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1.
石首鱼科鱼类小黄鱼（）是吕泗渔场重要的经济鱼种,为了解两者营养价值、摄食习性及食性转变,测定2018年秋季在吕泗渔场采集的46尾小黄鱼和36尾棘头梅童鱼脂肪酸组成,基于脂肪酸标记法进行食性分析。结果显示,小黄鱼和棘头梅童鱼PUFA/SFA比值、n-3/n-6比值在常见水产鱼类中较高,小黄鱼n-3/n-6比值与体长呈显著正相关（<0.01）。小黄鱼体长<70 mm时植物食性贡献较高（P<0.05）,体长≥100 mm时植物食性显著减少（<0.05）,小黄鱼（2.6~5.9）和棘头梅童鱼（2.6~3.3） DHA/EPA部分重合。研究表明,小黄鱼和棘头梅童鱼营养价值较高,大个体小黄鱼鱼油营养价值更高,小个体棘头梅童鱼则更有利于心血管健康。两者营养级部分重合,食性相似,都是随着体长增加植物食性减少,肉食食性增加且食性转变时的体长相近,因此,两者可能存在一定的食物竞争和生态位重合。 相似文献
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2011年1-3月,在巴塔哥尼亚大陆架公海进行了拖网探捕。本次调查海域位于巴塔哥尼亚大陆架海域渔场边缘,毗邻福克兰-马尔维纳斯大陆架海域渔场,渔获组成兼有这两个渔场的特征。结果表明,该渔场(45°01′-46°53′S,60°07′-60°47′W)底质平坦,水深在110-180 m之间,调查期间天气良好,适宜底拖网作业;在水深20-80 m水层存在温、盐跃层。底拖网渔获中主要有11种经济种类,按渔获量排序以阿根廷滑柔鱼(Illex argentinus)、拉氏南美南极鱼(Patagonotothen ramsayi)、阿根廷无须鳕(Merluccius hubbsi)、阿根廷鳀(Engraulis anchoita)与鳐类列前五位,占总产量的92.26%。探捕期间,相对资源量指数1月平均为(462.8±95.7)kg/h,2月平均为(713.8±194.1)kg/h,3月平均为(778.1±75.0)kg/h,呈逐月递增趋势。经济种类的数量分布有较大差异,多数经济种类的资源密集分布区位于渔场北部,渔场南部高产种类较为单一。阿根廷滑柔鱼优势胴长有逐月增大的趋势;阿根廷无须鳕优势体长变化不明显;拉氏南美南极鱼的优势体长皆小于其初次性成熟体长,其中1月采集的样本仅为110-130 mm,分析认为,本调查捕获的多为索饵洄游的幼鱼。 相似文献
3.
为了探究鱼类感应流速随体长因素的变化,以黄河上游2种裂腹鱼为研究对象,利用环形水槽实验装置,采用递增流速法,测试并分析了不同体长鱼类的感应流速。结果表明,体长(BL, 20.67±3.65) cm的花斑裸鲤(Gymnocypris eckloni)和BL (14.50±2.24) cm的黄河裸裂尻鱼(Schizopygopsis pylzovi)的绝对感应流速分别为(4.97±1.22) cm·s~(-1)和(4.52±0.92) cm·s~(-1),相对感应流速分别为(0.24±0.045) BL·s~(-1)和(0.31±0.052) BL·s~(-1);绝对感应流速与体长呈正相关关系,相对感应流速与体长呈负相关关系,相对感应流速与体长呈现负相关关系是由于绝对感应流速的增加速率小于体长的增加速率;2种裂腹鱼类的绝对感应流速差异不显著(P0.05);构建的绝对感应流速与体长的非线性回归模型能够有效地解释鱼类感应流速对体长的响应。该研究对其他较难捕获测试样本区域的鱼类游泳特性的定性预测研究具有一定指导作用,也可为过鱼设施的设计提供基础数据支撑。 相似文献
4.
蓝点马鲛(即鲅鱼)是我国沿海重要的经济鱼类之一,它肉质结实,味道鲜美,含脂量高,是上等的食用鱼类.近年来,我们将在浙江温台近海渔场的南凫岛附近捕获的鲅鱼,加工成各种水产品,销往国外,取得了较好的经济效益.本文就供出口的鲅鱼加工品种以及方法作一简介,以飨读者。 相似文献
5.
温台渔场龙头鱼的生长、死亡及最适开捕规格 总被引：1，自引：1，他引：1
在传统渔业资源衰退的情况下,龙头鱼等次要的经济种类逐渐成为东海海区的优势种群,具有重要的经济价值和生态地位。根据2015年11月—2016年8月在温州台州外海(120.93°~122.95°E,27.21°~28.97°N)调查采集的2 611尾龙头鱼的生物学数据,用ELEFANⅠ方法对其生长、死亡参数进行估算,并通过不完全β函数渔获量方程动态综合模型确定最适开捕规格,评估种群资源的利用状况。结果显示,温台渔场龙头鱼体长—体质量关系为W=0.000 5L3.87(R2=0.906 7),雌、雄个体间的体长—体质量关系无显著性差异;龙头鱼的Von Bertalanffy生长方程参数L∞、K、t0分别为32.13 cm、0.39和–0.69龄,体质量生长拐点年龄为2.78龄;根据体长组成资料的线性渔获量曲线估算出龙头鱼的总死亡系数2.55,用Pauly经验公式估算出自然死亡系数0.66,捕捞死亡系数1.89和开发率0.74;动态综合模型评估表明,应适当提高开捕年龄,增大开捕体长,最适开捕年龄tc为1.15龄,相应开捕体长为16.5 cm。 相似文献
6.
浙江嵊泗枸杞岛岩礁生境两种刺网采样网具的比较 总被引：4，自引：3，他引：1
为寻求适宜于岩礁生境的采样网具和采样方式,于2011年7、8月份进行欧洲引进的定置单片刺网和国内常用定置三重刺网的对比实验,对两种不同采样网具的渔获物组成和差异进行了分析,结果显示:(1)定置单片刺网的渔获量和种类数显著低于定置三重刺网,定置单片刺网捕获鱼类20种,渔获物8 572.6 g,定置三重刺网捕获鱼类29种,渔获总重为20 793 g;(2)定置单片刺网的主要优势种类为褐菖鲉、斑头鱼、棘头梅童鱼,定置三重刺网的主要优势种类为褐菖鲉、鲐、棘头梅童鱼、斑头鱼,欧洲定置单片刺网对鱼类种类的选择稍强于定置三重刺网;(3)两种网具获得的岩礁生境多样性指数无显著性差异,但两种网具的渔获物相似度并不高,仅为0.41;(4)两种网具对渔获大小的选择性不同,定置单片刺网渔获的平均体长为106.1 mm,定置三重刺网为119.1 mm;(5)不同网目下鱼类分布具有一定的选择性,优势种类褐菖鲉、斑头鱼、棘头梅童鱼等集中分布在几个网目尺寸.通过对比实验发现,定置三重刺网的渔获率高于定置单片刺网,渔获体长分布较广,反映的多样性指数并无差异,两者均通过多网目组合来消除选择性强的特点,但欧洲定置单片刺网的设计构造强度较低,渔获效率较低,相比之下,定置三重刺网较为适宜岩礁生境的调查. 相似文献
7.
8.
闽东北外海鱼类组成调查研究 总被引：4，自引：1，他引：4
引言 闽东北渔场位于东海甫部、台湾海峡北部口外,包括闽东渔场及台北渔场北部、温台渔场南部。渔场水系由台湾暖流、闽浙沿岸流、以及这两个水系混合变性而成的混合水所构成。环境因子变化比较复杂,是各种鱼类越冬、产卵集聚的良好场所,渔业资源种类较多。本文根据1989和1990年两次大面积定点拖网探捕调查及1992年鲨鱼延绳钓探捕渔获标本的分析,对闽东北渔场鱼类种类组成作初步探讨,为合理利用鱼类资源提供科学依 相似文献
9.
我国渔场近十年来人工培育的名贵鱼类增加了1．5倍以上。1982年仅向天然水域投放的鲑科鱼类的稚鱼就有10多亿尾，鲟科鱼类稚鱼为1．26亿尾。为了评价养殖措施的效益，必须制订综合评价渔场培育稚鱼质量的方法。通常使用的鱼的体长一体重指标有时不能正确反映出稚鱼的生物学状况。显然， 相似文献
10.
基于贝叶斯方法的黄海北部鳀鱼体长与体重关系式参数估计 总被引：1，自引：2，他引：1
根据2011年12月,2012年1月、5月、9–11月,2013年5月、9–12月和2014年5月在山东威海市中心渔港、石岛渔港拖网、双岛湾定置网渔获物中采集的鳀鱼(Engraulis japonicus)样本,分别采用相加的误差结构和相乘的误差结构,利用贝叶斯方法估计了黄海北部鳀鱼体长与体重关系式参数a和b,结合以往研究计算鳀鱼体型因子的分布范围。结果表明,贝叶斯方法能够很好地计算参数a和b的估计值及不确定性;偏差信息准则可以从备选模型中选择出合适的模型,将具有相乘误差结构的体长与体重关系式选为最佳模型。春季、秋季和冬季鳀鱼样本的体长(L,cm)与体重(W,g)关系分别为W=6.186×10–3L3.1360,W=4.892×10–3L3.1774,W=4.479×10–3L3.2206。3个季节样本的体长与体重关系曲线差异显著,春季样本的体长与体重关系曲线明显高于秋季和冬季样本的曲线,秋季与冬季样本的体长与体重关系曲线较为接近。全年数据的体长与体重关系曲线会低估春季鳀鱼的体重,高估秋冬季鳀鱼的体重。从1964年至今,鳀鱼参数a没有太明显的变化规律;从2004年起参数b有变大趋势,2004–2014年估计的参数b明显大于以往估计值。20世纪90年代末至今估计的鳀鱼体长与体重关系曲线明显高于20世纪60~80年代估计的曲线,显示着同体长鳀鱼的平均体重较以往变大了。黄海北部鳀鱼全长与叉长的关系为TL=0.0615+1.0908FL,鳀鱼体型因子的分布范围为0.004 73~0.006 60,中位数为0.006 03,鳀鱼体型因子可作为定量描述其体型特征的一个指标。研究结果为探讨鳀鱼对捕捞压力和环境变化的响应机制及鳀鱼资源评估积累了基础参数。 相似文献
11.
鱼类体长数据较易获得,常用于数据有限的渔业资源评估和管理,且基于鱼类体长的指标可以作为渔业生态系统的生态监测指标。本文根据山东半岛南部海域底拖网季度调查收集的方氏云鳚体长数据,应用计算机模拟重采样方法,研究了调查站位数对估计方氏云鳚（Enedrias fangi）体长频率分布和平均体长的影响。结果表明,在各个季节,方氏云鳚体长频率分布离散指数（DI）变化范围为0~0.91,大部分站位的DI值为0.75~0.90,说明调查站位间体长频率分布较为相似,可以对调查站位数进行优化,提高采样效率;调查站位越多,体长频率分布和平均体长估计精确度越高;由于对不同体长数据指标估计的精度不同,用以估计体长频率分布和平均体长的样本量存在差异;20个和30个调查站位分别为估计方氏云鳚体长频率分布和平均体长的可接受样本量。本研究结果可为基于不同体长指标的渔业资源调查设计提供一定的理论支撑,有助于对基于体长指标有效站位数的初步了解,为山东半岛南部海域的鱼类资源科学调查和科学管理提供参考。 相似文献
12.
鱼类体长-体重关系参数估计的准确与否影响进一步的渔业资源评估和管理。不同采样设计获得的生物学数据,对鱼类体长-体重关系参数b估计可能会有一定的影响。本文基于2013-2014年在黄河口水域调查获得的矛尾虾虎鱼(Chaemrichthys stigmatias)体长、体重数据,采用计算机模拟重抽样方法,选取相对估计误差和相对偏差两个指标,比较了不同采样设计对估计矛尾虾虎鱼体长-体重关系参数b的影响。结果表明,增加样本量可有效提高其体长-体重关系参数b的估计精度。不同季节数据对参数估计精度具有不同影响,应用多季节调查采样数据估计参数精度往往优于单季节采样。夏季数据对矛尾虾虎鱼体长-体重关系参数估计尤为重要。方案9(夏-冬季方案)在样本量达到540尾时,相对估计误差REE为2.08%,相对偏差RB的绝对值为0.71%,在相同样本量下该设计方案表现最好。在估计黄河口矛尾虾虎鱼等鱼类体长-体重关系参数时,应保证获得一定样本量的对参数估计具有较大影响的季节的生物学数据。 相似文献
13.
1999年2月黄海声学调查鳀鱼种群群体结构评估 总被引：2，自引：2，他引：2
IntroductionEstimation of the size structure of a fish population is often one of the primary objectives of an acoustic/trawl survey (Gunderson 1993;Honkalehto and Williamson 1996 ) .The size structure contains much informa-tion enabling a quick estimate of the fishable size of a stock in a regulated fishery or the recruitment status ofa stock.It is also a common practice to use the number at length of a population together with the age/lengthkey to produce the age structure of the fish popul… 相似文献
14.
黄河口渔业资源底拖网调查采样断面数对资源量指数估计的影响 总被引：2，自引：2，他引：0
为查明采样强度对多种类渔业调查中资源量指数估计的影响,实验根据2013年8月、10月和2014年2月、5月黄河口渔业资源底拖网调查数据,选取短吻红舌鳎、方氏云鳚、矛尾虾虎鱼、枪乌贼、口虾蛄、日本蟳和小型鳀鲱鱼类为调查目标,利用计算机模拟方法,以相对估计误差(REE)、相对偏差(RB)、变异系数(CV)和准确度变化率(ACR)等为评价指标,研究了调查样本量对不同种类资源量指数估计的影响。结果显示,各种类资源量指数估计的REE、CV和ACR随断面数增加均逐渐降低并趋于稳定;除在断面数3减到1时,日本蟳、口虾蛄和方氏云鳚等个别种类RB绝对值增大外,其他RB不存在一致性的增大或减小趋势。研究表明,由于不同种类的分布存在时空差异,不同种类需要的调查断面数不同;当目标种类数量空间分布变异较小时,减少调查断面数对采样精确度影响较小,反之则需要更多调查断面数。对于多种类渔业资源调查,需要综合权衡各目标种类来确定最适调查断面数。 相似文献
15.
Landings, logbooks and observer surveys: improving the protocols for sampling commercial fisheries 总被引：1，自引：0，他引：1
The sampling of commercial marine fisheries for management purposes often displays a key weakness in the form of poor documentation of the scientific basis of sampling and estimation, the assumptions made, and the practical constraints. This paper reviews systematically the theoretical and practical options that can remedy this situation and recommends that decisions be archived in regularly updated ‘Sampling Approach and Modifications’ (SAM) documents. Defining the target population, the observable population (usually a subset of the target), and the assumed links between them is important, along with the distinction between design‐ and model‐based sampling approaches. Fleet‐targeted and stock‐targeted sampling strategies are contrasted, the latter being much harder to implement. Sampling protocols aimed at estimating quantities of fish landed and discarded, length–frequency distributions, length‐related variables such as age, weight and maturity, and ratio variables such as catch per unit of effort and the proportions of discards are discussed, together with the raising of estimates to fleet and/or stock levels. The ideas are summarized in the specific contexts of landings sampling, logbook schemes and sea‐going observer surveys. SAMs are commended for enhancing the scientific value of fishery sampling, and for encouraging methodological discussions among users and producers of the data. 相似文献
16.
Aatu Turunen Andrés Salgado-Ismodes Hannu Huuskonen Kimmo K. Kahilainen Mikko Olin Jukka Ruuhijärvi Anssi Vainikka 《Fisheries Management and Ecology》2023,30(1):99-108
Management of inland recreational fisheries would benefit from stock abundance and size structure data. Feasibly standardised angling methods such as ice fishing could produce representative catch-per-unit-effort (CPUE) information on the abundance of different-sized fish in small lakes. Here, we first used standard Nordic multimesh gillnets to obtain number-per-unit-effort (NPUE), biomass-per-unit-effort (BPUE) and size structure data on Eurasian perch (Perca fluviatilis) stocks in 11 small boreal lakes in summer. Second, the same lakes were ice-fished by voluntary anglers using a pre-defined, loosely standardised protocol to obtain angling-based NPUE, BPUE, and length frequency distributions. Effects of environmental variables such as water oxygen concentration and light penetration on angling catch rates were controlled statistically. Neither perch Nordic gillnet NPUE nor BPUE corresponded to ice-fishing CPUEs. However, the length distribution of the catch did not differ between methods. Our results imply that traditional ice fishing applying natural baits is relatively unselective for fish size and could produce valid length-based indicators for management purposes while angling CPUE was poorly related to Nordic gillnet CPUE. 相似文献
17.
Abstract The efficiencies of three different techniques for 0+ fish point abundance sampling by electric fishing were tested on a sandy beach of the Morava River, Czech Republic. During direct electric fishing (DE), the operator immerses an anode fastened on an extension pole. During thrown anode electric fishing (TE), the anode is thrown at a distance from the bank. During remote electric fishing (RE), a pre-positioned anode is activated after allowing sufficient time for fish to recolonise the area. The DE technique was found to disturb fish and that fish tend to escape, thereby reducing its efficiency (30% of efficiency of RE). There was no significant difference in relative abundance estimates or size structure of assemblages between DE and RE, but TE seemed to be a species selective technique on sandy river beaches, significantly overestimating relative abundance of bleak. Of the three techniques tested, RE was the most efficient and if time required for deployment could be reduced, it would be also the most suitable for monitoring 0+ fish assemblages on sandy river beaches. 相似文献
18.
The CEN (2005) methodology for fish monitoring of mesotrophic to eutrophic Mediterranean lakes was evaluated. The contribution of gillnet (benthic and pelagic) and electrofishing catches on species richness was examined. Additionally, the contribution of benthic gillnet sampling effort on species richness and precision of catch‐per‐unit‐effort (CPUE) estimates, considering both number of specimens (ΝPUE) and biomass (BPUE), was assessed. Subsequently, the impact of reduction in sampling effort on the parameters mentioned above was estimated and the effort needed to acquire the desired precision level considering different NPUE values was modelled. The use of different sampling gears was found to contribute to species richness assessment, while sampling effort could be reduced in the deepest zones of the lakes. The resultant model can reliably guide assessment of the sampling effort required in the Mediterranean and central European lakes with high fish densities. 相似文献
19.
Sarah Ann Thompson Marisol García‐Reyes William J. Sydeman Mayumi L. Arimitsu Scott A. Hatch John F. Piatt 《Fisheries Oceanography》2019,28(6):658-671
Climatic drivers of the size and body condition of forage fish in the North Pacific are poorly known. We hypothesized that length and condition of forage fish in the Gulf of Alaska (GoA) vary in relation to ocean temperature on multiple scales. To test this hypothesis, we analyzed morphometric data for capelin (Mallotus catervarius) and Pacific sand lance (PSL; Ammodytes personatus) sampled by a seabird (Cerorhinca monocerata) in two regions of the GoA, 1993–2016. Based on previous studies, we predicted that capelin length and body condition (Fulton's K) would be negatively related to the Pacific Decadal Oscillation (PDO) and sea surface temperature (SST), whereas PSL length and condition would be positively related. Interannual variation in length and body condition was evaluated relative to seasonal values of ocean climate using regression. Forage fish length and condition varied interannually, between sampling regions, and were dependent on the size/age class of the fish sampled. As predicted, length and body condition of capelin (mostly age 1+) were negatively related to the PDO and SST. Relationships with ocean climate for PSL varied by size/age class: positive for putative age‐0 fish and negative for putative age‐1+ fish. We conclude that our hypothesis was supported for capelin and partially supported for PSL. This study demonstrates that ocean climate determines key morphometric characteristics of forage fish that may relate to interannual variation in the energetic value of prey, and provides an example of how seabirds can be used to obtain specimens for evaluations of potential prey quality. 相似文献
20.
Drennan JD Lapatra SE Samson CA Ireland S Eversman KF Cain KD 《Journal of fish diseases》2007,30(6):367-379
Pectoral fin tissue of white sturgeon was investigated as a potential non-lethal sample source for the detection of white sturgeon iridovirus (WSIV) infection. Histopathology and polymerase chain reaction (PCR) results using fin tissue were compared with the standard lethal histopathology sampling method that utilizes head tissue. Tissues for each of the three sampling methods were collected weekly for 8 weeks from individual sturgeon undergoing an experimental cohabitation challenge with fish infected with the Abernathy isolate of WSIV. Non-lethal fin histopathological evaluation did not reveal infection during the first 3 weeks of sampling, while non-lethal PCR and the lethal method were variable. However, all three sampling methods were equally capable of identifying infection from 4 to 8 weeks post-exposure. Of the survivors tested, all were negative by PCR and the lethal method, and only one fish was identified as being positive by non-lethal fin histopathology. In another experiment, all three sampling methods were applied to asymptomatic WSIV carriers in a case study conducted at the Kootenai Tribal Sturgeon Conservation Hatchery. Results showed that both lethal and non-lethal fin histopathology were equally effective in detecting infection, but PCR was unable to identify this strain of WSIV. Depending on the virus isolate, these results suggest that non-lethal sampling of fin tissue (histopathology or PCR) is comparable with the lethal sampling method at identifying WSIV infection once infection is established, and under certain circumstances may provide an alternative to lethal sampling. 相似文献