Fish mediate high food web connectivity in the lower reaches of a tropical floodplain river.

摘要: High levels of hydrological connectivity during seasonal flooding provide significant opportunities for movements fish between rivers and their floodplains, estuaries the sea, possibly mediating food web subsidies among habitats. To determine degree utilisation sources from different habitats in a tropical river with short floodplain inundation duration (~2 months), stable isotope ratios fishes available were measured three (inundated floodplain, dry season freshwater, coastal marine) lower reaches Mitchell River, Queensland (Australia). Floodplain constituted majority diet large-bodied (barramundi Lates calcarifer, catfish Neoarius graeffei) captured on wet gonadal tissues common herbivorous (gizzard shad Nematalosa come), latter suggesting that critical reproductive phases are fuelled by production. also subsidised barramundi recreational fishery adjacent estuarine areas, broader community freshwater lagoon. These findings highlight importance supporting production large spite episodic nature relatively compared to floodplains humid regions. They illustrate high mediated mobile this system absence human modification, point potential consequences water resource development may reduce or eliminate its floodplain.