庄河海域菲律宾蛤仔底播增殖区自身污染

采用生物沉积物捕集器和封闭式代谢瓶,周年现场研究了庄河海域菲律宾蛤仔的生物沉积速率、排氨率和排磷率.结果表明:菲律宾蛤仔的生物沉积速率、排氨率和排磷率均具有明显的季节变化.生物沉积速率为0.15～1.47 g·ind-1·d-1(年均0.61 g·ind-1·d-1);其排氨率及排磷率分别为0.02～0.40 mg·ind-1·d-1(年均0.17 mg·ind-1·d-1)和0.01～0.39 mg·ind-1·d-1(年均0.13 mg·ind-1·d-1).根据以上结果,估算庄河海域底播增殖菲律宾蛤仔每年产生的生物沉积物达到5.46×107t(干质量),折合有机物9.07×106t、有机碳1.00x106t和有机氮1.18xlO5t;而氨氮和磷酸盐分别为1.49x104t和1.15x104t.表明浅海高密度、规模化菲律宾蛤仔增养殖区自身污染严重,其对环境的影响不可忽视.

Self-pollution in Ruditapes philippinarum bottom-cultured area of Zhuanghe coast

By using sediment trap and closed respirator, a year-round in situ investigation was made on the bio-deposition rate, ammonia excretion rate, and phosphate excretion rate in the Ruditapes philippinarum bottom-cultured area of Zhuanghe coast. The three test rates of R. philippinarum all showed obvious seasonal variability, with the bio-deposition rate ranged in 0.15-1.47 g x ind(-1) x d(-1) (annual average 0.61 g x ind(-1) x d(-1)), ammonia excretion rate ranged in 0.02-0.40 mg x ind(-1) x d(-1) (annual average 0.17 mg x ind(-1) x d(-1)), and phosphate excretion rate ranged in 0.01-0.39 mg x ind(-1) x d(-1)(annual average 0. 13 mg x ind(-1) x d(-1)). Based on these, it was estimated that the annual bio-deposit production by the bottom-cultured R. philippinarum in Zhuanghe coast could reach as high as 5.46 x 10(7) t dry mass, amounting to 9.07 x 10(6) t organic matter (OM), 1.00 x 10(6) t organic carbon (OC), or 1.18 x 10(5) t organic nitrogen (ON), and the annual NH4+ -N and PO4(3-)-P productions were 1.49 x 10(4) t and 1.15 x 10(4) t, respectively. Our results suggested that for the large scale and high density bivalve culture in China coasts, the potential impacts of self-pollutants by filter-feeding bivalves on the environment should not be neglected.