The Food Web of a Tropical Island Stream

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Quantitative food webs describe the connectivity between consumers and resources, but also combine diet analyses with taxon-specific production estimates to determine energy flow between species. The resulting web tells us how much each food source is responsible for the production of each species and their trophic position. In this study we estimate annual secondary production and develop a quantitative food web of the benthic insect communities present in two small streams at the Luquillo Experimental Forest (LEF), Puerto Rico. We examined the gut content of the dominant aquatic insect groups: Leptophlebiidae and Baetidae mayflies, Calamoceratidae and Hydropsychidae caddisflies and Chironomidae midges and found that these groups rely heavily on plant tissue and amorphous detritus. Overall, aquatic insects in the LEF have low biomass; therefore, their production is relatively low compared with available estimates. Secondary production appears to rely more on allochthonous organic matter, rather than primary production. This study is one of the first to quantify the production and food web of the benthic insect community in tropical island streams.


Society for Freshwater Science Annual Meeting (SFS)


Milwaukee, WI