Estimating the population density of prawns by the use of catch per effort data from prawn trawlers at Chilaw

The penaeid prawns of Sri Lanka from estuaries and sea are an important commercial fishery resource. This resource has been exploited over the last century or more by local fishermen using indigenous fishing gear from locally sail-driven or oar-driven fishing crafts. In more recent times, the Fisheries Research Division of the Department of Fisheries undertook surveys of the seas and lagoons of Sri Lanka with a view to ascertain whether any unexploited resources of prawns existed. These publications deal with the species composition, biology, distribution and abundance in the lagoons and inshore waters of Sri Lanka.

澜沧江中上游鱼类生物多样性现状初报

　对澜沧江上游及支流的鱼类和环境调查显示流域片段化对鱼类生物多样性产生了 较大的影响。从漾濞江和西洱河的比较可以看出, 前者因为没有梯级电站, 鱼类的种类和数量并 无太大的变化, 而西洱河由于过度的梯级开发和污染, 鱼类濒于灭绝, 洱海由于江湖的隔绝, 外 来种的引入使得土著鱼类种群数量急剧减少。干流上大坝(漫湾水电站) 的修建使得流水变为静 水环境而产生一系列的变化使鱼类的种类和种群数量产生变化。

How much do we spend to save? Calculating the embodied carbon costs of retrofit

The drive to reduce carbon emissions from domestic housing has led to a recent shift of focus from new-­‐build to retrofit. However there are two significant differences. Firstly more work is needed to retrofit existing housing to the same energy efficiency standards as new-­‐build. Secondly the remaining length of service life is potentially shorter. This implies that the capital expenditure – both financial and carbon -­‐ of retrofit may be disproportionate to the savings gained over the remaining life. However the Government’s definition of low and zero carbon continues to exclude the capital (embodied) carbon costs of construction, which has resulted in a lack of data for comparison. The paper addresses this gap by reporting the embodied carbon costs of retrofitting four individual pilot properties in Rampton Drift, part of an Eco-­‐Town Demonstrator Project in Cambridgeshire. Through collecting details of the materials used and their journeys from manufacturer to site, the paper conducts a ‘cradle-­‐to-­‐gate’ life cycle carbon assessment for each property. The embodied carbon figures are calculated using a software tool being developed by the Centre for Sustainable Development at the University of Cambridge. The key aims are to assess the real embodied carbon costs of retrofit of domestic properties, and to test the new tool; it is hoped that the methodology, the tool and the specific findings will be transferable to other projects. Initial changes in operational energy as a result of the retrofit works will be reported and compared with the embodied carbon costs when presenting this paper.

三峡水库蓄水前后香溪河氮磷污染状况研究

分别于三峡水库蓄水前的上世纪1996—1997年及蓄水后的2004年采集了香溪河水样及沉积物样,研究了蓄水前后香溪河氮磷的污染状况。结果表明,蓄水前上游总磷浓度低于0.05mg/L,下游在0.22—0.34mg/L之间,其浓度与生活污水及工业废水排放有关;总氮浓度变化不大,在0.7—1.1mg/L之间。蓄水后磷、氮浓度明显升高,但总磷在回水区由于沉降作用反而低于蓄水前。蓄水后下游氮磷比普遍高于10,加之水流变缓,使香溪河库湾发生“水华”的可能性增加。香溪河沉积物磷污染严重,总磷含量高达1221mg/kg,

澜沧江中上游鱼类生物多样性现状初报

对澜沧江上游及支流的鱼类和环境调查显示流域片段化对鱼类生物多样性产生了较大的影响。从漾濞江和西洱河的比较可以看出，前者因为没有梯级电站，鱼类的种类和数量并无太大的变化，而西洱河由于过度的梯级开发和污染，鱼类濒于灭绝，洱海由于江湖的隔绝，外来种的引入使得土著鱼类种群数量急剧减少。干流上大坝（漫湾水电站）的修建使得流水变为静水环境而产生一系列的变化使鱼类的种类和种群数量产生变化。

食物种类和浓度对壶状臂尾轮虫实验种群动态的影响

使用浓度为0．3mg／mL的椭圆小球藻、尖细栅藻和两者以1：1（湿重比）组成的混合藻在26±1℃下对壶状臂尾轮虫进行单个体培养研究。结果表明，虽然三类食物对轮虫的胚胎发育时间和平均寿命无显著影响，但投喂小球藻时轮虫的生殖前期明显比投喂栅藻或混合藻时短，投喂小球藻时轮虫的生殖期明显比投喂栅藻时长；轮虫的生殖后期历时以栅藻组最长，混合藻组次之，小球藻组最短，三者间具显著差异。轮虫的繁殖率、产卵量和种群内禀增长率均以小球藻组最高，混合藻组次之，栅藻组最低。由此可见，小球藻是该种轮虫培养的最适饵料。以浓度为0．3

日本医蛭的染色体数目和形状

日本医蛭的染色体数目和形状ＣＨＲＯＭＯＳＯＭＥＮＵＭＢＥＲＡＮＤＣＨＡＲＡＣＴＥＲＩＳＴＩＣＳＯＦＡＨＩＲＵＤＩＮＩＤＡＥＬＥＥＣＨＨｉｒｕｄｏｎｉｐｐｏｎｉａ关键词日本医蛭，精巢和卵巢，染色体数目，蛭类系统发生ＫｅｙｗｏｒｄｓＨｉｒｕｄｏｎｉｐｐｏ...