桑沟湾贝藻养殖区附着生物生态效应研究

IOCAS-IR > 海洋环流与波动重点实验室

	桑沟湾贝藻养殖区附着生物生态效应研究
其他题名	Ecological Effects of Fouling Organisms on Shellfish and Coastal Environment
	齐占会
学位类型	博士
	2009-05-14
学位授予单位	中国科学院海洋研究所
学位授予地点	海洋研究所
关键词	附着生物鞘扇贝牡蛎呼吸排泄生物沉积桑沟湾
摘要	附着生物又称污损生物，是附生在海洋设施和生物体表面的动物、植物和微生物等生物的总称（Azis et al., 2001）。附生在养殖器材和生物体表面的数量巨大的附着生物，对贝类养殖和海湾生态系统内的物质和营养盐循环等多个方面产生影响。本研究以北方重要的养殖海湾----桑沟湾为研究对象，对贝藻养殖区附着生物的群落演替及其生态效应进行了研究。主要研究结果如下： ① 2007年5月至2008年5月，采用挂网的方法对桑沟湾栉孔扇贝和海带混养区的附着生物的季节变化进行了研究。结果显示挂网上的附着生物具有显著的季节变化特征，网片上的附着生物湿重与水温的变化相一致，生物量为3~1210 g•m-2。2月份附着生物的生物量最低，8月份最高。2007年9月至11月，对栉孔扇贝养殖笼上和贝壳上的附着生物种类和数量进行了研究。结果显示9月份养殖笼上附着生物的湿重约为1.94 kg，10月份降至0.99 kg，11月份又稍有增加，为1.03 kg。扇贝壳上的附着生物变化趋势与养殖笼上的相同，9~11月份壳上附着生物的数量约0.49~2.09 g。扇贝养殖笼上可鉴定的大型附着生物约23种，包括藻类、海鞘类、苔藓虫类、环节动物、腔肠动物、软体动物、甲壳动物和海绵动物等。玻璃海鞘、柄海鞘、紫贻贝和苔藓虫等是附着生物群落中的优势种。 ② 通过在栉孔扇贝和虾夷扇贝上壳上添加不同重量的“模拟附着生物”（速凝水泥）的方法，研究了贝壳上附着生物的重量对这两种扇贝生长和存活的影响。结果显示水泥重量是上壳重0.5-3倍的各组实验组扇贝的生长和存活与对照组（未添加水泥的扇贝）之间没有显著差异。说明贝壳上附着生物重量为上壳的3倍重时，也不会显著影响扇贝生长存活。9-11月份贝壳上的自然附着生物的重量约为1.47-2.09 g，为上壳重的28.16 (±38.6)%—31.29 ± (31.63)%。因此，贝壳上附着的生物重量不太可能对扇贝的生长存活造成显著的负面影响。 ③ 在桑沟湾现场测定了玻璃海鞘和柄海鞘的生物沉积速率。9月份（水温约24℃）玻璃海鞘和柄海鞘的生物沉积速率分别为32.14和90.06 mg•ind-1•d-1或（858.99 和467.76 mg•gdw-1•d-1），据此计算，养殖笼上的两种海鞘的生物沉积速率约为84.29 mg•m-2•d-1。海区的自然沉积速率为41.49 mg•m-2•d-1；玻璃海鞘和柄海鞘沉积物中有机质含量分别为14.34%和13.77%，对照组海区自然的有机质含量为14.36%；以上三者有机碳的含量分别为24.72%，23.74%和24.76%；氮的含量分别为0.27%和0.25%，自然沉积物中的氮含量为0.30%。9月份扇贝养殖笼上附着的海鞘将产生2588.16吨的沉积物，即向底部沉积363.77吨的有机物、6.99吨的氮和1.79吨的磷。 ④ 通过测定扇贝养殖笼上优势种附着生物--玻璃海鞘、柄海鞘和贻贝的摄食、呼吸和排泄，研究了这些优势种类对贝类养殖和海湾环境的影响。9月份（水温约24.5℃）玻璃海鞘和柄海鞘对颗粒有机物（POM）的摄食率分别为14.30 和17.01 mg• h-1•ind-1。根据实验结果计算这两种海鞘摄取的颗粒有机物相当于312个扇贝的摄取量，大于笼内养殖的扇贝的摄取量；玻璃海鞘和柄海鞘的耗氧率分别约为0.32和0.18 mg•h-1•ind-1，养殖笼上的这两种海鞘消耗的溶解氧约等于75个扇贝消耗的溶解氧。栉孔扇贝、玻璃海鞘、柄海鞘和贻贝的排氨率分别为33.66 ±11.34，117.90±23.46，35.91±6.22，28.08±3.41 ug NH4-N•gdw-1•h-1。以此估算，9月份玻璃海鞘、柄海鞘和贻贝每天排泄的氨氮约为654.08 kg，相当于16467吨栉孔扇贝（鲜重）排泄的氨氮。海鞘和贻贝排泄的氨氮可提供浮游植物等所需的2.75%的氮，可以提供1204吨海带的生长所需的氮。 ⑤ 一个养殖笼内的栉孔扇贝和全部附着生物（Scallop Culture Unit, SCU）在夏季（6-9月）对颗粒有机物的摄食速率约为43.13-98.94 mg/h，平均74.05 mg/h，期间桑沟湾养殖的栉孔扇贝及附着生物摄取的POM约为1279.58吨；同期，SCU对氨氮和磷（PO4-P）的排泄速率分别为125.59-1432.23 μmol•h-1和76.2-252.89μmol•h-1，期间桑沟湾养殖扇贝及附着生物排泄的氮磷分别为211.09 吨和83.79 吨。一串牡蛎及吊绳和牡蛎壳上的附着生物（Oyster Culture Unit, OCU），夏季摄食率为5-41.43μmol•h-1，耗氧率为16.54-41.76μmol•h-1，对氨氮和磷（PO4-P）的排泄速率分别为35.56-489.34μmol•h-1 和9.92-16.68μmol•h-1。以此估算，夏季OCU可摄取POM535.68吨，消耗溶解氧955.58吨，排泄氮磷分别为62.37 吨和15.50 吨。
其他摘要	Biofouling is defined as the attachment and subsequent growth of a community of plants and animals on structures exposed to the seawater environment (Aziset al., 2001). Biofuling is common phenomenon in the cultivation of bivalves worldwide. Many net pens are made of multi-filament netting materials which are ideal substrates for bio-fouling. Biofouling influence bivalves’ cultivation and water column in many ways. In this paper, the successional development of fouling communities on the scallop cultivation alntern nets and their ecological effects on the cultured scallop Chlamys farreri and the ambient water column characteristics were studied. The main resultes are as follows: The ecological succession of fouling communities on the experimental panels of net material at the scallop and kelp polyculture site was studied from May 2007 to April 2008. Seasonal succession of fouling on the scallop cultivation net and scallop shell were also investigated. The biomass of fouling organisms on the 1-month panels were positively correlated with water temperature, ranged from 3~1210 g•m-2. The wet weight of biofouling was lowest during February and highest in August. The biofouling on 3-month panels was most abundant on the summer and lowest during the winter, with a wet weight of about 2.20 and 0.65 g•m-2, respectively. Fouling quantities on both lantern nets and scallop shells were characterized by a pronounced seasonal pattern. Fouling on lantern nets peaked in September with an average wet weight of 1.94 kg and dropped precipitously in October, followed by a slight increase in November. Similarly, shell fouling declined from September to October, and re-increased in November. The mean weights were 1.47 g, 0.49 g and 2.09 g, respectively. Fouling community on scallop nets and shells is a complex assemblage composed by several taxonomic groups, including Alga, Ascidiacea, Bryozoa, Annelida, Colenterata, Annelida, Mollusa, Crustacea and Spongia. Twenty-three macro-fouling species were identified. In September, the most abundant fouling was ascidians, C. intestinalis and S. clava. In October, the fouling community was predominated by C. intestinalis and blue mussel, M. edulis. The M. edulis was the dominant fouling in November. The artificial fouling which was three times of the upper valve mass did not negatively affect the survival and growth performance (e.g. shell length, muscle, and remaining soft tissue) of the scallop. Under culture conditions, the wet weight of fouling organisms on C. farreri shell was about 28.16(±38.60) % of the mass of the upper valve in September and the dry mass of fouling on P. yessoensis shell was approximately 7.82 (±2.38) % of the dry mass of the upper valve in August, which were much lower than the mass of artificial fouling in this study. Thus, it is unlikely that the mass of natural fouling would exert markedly negative effects on the growth or survival of C. farreri and P. yessoensis. The in situ biodepostion rates of two ascidians C.intestinalis or S.clava were 32.14 and 90.06 mg•ind-1•d-1 (or 858.99 and 467.76 mg•gdw-1•d-1 ), respectively, in September, under a water temperature of 24℃.The organic matter contents were 14.34% and 13.77%, respectively, and the organic carbon contents were 24.72% and 23.74%. The nitrogen contents were 0.27% and 0.25%, respectively. The C.intestinalis and S.clava on one scallop cultivation net may produce 4.14 and 2.55 mg nitrogen one day. In September, the ascidians which fouled on the scallop cultivation nets produced 2588.16 tons biodeposition, including 363.77 tons organic matter, 6.99 tons nitrogen and 1.79 tons phosphorus. The present experiment results indicated that the biodeposition of ascidians may strongly enhance the pelagic-benthic coupling and play an important role in the nutrient regeneration. Thus, the ascidians should be considered as an important component in the bay’s ecological processes ecosystem. The POM uptaked by C.intestinalis and S.clava in Sepember were 14.30 and 17.01 mg• h-1•ind-1, respectively. The POM consumed by C. intestinalis or S. clava of one lantern net was equal 312 scallops. The dissolved oxygen consumed by C. intestinalis or S. clava were 0.32 and 0.18 mg•h-1•ind-1, the oxygen consumed by the ascidians on the lantern net was equivalent to the oxygen consumed by 75 scallops. The ammonium excretion rates of C. intestinalis, S. clava and M. edulis were 117.90 and 35.52 and 28.08 ug NH4-N•g-1•h-1, respectively. The C. intestinalis, S. clava and M. edulis contribute 654.08 kg NH4-N•d-1 to the bay in September, which equal to the NH4-N excreted by 1019 tons of scallop (DTW). The ascidians and blue mussel on lantern nets would provide 2.75% of N demands for primary production and can support a production of kelp about 1204 tons. The assemblage of scallop in one cultivation net and the organisms which fouled on cultivation net and scallop shell was defined as scallop culture unit (called, SCU). The assemblage of oyster on a culture rope and organism on rope and oyster shells was defined as oyster culture unit (called, OCU). From June to September the uptake of POM by SCU ranged from 43.13 to 98.94 mg•h-1, with a mean value of 74.05 mg•h-1. The excretion of NH4-N ranged from 125.59 to 1432.23 μmol•h-1, and the excretion of PO4-P ranged from 76.2-252.89μmol•h-1, from June to September, which means the SCU contribute 211.09 tons N and 83.79 tons. The uptake of POM by OCU in June, August and September ranged from 5 to 41.43 mg•h-1 indicating that the OCU consume 535.68 tons of POM from the bay. The oxygen consumption of OCU ranged from 16.54 to 41.76 mg•h-1，from May to September. The OCU consume 955.58 tons dissolved oxygen from May to September. The excretion of NH4-N by OCU ranged from 35.56 to 489.34 μmol•h-1. The excretion of PO4-P by OCU ranged from 9.92-16.68 μmol•h-1, which means the OCU contribute 62.37 tons N and 15.50 tons PO4-P to Sanggou Bay, from June to September.
页数	91
语种	中文
文献类型	学位论文
条目标识符	http://ir.qdio.ac.cn/handle/337002/1353
专题	海洋环流与波动重点实验室
推荐引用方式 GB/T 7714	齐占会. 桑沟湾贝藻养殖区附着生物生态效应研究[D]. 海洋研究所. 中国科学院海洋研究所,2009.

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