Turnitin: Prosiding DFC 2017 - Aquatic invertebrate diversity and community composition at Quitobaquito, Organ Pipe Cactus National Monument

Abstract

Quitobaquito spring and pond support the only natural populations of endangered Sonoyta pupfish and mud turtle in the United States. Despite long-term monitoring of pupfish and mud turtle populations, little is known about the food web that supports these imperiled species. To address this knowledge gap, we began a comprehensive inventory of aquatic invertebrates at Quitobaquito in April 2017. We will sample four times a year in the primary aquatic macrohabitat units at Quitobaquito, including the headspring, the pond and moat, and spring channel riffles, runs, and pools. To date, we have identified 116 aquatic invertebrate taxa from our collections, which nearly doubles the number of taxa known from previous surveys at Quitobaquito. In April 2017, moat and spring channel pool samples were the most diverse (mean taxon richness = 33 and 30, respectively). Riffle samples were the least diverse (mean taxon richness = 15), but were the primary habitat for several rare taxa (e.g. riffle beetles, aquatic moths). Several taxa greatly increased in abundance between April and June, including Helicopsyche caddisflies. The impact of these changing invertebrate abundances on pupfish and mud turtles or general food web dynamics remains to be determined. In October 2017, we will expand sampling efforts to include tissue collection from important food web components (e.g. algae, zooplankton, detritus) for use in stable isotope analyses. These analyses should yield clues as to why Sonoyta pupfish and mud turtle populations fluctuate through time at Quitobaquito.