Effects of different aquaculture methods for introduced bivalves (Hyriopsis cumingii) on seston removal and phosphorus balance at the water–sediment interface

Abstract

A field simulation experiment was conducted to test the hypothesis that altering bivalve aquaculture methods could promote the restoration of eutrophic waterbodies. We used three aquaculture methods – benthic aquaculture, suspended aquaculture, and macrophytes/bivalve combined aquaculture – to (1) investigate their effects on seston removal through monitoring water turbidity, pelagic and benthic algae, and (2) compare their impacts on the phosphorus (P) balance at the water–sediment interface by determining different forms of P contents in the water and sediments. The results showed that the seston removal effects did not differ significantly among these three aquaculture methods. Furthermore, the changes of all investigated P parameters in the water and sediments showed that P release occurred in the benthic and suspended aquaculture treatments. The suspended aquaculture strengthened the regeneration of P from sediments into the water compared with the benthic aquaculture. In addition, the results of a principal component and classification analysis showed that macrophytes/bivalve combined aquaculture promoted the maintenance of restoration effects and P balance at the water–sediment interface. In conclusion, benthic aquaculture coupled with replanting submerged macrophytes is a better choice for water managers when using biomanipulation of bivalves to remedy eutrophic waterbodies.