Benthic algal–detrital-chironomid pathway sustains high secondary production in a Great Salt Lake wetland

Sheet-flow wetlands of Farmington Bay in Great Salt Lake (Utah, USA) support some of the largest concentrations of migratory waterbirds in North America, yet the trophic mechanisms sustaining this exceptional productivity remain poorly understood. Here we present the first ecosystem-scale Ecopath model of a Great Salt Lake sheet-flow wetland and use ecosystem network analysis to reveal how benthic production and detrital recycling structure energy flow in this highly productive wetland ecosystem. Our model included 33 functional groups spanning primary producers, microbial compartments, benthic invertebrates, and avian consumers. Whole-system metrics indicated extremely high ecosystem productivity (total system throughput = 7247 t km⁻² yr⁻¹; net primary production > 5400 t km⁻² yr⁻¹). Energy flow was strongly dominated by detrital pathways, with approximately 51% of total system throughput originating from detritus and trophic transfer efficiency from detrital pathways (6.3%) exceeding that from primary producers (1.9%). Ecosystem Network Analysis revealed extensive internal recycling (Finn’s cycling index = 40%) and long energy pathway lengths (Finn’s mean path length = 13.2), indicating prolonged retention and repeated reprocessing of organic matter. Network organization metrics indicated low ascendency and high system overhead (A/C ≈ 0.26; O/C ≈ 0.74), suggesting a structurally redundant and resilient ecosystem but one that may be vulnerable to disturbance due to bottlenecks in benthic invertebrate taxa. Together, these results indicate that Farmington Bay wetlands operate through a benthic algal–chironomid detrital pathway that efficiently converts basal production into invertebrate prey supporting large migratory waterbird populations. More broadly, this study demonstrates how detrital recycling and benthic production can bolster high secondary production in shallow wetland ecosystems, providing a quantitative baseline for evaluating environmental change and guiding ecosystem-based management of Great Salt Lake wetlands.