辽宁北部典型流域水生态功能区水生态安全评价

基于流域水生态功能分区的水生态安全评价是指导流域水生态“分类、分区”综合管理的前提,本文在流域中小尺度上依据水生态空间格局分异的自然特征和社会属性,以辽河流域的清河和凡河支流为对象,在流域水生态功能三级分区的基础上,运用“压力-状态-响应模型”（PSR）,通过对流域社会经济压力指标、环境压力指标、城市发展指标、资源环境发展指标、投资指标、治理指标等因素分析,筛选出13个评价指标。利用生态安全综合指数法,将流域水生态安全划分为极不安全、不安全、基本安全、安全、非常安全五个级别。其中,清河流域Ⅳ-5-9、Ⅳ-5-10、Ⅳ-5-11、Ⅳ-5-12、Ⅳ-5-14区处于基本安全,Ⅳ-5-8、Ⅳ-5-13属于不安全;凡河流域4个水生态功能三级区中,Ⅳ-5-1、Ⅳ-5-2、Ⅳ-5-3区属于基本安全、Ⅳ-5-4区为较安全。基于水生态功能分区的水生态安全评价和级别划分可为辽河流域水生态保护与流域生态管理提供科学依据。     

水库浮游细菌生产和呼吸过程代谢内外源有机碳研究

全球气候变化和人类活动的加剧影响水生生态系统中溶解性有机碳(DOC)的种类和浓度.浮游细菌生产和呼吸过程对碳源变化的响应,可能影响水体乃至区域的碳循环特征.本研究选取了南京市11座中小型水库,利用碳稳定同位素技术和双端元混合模型定量分析浮游细菌在生产和呼吸代谢过程中对内外碳源的利用.依据DOC中内外碳源的比例,将11座...     

老碳对水生态系统食物网的贡献

传统理论认为,支撑水生态系统食物网的碳主要来自于系统内部的初级生产者,如藻类、大型水生植物等,或者来自陆源输入的新鲜且容易分解的有机质;而部分生物或非生物生产的有机碳,在冰川、冻土等环境中可停留数百年至数千年(定义为老碳),由于储存环境稳定、物理化学性质顽固,难以参与水生生态系统有机碳循环.近年来这一观念不断被挑战.研究表明老碳能够参与水生态系统食物网碳循环:可以被微生物分解利用;被浮游动物、无脊椎动物直接或者间接摄取、或沿着营养级传递至鱼类、水禽等高级消费者.这意味着除了内部初级生产,老碳是支撑水生态系统重要的碳源.本文概述了当前老碳与水生态系统食物网关系研究最新进展和所取得的研究成果,介绍放射性14C同位素技术在水生态学领域的应用,同时提出研究中存在的问题以及未来研究应关注的方向,以期促进我国水生态系统碳循环研究的进一步发展.     

大型底栖动物在水生态系统健康评价中的应用

大型底栖动物是维系水生态系统结构和功能的重要组成部分,也是影响水生态系统健康与功能的重要水生生物指标。随着中国对基于流域完整性水生态管理的日益重视,水生态系统健康的研究也更加深入,因而底栖动物的研究在深度和广度上均有所提高。概述了近年来国内外底栖动物的主要研究方向、影响因素及其分析方法。结果表明：在研究方向上,由于底栖动物对水生态系统变化的响应具有明显的空间尺度效应,因而以不同尺度空间上的自然环境、生境条件和水质等因子为分界,分析其对底栖动物多样性及其群落结构的重要影响。综合分析各种影响因素,流域内人类活动所造成的水环境因子变化或生境受损可直接影响底栖动物物种组成和种群特征。对底栖动物的研究方法可分为模型分析法和生物指数评价法两类,在应用中可侧重不同模型和指数的特点进行针对性选择。     

大型水生昆虫龙虱及桂花蝉的生物学特性和养殖利用初步研究

描述了大型水生昆虫龙虱和桂花蝉的生物学特性并报告了它们的养殖和食用药用初步研究结果,为这两类水生昆虫在淡水水产资源和人类药物食物的开发利用提供科学依据和基础。     

鱼类吹风冻结保鲜的组织变化研究

利用电子显微镜观察石斑鱼冻结后的组织变化情况,研究现行吹风冻结工艺的保鲜效果。结果表明,冻结时间10h的石斑鱼组织结构中出现肌原纤维以及蛋白质受到破坏的现象,从而使其风味、营养受到严重影响。因此,有必要提高现行的吹风冻结速度。     

Holocene development of aquatic vegetation in shallow Lake Njargajavri,Finnish Lapland,with evidence of water-level fluctuations and drying

Holocene development of aquatic plant communities in subarctic Lake Njargajavri, Finnish Lapland, was studied using plant macrofossil analysis. Sediment lithology, grain size, and C/N ratios showed distinct lithological phases, indicating past water-level fluctuations. The colonization of limnophytes took place right after the formation of the lake (after ca. 11,500 cal. BP). The earliest plant macrofossil assemblages indicate nutrient-rich conditions and a warmer climate than at present. After this primary succession phase, aquatic vascular plants were replaced by aquatic bryophytes (before ca. 10,200 cal. BP). Together with lithological evidence, we interpret this as being related to the lowering water table. According to palynological, chronological, and sedimentological evidence, Njargajavri underwent a very shallow phase between ca. 10,000 and 9500 cal. BP and dried out for an unknown period of time between ca. 8000 and 5000 cal. BP. After the dry phase, the water level started to rise and sedimentation at the coring point began again. Despite re-establishment of the lacustrine habitat, late-Holocene plant macrofossil data show no marked recolonization of either vascular limnophytes or bryophytes. The reason for all limnophytes being presently absent from the lake remains speculative. The lack of nutrients and/or the cooling climate (especially shortening of the open-water season) during the latter part of the Holocene may explain why limnophytes failed to recolonize the lake.     

外源凝集素──水产动物御敌的有力兵器

外源凝集素是非免疫起源的热敏蛋白质或糖蛋白，由于其多价构型及对持定细胞多糖具结合亲和力，它们选择凝集某些细胞（包括脊椎动物血球及一些病原微生物）和沉淀某些复杂碳水化合物；其凝集活动常被单糖所抑制，有的却需某些二糖、三糖或多糖。外源凝集素分离自广泛的低等和较高等的生物。一些地区水产养殖业受挫，因素较多，但对发病机理认识之缺乏和调动养殖对象本身防病积极性之不足，是其重要原因。外源凝集素可在诸如凝集外来细胞，调理作用等的防御活动中扮演识别因子，协助一些生理活性物发挥作用，参与吞噬、胞囊、凝固、止血及创伤修复等作用。在生物学、细胞学、生物化学、医学和食品科技上有广泛用途。迄今外源凝集素的许多性能并未全清，在自然界中的精细生理作用仍是个谜。本文论述外源凝集素的定义、性能及用途，以提请有关人士重视。     

The role of biological research in supporting policy needs

Within the UK, the Department for Environment, Food and Rural Affairs (DEFRA) is one of several government departments which undertakes research in support of its policy aims. For example, DEFRA has responsibility for licensing the deposit of materials in the sea in order to protect the environment, public health and prevent interference with other uses of the sea. This includes assessment of pollutant responses in marine organisms. The objectives include assessment of the sub-lethal effect that pollutants have at the cellular, organ and individual level, for example in normal genetic, behavioural and reproductive activity and extrapolation of the potential impact of pollutants to populations. This work helps DEFRA to establish whether individually or in combination, pollutants have an adverse effect on the environment. This paper gives some examples of the research undertaken and demonstrates how biological research can provide cost effective solutions to analytical problems and an opportunity to predict the way in which proposed disposal operations may have an impact on the marine environment. The way such research may influence policy is also discussed.