长江上游珍稀特有鱼类保护区水文情势时空变化特征初步分析

为科学评价预测长江上游珍稀特有鱼类保护区水文情势变化特征,以长江上游珍稀特有鱼类保护区内的屏山、朱沱和寸滩3个水文站的实测逐日流量序列为基础,采用基于32个IHA指标的RVA方法,分析保护区水文情势的自然特征和不同历史时期的变化情况。并通过梯级水库联合调度运行模拟,研究金沙江下游梯级水库运行后保护区未来的水文情势变化。研究表明：上世纪80年代之前保护区的水文变化比较稳定;1990年后保护区水文情势变化有所增加;金沙江梯级水库运行后保护区屏山站的水文变化加剧,但朱沱和寸滩站的水文变化不大,显示保护区支流水量汇入显著减缓了水库调度对保护区中下游河段水文情势的影响。     

水电开发背景下长江上游保护区珍稀特有鱼类保护实践

长江上游珍稀特有鱼类国家级自然保护区位于向家坝坝下江段,随着金沙江下游梯级水电站相继蓄水运行和“十年禁渔”政策的实施,保护区干流段鱼类群落可能会发生改变。为探究“十年禁渔”前保护区干流段鱼类群落结构特征,基于该江段2017—2019年渔获物监测数据,对鱼类种类组成、生态类型、群落相似度、物种优势度、生物多样性以及群落结构稳定性等特征进行分析。结果显示,本次调查共采集到鱼类134种,隶属于7目21科83属,其中长江上游特有鱼类有27种,外来物种有12种,分别占总种类数20.15%和8.96%。鱼类群落以底层、产沉性卵、杂食性鱼类为主。等级聚类分析 (Cluster)和非度量多维尺度分析 (NMDS)显示,在一定的相似性水平上,保护区干流段鱼类的群落类型基本可分为3组,宜宾、泸州与合江可以聚为一组,巴南、江津分别独立成组。保护区干流优势种共有14种,其中瓦氏黄颡鱼是整个研究区域的优势种,在合江站点的优势度最高,IRI值为27.00%。Shannon-Wiener 指数、Simpson 指数、Margalef 指数和Pielou 指数变化范围分别为2.725~3.306、0.883~0.942、5.833~8.811和0.699~0.773,表明保护区干流鱼类物种丰富,群落分布均匀度较高。ABC曲线分析结果显示,江津站鱼类群落结构稳定性相对较高,其余站点鱼类群落结构均受到中度干扰。本研究补充了保护区干流鱼类群落研究的基础数据,以期为该江段鱼类资源管理与“十年禁渔”生态评估提供科学依据。     

溪落渡水利工程对长江上游珍稀特有鱼类的影响探讨

溪落渡水电站位于金沙江下游 ,长江合江 -雷波段国家级珍稀鱼类自然保护区核心区边缘 ,地处云南永善县和四川雷波县境 ,下距宜宾市 185公里 ,上距攀枝花市 597公里。地貌为连续的呈“Ｖ”形峡谷 ,谷底一般宽 150～ 2 50米 ,两岸山高为150 0～ 30 0 0米 ,库区江面宽多为 80～ 10 0米 ,年平均流量 4 580米3/秒 ,最大流量 2 90 0 0米3/秒 ,最小流量 10 60米3/秒。河道枯变水位变幅约 2 5米 ,年平均流速 2 1～ 2 6米 /秒 ,年平均含沙量 1 59公斤 /立方米。溪落渡水电站坝高 2 73米 ,设计总发电量 12 0万千瓦 ,水库尾水到云南的巧家县 ,长约2 0…     

金沙江下游与长江上游珍稀、特有鱼类国家级自然保护区鱼类物种多样性比较

为探讨长江上游珍稀、特有鱼类国家级自然保护区对金沙江下游现有鱼类资源可能发挥的替代生境保护作用,在对金沙江下游鱼类进行多次实地采样调查基础上,结合历史文献记载,梳理了金沙江下游的鱼类名录,并与“保护区”内的鱼类物种多样性进行了对比。结果表明,分布于金沙江下游的鱼类共有194种,其中土著鱼类162种,隶属于5目15科79属;分布于“保护区”内的鱼类197种,其中土著鱼类187种,隶属于6目21科94属。进一步分析显示,既见于金沙江下游又见于“保护区”的土著鱼类129种,反映出两者在鱼类种类组成上有较大的相似性;“保护区”内未能包括的仅见于金沙江下游的鱼类多为金沙江下游支流或附属高原湖泊中生活的种类,“保护区”在一定程度上可以发挥金沙江下游替代生境的作用。     

长江上游珍稀鱼类资源调查启动

11月26日，由农业部水生野生动植物保护办公室、长江渔业资源管理委员会和中国三峡工程开发总公司共同主办的“长江上游珍稀特有鱼类国家级自然保护区资源与环境综合调查”在四川宜宾启动。[第一段]     

长江上游珍稀特有鱼类国家级自然保护区保护行动规划调研组到贵州调研

6月上旬,由长江渔业资源管理委员会牵头,以西南大学姚维志、苏胜齐、郑永华等教授及美国大自然保护协会中国官方代表杨波博士组成的调研组,对长江上游珍稀特有鱼类国家级自然保护区贵州江段(以下简称保     

长江上游珍稀特有鱼类保护区水环境因子时空分布格局研究

基于2006-2013年对长江上游珍稀特有鱼类国家级自然保护区水环境因子的监测数据,对区域内长江干流和赤水河的水环境因子时空分布特征进行了比较分析。结果显示,保护区水体总氮含量较高,长江干流总氮含量在0.5～1.5 mg/L的范围内波动,而赤水河的总氮总体超过2.5 mg/L。空间上,长江干流水温、溶解氧、氨氮和总磷含量高于赤水河,而总氮和硝态氮含量低于赤水河。在长江干流,溶解氧自上游至下游逐渐降低,总氮和硝态氮则自上而下平缓升高。赤水河水温自上而下逐渐升高,而溶解氧、总氮和硝态氮均显示出自上而下逐渐降低的趋势。时间上,总氮和硝态氮逐年上升,氨氮在长江干流逐年下降。基于各水质因子对样点的聚类分析表明,长江干流与赤水河呈现出明显的差异;河流内部空间距离越近,各样点的水环境相似程度越高,甚至分处向家坝水电站上下游的两个断面被发现亦具有较高的相似性,表明在研究期间较低的监测频率下,这两个断面并未因大坝的阻隔显示出上述水环境因子的显著差异。     

长江鱼类资源的现状及其增殖保护

长江鱼类资源无论其种数或渔获量均位于国内各主要江河之首，我国发展淡水渔业的鱼类种质９０％来源于长江水系。因此，长江鱼类资源的兴衰不仅直接左右我国淡水渔业的发展，而且与生物多样性和淡水生态系统保护有密切的关系。这是一个关系社会经济与生态的综合性课题。一、长江鱼类资源现状根据渔获量变动分析，长江鱼类资源衰退始于上世纪７０年代前后；长期以来我国致力于发展养殖，而对于鱼类自然资源增殖与保护相对地重视不够，加之一系列的环境问题的困扰，长江（包括其它天然水域）鱼类资源衰退不可避免，这是发展经济所付出的环境代…     

长江上游珍稀特有鱼类保护区鱼类生境特征初步研究

长江上游珍稀特有鱼类保护区是我国最长的河流型自然保护区,保护了多种珍稀特有鱼类,具有重大的生物多样性保护价值。随着金沙江梯级开发的实施,长江上游保护区鱼类栖息条件将受到不同程度的影响。本研究基于长江上游珍稀特有鱼类保护区的地形、地貌、水文、水动力等条件,提出了保护区鱼类生境特征表征指标体系,并根据该指标体系初步分析了保护区栖息地生境特征。研究结果可为长江上游珍稀特有鱼类保护区鱼类资源保护措施的制定提供参考依据。     

长江上游珍稀、特有鱼类种群动态现状及变化趋势分析

为了解长江上游珍稀特有鱼类种群动态现状,本研究基于长序列调查与研究数据分析了长江上游特有鱼类种群动态演变。结果显示:长江上游不同江段,根据鱼类特性、栖息地特征、水系、产卵类型等划分,鱼类区系组成不同。金沙江一期工程蓄水后,长江上游珍稀特有鱼类种群开发率较蓄水前高,约77.5%的特有鱼类处于过度开发状态,22.5%未过度利用。金沙江一期工程蓄水后平均捕捞死亡系数大于蓄水前,细鳞裂腹鱼(Schizothorax chongi)、张氏■(Hemiculter tchangi)、前鳍高原鳅(Triplophysa anterodorsalis)等经济价值低的特有鱼类自然死亡系数高于捕捞死亡系数,而长薄鳅(Elongate loach)等经济价值较高的鱼类自然死亡系数低于捕捞死亡系数。2011-2018年珍稀特有鱼类出现频率、资源量均呈下降趋势。     

A simple approach for assigning the conservation status of freshwater fish based on their natural variability – a case study from the Iberian Ecoregion

A simple, non‐lethal method for assigning conservation status is proposed based on three conservation classes (favourable, unfavourable/inadequate and unfavourable/bad) to fish species based on their natural population variability. To demonstrate this approach, conservation classes were allocated to three native fish species (brown trout Salmo trutta L., northern Iberian chub Squalius carolitertii (Doadrio), and northern straight‐mouth nase, Pseudochondrostoma duriense (Coelho) based on basic population variables (density and biomass) using a 9‐year dataset (2004–2012) from 15 different sampling sites in Spain. The classification of the population variables into conservation classes was made using previously described nonparametric methods and percentiles categorisation, and the current conservation status of the studied species was established. Temporal trend analyses showed that S. carolitertii experienced a progressive significant decrease during the study period, whereas both S. trutta and P. duriense exhibited weak increases in density. The study exemplifies the need to quantify the natural variability of fish resources to reveal their current conservation status and to determine whether short‐term and long‐term management actions are needed to rehabilitate native fish assemblages. The proposed approach could easily be employed by fisheries managers to monitor the conservational status of other native species.     

Quantifying the rare: Baselines for the endangered Napoleon Wrasse,Cheilinus undulatus,and implications for conservation

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Fisheries and conservation assessment of sharks in Pacific Panama

1. In Panama, shark fisheries were initially developed in the 1980s and progressively increased in production in the 1990s mainly due to the high demand for shark fins and meat from the international Asian market. Since then, and despite the exploitation rate (average 3,514 t year^–1) and endangered status of some species, shark fisheries have seldom been studied, and official statistics are general or incomplete and not suitable for the development of appropriate conservation and management strategies.
2. To understand the dynamics of shark fisheries in Panama, field surveys were conducted between 2007 and 2009 at several landing ports of small‐scale and industrial fisheries, at fish processing plants and on‐board fishing vessels in Pacific Panama, where most of the fishing vessels of the country operate.
3. In general, it was found that the artisanal and industrial fisheries of the Pacific coast of Panama regularly exploit at least 18 species of sharks, which are also being exploited by neighbouring countries in the eastern Pacific, suggesting the importance of coordinated conservation initiatives across the multiple jurisdictions. A large number of the individuals caught were immature, implying a certain level of impact on recruitment rates. This pattern was particularly evident in species such as Sphyrna lewini, for which immature individuals represented at least 99% and 63% of the total catch by small‐scale and industrial fisheries, respectively. Catch per unit of effort analyses showed that Carcharhinus and Sphyrna species were the most exploited (representing ~80% of the catches) by industrial fisheries in Panama between 2006 and 2009, suggesting that fishery management should provide special attention to these groups.
4. It is expected that the information presented here provides a baseline to develop new regulations, including the implementation of annual quotas and fishing seasons and the protection of nursery areas, for the long‐term sustainability and conservation of sharks in Panama.

     

北极阿拉斯加水域鱼类生态特征及其重要性评价

为了对北极鱼类的生态特征进行研究,从而科学合理地开发和管理北极鱼类资源,以现有北极阿拉斯加水域鱼类生态科学信息为基础,针对北极阿拉斯加水域104种主要鱼类,从栖息深度、营养级、昼夜垂直移动及季节性洄游、生态重要性、传统文化重要性及商业重要性等多个方面进行了分析。结果显示,大多数北极阿拉斯加海洋鱼类为中上层鱼类或中层鱼类,栖息水域多在1 000 m以浅的陆架或陆坡水域;营养级范围为3.0～4.5,处于较高和较低营养级的鱼种较少;大部分鱼类的重要性知之甚少,目前仅少量鱼种在北极海域生态系统、传统文化以及商业性渔业中起到关键作用;具昼夜垂直移动及季节性洄游特性的鱼种各占一半左右;基于聚类分析,以栖息深度、垂直移动、季节性洄游及营养级4个指标作为变量,该水域属于5个生态类群,而以生态、传统文化以及商业重要性3个指标为变量,则该水域鱼类可划分为3个类群。本研究结果可为进一步开展北极鱼类生态学研究及北极渔业资源的开发潜力评价提供数据支持,并为我国参与北极鱼类资源潜力的开发及国家权益的争取提供参考信息。     

Diversity of fish and fisheries from the Lake Encantada Environmental Protection Area,Ilhéus,Brazil

• 1. Lake Encantada, in the basin of the Almada River (Bahia State), has an area of 650.5 ha and a perimeter of 13.3 km. In 1993, an area of 11 800 ha around the lake was designated an Environmental Protection Area (Class V category). The main goal of this study was to identify fish species in the lake and to determine possible threats to their conservation.
• 2. Fish samples were obtained with gillnets between May 2002 and February 2004, and used to calculate indices of species diversity Shannon (H′), richness (d) and evenness (J′).
• 3. Eleven fish species comprising nine families were collected during the sampling period. Three introduced species occurred in the lake: Prochilodus argenteus, endemic to the São Francisco river basin, and two African species, Oreochromis niloticus and Clarias gariepinus. In overall ranking, Prochilodus argenteus was first in number of individuals (46%) and weight (59%), followed by Genidens genidens in numbers (31%), and Clarias gariepinus in weight (15%).
• 4. The occurrence and dominance of introduced species is discussed as well as their possible impacts on the trophic structure of this ecosystem.

Copyright © 2007 John Wiley & Sons, Ltd.     

Riverine connectivity,upstream influences,and multi‐taxa representation in a conservation area network for the fishes of Michigan,USA

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Priority habitats for the conservation of large river fish in the Ganges river basin

• 1. Three classes of habitat used by groups of fish species classified as conservation and management priorities were developed for the Gerua River (also known as the Girwa River, Karnali River) in the Ganges river basin. This river is large (mean annual discharge ca 1500 m³ s^?1, up to 900 m wide), surrounded by protected lands of India and Nepal, and upstream of major diversions and river alterations.
• 2. Fish and habitat sampling was conducted at 45 sites from 2000 to 2003. Data were analysed for 2172 fish of 14 species. Species and life stages found occupying a statistically distinct subset of the river habitats were grouped to identify classes of river habitat for conservation.
• 3. Most species and life‐stage groups specialized on specific habitat conditions revealed by multivariate analyses of variance and a principal component analysis. The most numerous and diverse group (six species, 15 life stages) was associated with deep depositional habitats with sandy substrate. Two species covering three life stages were primarily oriented to erosional habitat marked by fast current velocity with pebble and cobble substrate. A third group of three species of adults and juveniles were intermediate in habitat use.
• 4. River conservation for fish faunas should maintain both erosional and depositional channel habitats with depths, substrates, and current velocity inclusive of the ranges reported. The erosional and depositional nature of the key habitats requires that rivers be maintained with flows capable of channel‐forming functions.

Copyright © 2006 John Wiley & Sons, Ltd.     

鄱阳湖湖口鱼类资源现状调查

2014年5月-12月对鄱阳湖湖口县水域鱼类资源进行逐月调查,对该水域鱼类种类组成、渔获物结构、优势种、群落多样性指数和单位捕捞努力量渔获量(CPUE)进行分析。结果显示,在鄱阳湖湖口水域共采集鱼类52种,隶属于7目12科40属;优势种分别为鲤(Cyprinus carpio)、鲢(Hypophthalmichthys molitrix)、鲫(Carassius auratus)、鳙(Aristichys nobilis)和光泽黄颡鱼(Pelteobagrus nitidus),占样本个体总数的61.34%;Shannon-Wiener多样性指数(Hi)为2.59,Margalef种类丰富度指数(D)为6.09,Pielou均匀度指数(J')为0.65,Simpson优势度指数(λ)为0.87,相对稀有种数(R)为97.87%;该水域定置网CPUE为1.10~6.21 kg/d,与湖口水位呈显著正相关(P0.05)。鄱阳湖湖口水域渔业捕捞个体以小型鱼类居多,洄游型鱼类的幼鱼补充群体数量极少,鱼类群落多样性指数有上升趋势。     

Status of freshwater fish around the Korean Demilitarized Zone and its implications for conservation

• 1. The Korean Demilitarized Zone (DMZ), which divides the Korean peninsula, currently serves as a sanctuary for diverse biological resources, owing to limited development and human activities. The fish fauna of the DMZ areas, including the Civilian Control Zone (CCZ) and Military Facility Protection Area (MFPA), was investigated by quarterly sampling at 53 sites from August 2001 to May 2004.
• 2. In total, 10 946 fish were collected and classified into 99 species and 26 families. Zacco platypus (relative abundance, RA 18.6%) was the dominant species, while other key species were Rhynchocypris steindachneri (16.0%), Pungitius sinensis (12.5%) and Zacco temmincki (8.5%).
• 3. Thirty species were found to be Korean endemics, representing seven families. Eight Korean vulnerable species and two Korean natural monument species were recorded. Three exotic fish species (Carassius cuvieri, Micropterus salmoides and Lepomis macrochirus) were collected at 13 study sites, all but one of which are outside the CCZ. There were significant relationships between altitude and fish species richness (r²=0.448, P<0.001) and the number of endemic fish species (r²=0.487, P<0.001).
• 4. Owing to very limited human interference, the DMZ could provide good benchmark sites to enable ecological restoration on other rivers and streams for maintenance of natural freshwater fish biodiversity. It is suggested that a natural park is instituted around the DMZ areas for ecological protection and as a symbol of peaceful coexistence between South and North Korea.

Copyright © 2007 John Wiley & Sons, Ltd.