气候变化对长江口鱼类资源密度分布的重塑作用

本研究以2012-2013年长江口鱼类资源密度分布为基础,通过动态生物气候分室模型(DBEM)预估了不同气候变化情景下(IPCC,RCP2.6、RCP6.0和RCP8.5)长江口鱼类资源密度增量分布的变化.在RCP2.6、RCP6.0和RCP8.5这3种气候变化情景下,鱼类资源密度增量、底层鱼类资源密度增量随着时间推移均呈递增趋势,且递增程度和增量重心分布范围随着温室气体排放的增加而扩大(RCP8.5＞RCP6.0＞RCP2.6).鱼类资源密度增量重心主要分布在长江口崇明岛沿岸水域,长江口外侧水域资源密度增量相对较低,并且资源密度增量重心有向南迁移的趋势.     

渔业科技前沿

全球海洋酸化正在加剧西班牙国家研究委员会(CSIC)、加泰罗尼亚高等研究院(ICREA)及巴塞罗那自治大学的研究人员警告说,人类排放的二氧化碳已经严重改变了海水的化学结构,海洋正以前所未有的速度酸化。其相关研究成果发表在《科学》杂志上。研究表明,海洋酸化正影响着海洋生物和生态系统。在过去的300万年中,海洋化学环境发生了较大变化,但目前海洋水质的酸化速度要比过去的任何一个时间点都要快,这或将为整个海洋生态系统带来毁灭性的灾难。人类活动排放的二氧化碳有30%进入了海洋,这直接导致了海洋的酸化。海洋酸化威胁到了一些海洋生物种类的生存。比如,海洋酸化降低了珊瑚、软体动物等生     

温度和盐度对中华原钩虾幼体孵化、存活及生长的影响

采用室内受控实验方法测定了不同温度(15,20,25和30℃)和盐度(盐度5,10,15,20,25,30和35)以及温度和盐度交互作用对中华原钩虾幼体孵化、存活及生长的影响。结果表明,中华原钩虾幼体孵化的数量受水温影响显著(P<0.05),20℃幼体孵化率最高,平均每只亲体孵化幼体30.67个。水温对幼体生长的影响差异十分显著(P<0.01),15~25℃范围内,幼体的日增长和特定生长率随水温升高而增加,水温25℃时达到最大值,平均日增长体长为0.23 mm/d、体质量平均日增长体质量为0.20 mg/d,特定生长率体长为6.40%/d、体质量特定生长率为15.79%/d;当水温高于25℃,钩虾的日增长和特定生长率降低。根据相关性方程式推算其最适孵化温度为21.50℃,最适生长温度为20~25℃。中华原钩虾幼体的存活率受温度的影响差异不显著(P>0.05),20℃钩虾幼体存活率最高,为98%,30℃存活率最低,为87.67%。盐度对中华原钩虾孵化幼体数量、存活率及幼体生长的影响差异不显著(P>0.05)。温度和盐度交互作用结果表明,中华原钩虾对盐度有较好的适应能力,温度对中华原钩虾种群发展的影响要大于盐度的影响。     

温度、盐度和pH对双线紫蛤幼贝生长率的联合效应

为探究双线紫蛤(Sanguinolaria diphos)幼贝最适生长条件,采用响应面法研究了温度(24℃、27℃、30℃)、盐度(20、25、30)和p H(7.3±0.03,8.3±0.03,9.3±0.03)对双线紫蛤幼贝日生长率的联合效应。实验结果表明:1)温度对幼贝生长率影响极显著(P0.01),3种生态因子对幼贝生长率影响程度大小顺序是:温度盐度pH;2)通过Design-Expert 8.0.6软件进行响应面分析实验,得出双线紫蛤幼贝最适生长环境组合是温度为26.43℃、盐度为25、pH为8.3,理论最佳日生长率为2.90%。经模型验证实验后,得到的日生长率为2.76%。实验验证结果与预测结果较接近,响应面分析法可靠。研究结果为双线紫蛤池塘大面积养殖的推广提供科学参考依据。     

海水酸化胁迫对紫贻贝能量分配的影响

2016年5～6月在山东桑沟湾楮岛海区,采用野外围隔和现场流水相结合的方法,以紫贻贝(Mytilus galloprovincialis)为研究对象,以pH为8.0作为对照组,探讨了酸化胁迫(p H=7.7)对其能量分配的影响。结果显示,短期(10d)海水酸化胁迫下,紫贻贝的滤水率、同化效率、氧氮比显著下降(P0.05),排氨率极显著增加(P0.01),耗氧率无显著差异(P0.05);中期(30d)海水酸化胁迫下,紫贻贝的滤水率和氧氮比显著下降(P0.05),而同化效率、耗氧率、排氨率显著升高(P0.05)。能量收支的结果显示,短期(10 d)酸化胁迫下,紫贻贝的摄食能和吸收能显著降低(P0.05),呼吸能无显著差异(P0.05),排泄能显著增加(P0.05),生长余力极显著降低(P0.01);中期(30d)海水酸化胁迫下,摄食能降低(P0.05),吸收能、呼吸能、排泄能、生长余力显著升高(P0.05)。氧氮比的结果显示,在海水酸化胁迫下,氧氮比的波动范围为14.28～20.46,贝类体内的供能物质由脂肪和碳水化合物逐渐向蛋白质过渡。研究结果为揭示紫贻贝应对海水酸化胁迫的生理响应提供了基础数据。     

循环水和网箱两种养殖模式下黄姑鱼生长、免疫及血清生化的差异

为探讨黄姑鱼(Nibea albiflora)生长、免疫、血清生化指标对不同养殖模式的响应,设置了循环水养殖和近海网箱养殖两种模式,进行300 d的养殖实验,通过检测特定生长率、血清溶菌酶以及肝脏总抗氧化能力等指标,比较黄姑鱼的生长、免疫及血清生化的差异。结果显示,在本实验的循环水和网箱两种养殖模式条件下,黄姑鱼的特定生长率分别为0.31%和0.33%,存活率分别为(64.85±4.72)%和(77.50±5.32)%,饵料系数分别为1.21和1.07;溶菌酶、血清葡萄糖、皮质醇指标在两种养殖模式中均有显著升高;IgM呈先上升后下降的变化趋势;循环水系统中黄姑鱼肝脏的抗氧化指标在0~50 d期间均有显著提高,并且都与网箱系统中的黄姑鱼肝脏的抗氧化指标有显著性差异(P0.05);循环水系统中黄姑鱼总抗氧化能力从实验开始时的(7.683±0.731)U·mgprot~(-1)上升到100 d时的(60.808±12.937)U·mgprot~(-1),后期虽有所回落,但仍与0 d时有显著性差异(P0.05);网箱系统中黄姑鱼抗氧化指标在整个实验期间变化比较平稳,无显著性差异(P0.05)。结果表明,在本实验条件下循环水系统对黄姑鱼的胁迫大于网箱系统。     

诸氏鲻虾虎鱼“溃烂病”病原及其致病影响因子分析

为研究诸氏鲻虾虎鱼(Mugilogobius chulae)"溃烂病"病原及其致病性,对患病鱼进行了病原分离、人工感染实验以及病原生理生化鉴定和gry B分析,研究了不同温度、盐度、p H条件对其致病性的影响。结果显示,病原菌为迟缓爱德华菌(Edwardsiella tarda),对诸氏鲻虾虎鱼和斑马鱼(Danio rerio)的半致死剂量(LD50)分别为57 CFU·尾~(–1)和2.0×10~4 CFU·尾~(–1),毒力基因(cit C、muk F、esr B、kat B、fim A、gad B)检测结果均为阳性,其基因序列与已知迟缓爱德华菌相应的毒力基因序列同源性高达99%。病理结果显示,患病鱼肾脏、肝脏、皮肤细胞均出现不同程度的变性、坏死和炎性细胞浸润等,其中肾和肝组织病变最为严重。25℃和30℃实验组5 d累计死亡率分别为(33±15)%、(60±10)%,显著高于20℃实验组和对照组(P0.05);盐度15和30实验组5 d累计死亡率分别为(60±10)%、(63±21)%,显著高于盐度3实验组[(20±10)%,P0.05];而p H 6.0、p H 7.5、p H9.0实验组之间5 d累计死亡率无显著差异(P0.05)。结果表明,迟缓爱德华菌是诸氏鲻虾虎鱼"溃烂病"病原,具有强致病性,养殖温度和盐度对其致病性具有显著影响。     

水温对施氏鲟、小体鲟和西伯利亚鲟幼鱼生长的影响

在电子控温循环水系统中,研究不同水温(15℃、18℃、21℃、24℃和27℃)对56日龄的施氏鲟Acipenser schrenckii、小体鲟A.ruthenus和西伯利亚鲟A.baerii幼鱼生长的影响。结果表明,24℃组施氏鲟幼鱼的体长特定生长率(SGRL)显著高于其它温度组(P<0.05),而体质量特定生长率(SGRW)差异不显著(P>0.05);在18~27℃范围内,体长绝对增长率(AGRL)随温度的升高而降低,且显著高于15℃组(P<0.05)。18~24℃组的体质量绝对增长率(AGRW)显著高于15℃和27℃组(P<0.05)。在18~24℃范围内,施氏鲟幼鱼的体长相对增长率随温度的升高而增加,显著高于15℃和27℃组(P<0.05),最适生长温度为24℃。18℃组小体鲟幼鱼的SGRL显著高于其他温度(P<0.05),SGRW则差异不显著(P>0.05)。在15~27℃温度范围内,小体鲟幼鱼的AGRW升高后降低,其中18℃和24℃的SGRW分别为0.61g/d和0.64g/d,显著高于其他组。15℃组AGRL最低(1.6mm/d),显著低于其他组(P<0.05)。小体鲟幼鱼的最适生长水温范围为18~24℃,最适生长温度为18℃。在15~27℃范围内,21℃组西伯利亚鲟幼鱼的SGRL、AGRL和体长相对生长率均显著高于其他温度组(P<0.05),但27℃组存活率最低。西伯利亚鲟幼鱼的最适生长范围为15~24℃,最适生长水温为21℃。不同温度下,3种鲟幼鱼的肥满度变化不同,施氏鲟幼鱼的生长类型为强异速度生长,不同于小体鲟幼鱼与西伯利亚鲟幼鱼。在15~27℃范围内,3种鲟幼鱼的最适生长温度不同,在早期生长培育时应选用不同的培育温度。     

温度和盐度对墨吉明对虾（Fenneropenaeus meiguiensis）生长与存活的联合效应

采用中心复合设计(CCD)和响应曲面法(RSM),研究了温度(16–35℃)和盐度(5–29)对墨吉明对虾生长与存活的联合效应。结果显示,温度的一次效应和二次效应对墨吉明对虾的特定生长率和存活率具有显著影响(P<0.05);盐度的一次效应对墨吉明对虾的特定生长影响不显著(P>0.05),但对墨吉明对虾存活率的影响达到显著水平(P<0.05);盐度二次效应对特定生长率与存活率具有极显著影响(P<0.01);温度和盐度对墨吉明对虾的生长与存活不存在显著的交互作用(P>0.05)。采用中心复合设计建立了温度和盐度对墨吉明对虾特定生长率和存活率影响的模型方程,该方程的决定系数分别为0.9014、0.9631,校正系数分别为0.8310、0.9367,表明模型具有较好的拟合度,可用于预测墨吉明对虾特定生长率与存活率的变化。通过模型优化和验证实验,得出温度为26.6℃、盐度为15.5时,特定生长率和存活率均达到最大值,分别为1.296%,98.34%,其满意度为0.970。结果显示,墨吉明对虾在工厂化养殖过程中温度为26–27℃、盐度为15–16时,有利于墨吉明对虾的存活与生长。     

不同投饲率对日本黄姑鱼幼鱼生长及鱼体生化成分的影响

采用一种饲料5个投喂水平(鱼体重1.0%、2.0%、3.0%、4.0%、5.0%)在水温26~28℃的条件下对日本黄姑鱼幼鱼(26.85±1.69g)进行了40d生长实验。结果表明:特定生长率和相对增重率随着投饲率的增加呈先上升后平稳的趋势,饲料利用率随着投饲率的升高呈先下降后平稳再下降的趋势;鱼体的水分含量随投饲率的增加而下降,蛋白质和脂肪含量随投饲率的增加而升高,投饲率对灰分无影响。根据最大相对增重率和最大饲料利用率,确定日本黄姑鱼幼鱼适宜投饲率在水温26~28℃时为3.0%。     

Status quo and prospects of fishing technology of ocean fishery of China

报道了我国大洋渔业技术现状，评述了技术水平、发展趋势，分析渔业技术存在的问题，提出了大洋渔业可持续发展应当进行的研究课题及建议。     

二氧化氯在海洋馆水处理中的应用研究

应用二氧化氯代替次氯酸钠进行消毒杀菌试验，找出了二氧化氯的最佳投量。研究结果表明：在人造海水维生系统的水体中，二氧化氯浓度维持在0．03－0．05mg/L，能有效改善水质和预防海洋动物疾病，且不伤害维生系统的功能，是一种优良的替代消毒剂。     

Distribution patterns and population structure of the blue shark (Prionace glauca) in the Atlantic and Indian Oceans

The blue shark (Prionace glauca) is the most frequently captured shark in pelagic oceanic fisheries, especially pelagic longlines targeting swordfish and/or tunas. As part of cooperative scientific efforts for fisheries and biological data collection, information from fishery observers, scientific projects and surveys, and from recreational fisheries from several nations in the Atlantic and Indian Oceans was compiled. Data sets included information on location, size and sex, in a total of 478,220 blue shark records collected between 1966 and 2014. Sizes ranged from 36 to 394 cm fork length. Considerable variability was observed in the size distribution by region and season in both oceans. Larger blue sharks tend to occur in equatorial and tropical regions, and smaller specimens in higher latitudes in temperate waters. Differences in sex ratios were also detected spatially and seasonally. Nursery areas in the Atlantic seem to occur in the temperate south‐east off South Africa and Namibia, in the south‐west off southern Brazil and Uruguay, and in the north‐east off the Iberian Peninsula and the Azores. Parturition may occur in the tropical north‐east off West Africa. In the Indian Ocean, nursery areas also seem to occur in temperate waters, especially in the south‐west Indian Ocean off South Africa, and in the south‐east off south‐western Australia. The distributional patterns presented in this study provide a better understanding of how blue sharks segregate by size and sex, spatially and temporally, and improve the scientific advice to help adopt more informed and efficient management and conservation measures for this cosmopolitan species.     

Movements and behaviors of swordfish in the Atlantic and Pacific Oceans examined using pop‐up satellite archival tags

Swordfish are highly specialized top‐level predators that have been challenging to study. In this paper, data from 31 pop‐up satellite archival tags attached to swordfish from (i) the eastern Pacific, (ii) central Pacific, and (iii) western North Atlantic‐Caribbean were analyzed. Common across locations was a pronounced diel vertical pattern with daytime hours spent primarily below the thermocline and nighttime hours spent in warmer waters, close to the surface. One exception to this pattern was periodic daytime basking events which were most common in cooler waters off California. Maximum daytime depths were significantly correlated with light penetration as measured by the diffuse attenuation coefficient at 490 nm. Temperature did not appear to influence daytime depths, and swordfish tolerated both extremely low temperatures (4°C) and rapid and dramatic temperature changes (>20°C). Temperature did appear to influence the nighttime depths in the Pacific where fish typically remained in the surface mixed layer. In contrast, in the warm tropical Atlantic this was not the case, and nighttime depths were much deeper. In all areas, nighttime depth increased around the full moon. Given the parallels between the vertical movement patterns of swordfish and those of the deep sound scattering layer we suggest that swordfish vertical distribution patterns, especially during daytime, are influenced largely by resource availability. At night, when swordfish are typically targeted by fisheries, both ambient light and temperature influence movements. Understanding vertical movement patterns of swordfish can help evaluate gear vulnerability, improve population assessments, and potentially reduce fisheries bycatch.     

Broad‐scale movements and pelagic habitat of the dusky shark Carcharhinus obscurus off Southern Australia determined using pop‐up satellite archival tags

We investigated the broad‐scale movements and pelagic habitats of large juvenile dusky sharks (Carcharhinus obscurus) off Southern Australia. Pop‐up satellite archival tags (PSATs) were deployed on three large juvenile dusky sharks (～2.2–2.6 m total length) for 6 months in Spencer Gulf during 2010. Tagged dusky sharks all migrated westward and across the Great Australian Bight (GAB) during autumn to offshore shelf waters off Western Australia. Estimated minimum distances travelled ranged from 1760 to 2736 km. Depths occupied by tagged dusky sharks ranged from the surface to 355 m. The most common thermal ranges occupied were 19–22°C. Broad‐scale movements of large juvenile dusky sharks across the continental shelves combined with periods of residency in semi‐protected gulf waters indicated that a multi‐jurisdictional management approach may be appropriate for this species.     

印度洋东部黄鳍金枪鱼的渔业生物学

根据在印度洋东部海域的延绳钓生产实践 ,对所渔获的黄鳍金枪鱼 (Thunnus albacares)群体的构成、繁殖等基本生物学特征进行了初步探讨。结果显示 ,渔获黄鳍金枪鱼纯重范围为 10～75 kg,叉长范围为 80～ 15 0 cm,纯重、叉长关系为 W=1.5 2 7× 10 -5L3,渔获构成月间变化明显 ,不同年龄个体性成熟与繁殖节律差异显著     

印度洋金枪鱼延绳钓主要渔获种类及分布

根据印度洋金枪鱼管理委员会IOTC的金枪鱼生产数据库,对1967-2004年间印度洋金枪鱼延绳钓主要渔获种类的产量按年进行汇总和基于5度格网进行了空间上的统计,采用GIS软件制作了印度洋金枪鱼延绳钓主要渔获种类的捕捞产量的地理空间分布图,分析了其资源的空间分布特征。分析结果表明,大眼金枪鱼Thunnus obesus、黄鳍金枪鱼Thunnus albacares、长鳍金枪鱼Thun-nus alalunga和剑鱼Xiphias gladius是印度洋金枪鱼延绳钓的主要渔获种类,其产量之和占到总产量的90%,这4种印度洋金枪鱼延绳钓的主要渔获种类从1967-2004年的产量均呈上升趋势,但产量的峰谷变化各不相同;空间分布特征研究表明,尽管在印度洋海域分布范围广泛,但产量丰沛的区域存在明显差异。     

印度洋西北海域表层浮游动物数量组成及其分布

根据2004年10～11月印度洋西北海域12°00′～21°30′N、58°00′～65°00′E表层浮游动物的调查资料,对其种类组成、生物量及其平面分布进行了分析。结果表明,浮游动物有腔肠动物水母类3目7科11属15种;浮游甲壳动物7目24科34属40种;浮游软体动物2目5科5属5种;毛颚动物1目1科1属3种;被囊动物1目2科4属4种。生物量较大的种类主要是甲壳动物的尖尾海萤、桡足类、莹虾类、磷虾类、端足类和糠虾类,以及毛颚动物的箭虫类。调查海域总生物量和丰度的平均值分别为39.51±114.06mg/m3和3020±7929个/m3。其中尖尾海萤的生物量(24.30mg/m3)和丰度(1498个/m3)为最高,其次为箭虫类。总生物量和丰度平面分布差异显著,呈现北部(17°N以北)高于南部(17°N以南)、东部(62°E以东)高于西部(62°E以西)的趋势,同时不同纬度浮游动物的种类组成也有差异。     

中东太平洋金枪鱼延绳钓渔获量及其分布

根据2000年9月至2002年8月两年的中东太平洋金枪鱼延绳钓探捕调查结果,对延绳钓渔获量及其分布特征进行了初步分析。结果显示,延绳钓渔获物以金枪鱼为主,大眼金枪鱼(Thun-nusobesus)等3种金枪鱼的渔获量占总渔获量75·9%。“海欣”船延绳钓作业的平均日产量为(994·8±19·9)kg/d,上钩率为(12·5±0·3)ind/103钩。主要目标鱼种大眼金枪鱼和黄鳍金枪鱼(Thunnusalbacares)的平均日产量分别为(466·9±13·9)kg/d和(190·6±7·2)kg/d。探捕期间日产量的月间差异显著(P<0·001),6~8月为渔发汛期,日产量较高;2~5月为相对淡季,日产量较低。探捕区南部的平均日产量最高,与中、北部比较差异显著(P<0·001);东部平均日产量与西部比较差异不显著(P>0·05)。     

Morphometric analysis of four different populations of Penaeus monodon (Crustacea,Decapoda, Penaeidae)

The morphological variation of Penaeus monodon was studied based on the morphometric analyses of samples collected throughout Banda Aceh, Khanom, Mozambique and Sanya. A total of 470 samples were investigated using eight measurements. Multivariate analyses [principal components (PCA), discriminant function (DFA) and cluster analyses (CA)] revealed obvious morphometric differences among the four geographical populations. PCA indicated that the first three components of the females and the first two components of the males accounted for 75.17% and 71.84% of the total morphological variability respectively. In DFA, the overall assignment of female and male individuals into their original population was 78.95% and 84.37% respectively. For females, the proportion of individuals correctly classified into their original population was 76.0%, 92.8%, 92.6% and 54.5% for population 1, 2, 3 and 4 respectively. For males, the proportion was 97.2%, 68.1%, 100% and 72.2% respectively. For females and males, CA showed that the four populations could be divided into two main clusters of morphological characteristics. CA also indicated that the morphological variation of population 3 was greater, whereas the morphology of population 2 was strikingly similar to that of population 4.