Impact of hurricane Dean on Chinchorro Bank coral reef (Western Caribbean): Temporal variation in the food web structure

Approaches to conservation have undergone considerable changes over time, broadening in vision to incorporate the conservation of functional ecosystems as well as description of the changes brought about by diverse factors at system level. Topological network analysis has the aim of: i) furthering our understanding of how diversity is structured; ii) analyzing changes in the network caused by both anthropogenic and natural activities; and iii) evaluating the contribution of landscape elements to the maintenance of connectivity and ecological flows. Several studies have described changes caused by the impact of hurricanes on the coral reefs; however, there has been a lack of analysis that integrates the different ecological components. The objective of this study was to evaluate the effects of hurricane Dean (2007) on the food web structure at Chinchorro Bank coral reef ecosystem in Mexico, using topological network analyses covering the period before the impact of the hurricane (2007A), immediately afterwards (2007B) and for the following four consecutive years (2008, 2009, 2010 and 2011). Our results considered a total of 74 fish species, five functional groups, and 32 biological assemblages that formed a total of 111 nodes, evidencing that hurricane Dean caused changes in the structure (number of nodes), but did not present an important change in food web functioning. The key species (Lutjanus apodus, Sphyraena barracuda, Epinephelus striatus, Cephalopholis cruentata) were constant over the years following the hurricane, with a prominence of secondary and tertiary consumers. We conclude that the impact of hurricane Dean caused structural, but not functional, changes in the Chinchorro Bank ecosystem of the Banco Chinchorro Biosphere Reserve.