胶州湾曼氏无针乌贼资源量与季节变化的调查研究

根据2005年和2006年逐月在胶州湾进行的底拖网调查，并对底拖网渔获物中的头足类进行定性定量分析与测定，利用扫海面积法评估胶州湾海域曼氏无针乌贼的资源量。调查分析了其分布特点与季节变化，并进行了渔获物中头足类组成的比较，分析了其种类组成、分布特点与季节变化特征。结果表明，胶州湾曼氏无针乌贼资源量有明显的季节变化，夏、秋两季的资源量明显高于其他季节，分别达到26.7t和21.5t（2006）；夏、秋两季的重量比明显高于其他季节，分别达到23.4%和27.8%。近几年，以曼氏无针乌贼为主捕对象的头足类资源量基本保持稳定，年平均资源量约14t，接近20世纪90年代中期的水平。     

鸢乌贼渔业资源研究进展

<正>鸢乌贼(Sthenoteuthis oualaniensis)属头足纲柔鱼科鸢乌贼属,是世界重要的大洋性经济头足类之一,广泛分布于印度洋、太平洋的热带和亚热带海域^[1-2]。鸢乌贼在印度洋西北部海域和中国南海的资源量较为丰富^[3-4],根据联合国粮食及农业组织估算,其总资源量约为800～1120万t^[5]。     

东海台风与乌贼的丰歉

<正> 东海乌贼有几种,其中数量最高的是曼氏无针乌贼,每年5～6月在浙江沿岸大量集群,进行繁殖形成渔汛,产量较高,是我国四大经济“鱼类”之一。乌贼为一年生动物,其产量年间波动很大(如图),在渔区中对于乌贼产量     

金乌贼人工养殖技术

金乌贼是我国黄渤海海域经济价值较大的头足类品种,年捕获量在乌贼科中排名第二,曾与大黄鱼、小黄鱼和带鱼一起并称我国传统四大渔业。但自20世纪80年代以来,因过度捕捞、环境污染和产卵场被破坏等原因,其资源量锐减,目前在很多海域已经消失,因而开展金乌贼人工增养殖研究已迫在眉睫。本文对金乌贼的分类地位、形态特征、生活习性、渔业概况、苗种繁育、池塘养殖和越冬等进行综述,以期为金乌贼的人工养殖和增殖放流提供技术支撑。     

南海春季月相、水深、作业时间与鸢乌贼CPUE的关系

根据2015和2016年春季灯光罩网渔船分别在南海南部和北部海域作业的鸢乌贼产量数据,研究作业条件水深、时间和月相与单位捕捞努力量渔获量(CPUE)的关系。GAM模型分析,作业时间和农历日对CPUE的影响显著。结果显示,月光天时,0～999 m水深范围CPUE较低;月黑天时,各水层CPUE变化不大,2 500～2 999 m水深范围CPUE较高;作业时间在上半夜(21:00—23:00),CPUE较高,最高达399.4 kg/网,下半夜(0:00—5:00) CPUE逐渐下降;月光天和月黑天产量差别较大,分别为267.0和321.6 kg/网;厄尔尼诺现象在一定程度上影响了鸢乌贼资源量在各水层的变化。各作业条件对鸢乌贼CPUE影响的研究能够为渔场的寻找提供参考。     

曼氏无针乌贼(Sepiella maindroni)生物学研究现状及展望

曼氏无针乌贼作为我国主要的海产捕捞对象,由于长期以来过度捕捞、自然产卵场破坏等原因,资源量急剧下降。近年来在广大科研工作者不懈的努力下,曼氏无针乌贼的生物学研究和人工养殖都取得了可喜的成绩,人工放流取得显著的效果,资源量有显著回升。本文简单介绍近年来曼氏无针乌贼研究领域内取得的一些成绩,并且提出了展望。     

金乌贼人工繁育及养殖技术

<正>金乌贼是我国沿海重要的经济头足类之一，是一种具有较高经济价值的优良野生品种。20世纪80年代初，日照近海金乌贼产量比较高，每年春季产卵季节，在附着基或乌贼笼上附着有大量的金乌贼受精卵。随着捕捞强度加大及海洋生态环境被破坏，金乌贼资源出现衰减，至21世纪初，金乌贼的自然资源量濒临枯竭。     

南海鸢乌贼(Sthenoteuthis oualaniensis)资源评估的新方法

为了解南海鸢乌贼(Sthenototeuthis oualaniensis)资源量与分布状况,本研究利用建立在灯光罩网船上的北斗星通渔业信息采集网络,搜集南海鸢乌贼生产数据,并根据灯光罩网作业特点,创建了光诱资源量评估模型,使用克里金插值法,绘制出南海鸢乌贼的分布密度图,估计其总资源量和年可捕量。研究结果表明,鸢乌贼在南海有着广泛的分布,以110.5°–111.5°E、11°–12°N之间的海域和115.5°–116.5°E、9.5°–11.5°N之间的海域资源密度最高,在4 t/km2以上;以112°–112.5°E、14.5°–15°N之间的海域和113°–115°E、15°–16.5°N之间的海域单位努力量渔获量(CPUE)最高,达1 kg/(kW·d·km2)以上。根据克里金插值法估算,在南海108°–118°E、9°–20°N之间的359个渔区,鸢乌贼资源量为204.94万t,总可捕量为99.40万t。评估认为,南海鸢乌贼资源开发潜力大,是未来南沙渔业开发的主要种类。     

基于灯光罩网法的南海鸢乌贼声学评估技术研究

南海中南部深水海域蕴藏着丰富的鸢乌贼资源,为推动南海外海渔业资源开发,实验探索了灯光罩网与声学手段相结合的鸢乌贼资源量评估方法。根据2011年4—5月在南沙群岛海域灯光罩网和Simrad EY60科学鱼探仪同步采集鸢乌贼生物学和声学数据,对鸢乌贼的趋光性行为、种群结构、声学映像和分布水层等特征进行分析。结果表明,灯光诱集结合罩网采样可确定南海鸢乌贼的单体回波,分布于0～100 m水层;通过背景噪声消除、鱼类和浮游动物目标限定、单体目标检测等处理,确定鸢乌贼现场目标强度-67～-52 dB;选择鸢乌贼渔获比例较大的网次,统计得到鸢乌贼胴长10.4～14.2 cm,对应目标强度-60.7～-58.0 dB,胴长与目标强度经验公式为TS=21.23LogML-82.48。研究认为,声学与灯光罩网相结合的调查方法可以作为南海今后开展鸢乌贼资源量评估的基本方法。     

日照市岚山头近海金乌贼生长特征初步研究

为进一步改善日照市岚山头近岸金乌贼增养殖效果、保护野生资源量,该文探究了岚山头海域金乌贼生长特征季节变化规律。研究表明:(1)每年7月,岚山头近海金乌贼平均胴长最小,约5.53 mm,平均体质量最小,约0.07 g,随着个体生长发育不断进行,第2年5月金乌贼平均胴长达到最大值,约174.9 mm,平均体质量亦达到最大值,约883.4 g;(2)金乌贼自稚仔生长至成体过程中,平均体质量与平均胴长呈二次函数递增关系。     

Trawling for cephalopods off the Portuguese coast—Fleet dynamics and landings composition

Fleet dynamics was addressed for three cephalopod taxa of commercial interest, the squid Loligo vulgaris, the octopuses Octopus vulgaris and Eledone cirrhosa, and the cuttlefish Sepia officinalis, for 48 trawlers of the fish trawling fleet. Landing profiles (LP) were identified based on the species composition of the landings using hierarchical cluster analysis. Four out of a total of 12 different LP were related to cephalopods and other species associated with them.The effects on the landing proportions of a number of variables, year, season and vessel, are analysed for each of the species studied using generalized linear models (GLM). The factor “vessel”, including an ensemble of technical characteristics as well as the abilities of individual skippers, explained most of the model deviance, strongly reinforcing the existence of a fleet component dedicated to catch cephalopods. However, time also explains much of the variation found in the data.Seasonal alternation between landings of octopodidae and cuttlefish was observed within a small group of old trawlers operating mainly off the south coast, following the abundance cycles of these species. For a larger group of more modern trawlers, operating off the western coast, inter-annual shift between octopus and squid was found, together with a well marked seasonal pattern between the catches of cephalopods and horse mackerel.Spatial patterns of activity were identified using vessel monitoring system (VMS) data available for trawlers in Portugal, demonstrating the existence of cephalopod targeting strategies in Portuguese fish trawling activities.     

拟目乌贼繁殖行为学的初步研究

拟目乌贼在繁殖期间的行为较为复杂,包括求偶、雄性争斗、交配、雄性陪护、产卵等行为。拟目乌贼在生殖策略上并非"一夫一妻"制,交配时,雄性用第1、2对腕固定雌性的头部,然后用茎化腕将精荚输送至雌性纳精囊内。雌性受精后不久便产卵,拟目乌贼雌性轮流在产卵区产卵。卵白色,半透明,卵群葡萄状,分枝,刚产出的卵短径约1.2cm,长径约2.4cm,拟目乌贼平均产卵量为354枚。     

浙江南部外海头足类种类组成和数量分布

根据2006年5月、8月、11月和2007年2月浙江南部外海底拖网渔业资源调查资料,用渔获率作为资源分布的数量指标,对浙江南部外海头足类种类组成、数量分布、季节变化趋势作了定量分析。结果表明:浙江南部外海调查海域头足类种类有36种,其中:群体数量较大,经济价值较高的常见种有杜氏枪乌贼、剑尖枪乌贼、中国枪乌贼、长蛸、针乌贼、真蛸、神户乌贼、珠乌贼、罗氏乌贼、短蛸、椭乌贼、太平洋褶柔鱼、多钩钩腕乌贼等13种。调查海域以夏季头足类资源密度较高,数量分布主要集中在100~200 m水深的外侧海域;秋季和冬季尽管头足类资源数量在下降,但其数量的地理分布与夏季相近;而春季分布较密集的区域则在80~200 m水深海域。年间不同水深海域的头足类资源密度是80~100 m水深海域低于100~200 m水深海域。与近海渔场相比,浙江南部外海调查海域头足类种类多而且资源较丰富,其渔获量仅次于鱼类,是浙江南部外海底拖网的主要捕捞对象,特别是枪乌贼科的种类是今后可供底拖网作业开发利用的主要渔业资源之一。     

闽南-台湾浅滩渔场单船拖网作业调查与分析

根据2009—2010年闽南-台湾浅滩渔场单船拖网作业监测调查资料和生产统计数据,阐明单船拖网作业的渔业地位、渔场分布、网具类型,着重分析该作业渔获种类组成及主要捕捞对象的资源动态。结果表明:单船拖网作业产量位居闽南-台湾浅滩渔场各种海洋捕捞作业的首位,大吨位、大功率渔船数量连续多年不断增长;渔具型式以有翼单囊网具为主;部分渔船使用的拖网网囊尺寸远远低于国家标准;带鱼、二长棘鲷幼鱼损害现象较为严重;秋季8—10月蓝圆鲹和鲐鱼群体绝大多数个体可达到最小可捕规格。调查研究结果还表明,2002年以来单船拖网渔业资源结构已发生较大变化,生命周期短、营养级较低的蟹类、枪乌贼类、乌贼类和虾类资源渔获比重显著增长;原优势种类绿布氏筋鱼资源已出现严重衰竭;二长棘鲷资源量逐年减少,渔获群体明显趋向小型化、低龄化。     

Combining fishers’ knowledge and cost‐effective monitoring tools in the management of marine recreational fisheries: A case study of the squid and cuttlefish fishery of the Ría of Vigo (NW Spain)

A new methodology based in the use of fishers’ knowledge and cost‐effective tools to obtain information about marine recreational fisheries (MRF) is presented. The squid and cuttlefish fishery of the Ría of Vigo (NW Spain) was selected because it is managed in a data‐poor environment. In‐depth interviews (57) were conducted with fishers, collecting ecological and socio‐economic information. A cartography of fishing grounds based on their knowledge was obtained, while the intensity of effort and catches was mapped by the monitoring of two vessels with low‐cost GPS data loggers. The 102 shore anglers and 248 recreational boats catch 8 t/year of European squid Loligo vulgaris and 11 t/year of common cuttlefish Sepia officinalis (11% of total catches on these species in the area). Shore anglers fish from 11 ports, while boat fishers use 14 fishing grounds (covering 30 km²). Most of the catches (86%) are landed by boats, and their CPUE is higher in the outer part of the Ría of Vigo. The use of fishers’ knowledge and cost‐effective monitoring is encouraged to obtain information for the management of MRF. Given the economic contribution of MRF (260,000 €/year in direct expenses), this activity should be considered in the regulations.     

Baseline assessment of total fisheries-related biomass removal from Japan’s Exclusive Economic Zones: 1950–2010

The rise and fall of Japan’s marine fisheries have been well documented and are clearly evident in official landings statistics. However, the extent of illegal, unreported and unregulated fisheries, including recreational fisheries, and the discarding of unwanted catch in Japanese waters, both of which may have significant implications on the success of management regimes, have yet to be closely examined. This study reassessed the impact of fisheries on the marine ecosystems of Japan’s Exclusive Economic Zones (EEZ) by estimating the total marine biomass removed through the use of an established catch reconstruction approach. Since 1950, 368 million t of marine biomass have been extracted from the Japanese EEZ as commercial catch, recreational catch, illegal catch and discards. Commercial catch accounted for 87 % of the total, while discards accounted for an additional 8 %. The disparity between the estimated biomass removals and the reported commercial catch is 48 million t, or 15 % of the reported catch. The difference is not as large as observed in similar studies of other regions. Nonetheless, the reconstructed biomass removals represent a better baseline for the management of fisheries in the Japanese EEZ, particularly if Japan is to move forward with implementation of output control management.     

Determining the effects of stocking density and temperature on growth and food consumption in the pharaoh cuttlefish, <Emphasis Type="Italic">Sepia pharaonis</Emphasis>, Ehrenberg 1890

The purpose of this experiment was to observe the impact of stocking density on growth and food consumption of juvenile Sepia pharaonis reared at 23 and 28°C. Two groups of 32 cuttlefish each were reared in closed recirculating seawater systems with water temperatures of 23°C (group A) and 28°C (group B). Each group was divided into three treatments with two replicates per treatment: low-density (equivalent to 20 cuttlefish m⁻²), medium-density (equivalent to 100 cuttlefish m⁻²), and high-density (equivalent to 200 cuttlefish m⁻²). Measured amounts of live food were added three times a day and the wet body weight of each cuttlefish was measured once a week during the 42-day study. Cuttlefish in group B had higher growth rates and food consumption than cuttlefish in group A. The different stocking densities in group B affected the size of the cuttlefish whereas the stocking densities of the cuttlefish in group A treatments did not lead to different sizes between densities. Overall, the gross growth efficiency of the high-density treatments was lower than that of the low-density treatments, as was the weight of the cuttlefish in the high-density treatment. Although the wet weights of group A treatments were not significantly different (P > 0.05), the wet weights of the cuttlefish in the high-density, group B, treatment were lower than those in the low and medium density treatments. This decrease in individual size suggests that stocking densities of 100 to 200 cuttlefish m⁻² may interfere with growth.     

2006-2013年黄海秋季头足类资源状况调查与分析

为摸清中国黄海秋季头足类的资源状况,本研究根据2006–2013年秋季黄海渔业资源调查所取得的292个站位底拖网资料,以渔获率作为头足类资源分布的数量指标,分析黄海秋季头足类的种类组成、数量分布、年度变化以及空间分布格局。结果表明,黄海秋季分布的头足类有14种,隶属于3目6科8属,不同年度头足类的种类变化为(8±2)种/年,以温带种占优势,也有一定数量的暖水种,未出现冷水种,明显反映出暖温带海区的动物区系特征。黄海秋季头足类的优势种为太平洋褶柔鱼(Todarodes pacificus)、日本枪乌贼(Loligo japonica)、剑尖枪乌贼(L.edulis)、针乌贼(Sepia andreana)和双喙耳乌贼(Sepioda birostrata),年际间优势种稍有不同。更重要的是,此阶段调查捕获了3个黄海新记录种:罗氏乌贼(Sepia robsoni)、多钩钩腕乌贼(Abralia multihamata)和真蛸(Octopus vulgaris)。根据这3个暖水种在黄海其出现的位置、频率和数量,分析可能的原因是全球气候变暖使得头足类暖水种分布的纬度发生变化,导致其栖息范围扩大。调查还发现,柔鱼类和枪乌贼类为秋季黄海头足类优势类群,不同类群头足类的渔获量在年际间存在一定波动,且过去的十多年间黄海秋季头足类资源组成结构已有所变化。黄海不同区域间头足类资源量从北往南呈现递增趋势,黄海北部、中部、南部头足类的平均渔获率分别为0.55 kg/h、0.67 kg/h、0.98 kg/h。本研究结果可为黄海头足类资源养护和可持续利用提供理论依据。     

Effect of Artificial Diets on Growth,Survival and Condition of Adult Cuttlefish, <Emphasis Type="Italic">Sepia officinalis</Emphasis> Linnaeus, 1758

The effects of artificial diets on growth and body condition of adult cuttlefish, Sepia officinalis were tested in two experiments. Supplemented prepared diets (fish myofibrillar protein concentrate) were fed during a 30-day and a 21-day experiments. Growth, feeding rate and food conversion of group-reared cuttlefish were analyzed. The first of these experiments tested four artificial diets, made with increasing levels of lysine, on adult cuttlefish. According to the chemical analysis, diets 1–3 had limiting concentrations of lysine and other essential amino acids (compared to mantle composition of the cuttlefish), while diet 4 was the only one where almost all essential amino acids were present in concentrations similar or higher than the ones present in cuttlefish mantle. A second experiment was conducted by isolating 16 adult cuttlefish individually, and feeding them the same four artificial diets, in order to obtain individual data. During Experiment 1, only the diet with the best chemical score (diet 4) produced growth (p < 0.05), with a mean instantaneous growth rate (MIGR) of 0.30% wet body weight (BW) d⁻¹. Similarly, individually reared cuttlefish fed diet 4 produced the highest IGR’s (0.26, 0.38 and 0.48% BW d⁻¹) and grew larger (p < 0.01). Comparison of cuttlefish fed the artificial diets vs. thawed shrimp and unfed cuttlefish indicated that cuttlefish fed the artificial diets were in an intermediate state. Growth rates obtained with the artificial diets (<0.4% BW d⁻¹) were considerably lower compared to natural prey, live or frozen, reported by other authors.