莱州湾鱼类群落的营养结构及其变化

2011年5月~2012年4月期间对莱州湾进行了9次底拖网调查,对采集的20种鱼类4 854个胃含物样品进行了分析。结果表明,莱州湾鱼类群落包括浮游动物食性、底栖动物食性、鱼食性、杂食性和广食性5种食性类型,其中底栖动物食性鱼类是莱州湾各月份鱼类群落的重要食性类型,钩虾和双壳类等底栖动物饵料在莱州湾生态系统的食物关系中起着关键的作用。秋末和初春的莱州湾鱼类群落以底栖动物食性鱼类为主,食性类型单一;随着水温升高,鱼类群落的食性类型逐渐变得丰富。分析表明,莱州湾海域鱼类群落的营养结构有利于增殖放流品种后期的生长存活,建议跟踪调查增殖放流点周边海域的食物关系和饵料基础,同时结合多学科调查,选择最佳的增殖放流地点和时间,才能切实有效地保证增殖放流的效果。     

基于生长参数及产量方程的鱼类放流效益调查估算

为量化评估增殖放流鱼类产生的经济效益和生态价值,根据广西2013年度中央财政渔业资源保护项目增殖放流鱼类的品种、规格、数量,利用鱼类的生长特征参数、自然死亡系数和捕捞死亡系数,通过巴拉诺夫产量方程估算增殖放流鱼类的回捕量以及水生生物营养转换传递参数、成本参数和市场价格。结果显示,该项目增殖放流鱼类回捕的直接经济效益为10 293万元,投入产出比为1∶25;回捕的放流鱼类从水域中提取氮127.9 t,磷25.6 t,碳汇输出1 874.5 t;回捕放流鱼类及存留鱼类共消耗水域底栖动物44 327.2 t;年度放流总生态价值5 775万元。调查结果表明,开展鱼类增殖放流能产生较好的渔业经济效益和生态效益,有利于维护渔业生态环境健康。     

大型底栖动物快速生物评价指数在城市河流生态评估中的应用

为提供更加全面和有效的生态评估方法用以指导城市河流修复和保护,2017年3-4月选择深圳典型城市化区域河流,设置21个监测样点,开展大型底栖动物快速生物评价指数的适用性研究。分别选择生物多样性指数、群落结构指数、敏感性指数和耐污性指数,在评估不同指数适用性的基础上,筛选和构建用于城市河流健康评价的大型底栖动物快速生物评价综合指数。龙岗河大型底栖动物共采集到28科43种,寡毛类是龙岗河的主要优势类群。基于底栖动物群落结构特征对6个大型底栖动物快速生物评估指数进行了比较和分析,其中3种指数较适用于龙岗河城市河流健康评估。在考虑各参数离散度和相关性的前提下,可选择物种数、寡毛类相对丰度和科级耐污生物指数(Family Biotic Index, FBI)构建综合指数用于深圳市河流快速生物评价。健康评价的结果表明龙岗河2个样点为"理想状态",6个样点属于"亚健康"等级,其余13个样点处于"不健康"和"病态"。我国城市河流的有机污染总体较重,以大型底栖动物耐污类群或者敏感类群构建的快速生物评价指数能够较为灵敏地指示河流生态修复成效。     

河北省海洋与水产科学研究院到磁县岳城水库开展水生生物资源量和增殖放流效益评估调查

<正>3月23日,河北省海洋与水产科学研究院专家张海鹏带队一行4人,深入磁县岳城水库开展水生生物资源量和增殖放流效益评估调查。分别对水库的水质、水生生物、底栖动物及现有鱼类品种进行现场调查。此次调查的目的在于弄清岳城水库水生生物和鱼类资源现状,评价水质营养与污染程度,分析鱼类种群结构,为后期实施水库渔业资源增殖放流提供科学依据。     

基于PSR模型的黄河陕西段鱼类增殖放流生态安全评价

基于压力、状态、响应模型(PSR)和层次分析法(AHP),确定17项指标通过数据的标准化处理,指标权重赋值、权重一致性检验、评价等级确定以及评价模型的构建,用生态安全评价黄河陕西段鱼类增殖放流效果,分析生态安全所面临的主要问题。结果表明:黄河陕西段2013年增殖放流生态安全度(ESI)评价等级为Ⅱ级,为良好状态;2014年评价等级为Ⅲ级,处于一般状态;2015年评价等级为Ⅳ级,处于较差状态,属于临界不安全状态以下水平。生态安全形势呈现出逐年下降局势。不安全状态受到影响较大的前3个指标是:黄河径流量变化影响、重要生境保持率和公众资源环境保护意识的影响,3个指标下降值占到下降ESI值的64.93%。其次还受到污水排放达标率、鱼类增殖放流量、政策和管理水平、鱼类生物多样性指数、保护区建设、水质综合污染指数、群落结构等诸多因素影响。研究显示,现阶段增殖放流对黄河生态安全有一定影响,还存在一定提升空间。     

基于大型底栖动物完整性指数评价深圳茅洲河生态状况

对受人类活动强烈影响、几乎不存在常规参照点的城市河流开展生态评价存在很多困难。本研究以深圳市茅洲河为例,通过调查河流大型底栖无脊椎动物及水环境指标,用水体理化指标聚类法确定参照组、受损组样点,构建底栖完整性指数(Benthic index of biotic integrity, B-IBI)评价河流生态状况。研究发现：虽然茅洲河水环境质量整体较差,聚类分析仍然能将水质相对较好和较差的样点分成不同组。虽然底栖动物以颤蚓和摇蚊等耐污种为主,但底栖动物总分类单元数和集食者分类单元数对水环境变化较敏感。用这两个参数构建的B-IBI对各点的生态状况进行评价表明：12个位于干、支流上游或水库出水口附近的样点生态状况达到“好”等级;B-IBI主要受氮、磷营养盐、COD、溶解氧浓度的影响。建议参照 “好”等级样点的生态状况确定茅洲河现阶段修复目标,并以水质提升作为当前首要修复任务。     

于桥水库表层沉积物重金属分布特征及其与底栖动物的关系

对重金属生态风险分布特征及其与底栖动物群落结构及多样性分布特征之间的相关关系进行分析,为于桥水库生态系统重金属污染监测与治理提供技术支持。2015年7月至2016年6月,在于桥水库内布设11个采样点,采集水下表层15 cm的沉积物样品测定Zn、Cr、Cu、Pb、As、Hg和Cd浓度,潜在生态指数法评价污染风险;采集底栖动物鉴定种类、计算生物量和多样性指数。结果表明:于桥水库表层沉积物中重金属元素平均含量大小顺序为ZnCrCuPbAsHgCd,各重金属平均含量均低于背景值,但Cu、Zn、Cr、Cd、Hg的最高值均高于背景值;表层沉积物中重金属元素的平均潜在生态风险指数为66.13,整体处于轻微风险水平,各重金属元素的单项潜在生态风险从高到低的顺序为HgCdCuAsCrPbZn;底栖动物腹足纲密度、底栖动物Shannon-Wiener指数与ECd、EHg、RI均具有明显的负相关关系;底栖动物Margalef指数与ECu、EPb、ECd具有明显的负相关关系。于桥水库内重金属元素浓度高值区主要集中于库中心、水库入口、水库出口及水库北岸,应重点加强上游引水污染物控制。     

“淡水水生生物资源增殖放流及生态修复技术研究”通过验收

<正>3月20日,中国水产科学研究院长江水产研究所主持承担的公益性行业(农业)科研专项经费项目"淡水水生生物资源增殖放流及生态修复技术研究"(项目编号:200903048)在武汉通过了由农业部科技教育司组织的验收。"淡水水生生物资源增殖放流及生态修复技术研究"项目在长江、珠江和黑龙江流域全面开展了青鱼、草鱼、鲢、鳙等重要经济鱼类,中华鲟、达氏鲟、胭脂鱼等珍稀濒危鱼类和中华绒螯蟹共18种水生生物的增殖放流及效果评估工作。运用超声波遥测、科学回声仪探测、分子生物学及地理信息学等技术,建立了增殖放流苗种繁育和质量评价技术体系,解决了放流     

基于底栖动物多样性恢复的减脱水河段生态流量核算

本文以澜沧江支流景谷河引水式电站形成的过渡区减脱水河段为研究区域，根据底栖动物的丰度、生物多样性对适宜栖息地水深、流速的需求，采用栖息地模拟法建立景谷河减脱水过渡区生态流量核算方法。结果表明，研究河段69.0%的底栖动物种类在边滩中出现，47.30%在浅濑中出现，因此，边滩和浅濑是维持底栖动多样性的最优生境类型。模拟了13种工况下底栖动物最适栖息地面积的变化情况，最终确定景谷河减水河段底栖动物最适的生态流量需求为3.0-4.0m3/s。本文为以水生生物实际需求为目标的生态流量核算奠定了基础。     

秦岭白云峡水域大型底栖动物群落结构调查

2016年春季对石头河支流-白云峡进行了首次大型底栖动物群落调查,5个调查点共采集到底栖动物2门2纲13科(种)。其中节肢动物门的昆虫纲11种,占总种类数的84.6%,环节动物门的蛭纲2种,占总种类数的15.4%。大型底栖动物平均密度为51.1个/m2,平均生物量为0.649 3g/m2。Shannon-Wiener多样性指数平均为1.76。调查结果表明,此水域水环境质量优良,无污染,大型底栖动物主要以水生昆虫幼体为主,种群数量较多,但群落结构简单。因此,在保护白云峡水域生态环境的同时,可适当进行秦岭特有冷水性鱼类增殖放流。     

渔业资源增殖评估研究进展与展望

渔业资源增殖是修复受损生物资源和维持渔业可持续发展的重要途径,近几十年来在我国以及全球许多国家有着较快发展。有研究指出很多资源增殖项目未能实现预期效果,甚至带来了负面的生态影响,这对资源增殖产业的未来发展提出了重要警示。本文简要回顾了我国以及全球渔业资源增殖的现状,围绕资源增殖评估研究所关注的问题,总结了资源增殖策略与增殖效果评估研究方面的进展;基于对增殖生态系统的认识,阐述了资源增殖中关键生态过程、生态机制与时空尺度问题,从基本原理、生态效应和空间尺度三个方面探讨了资源增殖评估方法的发展方向。研究表明渔业增殖生态系统具有复杂的结构与动态,资源增殖应基于对生态系统的全面了解,以前瞻性的评估研究指导资源增殖规划和合理避险。通过探讨增殖评估研究的不足之处与发展方向,本文旨在为渔业资源增殖的研究与实践提供科学参考。     

A qualitative ecological risk assessment of the invasive Nile tilapia,Oreochromis niloticus in a sub‐tropical African river system (Limpopo River,South Africa)

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Coupling dynamic energy budget and population dynamic models to inform stock enhancement in fisheries management

Extensive applications of fishery stock enhancement worldwide bring up broad concerns about its negative effects, creating a pivotal need for science-based assessment and planning of enhancement strategies. However, the lack of mechanistic understanding of enhanced population dynamics, particularly the density-dependent processes, leads to compromise in model development and limits the capacity in predicting enhancement effects. Here, we developed an individual-based model based on dynamic energy budget theory and full life-history processes, to understand the mechanism of density dependence in population dynamics that emerge from individual-level processes. We demonstrated the utility of the model framework by applying it to an extensively enhanced species, Chinese prawn (Fenneropenaeus chinensis, Penaeidae). The model could yield projections reflecting the observed trajectory of population biomass and yields. The model also delineated the key effects of density dependence on the vital rates of growth, fecundity and starvation mortality. Regarding the manifold effects of stock enhancement, we demonstrated a dampened shape in population biomass and yields with increasing magnitude of enhancement, and trade-offs between the ecological and economic objectives, that is, pursuing high benefit might compromise the wild population without proper management. Furthermore, we illustrated the possibility of combining stock enhancement and harvest regulation in promoting population recovery while maintaining fisheries yields. We highlight the potential of the proposed model for understanding density dependence in enhancement programme, and for designing integrated management strategies. The approach developed herein may serve as a general approach to assess the population dynamics in stock enhancement and inform enhancement management.     

Integrating seabird dietary and groundfish stock assessment data: Can puffins predict pollock spawning stock biomass in the North Pacific?

Information on the annual variability in abundance and growth of juvenile groundfish can be useful for predicting fisheries stocks, but is often poorly known owing to difficulties in sampling fish in their first year of life. In the Western Gulf of Alaska (WGoA) and Eastern Bering Sea (EBS) ecosystems, three species of puffin (tufted and horned puffin, Fratercula cirrhata, Fratercula corniculata, and rhinoceros auklet, Cerorhinca monocerata, Alcidae), regularly prey upon (i.e., “sample”) age-0 groundfish, including walleye pollock (Gadus chalcogramma, Gadidae) and Pacific cod (Gadus microcephalus, Gadidae). Here, we test the hypothesis that integrating puffin dietary data with walleye pollock stock assessment data provides information useful for fisheries management, including indices of interannual variation in age-0 abundance and growth. To test this hypothesis, we conducted cross-correlation and regression analyses of puffin-based indices and spawning stock biomass (SSB) for the WGoA and EBS walleye pollock stocks. For the WGoA, SSB leads the abundance of age-0 fish in the puffin diet, indicating that puffins sample the downstream production of the WGoA spawning stock. By contrast, the abundance and growth of age-0 fish sampled by puffins lead SSB for the EBS stock by 1–3 years, indicating that the puffin diet proxies incoming year class strength for this stock. Our study indicates connectivity between the WGoA and EBS walleye pollock stocks. Integration of non-traditional data sources, such as seabird diet data, with stock assessment data appears useful to inform information gaps important for managing US fisheries in the North Pacific.     

A new system for the culture and stock enhancement of sea cucumber,Apostichopus japonicus (Selenka),in cofferdams

A new multilayer, plate‐type system for the culture and stock enhancement of sea cucumbers in cofferdam was developed. To optimize and evaluate the system, four experimental designs were implemented using polyethylene (PE)‐corrugated sheets of various colours, interval spacing and shapes/styles. Results showed that a system equipped with black PE‐corrugated sheets attracted more animals than either blue, green, transparent or a selection of mixed sheets (six transparent sheets in the upper layer and five black sheets in the lower layer) (P<0.05). Also, more animals gathered in the system with oblique‐angled sheets (30° to the base plate) than either a wavy (the bottom and every second sheet was at an angle of 10° to the base plate) or parallel arrangement (P<0.05), and more animals assembled in the system with 2 cm between sheets than spacings of 3, 4 or 5 cm (P<0.05). As expected, the upper layers of the systems attracted more animals than lower layers in most cases except for those with transparent and mixed oblique‐angled sheets with a 3 cm spacing (P<0.05). Thus, a system with black, oblique‐angled‐corrugated sheets and 2 cm spacing is recommended for Apostichopus japonicus (Selenka) culture and stock enhancement in cofferdams or ponds.     

Forecasting the genetic influences of red drum stock enhancement in South Carolina

The South Carolina Department of Natural Resources (SCDNR) began stocking red drum, Sciaenops ocellatus (Linnaeus), in 1989 to augment the abundance of juveniles available for recreational harvest in South Carolina estuaries. While stock enhancement can help supplement wild populations under high fishing pressure, releasing hatchery‐raised fish into the wild also presents the risk of decreased genetic diversity. An individual‐based model (IBM) was developed to forecast the genetic influences of stocking on the wild spawning population to inform responsible stocking strategies. Model results indicated the SCDNR red drum stock enhancement programme should maintain mean contributions of stocked fish no greater than 30% per year class over a 45‐year stocking period, coupled with at least 10 effective breeders in the hatchery replaced annually, to maintain current levels of genetic diversity estimated in the wild population. The IBM is a useful tool for hatchery managers to guide responsible stock enhancement.     

Spatial variation in the somatic growth rates of European barbel Barbus barbus: a UK perspective

The European barbel Barbus barbus is threatened in areas of its range because of its sensitivity to anthropogenic disturbance in riverine habitats and, in the UK, is indigenous to a relatively small number of east‐flowing rivers, with nonindigenous populations present in other rivers following introductions for angling enhancement. Fish stock assessment surveys completed between 2002 and 2010 collated age and growth data from 20 rivers across their indigenous and nonindigenous UK range. Analyses revealed that individuals present in samples are of 21 years old, with growth rates highly variable between rivers. There was no relationship between growth rates and the maximum age of fish per river, and there was no difference in growth rates between their indigenous and nonindigenous ranges. A range of abiotic data were collated and analysed against the growth data; these analyses suggested higher mean growth rates were evident in rivers of higher biological water quality (expressed as British Monitoring Working Party Score) and higher mean air temperatures (used as a surrogate of water temperature). That growth of B. barbus was significantly and positively enhanced by increased biological water quality was in contrast to cyprinid fishes such as roach Rutilus rutilus and suggests that as river water quality continues to improve through reduced nutrient inputs, further ecological changes are likely in riverine fish communities.     

渔业资源增殖放流的生态风险及其防控措施

渔业资源增殖放流作为国内外水生生物资源养护领域普遍采用的一种做法, 其在提升增殖种类资源量的同时, 也会给野生资源种类和增殖水域生态系统健康带来诸多生态风险。现阶段, 系统评价增殖放流的生态风险、实施有效的生态风险防控已成为构建负责任增殖放流模式的必然要求。本文从种群、群落和生态系统3个层面系统评述国内外渔业资源增殖放流生态风险研究领域的最新进展, 阐述相应的生态风险防控措施, 以期为我国渔业资源增殖放流的生态风险防控工作提供理论参考。

     

Evaluation of a spatially sex‐specific assessment method incorporating a habitat preference model for blue marlin (Makaira nigricans) in the Pacific Ocean

Blue marlin, widely distributed throughout the Pacific Ocean, are sexually dimorphic, have certain preferred habitats, and migrate seasonally. These characteristics have been ignored in previous stock assessment models. A population dynamics model that includes spatial structure, and sex and age structure was therefore constructed and fitted to fisheries data for blue marlin, along with information on the relative density of the population over space derived from a habitat preference model that uses the oceanographic and biological variables sea‐surface temperature, mixed layer depth, sea‐surface height anomaly, and chlorophyll‐a concentration. Monte Carlo simulation was then used to examine the estimation performance of the stock assessment method. Estimates of management‐related quantities including current spawning stock biomass are substantially biased when the assessment method ignores seasonal movement and sexual dimorphism. We also found that (i) uncertainty about the relationship between catch rate and abundance influences estimation performance to a larger extent than uncertainty in catches, (ii) the outcomes of the assessment are sensitive to the values assumed for natural mortality and stock‐recruitment steepness, and (iii) the ratio of current spawning stock biomass to that at pre‐exploitation equilibrium appears to be the most robust among the quantities considered. We conclude that assessment methods for blue marlin in the Pacific Ocean need to take account of seasonal migration and sex structure to improve stock assessments.     

基于SPiCT模型对数据有限短生命周期阿根廷滑柔鱼的资源评估

以西南大西洋阿根廷滑柔鱼(Illex argentinus)为研究对象,基于连续时间的随机剩余产量模型(a stochastic surplus production model in continuous time,SPiCT),分析了6种方案下参数估计的变化及其对资源评估的影响。对比6种方案中阿根廷滑柔鱼的产量和单位捕捞努力渔获量(catch per unit effort,CPUE)的估计值与观测值间的最小残差平方和,方案3(设置了K、r、q的先验分布)为最适方案。相应的资源评估结果显示,2010年西南大西洋阿根廷滑柔鱼捕捞死亡系数小于最大持续产量时捕捞死亡系数F_(MSY),渔获量小于最大持续产量MSY,预期平衡生物量EEB大于最大持续产量时的生物量B_(MSY),这表明该资源在2010年尚未被过度开发利用。SPiCT模型综合考虑了环境因子、种群间相互作用和网具选择性等因素引起的观测和过程误差,较S、F-EDSP、S-F-EDSP模型及其他离散模型对数据要求低,计算方法简单,更适合数据有限、短生命周期渔业种类的资源评估。另外,可捕系数q值的设置严重影响了SPiCT模型K、B的估计,优化估计可捕系数q将有利于提高其资源评估的准确性。