虾夷扇贝对镉的蓄积和排放规律

实验研究了虾夷扇贝不同组织(鳃,内脏,外套膜和贝柱)在受到重金属Cd2+污染后的蓄积和排放规律。结果表明:(1)在染毒实验期间,海水中Cd2+不断被虾夷扇贝累积,且其内脏团、外套膜、鳃、贝柱中Cd2+的蓄积量均随暴露时间增加而增大。到第14 d均达到平衡。达到平衡后Cd2+蓄积量(干重)和蓄积速率均为:内脏团>鳃>外套膜>贝柱。其数值分别为:562.93×10-6和40.21×10-6/d,354.27×10-6和25.31×10-6/d,125.36×10-6和8.95×10-6/d,34.49×10-6和2.46×10-6/d。(2)排放实验期间,各组织中Cd2+蓄积量随排放时间的增加而逐渐下降。至排放第10天各组织中的Cd2+排出率为:贝柱﹥鳃﹥外套膜﹥内脏,各组织中Cd2+含量明显降低。表明:经短时间镉污染的虾夷扇贝,转入清洁海水一段时间对其体内Cd2+的排出是很有效的。(3)不同浓度Cd2+对虾夷扇贝各组织的影响实验表明:当Cd2+浓度相同时,扇贝不同组织蓄积量和富集系数次序均为:内脏团>鳃>外套膜>贝柱。虾夷扇贝各组织Cd2+蓄积量均随着暴露水体中Cd2+含量的增加而增加,海水中Cd2+浓度不影响Cd2+在虾夷扇贝各组织内的分配次序。而同一组织对Cd2+的富集系数与其蓄积量不同,它随着金属浓度的升高而呈现下降的趋势,贝柱的富集系数始终处在最低值。

Cadmium bioaccumulation and bioelimination in Patinopecten yessoensis

This experiment approached the rule of cadmium bioaccumulation and bioelimination in different tissues(gill,visceral mass,mantle and scallop) in Patinopecten yessoensis.The results showed that cadmium was accumulated constantly during the cadmium exposure experiment.And the bioaccumulation in gill,visceral mass,mantle and scallop increased with the elapse of time,which achieved balance on the 14th day.At this time,the order of their cadmium bioaccumulation(dry weight) and bioaccumulation rate(from large to small) was visceral mass,gill,mantle and scallop.The dates respectively were 562.93×10-6 and 40.21×10-6/d,354.27×10-6 and 25.31×10-6/d,125.36×10-6 and 8.95×10-6/d,34.49×10-6 and 2.46×10-6/d.The cadmium bioaccumulation(dry weight) droped with the elapse of time during the cadmium elimination experiment.And the order of their cadmium elimination rate(from large to small) was scallop,gill,mantle,viscera massl the 10th day.The cadmium elimination in each tissue droped obviously,which showed that it was effective for P.yessoensis,after exposured a short time,to eliminat cadmium by turning to clean water a period of time.The rule of the cadmium bioaccumulation and enrichment coefficient(from large to small) was visceral mass,gill,mantle and in the same cadmium concentration.And the cadmium bioaccumulation in each tissue increased along with the increase of the cadmium concentration,however the allocation sequence within the organizations wasn’t affected by it.The enrichment coefficient in the same tissue droped allong with the increase of cadmium concentration.And the scallop’s enrichment coefficient was always at the lowest.