摘要
扇贝保苗活动是在扇贝入海养殖前进行的暂养阶段,可提高扇贝的适应能力,但保苗过程中扇贝死亡情况时有出现。为了解扇贝幼苗养殖环境质量状况,于2017年4—5月对莱州扇贝保苗池塘进行了调查研究。结果显示,有机污染评价指数小于1,环境状况良好,未受到有机污染;营养状态指数大多大于1,富营养化现象频繁出现;综合环境质量评价指数大部分小于0.75,表现为轻度污染。化学需氧量和无机氮是各项污染的主要因素,尤需重视。研究共鉴定出浮游植物5门52种,硅藻种类数最多,优势种呈现稳定多样化,生物多样性高,生态结构较稳定。研究表明莱州扇贝保苗池塘环境质量整体上适宜扇贝幼苗的养殖,扇贝生长状态受自身体质的限制。
In the course of harvest season,we selected scallop which was with good growth condition and larger individuals to cultivate indoors,and we stimulated them to spawn eggs at the same time. The spawning interval was 20 days at the two time. The larva of scallop can be transferred to seedling preservation pond for about 40 days after about 20 days of indoor cultivation. Scallop seedling preservation is a temporary culture stage before scallop is cultured into the sea,which can improve the adaptability of scallop and the survival rate of the seedling breeding. So the quality of water environment in seedling preservation pond would directly affect the quality and yield of scallop in that year. In general,the water temperature of seedling preservation pool should be stable above 13℃,the temperature difference of seedling pond should be less than 2℃,the salinity difference should be 5,the chemical oxygen demand should be less than 3 mg/L,and the p H should be stabilized in the range of 8. 0 to 8. 4. All the same,the death of scallop occurred in the process of scallop seedling preservation. In particular,the growth of the second batches of seedlings was slow and the survival rate was low. The death of scallop may be caused by poor water quality or its own weak constitution. In order to comprehend the environmental quality of scallop seedling culture,investigation were conducted on the pool of scallop seedlings in Laizhou from April to May of 2017. The results showed that the organic pollution assessment index is less than 1. The environment was in good condition and was basically uncontaminated. The nutritional state index was more than 1,and the phenomenon of eutrophication was frequent. And the comprehensive environmental quality evaluation index was less than 0. 75,and showed mild pollution. Chemical oxygen demand and inorganic nitrogen was the greatest contributors to all kinds of pollution. There were a total of 52 species of planktonic algae were identified in the survey,with the largest number of Bacillariophyta,such as Gyrosigma sp.,Thalassiothrix sp.,Nitzschia sp.,Cymbella sp.,Diploneis sp.,Pinnularia sp.etc. The dominant species was stable and diversified, the biodiversity was abundant, and the ecological structure was more stable. On the whole,the environmental quality of the pool was suitable for the cultivation of scallop seedlings. But the seedling preservation activities made the environment of the seedling preservation pool deteriorate,the water quality dropped,and the inappropriateness of the seedling preservation environment led to the death of scallop seedlings. So it is necessary to recognize the present situation of environmental quality,pay attention to the existing problems and take effective measures to improve it. The results of seedling preservation showed that the death rate of the two groups of seedlings appeared earlier and the mortality rate was higher,which was influenced by the health of scallop seedlings and the quality of environment.Therefore,we should select the fine varieties with good growth state and larger physique as parent of shellfish.
作者
李希磊
于潇
杨俊丽
崔龙波
LI Xilei;YU Xiao;YANG Junli;CUI Longbo(College of Life Science,Yantai University,Yantai 264005,China)
出处
《渔业研究》
2018年第3期186-195,共10页
Journal of Fisheries Research
基金
山东省现代农业产业技术体系建设专项资金(SDAIT-14)
关键词
扇贝保苗
水质
浮游植物
cultivation of scallop seedlings
water quality
phytoplankton
