Effect of fishing effort on the trophic functioning of tropical estuaries in Brazil

A trophic web is a network of complex interactions and energy links between species. These can be simplified into trophodynamic models, such as Ecopath (EP) EcoTroph (ET), important tools providing the holistic view needed for ecosystem approach to fisheries. We described food structure by developing an EP model Santa Cruz Channel (SCC), large tropical estuarine system in northeastern Brazil, surrounded mangroves highly subject impacts domestic pollution, industry, artisanal fisheries, aquaculture. In addition, considering ecological fisheries perspectives, we developed ET models three neighboring Brazilian estuaries (SCC; Sirinhaém – SIR Mamanguape MAM) explore levels exploitation that affect their functioning. Our consisted 32 compartments (three primary producers, six invertebrates, 22 fish, detritus). Keystone Index Mixed Trophic Impact analysis pointed several groups commercial relevance are also ecologically relevant lack fishing regulations, Snooks (Centropomus spp.), Jacks (Caranx spp.) Barracudas (Sphyraena spp). Fishery across level spectrum differ ecosystems, which causes top-down effects depending on dynamics each system. The pressure affects mainly low intermediate Level (TLs) MAM SCC high TLs estuary. Consequently, decrease biomass TL was found with increasing effort, respectively. findings contribution modelling estuaries, indicating both approaches effective improve understanding functioning fishery effect ecosystems. Additionally, knowledge key processes systems may help enhance conservation initiatives sustainable use ecosystem, protected areas, temporal control fishing, catch size limit.