Bioremediation Effect Of Introducing Perinereis Aibuhitensis Grube And Scapharca Subcrenata Lischke On Shrimp Pond

Clam worms or Lischke of different density were introduced to enclosures breeding shrimp in this experiment, the ecological effects of these benthos on sediment quality and water quality were demonstrated in order to provide reference on practicing bioremediation of contaminated shrimp pond, and the results come out as follow:1. Effect of introducing Perinereis aibuhitensis Grube on sediment quality of shrimp pondThe effect of P. aibuhitensis on TN was prominent(p<0.05). Accumulation rate of nitrogen(KN) in the controls is 1.74%, while mean KN of treatments was 1.25%;TP decreased at forepart and increased later in all enclosures, and there was little difference among them; Sulfides of treatments increased slowly than that of the controls during the experiment, the max was (100.45±5.26)mg/kg, The accumulation of TOC is significantly different between control and treatments. Descending of Eh of treatments was slower than that of the controls. These results show that introducing P. aibuhitensis to shrimp pond can significantly improve the sediment quality. 2. Effect of introducing Perinereis aibuhitensis Grube on water quality and yield of shrimp pondTotally the production of enclosures with polychaete worms(treatment) is superior to that of enclosures without worms(control) and the feed efficiency of treatments is lower than that of control(p<0.05). the enclosures with density 0.4 kg·m-2 has the highest production([165.4±8.7)g/m2] and the water quality is the best. with the density of worm increasing, TAN, nitrite and pH tend to be higher and more unstable which may make the survive rate of shrimp decrease. Polychaetes also have significant effect on the transparency of pond water. According to these results, the presence of worms stimulates release of inorganic nitrogen from sediment to overlying water, which accelerate the growth of phytoplankton. Overly high worm...