沙蚕(Perinereis aibuhitensis)对老化贝类养殖沉积物的生物修复研究

在连续多年进行底栖贝类高密度养殖的滩涂海域,沉积物老化现象十分突出,养殖沉积环境的修复是改善养殖环境的重要途径,而沙蚕是一种优良的潜在生物修复物种。为了探索老化养殖沉积环境的最优生物修复方式。以文蛤(Meretrix meretrix)老化养殖滩涂沉积物为研究对象,投放不同密度(高密度:0.30 kg·m^-2,中密度:0.20 kg·m^-2,低密度:0.10 kg·m^-2)的双齿围沙蚕(Perinereis aibuhitensis),通过6个月的现场修复试验,检测分析沉积物中氧化还原电位(Eh)、温度(t)、pH、硫化物、总氮(TN)、总磷(TP)及总有机碳(TOC)含量的变化特征,研究双齿围沙蚕对沉积物的生物修复效果。结果表明,4-9月各试验组沉积物的Eh、pH、T整体上升,平均值分别为(-291.70±75.23) mV、(7.56±0.17)、(15.70±3.75)℃,9月各试验组沉积物中Eh、pH、t值最高分别为-116.43m V,7.91,20.36℃,但试验区域沉积物性质依然属于还原、弱碱性环境;4-9月各试验组沉积物的硫化物、TOC、TN整体下降,平均值分别为(400±66)mg·kg^-1、(1.10%±0.19%)、(0.17%±0.05%),9月中密度试验组沉积物中硫化物、TOC、TN最低,分别为269 mg·kg-1、0.83%、0.07%,TP呈前期略微下降,后期上下波动的趋势。研究结果表明双齿围沙蚕在一定程度上可以改善老化养殖沉积物的还原环境,降低老化养殖沉积物中过高的硫化物、TOC、TN、TP含量,其修复作用与投放沙蚕的密度有关,在该试验条件下,0.20 kg·m^-2的投放密度较为适宜。该研究为大规模的沿海老化滩涂底质环境修复提供了一定的理论和实践基础。

Study on Bioremediation of Perinereis aibuhitensison Aged Shellfish Culture Sediments

The sediments aging is a prominent phenomenon in the tidal flats where high-density culture of benthic shellfish is carried out for many years,and the remediation of the shellfish cultured sediments is an important way to improve the culture environment,ragworm is one kind of potential excellent bioremediation species for aged sediments.In order to explore the best bioremediation methods for aged shellfish culture sediments.In this study,Perinereis aibuhitensis with different densities(high density:0.30 kg·m^-2,medium density:0.20 kg·m^-2,low density:0.10 kg·m^-2)were putted on the aged culture sediments of Meretrix meretrix,and through 6 month field bioremediation test,the content of Eh,T,pH,sulfide,TN,TP,TOC in the sediments were detected and their change features were analyzed to study the bioremediation of P.aibuhitensis on aged shellfish culture sediments.The results showed that the Eh,pH and T in the sediments of each experimental group showed a continuous upward trend overall from April to September,the average values were(-291.70±75.23)mV,(7.56±0.17),(15.70±3.75)℃,respectively,the values of Eh,pH and T in the sediments of each experimental group were the highest in September,the highest values were-116.43 mV,7.91,20.36℃,respectively,however,the nature of sediments in the experimental area remains a reducing,slightly alkaline environment.The sulfide,TN,TOC in the sediments of each experimental group showed a continuous downward trend overall from April to September,the average values were(400±66)mg·kg^-1,(1.10%±0.19%),(0.17%±0.05%),respectively,the values of sulfide,TN and TOC in the sediments of each experimental group were the lowest in September,the average values were 269 mg·kg^-1,0.83%,0.07%,respectively,the TP showed a slight decline in the previous period,and fluctuated in the late stage.The results showed that P.aibuhitensis can improve the reducing environment of sediments to some extent,reduce the excessive content of sulfides,TOC,TN,TP in aged shellfish culture sediments,however,its repairing effect is related to the density of the P.aibuhitensis,the optimum density was 0.20 kg·m^-2 under given conditions.This study established a certain theoretical and practical foundation for the large-scale coastal aged tidal flat sediments environment restoration.