乌溪江水库富营养化程度及其影响因子时空分布探讨

为了解乌溪江水库主要水质指标的时空分布特征,探究其营养化程度的变化趋势,2019-2020年,对丽水市乌溪江水库的7个采样点（S1-S7）的水温、pH、总氮、总磷、叶绿素a等理化因子进行了监测。分析对比了综合营养指数和理化因子等关键指标在不同时期的分布特征。结果表明,乌溪江水库的营养盐浓度呈现出春夏高秋冬低、从上游（S1）至下游（S7）逐渐下降的趋势,平均综合营养指数也从47.1（S1）下降到32.5（S7）,整体上属于中营养化水库。总磷浓度在0.002-0.040mg/L间,平均值为0.012mg/L;总氮浓度在0.412-2.826mg/L间,氮的主要赋存形式为硝酸盐。叶绿素a含量均值为3.77 ug/L,河流区的叶绿素a含量显著高于下游的过渡区和湖泊区。分析表明：汛期地表径流带来的富营养化压力最大,同时也是氮磷等外源性营养盐输入水体的主要途径;WD、pH、TP和叶绿素a含量中等程度相关,水库生态系统具备很强的净化能力。但近年来富营养化程度加剧。     

桃山水库浮游植物群落结构及水质营养状态评价

2009年的枯水期（5月）和丰水期（7月），在桃山水库对浮游植物结构群落和水质状况进行了调查研究，结合生物监测和理化监测手段，基于浮游植物优势度、丰度、优势度以及综合指数评价方法，对研究水库进行了生态评价。结果显示：（1）桃山水库浮游植物共有7门46属73种及变种，其中以绿藻为主，分别占44 %；（2）生物量在2.29-10.96 mg﹒L-1之间，丰度变幅在(38.76-124.44)×105 ind.﹒L-1之间；（3）枯水期优势种以硅藻为主，丰水期优势种以以蓝藻、绿藻为主；（4）综合营养指数为42.0-60.1。综合评价结果表明：桃山水库枯水期和丰水期水质营养状态为轻富营养化，化学需氧量是影响桃山水库浮游植物群落结构的主要环境因子。     

衢州地区渔业水域水库水体富营养化水平及驱动因子研究

为探求衢州市渔业水域水库水体富营养化水平和主要驱动因子，本研究基于2018年水质监测数据，综合评价黄坛口水库(S1)、铜山源水库(S2)、狮子口水库(S3)、花园垄水库(S4)和金仓垅水库(S5) 5座不同水库水体富营养化水平，并采用相关性分析、主成分分析探讨水质环境因子对水体富营养化水平间的影响和相关关系。结果显示，叶绿素a (Chl-a)与综合营养状态指数法评价结果趋于一致，表明S1、S2和S3水库均为中营养，S4为轻度富营养，S5为重度富营养，水产养殖水域富营养化水平显著高于增殖放流水域(P<0.05)。5个水库中，S5为氮限制，其余水库均为磷限制。多元线性逐步回归分析表明，Chl-a与溶解氧(DO)、透明度(SD)、铜(Cu)、总磷(TP)、总氮(TN)、高锰酸盐指数(CODMn)的相关性较好，综合营养状态指数(TLI)与水温(T)、SD、Cu、TP、TN的相关性较好，得到模型：Chl-a=19.793 CODMn–32.065 TP–33.004，TLI =1.062 CODMn + 18.468 TP–0.06 SD +0.450 T+1.765 TN+33.886。综合相关性分析、主成分分析结果，CODMn、TP、SD、T和TN是影响衢州市水库水体富营养化的主要因子，其中，氮、磷营养盐和有机物是造成水库水体富营养化的主要影响因子，水温是造成各水库富营养化季节性变化的主要原因，而pH、溶解氧是水体富营养化后的结果，可以作为水库富营养化水平的指示因子。     

团结水库水质和饵料生物现状调查

2004年10月~2005年4月对团结水库水质和饵料生物进行了采样调查。该库水质属中等软水,主要污染物为有机物耗氧量与铵氮,有害物质中石油类、汞含量较高;浮游植物生物量平均为12.15 mg/L,浮游动物生物量平均为0.33 mg/L,底栖动物生物量平均为75.5 g/m2。水体呈富营养化。     

汤浦水库及入库支流水质时空变化特征与影响因素分析

运用聚类分析和主成分分析对汤浦水库及入库支流的水质时空特性进行了分析，聚类分析结果表明，汤浦水库水质可分为支流、支流入库库湾、水库库中3个典型空间区域和持续强降雨、雨季、非雨季3个季节时段。汤浦水库3个空间区域的主成分分析显示，第1、2主成分较好地反映了不同区域影响水质状态的主要因素。以水库库中为代表的水域水质明显不同于以北溪和南溪两条主要入库支流下游为代表和支流入库库湾两类区域，规律也不同，它主要受到随季节波动的库区初级生产力状况和无机盐的影响。汤浦水库3个典型季节的主成分分析显示，第1主成分较好地反映了不同季节影响水质状态的主要因素。以1至4月和9至12月非雨季为代表的水库水质变化与持续强降雨季节（6月）和降雨季节（5月、7月和8月）完全不同，主要受到气象因子和水位的双重影响，表现为营养水平波动、细菌等微生物的反硝化作用和水位涨落带的轻微有机及重金属污染。     

合浦水库浮游植物及营养现状评价

于2006年10月至2007年7月对合浦水库浮游植物进行调查，通过浮游植物数量及生物量现状，结合综合营养状态指数法对其营养现状进行评价。结果表明合浦水库已处于富营养化水平。同时Shannon—Veaner指数也表明合浦水库为富营养化状态。     

桂江鱼类物种组成及其群落时空变化格局的研究

为探究桂江鱼类群落结构现状，保护桂江鱼类物种多样性，于2015年1月（冬）、4月（春）、7月（夏）和10月（秋），对桂江平乐（S1）、昭平（S2）、五将（S3）、马江（S4）、木格（S5）、大郎（S6）、京南（S7）、倒水（S8）、梧州（S9）共计9个采样点，进行4次鱼类资源调查。分析了桂江鱼类物种组成、优势种和鱼类群落结构的时空变化；结果表明，本次调查共采集鱼类93种，隶属于6目、17科、 66属，其中以鲤形目为主（63种），占总种数的67.74%。鱼类相对多度（Relative density）显示，全年优势种为?（Hemiculter leucisculus），占总个体数的12.75%。不同季节的优势种有差异，冬季优势种为伍氏半?（Hemiculterella wui）、?和宽鳍鱲（Zacco platypus）；春季优势种不明显，个体数较多的有南方拟?（Pseudohemiculter dispar）和泥鳅（Misgurnus anguillicaudatus）；夏季优势种为?、大眼华鳊（Sinibrama macrops）和南方拟?；秋季优势种为?、莫桑比克罗非鱼（Tilapia mossambicus）和尼罗罗非鱼（T. niloticus）。无度量多维排序图（NMDS）和单因素相似性分析（ANOSIM）结果显示，除夏季与秋季之间外（P=0.178>0.05），其余季节之间鱼类群落结构存在显著性差异（P<0.05），这可能是珠江水系鱼类繁殖期（4-6月）及降水的季节性变化所致。采样点S1与S7、S8、S9，S6与S7、S8、S9，S2与S6、S9之间存在显著性差异。目前河流库区化、过度开采以及外来物种入侵是导致鱼类群落结构变化的主要原因。     

茜坑水库浮游植物时空分布及水质风险评价

浮游植物是判断水体富营养化程度的关键指标之一,藻类水华中有害蓝藻释放的蓝藻毒素会危害人类健康,对饮用水的安全构成威胁。2010年4月至2011年3月,按月对广东省深圳市茜坑水库的浮游植物群落进行了调查。结果表明,茜坑水库共采集到浮游植物7门、66属、127种,种类组成以绿藻(54%)和硅藻(25%)为主,水库属绿藻-硅藻型水体;浮游植物细胞密度年均值为1.10×107个/L,绿藻门、硅藻门、隐藻门和蓝藻门细胞密度所占比例较高;浮游植物多样性在茜坑水库各样点间不存在显著性差异(P>0.05),表明水体交换能力较强;结合3种水质评价方法,初步判断茜坑水库为轻污-中污型水体,并通过对潜在产毒蓝藻现存量的分析来评价水质安全存在的风险。7月的水质风险最大,应进行藻毒素测定。对理化因子的测定显示,水库总氮和总磷浓度均超过《GB3838-2002地表水环境质量标准》中Ⅱ类标准值。     

亚热带河流型水库浮游植物群落研究——以分水江水库为例

为了解亚热带河流型水库-分水江水库蓄水后的水体富营养化状况与浮游植物群落结构特征，于2006年1月至2007年12月，对其进行了20次采样调查。结果表明，分水江水库总氮浓度较高，平均值大于2mg／L，氮污染严重，磷污染较轻，水质总体评价较差，为劣V水体。分水江水库浮游植物群落组成以硅藻、隐藻和绿藻为主，密度为0．7×10^4-168310×10。个／L，以富营养种类为主。浮游植物组成随季节变化而有所不同，春季以直链藻（Melosira）、实球藻（Pandorina）、盘星藻（Pediastrum）为优势类群；夏季以微囊藻（Microcystis）、鱼腥藻（Ana-baena）、脆杆藻（Fragilaria）为优势类群；秋冬季以小环藻（Cyclotella）、针杆藻（Synedra）、蓝隐藻（Chroomonas）为主。分水江水库浮游植物密度、叶绿素a与降雨量均呈显著正相关，浮游植物的生长受水文气象条件变化的影响较大，间接说明分水江水库受面源污染比较严重。浮游植物密度和叶绿素a与水体理化因子也有较强的相关性，特别是水温、pH、溶解氧、高锰酸盐指数和总磷均与浮游植物呈显著正相关。     

龙头桥水库水质分析与评价

本文根据2006年12月至2007年10月间对龙头桥水库水质测定分析的结果，进行了简析和评价，为该水库发展渔业生产提供了科学依据。     

Association between the interannual variation in the oceanic environment and catch rates of bigeye tuna (Thunnus obesus) in the Atlantic Ocean

The environmental processes associated with variability in the catch rates of bigeye tuna in the Atlantic Ocean are largely unexplored. This study used generalized additive models (GAMs) fitted to Taiwanese longline fishery data from 1990 to 2009 and investigated the association between environmental variables and catch rates to identify the processes influencing bigeye tuna distribution in the Atlantic Ocean. The present findings reveal that the year (temporal factor), latitude and longitude (spatial factors), and major regular longline target species of albacore catches are significant for the standardization of bigeye tuna catch rates in the Atlantic Ocean. The standardized catch rates and distribution of bigeye tuna were found to be related to environmental and climatic variation. The model selection processes showed that the selected GAMs explained 70% of the cumulative deviance in the entire Atlantic Ocean. Regarding environmental factors, the depth of the 20 degree isotherm (D20) substantially contributed to the explained deviance; other important factors were sea surface temperature (SST) and sea surface height deviation (SSHD). The potential fishing grounds were observed with SSTs of 22–28°C, a D20 shallower than 150 m and negative SSHDs in the Atlantic Ocean. The higher predicted catch rates were increased in the positive northern tropical Atlantic and negative North Atlantic Oscillation events with a higher SST and shallow D20, suggesting that climatic oscillations affect the population abundance and distribution of bigeye tuna.     

Growth performance,digestive enzyme activity and immune response of Japanese sea bass,Lateolabrax japonicus fed with fructooligosaccharide

In this experiment, a feeding trial was performed to determine the effects of fructooligosaccharide (FOS) on growth performance, digestive enzyme activity and immune response of Japanese sea bass, Lateolabrax japonicus juveniles (initial weight 38.3 ± 0.5 g), and the fish were examined following feeding with six levels of FOS (0, 0.5, 1, 2, 4 and 6 g/kg) for 28 days. Significant enhancement of weight gain (WG) and specific growth rate (SGR) was found in fish fed 1 g/kg FOS incorporated diets (p < .05), while the feed conversion ratio (FCR) in the 1, 2 g/kg FOS groups reduced significantly compared with the control (p < .05). Besides, the crude lipid in the 4, 6 g/kg FOS groups increased significantly compared with the control (p < .05). On the other hand, the erepsin and lipase activities significantly elevated in intestine of fish fed 2 g/kg FOS (p < .05) and the lysozyme activity in serum of fish fed 2 g/kg FOS were significantly higher than that in the control (p < .05). Moreover, the alkaline phosphatase activities in serum of fish fed 0.5, 1, 2 g/kg FOS were significantly higher than in control (p < .05). Regression analysis showed that the relationships between dietary FOS levels and either SGR, FCR, erepsin or lysozyme activities were best expressed by regression equations, and the optimal inclusion levels are 1.37, 1.80, 3.06, 3.11, 1.93 and 1.80 g/kg for SGR, FCR, erepsin, lipase, lysozyme and total superoxide dismutase activities, respectively. Overall, this study revealed that FOS incorporated diets could beneficial for L. japonicus culture in terms of increasing the growth, digestion and immune activities. Under the present experimental condition, the optimal supplementary level of FOS in the diet of L. japonicus is 1–3 g/kg.     

Protein and amino acid composition from the mantle of juvenile O ctopus vulgaris exposed to prolonged starvation

Protein and amino acid composition of the mantle of juvenile O ctopus vulgaris (Cuvier, 1797) during fasting for 27 days were determined. Average protein content of octopus mantle was of 711.19 ± 46.80 g kg^?1 DW, and it decreased with increasing fasting days. The non‐essential amino acids content was higher (486.18 ± 11.08 g kg^?1 protein) than essential amino acids (425.82 ± 9.15 g kg^?1 protein) at the start of the experiment (unstarved animals). The results suggest that the amino acid profile of the mantle where the most abundant amino acids are Arg, His, Lys, Gly, Leu and Pro could indicate a prolonged fasting condition (>20 days) or poor nutrition of O . vulgaris. This study supports the idea of using mantle for metabolic needs of starved O . vulgaris suggesting that the degradation pathway of amino acids to pyruvate and tricarboxylic acid cycle intermediates was favoured contrary to the degradation pathway of ketogenic amino acids. Special considerations should be taken concerning Thr, Ile, Ser, Ala, Asx (Asp, Asn), Glx (Glu, Gln) (because of their fast intake) and Lys and His (due to their stable contents) during a prolonged period of fasting.     

Involvement of gonadal steroids in final oocyte maturation of white perch (Morone americana) and white bass (M. chrysops): in vivo and in vitro studies

Plasma estradiol-17 (E₂), testosterone (T), 17,20-dihydroxy-4-pregnen-3-one (DHP) and 17,20,21-tri-hydroxy-4-pregnen-3-one (20-S) levels were measured by radioimmunoassay (RIA) in white perch (Morone americana) and white bass (M. chrysops) that were induced to undergo final oocyte maturation (FOM) with human chorionic gonadotropin (hCG). Plasma DHP levels increased in females of both species in association with oocyte germinal vesicle migration (GVM) and germinal vesicle breakdown (GVBD) and decreased thereafter. Plasma 20-S levels also increased with oocyte GVM in white bass, but were several-fold lower than DHP levels. Circulating E₂ and T levels were greatest during GVM and GVBD in both species and decreased to low levels during oocyte hydration and ovulation. Follicles from white perch and white bass which received a priming injection of hCG in vivo, produced both DHP and 20-S in vitro after exposure to hCG and their oocytes underwent GVBD. Ovarian incubates from unprimed fish of either species produced only E₂ and T and their oocytes did not complete GVBD. Oocytes from unprimed bass, but not perch, matured when follicles were exposed to hCG in vitro. Both trilostane and cycloheximide blocked in vitro production of DHP and 20-S and oocyte GVBD by white perch follices. DHP and 20-S were equipotent inducers of FOM in the GVBD bioassay. None of several other structurally-related steroids tested were effective within a physiological range of concentrations. These results indicate a role for DHP and 20-S in the control of FOM in white perch and white bass.     

Cardiac,ventilatory and metabolic responses of two ecologically dissimilar species of fish to waterborne cyanide

Changes in heart rate, ventilatory activity and oxygen consumption were determined in trout (Salmo gairdneri) and brown bullhead catfish (Ictalurus nebulosus) during exposure to a steadily increasing concentration of waterborne cyanide selected to produce death in 8–9 hours for each species. The lethal cyanide concentration for the bullheads was an order of magnitude higher than for trout. Trout developed an immediate and gradually increasing bradycardia throughout the exposure period. Cyanide produced tachycardia in the bullhead followed by a gradual onset of bradycardia as the concentration of cyanide was raised. Pericardial injection of atropine (a muscarinic cholinergic antagonist) indicated that bradycardia in the trout was due initially to increased vagal tone but later due to the direct effect of cyanide on the heart. Hyperventilation in the trout persisted throughout the exposure period, although the rate and amplitude fluctuated and was variable between individual fish. During the last hour of exposure (highest cyanide concentration), ventilation was characterized by rapid, shallow breaths followed by a sudden respiratory arrest. The bullheads exhibited hyperventilation during the first 3 hours of exposure followed by a gradual, linear drop in ventilation rate and amplitude until death occurred. Cardiac and ventilatory responses in both species were attributed to stimulation of central and peripheral chemoreceptors by cyanide. Evidence is presented which suggests the initial response in the bullheads was due, at least in part, to gustatory stimulation by the cyanide. Oxygen consumption of the trout remained above pre-exposure levels for the majority of the test period. Oxygen consumption in the bullhead paralleled the changes in heart and ventilatory rates. Whole-body lactate levels of fingerlings of both species during cyanide exposure were measured to estimate the extent of anaerobiosis. Whole-body lactate levels were much greater in the bullheads than the trout, indicating a higher capacity for anaerobiosis, possibly due to a greater fuel supply. Overall, the trout responded to cyanide in a manner similar to that produced by environmental hypoxia whereas the bullheads experienced a gustatory stimulus which masked the hypoxia-like response.     

美人鱼发光杆菌对凡纳滨对虾非特异性 免疫功能及抗病力的影响

在基础饲料中分别添加0.1%和1%美人鱼发光杆菌灭活菌、0.1%美人鱼发光杆菌活菌配制成3种免疫实验饲料,以基础饲料为空白对照组饲料,每组设3个平行样。对个体质量为(4.83±0.36)g的凡纳滨对虾进行为期20 d的饲养实验,分别在0、5、10、15和20d进行取样,以血清中的酚氧化酶(PO)、酸性磷酸酶(ACP)、碱性磷酸酶(AKP)、超氧化物歧化酶(SOD)和溶菌酶(UL)活性为免疫指标,探讨了美人鱼发光杆菌作为免疫制剂对凡纳滨对虾非特异性免疫效应的影响;在投喂免疫饲料后的第22天,按0.004 2 kg/kg体重的剂量,直接投喂对虾白斑综合征病毒(WSSV)病料,并记录累积死亡率。结果表明,美人鱼发光杆菌免疫实验组对凡纳滨对虾血清中PO、ACP、AKP、UL和SOD活性影响明显高于对照组,并且在饲料中添加美人鱼发光杆菌后,明显提高了对虾抵御WSSV感染的能力。其中0.1%美人鱼发光杆菌活菌实验组的抗病毒感染能力最强,WSSV感染14d内累计死亡率为63.3%±5.8%;而对照组为96.7%±3.3%。研究表明,美人鱼发光杆菌添加在对虾饲料中能提高凡纳滨对虾非特异性免疫水平,增强抵抗疾病的能力,将其作为对虾免疫增强剂具有良好的应用前景。     

An overview of stress physiology of fish transport: changes in water quality as a function of transport duration

This study brings an integrated analysis about the relationship between water deterioration and its physiological consequences in live fish transport. The analysis was focused on the transport water and its deterioration, and physiological challenges imposed on the fish. Usual commercial handling procedures employed to mitigate fish stress during transport were discussed. Future topics of research for the establishment of safer fish transport protocols were proposed. Transport was classified into short (≤8 h) or long transport (>8 h). The main issue in short transports should be the prevention of water pH reduction, while in long transports it is the increase in ammonia. Plasma cortisol is the most employed marker for stress and is acutely elevated upon short episodes of transport, but remains elevated even in long‐transport events. Plasma glucose is perhaps a better marker for handling stress. Plasma lactate, pH, osmolality CO₂ and ions should be more often evaluated. Plasma Na⁺ and Cl^‐ are very useful markers of acidosis, due to their respective exchange for H⁺ and , for acid–base regulation. The establishment of species‐specific transport protocols should be preceded by such combined analyses of water and physiological parameters.     

Are hatchery‐reared abalone naïve of predators? Comparing the behaviours of wild and hatchery‐reared northern abalone,Haliotis kamtschatkana (Jonas, 1845)

Abalone populations have declined worldwide, generating interest in enhancement using hatchery‐reared individuals. In many cases, such restoration efforts have met with limited success due to high predator‐induced mortality rates. Furthermore, the mortality rates of outplanted hatchery abalone are often considerably higher than for wild individuals. This study uses northern abalone (Haliotis kamtschatkana) as a case study to determine whether hatchery‐reared abalone behave differently than their wild counterparts. In the field, outplanted hatchery‐reared abalone were significantly less responsive than wild abalone, in terms of number of abalone responding and intensity of response, to nearby movement and to physical contact with an inert probe. Also, when encountering a cue to which all abalone responded (a seastar predator), hatchery‐reared individuals remained subdued. Anti‐predator behavioural deficits in hatchery‐reared abalone were more pronounced in 4‐year‐old individuals than in 1‐year‐old individuals, suggesting an influence of either age or amount of time spent in the hatchery environment. These behavioural differences are expected to increase the vulnerability of hatchery‐reared abalone to predators, and are likely a major cause of their elevated predator‐induced mortality when outplanted.     

Effects of cadmium on the kinetics of calcium uptake in developing tilapia larvae, Oreochromis mossambicus

The toxic effects of Cd²⁺ on Ca²⁺ influx kinetics in developing tilapia (Oreochromis mossambicus) larvae were evaluated. Addition of 20 µg l^-1 of Cd²⁺ to the environment of 0 and 3 day-old larvae competitively inhibited the Ca²⁺ uptake within 4h resulting in a great increase in K_m values for Ca²⁺ influx (19.3 and 17.4 fold, respectively) as compared with their respective controls. Consequently, the actual Ca²⁺ influx of larvae in solutions of 0.2 mM Ca²⁺ are suppressed by 32–45%. Also, 3 day-old larvae were more sensitive to internally accumulated Cd²⁺ than 0 day-old larvae. Although the Ca²⁺ influx in 0 and 3 day-old larvae may be restored to the levels of their respective controls with 24h of being transferred to a 20 µg l^-1 Cd²⁺ solution, total body Ca²⁺ content was significantly reduced in 3 day-old larvae. Increased Ca²⁺ uptake efficiency ensures sufficient Ca²⁺ for normal growth. However, rapid increase in Ca²⁺ influx after hatching also leads to higher Cd²⁺ uptake. Exposure to Cd²⁺ will lead to a drop in body Ca²⁺ content resulting in retardation of larval growth. Therefore, we conclude that if Ca²⁺ uptake is interfered with at this critical stage of development, larvae will not be able to maintain normal levels of body Ca²⁺ and will show signs of Cd²⁺ poisoning.     

Migratory dynamics of stream-spawning longnose gar (Lepisosteus osseus)

Abstract– Literature evidence suggests that lake-dwelling longnose gar (Lepisosteus osseus) enter tributary streams to spawn, Until the present study, the dynamics of this breeding migration had never been investigated quantitatively. During the summers of 1991 and 1992, longnose gar were captured as they entered Weaubleau Creek, Missouri, a tributary of Harry S. Truman Reservoir. The in-stream spawning migration began in early April and ended in late May, and was positively correlated with stream flow and water level, and negatively correlated with water temperature. In-stream residence times ranged from 15 to 94 days, with males exhibiting longer residence times than females. Once in-stream, longnose gar travelled as far as 10 km upstream and occupied certain pools at greater relative frequencies. Although the reason for this preferential utilization is not completely understood, it may relate to pool depth and riffle proximity. Longnose gar disperse from the spawning stream great distances, with gar captured in Weaubleau Creek being recaptured up to 48 km away. This information should provide fisheries biologists the means to consider the reproductive ecology of this species in their conservation and management decisions.