), guilds (107 of 149), and trophospecies interactions (2368 of 4105), particularly zooplankton and other soft-bodied organisms. Nevertheless, the overall guild diversity, structure, and modularity of the reef ecosystem remained intact. Using methods developed previously, the fossilized community can be used to estimate food webs that are statistically indistinguishable from that of the modern coral reef community. These results have substantial implications for the integrity of fossil food web studies and coral reef conservation, and emphasize the validity and usefulness of paleoecological data to the field of conservation biology. The creation of deep-time paleocommunity food webs has the ability to enrich and advance our current knowledge of how natural systems behave, especially in response to future environmental changes.