The influence of Tubificid worms bioturbation on the exchange of phosphorus across sediment-water interface in lakes

To examine the effects of bioturbation of Tubificid worms on phosphorus exchange across sediment-water interface in lakes,the laboratory incubation experiments were carried out with sediments and lake water from Meiliang Bay and the estuary of Dapu River in Lake Taihu.Rhizon samplers were used to acquire pore water.Tubificid worms increased sediment water content and redox potential in surface sediment,and decreased Fe2+ in pore water.For sediment from Meiliang Bay,the Tubificid worms did not altered significantly SRP in pore water,while accelerated SRP release from sediment to overlying water.But for sediment from the estuary of Dapu River,Tubificid worms decreased SRP in pore water and inhibited SRP release from sediment to overlying water.It suggested that ferrous iron may play an important role in explaining different results.