Impact of clam and mussel farming on benthic metabolism and nitrogen cycling, with emphasis on nitrate reduction patways

The influences of suspended mussel and infaunal clam cultivation The influences of suspended mussel and infaunal clam cultivation on benthic metabolism and nutrient cycling were compared in Goro lagoon, Italy. Both aquaculture types stimulated benthic metabolism, with sediment oxygen demand (SOD), CO2 and ammonium effluxes of up to 14, 16 and 1.2 mmol m–2 h–1. However, whilst mussel farming preferentially stimulated anaerobic metabolism and sediment reduction, clam farming did not. The mussel ropes were also large oxygen sinks and ammonium sources, with oxygen consumption and ammonium production rates of 1.4 to 1.5 and 0.18 to 0.43 mmol kg–1 h–1. Consequently, the overall impacts of mussel farming on oxygen and nutrient dynamics were much greater than those of clam farming.