双台河口潮滩湿地不同植被沉积物脲酶、蛋白酶、磷酸酶活性及其与氮、磷含量关系

土壤中生物胞外酶参与土壤中有机物周转和营养物质循环,其活性是土壤中生物群落代谢需求和有效营养物质的直接表现。以2012年7月、9月和11月对双台河口滨海湿地野外调查获取的数据为基础,研究了生长不同植被的沉积物(土壤)脲酶、蛋白酶、磷酸酶活性及其与氮、磷含量的相关关系。翅碱蓬或芦苇单独生长区脲酶活性7月9月11月;翅碱蓬和芦苇混合生长区脲酶活性9月7月11月;芦苇、苣荬菜、艾蒿混合生长区脲酶活性9月11月7月。翅碱蓬单独生长区、翅碱蓬和芦苇混合生长区以及芦苇、苣荬菜、艾蒿混合生长区蛋白酶活性9月7月11月;芦苇单独生长区蛋白酶活性9月11月7月。翅碱蓬单独生长区、芦苇单独生长区磷酸酶活性7月9月11月;翅碱蓬和芦苇混合生长区磷酸酶活性9月11月7月;芦苇、苣荬菜、艾蒿混合生长区磷酸酶活性9月7月11月。除少数样点外,不同土层的脲酶、蛋白酶和磷酸酶活性0~10 cm土层10~20 cm土层20~30 cm土层。脲酶活性与土壤全氮含量正相关,蛋白酶活性与氨氮含量正相关,磷酸酶活性与速效磷含量正相关。河口滨海潮滩湿地生长不同植被的沉积物(土壤)脲酶、蛋白酶、磷酸酶活性不同,存在季节差异,且与沉积物中不同形态的氮、磷含量存在正相关关系。     

典型滨海翅碱蓬盐沼湿地土壤理化特征研究

为了解滨海潮间带盐沼湿地翅碱蓬生长的土壤环境,2013年7月～8月采集辽宁盘锦、辽宁庄河、天津、山东东营及江苏连云港5个不同纬度典型滨海翅碱蓬生长区域土壤,研究了其理化特征。结果表明,翅碱蓬可生长的我国滨海潮间带湿地土壤含盐量（2.5±0.5）g/kg～（19.0±6.1）g/kg、氯离子含量（1.16±0.04）g/kg～（11.27±0.3.43）g/kg、pH （7.05±0.01）～（8.96±0.01）、碱度（3.56±0.59）mmol/kg～（8.78±0.78）mmol/kg、全碳含量（7.70±1.84）mg/kg～（21.73±4.11）mg/kg,全氮含量（0.36±0.03）mg/kg～（0.87±0.04）mg/kg、无机氮含量（1.95±0.95）mg/kg～（16.10±1.57）mg/kg、速效磷含量（5.26±0.33）mg/kg～（39.98±0.61）mg/kg、速效钾含量（0.53±0.19）mg/kg～（1.77±0.01）mg/kg,其中铵氮含量（1.60±0.58）mg/kg～（8.76±0.16）mg/kg、亚硝酸盐氮含量（0.01±0.00）mg/kg～（0.11±0.00）mg/kg、硝酸盐氮含量（1.00±0.20）mg/kg～（2.54±1.09）mg/kg。土壤N:P比平均值为0.80±0.25、N:K比平均值为17.77±6.08、P:K比平均值为26.90±4.67;TC:TN比平均值为26.50±4.67。在符合这些土壤特征的滨海潮间带光滩可采用翅碱蓬进行生态修复。     

生态恢复视角下海滨湿地景观模拟 ——以江苏盐城湿地珍禽国家级自然保护区为例

选择盐城典型淤泥质海滨湿地区,从生态恢复的视角,模拟预测未来海滨湿地景观可能的变化结果,为海滨湿地的科学管理提供决策参考。盐城海滨湿地是区域重要的生态屏障,近年来,在人类与自然的双重作用下,区域湿地景观变化显著。为维护区域生态安全,发挥湿地应有的功能,以2000年和2011年遥感影像为基础,结合土壤水分和盐度数据,采用景观过程模型,从生态恢复的视角,对2020年盐城海滨湿地景观演变进行模拟,研究结果表明:(1)人工围堰、互花米草扩张和碱蓬沼泽退化是研究区面临的主要生态问题。(2)人工管理区,至2020年,碱蓬沼泽比现状条件下模拟结果增加了18.46倍,互花米草沼泽减少了66.04%;景观多样性指数从1.007增加到1.150,景观均匀度指数从0.626增加到0.715。(3)自然条件区,至2020年,互花米草沼泽的面积比现状条件下模拟结果减少了82.32%,碱蓬沼泽增加了19.65倍;景观多样性指数从1.082增加到1.237,景观均匀度指数从0.780增加到0.892。     

黄河三角洲盐地碱蓬对镉的吸收富集特征

为明确调水调沙背景下碱蓬对Cd污染的吸收富集特征，本研究以该区主要潜在生态风险因子镉（Cd）为切入点，利用温室栽培实验，分析了Cd输入对碱蓬生物量、Cd含量、富集系数及转移系数的影响。结果表明：少量的Cd输入（≤4.0 mg/kg）时碱蓬生物量高于对照，并在2.0 mg/kg处理时总生物量、茎和叶生物量取得最大值，而过高的Cd输入（>5.0 mg/kg）时生物量低于对照；随着Cd输入的增加，碱蓬根、茎及叶中Cd含量呈现增加趋势，而Cd富集系数则呈现先增高后降低的变化趋势，且在Cd输入量为2.0 mg/kg时，富集系数取得最大值（42.67、4.82和6.18）；整体上碱蓬根是富集Cd主要部位，但在低水平Cd输入（0.0 mg/kg和1.0 mg/kg）时，茎和叶部转运系数大于高水平Cd输入，表现出较强富集作用。以上结果表明碱蓬能有效富集土壤中的Cd元素，且在一定范围内碱蓬的富集能力随着Cd输入的增加而增加，但是过高的Cd浓度输入会抑制碱蓬的Cd富集能力。     

盐生植物碱蓬在富营养化海水养殖尾水修复中的应用

为了考察盐地碱蓬(Suaeda sala)由内陆生境转移到海水生境后的生长情况及对海水养殖池塘水体修复的效果,配制了4种不同富营养化程度的水体,采用水培的方法,测定了碱蓬对水体中COD、BOD_5、TN、TP的处理效果及植株体内试验前后TP、TN含量的变化。结果显示,随净化时间的延长,TN、TP均呈下降趋势,一周后TN浓度维持在1.5～3.0 mg/L;随着水体中TP、TN浓度的增大,碱蓬的处理效果增加,且试验前后碱蓬植株体内TP、TN的含量也随水体中TP、TN浓度的增大而增加。随着净化时间的延长,不同程度富营养化水体中的COD、BOD_5呈明显下降趋势。pH值在不同程度富营养化水体中呈先降后升的趋势,修复1周后,各水体均呈弱碱性。由于盐生植物吸收一定的盐离子维持自身的营养需要,水体盐度表现出下降。试验表明,盐地碱蓬从内陆生境转移到海水生境后,不但适应了水生环境,也通过根系吸收、根际微生物等作用方式对水中的氮、磷、COD等产生了良好的去除效果,盐地碱蓬修复海水养殖池塘水体具有良好潜力。     

生态化学计量法在刺参饵料中的应用

在人工饲养条件下,采用不同比例的孔石莼干粉与养殖海区底泥配制的人工饵料和商品刺参饵料投喂刺参,通过测定饵料、刺参及其粪便中的C、N、P含量,应用生态化学计量法分析研究了一定时期内,不同C、N、P元素比值的饵料对刺参自身及其粪便中C、N、P元素比值以及生长的影响。结果表明,摄食不同饵料的刺参均呈现体重增加。不同处理组刺参及其粪便中的C∶P比、N∶P比随着饵料中的C∶P比、N∶P比升高而升高。尽管不同饵料的C∶N比不同,但各处理组刺参和其粪便中的C∶N比差异较小。     

盐生植物碱蓬在富营养化海水养殖尾水修复中的应用研究

海水养殖废水的排放导致了严重的近岸海域生态环境问题。植物修复海水养殖废水颇具优势。为了考察盐地碱蓬(Suaeda sala)由内陆生境转移到海水生境后的生长情况及对海水养殖池塘水体修复的效果，配制了4种不同富营养化程度的水体，采用水培的方法，测定了碱蓬对水体中COD、BOD5、TN、TP的处理效果及植株体内实验前后TP、TN含量的变化。结果显示，随净化时间的延长，TN、TP均呈下降趋势，一周后TN浓度维持在1.5~3.0 mg/L；随着水体中TP、TN浓度的增大，碱蓬的处理效果增加，且实验前后碱蓬植株体内TP、TN的含量也随水体中TP、TN浓度的增大而增加。随着净化时间的延长，不同程度富营养化水体中的COD、BOD5呈明显下降趋势。pH值在不同程度富营养化水体中呈先降后升的趋势，修复1周后，各水体均呈弱碱性。由于盐生植物吸收一定的盐离子维持自身的营养需要，水体盐度表现出下降。实验表明，盐地碱蓬从内陆生境转移到海水生境后不但适应了水生环境，也通过根系吸收、根际微生物等作用方式对水中的氮、磷、COD等产生了良好的去除效果，盐地碱蓬修复海水养殖池塘水体具有良好潜力。     

碳、氮、磷营养对7种海洋微藻种群增长的影响研究

文章采用批次培养方式研究双胞旋沟藻(Cochlodinium geminatum)、米氏凯伦藻(Karenia mikimotoi)、中肋骨条藻(Skeletonema costatum)、牟氏角毛藻(Chaetoceros muelleri)、球形棕囊藻(Phaeocystis globosa)、亚心形扁藻(Platymonas subcordiformis)和眼点拟微绿球藻(Nannochloropsis oculata)在不同碳(C)、氮(N)、磷(P)条件下的生长特性,以期为养殖尾水的原位处理筛选优良藻种(株)。结果表明,这7种微藻的比生长速率与C、N、P浓度总体呈正相关。相较对照组,C对旋沟藻、骨条藻和拟微绿球藻比生长速率的促进作用分别为35%、19%和19%,P对比生长速率的最大促进作用介于25.01%~446.60%,硝酸盐为16.54%~77.52%,铵盐为15.79%~88.82%,尿素为25.16%~71.43%。7种微藻的最大比生长速率与细胞体积总体呈负相关,棕囊藻的比生长速率最高,拟微绿球藻和扁藻最大比生长速率与其他藻华种相比无显著差别。微藻的氮磷吸收速率随细胞体积增加呈升高趋势,单位氮磷利用效率随细胞体积增加呈降低趋势。培养液中P吸收速率显著高于N,氮磷比均呈升高趋势。眼点拟微绿球藻和亚心形扁藻可用于养殖尾水氮磷的快速去除。     

不同氮、磷比例对球等鞭金藻生长的影响

在不同氮，磷纟（N：P＝1：1，4：1，16：1，80：1，160：1）条件下，对球等鞭金藻进行了培养。通过对其生长和营养生理特性的研究发现：在N／P比等于16：1的条件下，球等鞭金藻的生长速度最快，单位水体内的细胞数量最多。此外，在高氮，磷比（N／P＝160：1，80：1）的条件下，其生长速度要优于低氮，磷比（N／P＝1：1，4：1）状态。藻细胞内碳水化合物和蛋白质的含量也明显受到氮，磷比的影响，其含量表现为16：1＞160：1＞80：1＞4：1＞1：1。此外，细胞内物质的积累合成与细胞生长的不同阶段密切相关。     

三峡水库小江流域常见鱼类肌肉碳、氮、磷生态化学计量特征

为探究三峡水库小江流域常见草食性、浮游生物食性、肉食性和杂食性鱼类肌肉的碳（C）、氮（N）、磷（P）生态化学计量特征，2018年1月（枯水期）和7月（丰水期）在小江流域7个设定断面，采集4种食性的鱼类样品，测定其生长特性指标，分析鱼类肌肉C、N、P生态化学计量特征及相关性。结果表明，鱼类肌肉C、N、P元素含量为34.75%~58.71%、 7.00%~15.45%、0.89%~8.21%，C:N、C:P和N:P为3.62~9.75、16.92~136.95、2.14~35.31，其中磷元素含量变化最大且是导致N:P变化的主要原因。小江流域不同食性鱼类肌肉元素组成差异不明显，其中仅草食性鱼类、浮游生物食性鱼类 的N含量和N:P显著大于肉食性鱼类和杂食性鱼类（P<0.05），其他元素及比例在各食性鱼类之间均无显著性差异（P>0.05）；不同采样断面的鱼类肌肉元素含量及比例无显著性差异（P<0.05）；相关性分析发现，小江流域鱼类肌肉N和 P含量呈负相关关系（P<0.05），除草食性外，各食性鱼类的N含量均与水体NO-3-N含量呈显著正相关（P<0.05）。研究结果对深入了解大坝干扰下水生态系统食物网营养关系及营养循环格局具有重要意义。     

Comparison of dietary protein and energy utilization in three Asian catfishes (Pangasius bocourti, P. hypophthalmus and P. djambal)

Dietary protein and energy utilization were compared in three Pangasiid species of high economical interest for fish farming in South‐East Asia. Feeding experiments were performed during 4 weeks on Pangasius bocourti, P. djambal and P. hypophthalmus fingerlings, 6.68, 7.69 and 6.41 g mean mass, respectively. A high‐protein diet containing mostly fishmeal was designed to provide proteins without energy limitation. Growth response, variation in body composition and nutrient utilization were compared for fish receiving variable amounts of diet corresponding to increasing protein supply, 0, 5, 15, 25, 35 and 45 g kg^?1 day^?1. The highest specific growth rate was observed for P. bocourti (6.0% day^?1), followed by P. djambal (5.6) and P. hypothalamus (4.1). Pangasius djambal exhibited the highest protein deposition rate, whereas P. bocourti was characterized by a high fat deposition rate even with a low feeding rate. Lower performance was obtained with P. hypophthalmus.     

影响畜禽脂肪沉积的遗传和营养因素分析

畜禽脂肪沉积受多种因素的影响。主要分析了遗传因素和营养因素,尤其是对影响动物脂肪沉积的相关基因作了重点分析,包括FABPs、PPARs、obese和leptin、UCPs、LPL、HSL、adiponectin、IGF2。     

Assessment of the production and dispersal of faecal waste from the sea‐cage aquaculture of spiny lobsters

Despite the rapid expansion of spiny lobster aquaculture, very little is known about its potential environmental impacts. In an effort to understand the potential impacts of sea‐cage culture of spiny lobsters, the faecal output and settling velocity of faeces of spiny lobster were quantified. These data were then used in hydrodynamic modelling to assess the dispersal pattern of faecal material from two sizes of hypothetical spiny lobster farms, so that inferences about likely benthic impacts could be made by modelling different scenarios of farm stocking density and food conversion efficiency. The overall mean settling velocity of lobster faecal strands was 0.9 ± 0.05 cm s^?1. There was a positive correlation between both the weight and density of faecal strands and their settling velocity. Conversely, neither the length nor the surface area of faecal strands was correlated with the settling velocity. Hydrodynamic modelling showed that faecal material deposition mainly occurred directly beneath the sea‐cages. The density of faecal material deposition increased proportionately with higher stocking density and FCR values. Overall, the results indicate that the deposition of faecal waste from sea‐cage lobster aquaculture is unlikely to cause widespread benthic impacts when operating to the current highest commercial stocking and feeding levels.     

高水平烟酸对吉富罗非鱼脂代谢和体脂沉积的影响

为探讨高水平烟酸对鱼类脂代谢和体脂沉积的影响,本研究以吉富罗非鱼(Oreochromisniluticus)为研究对象,设计了2个实验。在实验I中,为确定烟酸是否具有改善血脂作用及其适宜水平,首先通过高糖高脂饲料喂养初始体重(15.28±0.23) g的实验鱼40 d,建立高血脂模型,随后改投添加500 mg/kg、1000 mg/kg、2000 mg/kg烟酸的饲料。结果发现添加500～2000mg/kg的烟酸,均有降低实验鱼血清胆固醇和甘油三酯水平的作用,但以1000～2000 mg/kg的效果较为显著。在实验Ⅱ中,采用2×2双因素实验设计,研究了2种饲料类型(对照组和高糖高脂饲料)和2个烟酸水平(100 mg/kg和1000 mg/kg)对初始体重(24.45±0.07) g实验鱼生长、饲料利用、血脂水平和体成分的影响。养殖8周。结果发现,饲料类型或烟酸水平未对实验鱼的末体重、增重率、特定生长率、肥满度、脏体比和肠脂比,以及全鱼粗脂肪、粗蛋白、水分和灰分含量等生长性能指标产生显著影响(P0.05);对饲料粗蛋白和粗脂肪的表观消化率、饲料系数、摄食率等饲料利用指标也未产生显著影响(P0.05)。与投喂对照组饲料的相比,投喂高糖高脂饲料的实验鱼对饲料干物质和总能的表观消化率,及其血清胆固醇、甘油三酯和游离脂肪酸水平,肝脏、内脏、腹肌的粗脂肪含量显著升高(P0.05);而投喂高水平烟酸实验鱼的血清低密度脂蛋白、胆固醇和游离脂肪酸水平,肝脏粗脂肪含量则显著降低(P0.05)。饲料类型和烟酸水平仅对实验鱼血清的高密度脂蛋白和胆固醇水平存在显著的交互作用(P0.05)。结果表明,饲料中添加1000 mg/kg烟酸不会影响吉富罗非鱼的生长性能和饲料利用,并具有降低血脂水平和肝脏脂肪含量的作用。     

Effects of dietary lipid level and n‐3/n‐6 fatty acid ratio on growth,fatty acid composition and lipid peroxidation in Russian sturgeon Acipenser gueldenstaedtii

The growth performance, fatty acid composition, hepatic lipid content, hepatic somatic index and lipid peroxidation in Russian sturgeon were investigated using diets containing three lipid levels 50 g kg^?1 (L5), 150 g kg^?1 (L15) and 250 g kg^?1 (L25) and three n‐3/n‐6 fatty acid ratios (1 : 3, 1 : 1 and 3 : 1) for 8 weeks. Weight gain significantly increased with the increase in dietary lipid levels at n‐3/n‐6 fatty acid ratios of 1 : 3 and 1 : 1, but not at the 3 : 1 ratio. Correspondingly, fish survival gradually decreased with the increase in dietary lipid at the 3 : 1 n‐3/n‐6 fatty acid ratio. The dietary lipid level significantly affected the composition of whole‐body fatty acid. The retention of highly unsaturated fatty acid dramatically decreased at the level of 250 g kg^?1 dietary lipid. The liver malondialdehyde increased with the increase in dietary lipid levels and the n‐3/n‐6 fatty acid ratios. The contents of lipid and triglyceride in the liver and the hepatic somatic index also increased with the increase in dietary lipid. The diet combination of L25 + 3 : 1 showed the highest aspartate transaminase and alanine transaminase, indicatives of hepatic injury. This study indicates that the L25 + 1 : 3 diet can improve fish growth performance, whereas the L25 + 3 : 1 diet may lead to poor growth performance due to high lipid peroxidation.     

Dietary Lipid Levels Affect the Growth Performance,Lipid Deposition,and Antioxidative Capacity of Juvenile Scaleless Carp,Gymnocypris przewalskii,on the Qinghai‐Tibetan Plateau

A 56‐d growth trial was conducted to evaluate the growth performance, lipid deposition, and antioxidative capacity of juvenile scaleless carp, Gymnocypris przewalskii, on Qinghai‐Tibetan Plateau. One‐year‐old juveniles (initial weight: 15.99 ± 0.02 g) were fed practical diets with different lipid levels of 4, 5.5, 7, 8.5, and 10%, respectively. Results showed that the best specific growth rate (SGR), feed conversion rate, and total antioxidative capacity (T‐AOC) in hepatopancreas were observed in fish fed the diet with 7% lipid level. Fish fed with high lipid diets (8.5 and 10%) had significantly higher condition factor and viscerosomatic index as well as lipid in muscle, intestine, mesenteric fat tissue, and whole body. Highest level of hepatopancreas lipase and lipoprotein lipases activities as well as malondialdehyde content and the lowest level of feed intake and T‐AOC content in hepatopancreas and intestine were also observed in fish fed with high lipid diets (8.5 and 10%) (P < 0.05). In conclusion, based on SGR and hepatopancreas T‐AOC content, dietary lipid requirement of juvenile G. przewalskii was estimated to be 7.35 and 7.39%, respectively.     

Inter-river, -annual and -seasonal variability in fecundity of Atlantic salmon, Salmo salar L., in rivers in Newfoundland and Labrador, Canada

Abstract  Fecundity is an integral component of the calculation of Atlantic salmon, Salmo salar L., egg depositions in rivers. Fecundity determinations can be time consuming and prohibitively expensive in terms of application on a broad scale. Consequently, where river specific and annual data are not available, default means are used in calculations in Newfoundland and Labrador. It is important therefore to know the extent of variability among rivers, years and seasons and the potential error involved in using default values. Annual fecundity data were available for one river in Labrador and nine rivers in Newfoundland. Fecundity was determined from ovaries collected in the recreational fishery in the summer for all 10 rivers. For three of these rivers, fecundity determined from summer sampling was compared with that obtained from sampling at time of spawning in autumn. There was significant variability in fecundity with length as a covariate among rivers, years and seasons. Mean number of eggs per female decreased between 8.3% and 29.0% from summer to autumn while mean number of eggs per cm decreased from 5.0% to 28.5%. Depending on the measure of relative fecundity used (no. of eggs kg⁻¹ or no. of eggs cm⁻¹), results of simulations showed that estimates of egg deposition incorporating defaults can deviate from those obtained by applying year-specific and river-specific values by 50–75%, without adjusting for the seasonal reduction in fecundity, and by 30–50% with an adjustment. A sensitivity analysis revealed that of three parameters used in the calculation of egg deposition (size, percent female and fecundity), fecundity was the most influential.     

不同温度下刺参对有机沉积物的摄食与吸收

以常规实验生态方法,研究了不同温度下不同规格刺参对有机沉积物的摄食与吸收,在水温为13 2～22 3℃时,大、中、小3种规格刺参对有机沉积物平均摄食率[g/(g·h)]依次为0 00324,0 00648,0 00959,对有机沉积物平均吸收率依次为7 32%,13 49%,17 61%。温度为15 13℃时,大规格刺参的吸收率最高(15 32%);当温度上升到23 2℃,中、小两种规格刺参吸收率达最高(依次为23 56%、26 49%)。刺参对沉积物中有机物的吸收与利用,降低了水底有机物的含量,可有效抑制水体有害物质的积累及产生。     

Effect of taurine supplementation on the metabolism and body lipid‐to‐protein ratio in juvenile Atlantic salmon (Salmo salar)

Previously, we reported that methionine intake determined the taurine concentration in the liver of on‐growing Atlantic salmon fed plant protein diets. Further, the methionine intake and/or the increased taurine concentration following increased methionine intake affected the liver lipid metabolism. The following study therefore aimed to test whether taurine affected the growth or the type of growth when added in high plant protein diets naturally low in taurine but equal and adequate in dietary methionine. Juvenile Atlantic salmon [initial body weight (BW) of 2 g] were fed plant protein diets (16.5% fishmeal), which were supplemented with taurine or not for a period of 56 days. As a control for growth and normal metabolism, a fishmeal‐based commercial diet (68% fishmeal) was used. Supplementation with taurine to high plant protein diets had a slightly negative effect on weight gain, but the final body weight was not different. Interestingly, the pool of free amino acids in the liver and muscle was significantly higher in fish fed the supplemented diet as compared with fish fed the plant protein diet without taurine supplementation. Liver polyamine concentration was higher in fish fed the supplemented diet than in fish fed the similar diet without supplementation. Additionally, juvenile salmon fed the plant‐based diet supplemented with taurine had a lower body lipid‐to‐protein ratio due to a reduced whole‐body lipid content, while the whole‐body protein content was similar between treatments. Our study thus indicates that the addition of a low concentration of taurine to high plant protein diets interacts with lipid metabolism and storage, concomitantly affecting the general metabolism as the concentrations of the free amino acids and polyamines in the liver were significantly higher. The possible reasons for these changes are discussed.