Fish assemblages in the Southern California Current: relationships with climate, 1951–2008

We examined the dominant patterns of variability in the fish fauna of the southern California Current based on a principal component (PC) analysis of the California Cooperative Oceanic Fisheries Investigations ichthyoplankton data set, 1951–2008. Eighty‐six taxa were analyzed, including all ecologically dominant fish species, both exploited and unexploited. The first three PCs accounted for 20.5, 12.4 and 6.8% of the variance of the data, respectively (total: 39.7%). Each was dominated by taxa from particular adult or larval habitats. PC 1 predominantly represented the coherent response of 24 mesopelagic taxa from 10 families and was most highly correlated with long‐term trends in midwater oxygen levels. PC 2 was dominated by six of the seven most abundant ichthyoplankton taxa in the region, predominantly California Current endemics including key pelagic species (northern anchovy, Pacific sardine and Pacific hake), rockfishes (genus Sebastes) and two midwater taxa. It was correlated primarily with sea surface temperature and exhibited a significant declining trend. PC 3 was dominated by coastal and reef‐associated fishes with predominantly southerly affinities. It was positively correlated with sea surface temperature and sea level height, a proxy for diminished flow of the California Current. The taxa dominating PCs 2 and 3 mostly spatially co‐occur as ichthyoplankton. These results suggest that fish assemblages in the California Current are predominantly influenced by environmental forcing of their ocean habitats as adults or larvae, or both.     

Fine‐scale movements of the swordfish Xiphias gladius in the Southern California Bight

This study reports on the fine‐scale movements of swordfish (Xiphias gladius) outfitted with pop‐off satellite archival transmitters (PSATs) in the Southern California Bight (SCB). PSATs were deployed on basking swordfish using traditional harpoon methods from 2004 to 2006. Transmitters were programmed for short‐term deployment (2–90 days) and re‐acquired using a signal direction finder. High‐resolution (min^?1) depth and temperature data from nine swordfish (approximately 45–120 kg) were collected (>193 days). All swordfish displayed diurnal vertical movements similar to those reported for other geographic locations. The dominant diurnal movement pattern entailed swordfish remaining below the thermocline (>68 ± 15 m) during the day and near the surface, within the upper‐mixed layer, at night. Collectively, the average daytime depth (±SE) was 273 ± 11 m and the average night depth 31 ± 5 m. Three distinct vertical behaviors were recorded: 35% of the records following a strict diurnal pattern, with the entire day below the thermocline and the entire night near the surface; 52% of the records revealed routine surface‐basking events during the day, with an otherwise similar distribution at night; and 13% of the records exhibited surface‐oriented activity during the day and night. Surface basking (<3 m during the day) was recorded for eight individuals and occurred on 131 of the 193 days (68% of the dataset). Collectively, surface basking accounted for 8% of the total daytime records. The relevance of these vertical behaviors to SCB fisheries is discussed.     

近海浮绳式网箱养鱼技术

近海浮绳式网箱是在内海传统式网箱养鱼的基础上发展起来的一种优质、高产、高效、无公害的网箱养殖模 式。本文作者就海南省近海浮绳式网箱养鱼技术作扼要地介绍与探讨。     

闽东地区海水网箱养殖鱼类病害概况

近年来,由于种质退化、养殖密度过大、过量投饵、环境污染等因素的影响,鱼类病害频繁发生。本文作者结合闽东地区对海水网箱养殖鱼类病害进行调查作全面的概述。     

灯光诱饵技术对深水网箱养殖鱼类品质的影响

为评估太阳能灯光诱饵技术在深水网箱养殖鱼类品质改善方面的应用效果,本研究在青岛金沙滩海域的深水网箱中设计并安装太阳能灯光诱饵设备,通过“灯光诱饵”吸引活体饵料聚集于网箱内,从而为实验大黄鱼(Pseudosciaena crocea)、鲈鱼(Lateolabrax japonicus)和真鲷(Pagrus major)提供天然饵料,全程无人工投饵,使其在自然状态下,拟半野生化养殖至上市。大黄鱼、鲈鱼和真鲷经过5个月的实验网箱及传统网箱养殖后,通过测定其脂肪、脂肪酸和氨基酸含量判断其品质。结果显示,在安装灯光诱饵设备的影响下,网箱养殖大黄鱼、鲈鱼和真鲷的感官性状显著好于传统网箱养殖鱼类,11月3种鱼体肥满度比6月均显著下降(P<0.05)。灯光诱饵网箱养殖大黄鱼和真鲷肌肉内粗脂肪含量分别比传统网箱养殖低75.24%和46.81%,差异极显著(P<0.01),鲈鱼差异不显著(P>0.05)。灯光诱饵网箱养殖大黄鱼、鲈鱼和真鲷肌肉内DHA含量高于传统网箱养殖鱼类,差异极显著(P<0.01);总脂肪酸含量、棕榈酸含量低于传统网箱养殖鱼类,差异极显著(P<0.01)。灯光诱饵网箱养殖的3种鱼的肌肉内的呈味氨基酸、呈鲜味氨基酸、呈甘味氨基酸、总氨基酸和非必需氨基酸含量均升高,其中大黄鱼变化最显著,实验组比对照组的呈味氨基酸、呈鲜味氨基酸和呈甘味氨基酸含量分别高11.78%、9.17%和19.57%,差异显著(P<0.05)。研究表明,太阳能灯光诱饵深水网箱养鱼技术虽然降低了养殖鱼类的生长速度,但可以改善养殖鱼类品质,且养殖投入明显降低,养殖收入显著提高,该方法可显著提升产出效益,因此,可作为一种绿色健康养殖模式进行推广应用。     

浅议深水抗风浪大网箱的养鱼效果

大型抗风浪深水网箱是一种新型养殖设备,它是用防腐蚀、防污染、防紫外线的新型材料制成,由于它的应用,使网箱养鱼由小箱到大箱、由近岸到离岸,由内湾到外海、由低效益型变高效益型,代表了当今世界海水养殖技术的先进水平。大型抗风浪深水网箱通常圆形,直径10～20m,底面积约为100～200m2,容积1000～2000m3/个,4个网箱为一组固定。1　大型抗风浪深水网箱与小网箱的比较优势大连市金州区海洋与渔业局、水产科学研究所2002年春从浙江舟山海洋科技有限公司引进周长50m、直径16m、网深10m、容积2000m3/个的浮式抗风浪深水大网箱3组(12个箱),…     

军曹鱼海水网箱养殖技术

介绍了军曹鱼海水网箱养殖中饲养管理和病害防治的主要方法,内容包括:养殖海区的选择;网箱的准备;鱼种的放养;日常的饲养管理;淋巴囊肿病和弧菌病的防治;安全生产等。     

新型水产饲料添加剂--左旋肉碱 (L-Carnitine)

L-肉碱又称肉毒碱，是一种维生素的类似物。参与β-氧化等生理学作用，与脂肪代谢有关。能够维持水产动物体内的能量代谢的正常进行，是一种新型的功能性营养添加剂。在水产动物饲料中添加适量的L-肉碱，有着提高水产动物生长速度，降低饲料系数；提高水产动物蛋白含量，降低体脂率．改善肉质提高鱼类的繁殖率等功能。本文在大量相关研究文献的基础上，概述了L-肉碱的来源、水产动物对其吸收和代谢的机制、生物学功能以及在水产动物体内的营养生理学效应，并针对目前L-肉碱的使用存在的问题。提出了一些建议，展望了其广阔的应用前景。     

贵阳市百花湖网箱渔场突发性死鱼事故分析

１９９３年５月８日，贵阳市百花渔场１０６０平方米网箱内的鲤鱼和草鱼（鱼种），在短短的两个小时内死亡１９３１８．５公斤，死亡率高达８２．６３％，经组织多方面的力量调查分析，确认为工三排污积蓄物，在暴雨的冲刷下形成碱性水团，又经风力，污染水侵袭网箱区的结果。     

水库不投饵网箱养殖匙吻鲟生产性试验

2002年6月在隔河岩水库进行不投饵网箱养殖匙吻鲟生产性试验，结果表明：面积为360m^2的不投饵网箱，放养10cm左右的匙吻鲟鱼种l500尾，经1年养殖平均达到576．4g，成活率达90．5％，产匙吻鲟782．75kg，单产达2．17kg/m^2，产值共计75144元，折合亩产值139156元，生产性试验开支共计27820元，创利润47324元，单位网箱利润131．5元／m^2，每养殖l尾匙吻鲟创利润34．85元，折合亩利润8397l元。投入产出比1：2．70。水库不投饵网箱养匙吻鲟已显示出良好的经济效益、生态效益和社会效益，具有广阔的推广应用前景。     

我国海水鱼类网箱养殖现状及其发展前景

海水鱼的网箱养殖是一种新兴的养殖方式，发展的同时尚存在许多问题。本文从网箱种类，网箱养殖的地理分布及养殖品种，网箱养殖的有关技术三个方面综述了我国海水鱼类的网箱养殖现状，并且指出制约海水鱼网箱养殖发展的因素及其发展前景。     

我国深水网箱养鱼产业化发展前瞻

随着全球性海洋渔业资源衰退，市场对海水鱼类的需要日益增多的状况，海水鱼类养殖正以较快的速度发展，最引人注目的深入水网箱养鱼业的发展呈现方兴未艾之势。作者搜索国内外深水网箱养鱼的文献，概述国外深水网箱养鱼的现状，并对我国深入网箱养鱼产业化发展前景加予扼要阐述。     

军山湖网箱养殖大口鲶试验

网箱规格3 m×3 m×2.5 m,实行二级放养,投放规格为10~12 g/尾的鱼种1.2万尾。经152 d养殖,平均规格3.0 kg/尾,大的个体达到5.0 kg/尾以上,小的个体也在1.0 kg/尾。共生产商品鱼19 798kg,平均单产37.6 kg/m2,平均成活率55%,平均饵料系数3;投入产出比1∶1.41。     

温州市深水网箱养殖现状与发展前景

当前，我国渔业发展正面临着资源、市场、机制、观念等多种因素的交叉制约，尤其是当前国内外市场对名优海水鱼类的需求不断增加，而大范围超负荷养殖和过度的渔业捕捞，造成我国渔业资源难以为断的局面。因此以发展深水网箱养殖为主的浅海养殖已成为温州市发展现代化渔业的重要方向，不断扩大海水养殖区域，增加海水鱼产量已成为渔业经济发展的新亮点。基于此，本文就温州市深水网箱养殖的现状与前景，谈些不成熟意见。     

Fish use of ecohydraulic‐based mesohabitat units in a low‐gradient Illinois stream: implications for stream restoration

• 1. A classification scheme for ecohydraulic‐based mesohabitat units was developed for a summer low‐flow period. Mesohabitat unit designations were based on the integration of three‐dimensional channel hydraulics, geomorphic maintenance processes of bed morphology, and biological resource needs of fish. Ecological relevance of the units was evaluated by a study of fish mesohabitat use patterns, and species relationships to feeding guild. By portraying the stream as a mosaic of hydraulic habitat patches that provide specific biotic resource needs, this study's aim was to advance how ecological information may be incorporated into the stream restoration design process.
• 2. Nine mesohabitat units were designated, including pool‐front, ‐mid, and ‐rear units, scour pool, simple and complex riffles, glide, submerged point bar, and channel expansion marginal deadwater. Physical habitat structure differed among the nine mesohabitat units by length, water depth, and bed slope and complexity. Fish were collected in specific unit volumes by use of prepositioned areal electrofishing devices, in which distinct patterns of fish mesohabitat use were observed.
• 3. A key finding was the differences in fish assemblages among the pool units, in which fish densities were greatest in the pool‐front and scour pool units. Also, fish density in the pool‐front unit was positively correlated with pool entrance slope. Biomass was greatest in the pool‐front and ‐mid units, and it was correlated with maximum mid‐pool depth. Density and biomass were generally lowest in the pool‐rear unit. Other unique relationships were also observed among the mesohabitat units.
• 4. Based on feeding guild, patterns of fish mesohabitat use were observed for this summer low‐flow period; insectivores dominantly used pool‐front and scour pool units, herbivores dominantly used complex riffle units, and piscivores used pool‐front and ‐mid units.
• 5. Useful ecological information was derived from fish species‐habitat relationships observed in this study, linking mesohabitat units with species requirements for food resources. Such findings support advancements to ecological design strategies for stream restoration that promote hydraulic habitat diversity.

Copyright © 2008 John Wiley & Sons, Ltd.     

南方水域冬春季网箱养殖虹鳟试验

为充分发挥南方山区水资源特色与优势,进行了反季节虹鳟养殖试验,探索大中型水域冬春季应用大规格虹鳟鱼种进行网箱养殖的新途径。饲养147 d,共收获虹鳟4 701尾、3 373 kg,平均尾重0.718 kg,最大个体1.20 kg,平均产鱼8.65 kg/m3;总收入87 698元,盈利25 158元;成活率97.3%,平均投入产出比为1∶1.4。     

大龙口水库网箱养殖大口鲶试验

２只网箱共５０ｍ＾２,５月中旬购进３￣４ｃｍ规格大口鲶,长至１２￣２０ｃｍ时,入成鱼箱,饲养１２７ｄ,总产２０８５ｋｇ,合４１．７ｋｇ／ｈｍ＾２,尾重２．７５ｋｇ,成活率７５％。盈利１５１８２．７元,投入产出比１：１．５７。讨论分析了试验中存在的技术问题。     

低值鱼蛋白组织化模拟食品的研究

利用热塑挤压技术将低值鱼肉挤压重组,以重组产物为基料进行模拟食品研发。从基料复水、入味方法、干燥条件、山梨糖醇和蔗糖添加量等方面来确定中间水分模拟肉类食品工艺条件。试验结果表明,基料经100℃热水复水15 m in,选用佃煮法入味后在80℃条件下干燥3 h,添加山梨糖醇5%,蔗糖12%时可制得弹性好、风味优良的中间水分模拟肉类食品。     

Male‐biased sex ratio of nonanadromous Oncorhynchus mykiss in a partially migratory population in California

Abstract – Differential rates of anadromy between males and females are common in partially migratory salmonid populations, but this pattern is not fully clear for Oncorhynchus mykiss (rainbow trout/steelhead) from the limited but mixed data available. In particular, there are very few data on sex ratios of juvenile and nonanadromous (resident) fish to help assess sex composition of various life stages and life‐history types. We used a recently developed Y‐chromosome genetic marker to assess sex ratio of stream‐dwelling (i.e., juvenile and nonanadromous) O. mykiss in a small coastal basin in central California, USA. We analysed 384 samples collected from three contiguous study reaches over 3 years. Sex ratio was 1:1 among juvenile‐sized O. mykiss (<150 mm) but highly male‐skewed (83%) among nonanadromous‐sized individuals (≥150 mm), and this sex ratio × size pattern did not differ among years or study reaches. Our results suggest that the rate of anadromy differs between males and females in this basin. Our study also demonstrates the application of new genetic markers to determine sex composition of immature and nonanadromous salmonids, which will help assess sex‐specific life‐history behaviour in partially migratory populations of O. mykiss and other species.     

利用水库野杂鱼网箱养鳜的技术经验

鳜鱼(Siniperca chuatsi)俗称桂鱼、季花鱼,是淡水名贵鱼类.它终生以活鱼、活虾等动物性饵料为食,其肉质细嫩、肌间刺少、味道鲜美.