【作者】 周毅；

【导师】 相建海； 张福绥；

【作者基本信息】 中国科学院海洋研究所 ， 海洋生物学， 2000， 博士

【摘要】 近年来，由于对海区不合理的开发，我国浅海贝类筏式养殖接连遭受重创，这亟需从理论上和实践中确定养殖容量和养殖模式。本文在我国北方典型养殖海湾四十里湾对筏式养殖的贝类开展了现场生理生态学研究，对贝类对浮游植物等悬浮颗粒物的处理过程即贝类对颗粒有机物及营养元素C、N、P的摄食、吸收、排泄、排粪和生长进行了剖析，分析了贝类在沿岸养殖生态系中的物质和营养循环中所扮演的角色，为海区贝类养殖容量和养殖模式的最终确定提供了基础数据。另外，本文还对海水、沉积物及生物体中磷的分析方法进行了大量的实验工作。主要结果如下： ①比较系统地评述了双壳贝类的生物沉积（biodeposition）的原理、测定方法及其生态效应。贝类通过生物沉积在沿岸生态系中的物质和营养循环中扮演着重要的角色。国际上已有不少研究专门报道了贝类在海区现场的生物沉积。而在我国，这方面的研究却罕见。 ②综述了双壳贝类各种形态的N和P排泄及其生态效应。对于我国广泛养殖的栉孔扇贝、海湾扇贝和牡蛎等双壳贝类的TDN、TP排泄尚未见报道。 ③在6～7月，在四十里湾的不同养殖海区（8个站位）对扇贝的生物沉积进行了现场测定。在整个四十里湾海区，一龄栉孔扇贝（壳高41.1±4.1mm，软体干重0.48±0.10g/ind））每个每天所产生生物沉积物干重平均为59.9mg，对颗粒有机质（POM）、颗粒有机碳（POC）、颗粒有机氮（PON）和颗粒有机磷（POP）的生物沉积速率范围及平均值分别为：6.88、3.09、0.392和0.022mg/ind·d。还在一个站位测定了海湾扇贝（壳高24.6±2.3mm；软体干重0.14g/ind）的生物沉积速率为24.3mg/ind·d，或179.2mg/g·d。不同站位一龄栉孔扇贝的生物沉积速率有较大变化，这主要与饵料浓度不同有关。二龄栉孔扇贝（壳高60.9±8.2mm；软体干重1.91±0.32g/ind）的生物沉积速率平均为112.7mg/ind·d，对POM、POC、PON和POP的沉积速率分别是一龄扇贝的1.85倍、1.68倍、1.77倍和2.33倍。养殖海区与非养殖海区比较，前者近海底沉积速率是后者的1.51～3.47倍。根据以上数据，作者计算了中等规格栉孔扇贝（用壳高41.1±4.8mm扇贝估算）在四十里湾在夏季每天的生物沉积量达162吨（干重），或18.6tPOM、8.37tPOC、1.06tPON和60kgPP。在四十里湾的贝类筏式养殖海区，可以估计贝类每年因生物沉积的生产而循环427t N和98.0t P（包括20.0t OP的贡献），它们能分别满足浮游藻类生产所需求N和P的17.0%和28.3%（其中OP贡献6．9％）。可见，贝类在养殖生态系的物质和营养盐循环中扮演着重要的角色。高密度、大面积的贝类养殖使大量的生物沉积物聚集于海底，可能对海区环境产生冲击。作者分析，98年8月份烟台养殖区赤潮的发生很可能与海底生物沉积物营养盐的快速释放以及粕孔扇贝大面积死亡而使浮游藻类失去了摄食控制有关，而风平浪静和养殖笼对水流的阻挡也为赤潮的发生提供了有利条件。 一 ④采用半现场流水系统法测定了柿孔扇贝在不同养殖密度、不同养殖模式（扇贝单养、贝藻混养、贝藻参混养冲的生物沉积。实验时间尺度大，前后计80天。结果说明扇贝的生物沉积速率与其养殖密度呈反比关系。养殖密度的高低影响饵料浓度的变化（两者呈负相关的对数函数关系X 而饵料浓度的高低直接决定着扇贝的生物沉积速率的高低，两者呈正相关关系（生物沉积速率与POC和叶绿a分别呈对数和指数函数关系卜不仅生物沉积物的数量与养殖密度（或饵料浓度）有关，生物沉积物的质量同样与养殖密度（或饵料浓度）有关。柿孔扇贝的养殖使沉积物的有机质含量及C、N和P含量降低，且密度越高，它们的含量越低。这反映了扇贝对环境的适应能力。在海带和扇贝的混养模式中，海带对扇贝生物沉积物的数量和质量不构成影响，当然这是在海带不影响浮游植物数量的前提下得出的结果。而实际上在自然海区两者可能是竟争关系。 ⑤对从海区取回到实验室的多种滤食性动物，包括经济双壳贝类（柿孔扇贝、海湾扇贝、长牡顿、贻贝、菲律宾蛤仔等）和养殖中的污损动物（栖海鞘、玻璃海鞘、藤壶、玫斑棱蛤）的N和P排泄进行了测定，包括排泄成分和排泄速率。在N排泄中，NH厂H占主要部分，如笼式养殖的双壳贝类NH。－N占总N排泄的70％以上，平均值范围为70．8～80．1％。氨基酸是第二大排泄成分，平均占总N排泄的10～25％。其它形态的N，如尿素、亚硝酸盐和硝酸盐也有检出，如双壳贝类尿素氮在总氮排泄中占二～5％。但在双壳贝类中未检出尿酸氮。比较而言，海鞘、藤壶的尿素氮相对高一些。在 P排泄中，OP约占 TDP排泄的 15～27％。柿孔扇贝 TDP排泄速率为0二slpth＊／h一。作者以实验室测定结果计算，在整个四十里湾的夏季，所养殖的双壳贝类每天将排泄 4．54t总?更多还原

【Abstract】 Owing to irrational exploitation, the shellfish raft culture industry has been continuously inflicted by casualties, which urgently needs to ascertain carrying capacity and culture methods in coastal areas. In this paper, studies on the characteristics of physiological ecology of sea raft-cultured bivalves and the processing of suspended particulate materials by bivalves, i. e. ingestion, absorption, excretion and defecation of particulate carbon, nitrogen and phosphorus nutrients by mollusks, are conducted in order to understand the role played by bivalves in material and nutrient circulation of coastal culture ecosystem. In addition, a more accurate and simplified ignition method is developed for determination of inorganic, organic and total phosphate in sediments and organisms. The main results are as follows.(ID Biodeposit production by the scallop Chlamys farreri in summer in raft culture areas of Sishili Bay, Yantai, has been determined in situ in eight stations. The result shows that biodeposit of 59.9mg is produced every day by a one-year-old scallop with shell height of 41.1?.1 mm and soft body dry weight of 0.48?.lOg/ind, and the mean biodeposition rates of POM, POC and PON by the scallops are 6.88, 3.09, 0.392 and 0.022 mg/ind?d, respectively. In one station, biodeposition rate of the bay scallop Argopecten irradians, whose shell height is 24.6?.3mm and soft body dry weight is 0.14 glind , is 24.3 mglind d or 179.2mg/g d. The biodeposition rates of the one-year-old Chlamys farreri vary in different areas of the bay, which is mainly related to total suspended particulate matter. The average biodeposition rate of two-year-old Chlamys farreri with shell height of 60.9?.2mm, soft body dry weight of 1.91?.32 g/ind is 112.7 mg/md d, and POM, POC, POON and POP deposition rates of the scallop are respectively 1.85, 1.68, 1.77 times as high as that of the one-year-old scallop. Compared to non-culture areas, theA慖deposition rate of particulate matter near the bottom in shellfish cultUre reas is．sl～3．47times ashighasm成oftheformeL he eveWd叮 biodepositprowctionbyall of＊theyallcultivated scallops In the Sishili bay in summer is 62 t（ry weight），or 86t POP， 8．37 tPOC，1．06t PON and 60kg PR It is estimated that’427t N and 98．ot P are circufored ndregenerated every year owing to blodeposlt production by scallops，which can meet heannual demands for．0％and 28．3％of N and P resPectively for pelagic pnm叼production of＊thetion whole bay ②Blodeposit production by Chb呗 fo册ri was also determined In semi－ieldwater－flowing systems within longer length of time（80dnys）．The results show that theblod聊sition rate Is negatlvelycorrelated to scallop，orPOsltlvelycorrelated to foodconceddatlon which vanes ith scallop density Boththe quantity andthe quality of＊theyblodeposit re related to肋d conce血tion．The hi归 the number ofscallops，the lowerthe o用amc m劝贸 comem orC，N and P coment of＊the＊＝ sediments，Which reflects t比scallop’sablllty to叨apt to de environment．In Lamln皿m仰onica andobp灿八polycultUre patterns，there Is no markea effect of the kelp on btrieposit production of hescallop，but in hehe ield，the kelp culture m叮 reduce the blodeposltlon rate of＊theosltlon scallopvia effects on phytopl讪on production． ＠N毗 P excretion by vanous ilter feeding orgamsms collected肋m coastalculture reas，Incfu41ngo2p加ri，Ampecten u’毗的us，蜘疗us eMIs，o删ostreagpo，！udmpes p》f帅Jn—urn咖5uhg Ofg一S——伽2C0ye，0OnO fnoof7na7KBahuns amPhi”it6 and丹aPezium liratum），were studied．InN excretion，NH4－N Is themain form，which accow吐s for more than 70％（mean 70．8～80．l％）ofhh excretion．Although anunonla is the domin恤 form ofnltrogen excretedbythe spedes，amlno acidsare the second main component of N excretion In all stUdwt ofganlsms，Which amounts to10－25％ofTN excret＊．Other forms ofN excretion by the spedes are urea，mme and更多还原