No free lunch: displaced marsh consumers regulate a prey subsidy to an estuarine consumer

摘要: Pulse subsidies account for a substantial proportion of resource availability in many systems, having persistent and cascading effects on consumer population dynamics, energy flow within across ecosystem boundaries. Although the importance pulsed is well-established, mechanisms that regulate fluxes boundaries are not well understood. The aim our study was to determine extent marsh consumers regulated prey subsidy estuarine oligohaline reaches an Everglades estuary. We characterized cyprinodontoid, invertebrate sunfish move into upper estuary from adjacent drying marshes. In response pulse, we examined numerical, fitness dietary responses three focal estuary; two species (largemouth bass bowfin) accompanied as result drying, one (snook). At onset subsidy, switched diets consume larger (sunfishes), while bowfin maintained similar (cyprinodontoids invertebrates respectively) than pre post subsidy. From consumption this (marsh species) snook (estuarine exhibited gains did not. both benefitted found evidence freshwater shunted some away snook. Of sampled stomachs, 41% biomass eaten by consumers, 59% consumed consumer. conclude amount available may be greater absence thus magnitude could depend dynamics donor communities.