三沙市地处南海,除广阔的海域外,还有众多的岛屿(礁),自然资源丰富.西沙群岛、南沙群岛和中沙群岛等组成了我国三沙市南海诸岛.根据多年来我国科研人员在该海区的调查研究,作者对我国三沙市南海诸岛海区的海藻区系进行初步的植物地理学研究,以探讨该海域海藻区系的温度性质及其与其它相关海区海藻区系的关系.研究结果表明,我国三沙市南海诸岛底栖海藻区系与北太平洋西部海藻相同种数最多的是区系性质为热带性的南海南区,因此海藻区系的温度性质具有很明显的热带性.另外,三沙市南海诸岛海藻区系与印度洋海藻区系有很多共同成分,两地共有种数高达184种,为南海诸岛海藻总数的63％,进一步证明我国三沙市南海诸岛区系属于暖水性印度—西太平洋区,印—马亚区.研究结果对系统调查分析我国三沙市底栖海藻资源进而开发利用南海资源有重要的意义.

Based on the specimens of Polysiphonia collected from Hainan Island,South China Sea in 2007 and 2008,we found that the morphology of some specimens differ from other known species.After careful examination,we drew the conclusion that these specimens belong to a new species Polysiphonia hainanensis sp.nov.The description of the new species is given below:Polysiphonia hainanensis sp.nov.(Fig.1:1—5;Fig.2) Description:Thallus erect and caespitose,2—5cm high,up to 7cm,creeping branches in disorder at base,prostrate branches 125—132μm in diameter,of segments about 0.5—0.8 diameter long,attached by numerous unicellular rhizoids,which are cut off from the proximal ends of the pericentral cells and terminate in lobed discs;erect branches arising from creeping branches,segments compressed and short,150—310μm in diameter,segments of main branch about 0.2—0.3 diameter long,every 2—3 segments in a spiral arrangement with 1/4 divergence,lateral brachlets at low a few,upper dense,cervicornis branching at more upper place,ultimate short and attenuated to a point apex,about 33.0—49.8μm in diameter,usually to outer turn curve;apical cell small,as a colorless awn point;trichoblasts once or twice forked,soon deciduous leaving,no scar-cells;pericentral cells 12(—14);ecorticate.Tetrasporangia spiraling somewhat in long continuous series the ultimate,subspherical to ovoid,(39.6—46.2)μm×(52.8—59.4)μm.Antheridial branches and cystocarps were not found.The present new species is closely related to Polysiphonia hendriyi var.luxurians Holl.in external appearance,branching,numbers of pericentral cells,ecorticate and color of frond,but this new species can be distinguished from Polysiphonia hendriyi var.luxurians Holl.by the thickset frond,2—5(—7)cm high,and the segments in the main axes commonly 0.2—0.3 diameters long.Remark:This new species is also closely related to Polysiphonia howei Hollenberg in Taylor by the pericental cells 10—12 and ecorticate,but differing in its frond small,1—2cm high,prostrate,produced large patches(cushion) on rock,unbranched or with few to several short laterals,and tetrasporangia in spiral series.Etymatogy:The specific name hainanensis is named after the type locality.Holotype and paratypes are deposited at the Marine Biological Museum,Chinese Academy of Sciences(Qingdao).

Three sampling sites within intertidal zones of Xindao,Jiaozhou Bay,Shandong Peninsula,were set up to explore the community of macrobenthos during August 2003 to May 2004.Fourty-three species were found in the intertidal zones,of which 27 distributed in low tidal zone(X3),20 in medium tidal zone(X2) and 19 in high tidal zone(X1),and only 6 species are common in the three tidal zones.The total average density of benthos is 102.5 ind./m2,the highest in May,144.67 ind./m2,the lowest in February,52.66 ind./m2;while the total average biomass is 60.01g/m2,the highest in November,102.99 g/m2,the lowest in February,11.87 g/m2.Meanwhile,the density and biomass are evidently different within four seasons.

利用2002年9月在长江口附近海域进行的大型底栖动物定量采集样品,采用物种优势度计算方法和大型多元统计分析软件PRIMER,研究了该海域大型底栖动物群落的优势种组成和物种多样性、生物量和丰度、群落等级聚类分析（CLUSTER）和非度量MDS标序以及群落受污染扰动情况。本次调查共获得长江口附近海域大型底栖动物154种,其中多毛类环节动物60种,甲壳动物30种,软体动物28种,棘皮动物25种,其它类群动物11种。群落中优势种的地位都不明显,只有虫（Listriolobussp.）、豆形短眼蟹（Xenophthalmus pinnotheroidesWhite）、拟单指虫（Cossurella dimorphaHartman）为相对重要的种类。栖息种数、平均生物量和丰度以及3个多样性指数H′、D和J的空间分布无明显的规律,在122°E以东海域呈不连续的斑块或镶嵌状分布。群落结构聚类分析和MDS标序表明,20个取样站的群落结构相似性程度都非常低,为10%-30%,仅有A12和E4两个站Bray-Curtis相似性系数达到50%。ABC曲线表明,近长江口的A4站和A14站的底栖动物群落已有受到一定程度的轻微污染扰动的趋势;而距长江口较远的P9和P5两站ABC曲线状况正常,表明该处的大型底栖动物群落尚未受到干扰。

于2003年3-10月,通过在太湖中设置15个封闭性实验围隔,构建出5种生态型中华绒螯蟹养殖模式,即放养中华绒螯蟹(规格6.25±0.36g/ind)+ 螺蛳+水草分别为:3000ind/ha+0kg/ha+3000kg/ha(Ⅰ)、3000ind/ha+2250kg/ha+3000kg/ha(Ⅱ)、4500ind/ha+2250kg/ha+6000kg/ha(Ⅲ)、4500ind/ha+3375kg/ha+6000kg/ha(Ⅳ)、6750ind/ha+3375kg/ha+6000kg/ha(Ⅴ),比较分析其养殖效果及其生态环境效应.结果表明,生物学效果综合指数依次为Ⅳ＞Ⅴ＞Ⅲ＞Ⅱ＞Ⅰ,其中Ⅳ、Ⅴ、Ⅲ显著高于Ⅱ、Ⅰ(P＜0.05).各养殖模式的水温、pH值、CODCr含量和浮游动物多样性指数、底栖动物多样性指数与湖区无显著性差异(P＞0.05),而各养殖模式的DO和Ⅲ、Ⅳ的SD、水色、电导率、TSS、N、P、浮游植物密度和浮游植物多样性指数等理化和生物环境指标均显著优于湖区(P＜0.05);N、P平衡分析表明,在全部采收养殖体系内水草的情况下,各养殖模式均能从水体中净输出N、P,其中Ⅲ、Ⅳ的净输出效率最高.相关分析显示,养殖体系内的水质环境状况随着水草和螺蛳数量的增加而得到显著改善.因此,增栽水草、放养螺蛳、适中的中华绒螯蟹放养量和适宜的管理措施是维持中华绒螯蟹养殖生态系统环境效益和养殖效益良好的重要条件,有利于太湖渔业生产和环境保护的可持续发展.

Field research of macrobenthic fauna at 10 stations in Jiaozhou Bay was carried out seasonally from February of 1998 to November of 1999. There were fewer species and the indices of biodiversity (Shannon-Wiener index) were lower in Stations 2, 3, 7 and 9 than in other stations. Stations 2 and 3 were situated in the inner area near Cangkou, a heavily polluted area. Stations 7 and 9 were situated at the mouth of the bay, where the bottom sediment was coarse sand. The indices in Stations 1 and 6, where the bottom sediment was soft mud, were high. The average Shannon-Wiener index of all the 10 stations was lower in 1999 than in 1998, although the difference was not remarkable. In both of the two years, the average Shannon-Wiener indices were lower in spring and autumn than in winter and summer; Pielou’s evenness index was highest in summer and lowest in spring; and the species richness index was slightly higher in winter and slightly lower in autumn. The relationship between biodiversity of the macrobenthos in Jiaozhou Bay and human activities should be studied further.