镉在海藻中的化学形态

利用化学试剂逐步提取法研究了紫菜、海带、裙带菜和羊栖菜中镉的存在化学形态。研究结果表明:镉以多种化学形态存在于4种海藻中,1 mol/L氯化钠提取态镉和 2% 醋酸提取态的镉所占比例较大,两者约占总镉含量的76.3%～92.9%。0.6 mol/L盐酸提取态、去离子水提取态和80%乙醇提取态镉所占比例较小,其中乙醇提取态(离子态镉)约仅占总镉含量的0.4%～9.2%,且对于4种海藻,紫菜中的离子态镉所占比例最低(均小于1%)。实验进一步证实以海藻中总镉含量作为检测标准不能准确反映海藻及其制品的食用安全性,因此亟需建立海藻中针对毒性较强的离子态镉的检测标准限量和快速有效的检测方法,以保障我国海藻产业和出口创汇经济的顺利发展。     

高效液相色谱氢化物发生原子荧光（HPLC-HG-AFS)联用技术检测海藻食品中无机砷

海藻食品中无机砷的含量是水产品质量检验中主要的安全卫生指标。实验采用高效液相色谱氢化物发生原子荧光联用技术（HPLC-HG-AFS）对海藻食品中无机砷的检测进行了研究。通过实验优化了提取剂、提取时间及其仪器条件,建立了HPLC-HG-AFS联用技术检测海藻食品中无机砷含量的方法。用1.2 mol/L HCl在70 ℃水浴下提取1 h,用过氧化氢（H₂O₂）氧化;pH 6.0的15 mmol/L (NH₄)₂HPO₄溶液为流动相,HPLC-HG-AFS上机分析。样品加标量在0.10 mg/kg和1.00 mg/kg时的平均回收率均在92%以上,相对标准偏差均低于4%,方法精密度较高。研究结果表明,该方法测定海藻中的无机砷较为准确、可靠,为制定农业行业标准海藻食品中无机砷的测定,提供技术支持。     

The economic feasibility of adoption of a new in-pond mechanical grader for food-sized channel catfish (Ictalurus punctatus)

An economic analysis of an in-pond horizontal floating bar grader for food-sized channel catfish was performed. Data from previously reported field trials were used to determine whether farmer adoption of this grader is economically feasible. Scenarios for four farm sizes (65, 130, 259, and 478 ha) were evaluated. Partial budget, payback period, net present value, internal rate of return, and Taguchi quality loss function analyses were used to quantify and compare economic losses due to deviation from the target fish size. Partial budget results indicated positive net revenue for all farm sizes. Net revenue increased with farm size, market price, and increased dockage penalties. Payback periods ranged from 0.1 to 2.0 years depending on the scenario. Net present values were positive and increased with increasing farm size. Estimated internal rates of return were higher than the current opportunity cost of capital and increased with increasing farm size. The value of the gain in quality from reducing size variation from use of the UAPB grader was estimated to range from $770 to $5575/year, depending on farm size. Producer adoption of the UAPB grader is economically feasible for the scenarios analyzed.     

The feasibility of offshore aquaculture and its potential for multi-use in the North Sea

Following the Blue Growth ambition of the European Commission, the interest in the potential of offshore is growing. This paper aimed to contribute to the discussion on the feasibility of offshore aquaculture development and its potential for multi-use with other maritime activities. A review of national and international projects forms the basis of the paper, where the Dutch North Sea is used as a case-study area. Analysis of technical, economic and ecological boundaries indicated that the potential of fish culture is limited, that seaweed cultivation is likely to gain potential when challenges related to processing will be overcome and that mussel culture has the highest potential in the near future. The North Sea is an area where many stakeholders claim space, which might set boundaries to the number of sites available for mussel culture. Competing claims are a potential source of conflict but may also lead to mutual benefits when smart combinations are sought, e.g. with wind parks, fisheries and nature conservation; especially, the possibility of combining mussel culture in or around wind parks is worthwhile to be further explored. A spatial distribution model adapted for the Dutch North Sea conditions demonstrated that offshore mussel production in wind farms can be profitable. Yet, the commercial interest for offshore development of mussel culture is still limited. Actions required to stimulate further development of the offshore mussel industry are presented for the government, the private sector, research institutes and civil society organizations.     

岛礁海藻场沉积有机物来源辨析

海藻场的沉积有机物(sedimentary organic matter,SOM)是实现海藻场生态系统服务功能的重要物质基础,本实验以枸杞岛北部海藻场为研究区域,围绕大型海藻周年生活史的幼苗生长、成熟茂盛和衰退凋亡3个阶段,于2014年7月凋亡期、2014年10月生长期和2015年5月茂盛期对海藻场的SOM进行样品采集,并运用碳、氮稳定同位素技术,以C/N、δ~(13)C和δ~(15)N为指标分析了SOM的来源及变化。结果显示,1)7月、10月和翌年5月的SOM C/N的变化范围分别为5.9~6.6、6.0~6.9和5.4~6.2,可判定海藻场SOM是典型的海源性来源;2)7月不同水深的SOMδ~(13)C值空间变化明显,介于–20.3‰~–17.6‰,而10月和翌年5月都不显著,分别介于–22.3‰~–21.7‰和–21.4‰~–21.0‰;3)SOM的δ~(13)C值存在时间变化,而7月δ~(13)C值存在不同水深的空间变化;4)δ~(13)C、δ~(15)N和C/N之间的关系表明,7月SOM主要来源于浮游植物和大型海藻的混合贡献,而10月和翌年5月SOM则主要来源于浮游植物贡献;5)根据碳稳定同位素质量平衡混合模型计算得到,7月大型海藻对该海藻场SOM的平均贡献率最高可达53.71%;6)大型海藻产生的碎屑在SOM占比受波浪等海域动力环境影响显著。     

紫菜中无机砷含量的分析研究

本文针对紫菜中的无机砷超标问题,采用高效液相色谱—原子荧光光度法联用技术(HPLC-AFS)对紫菜中砷的形态进行分析,并测定了紫菜中的无机砷的含量。通过分析发现,紫菜中砷主要以一甲基胂酸、二甲基胂酸及砷糖、甜菜碱、砷胆碱等多种形态的有机砷化合物的形态存在于藻体中,无机砷的含量很少,仅在0.2mg/kg左右。采用HPLC-AFS能进行无机砷的分析测定时,由于三价砷的出峰时间与第1个峰的有机砷化合物出峰时间重叠,采用过氧化氢将其氧化成五价砷,可以很好地解决这一问题。通过验证,其加标回收率可达到80.19%,方法的准确性高,回收率符合检测的要求,适用于紫菜中无机砷的测定。     

东海北部和黄海南部鲐鱼年龄和生长的研究

本研究采用2002年11月～2003年8月在东海北部和黄海南部海域(30°～34°N、126°E以西)所获取的鲐鱼渔获样品,合计采集777ind,通过对鲐鱼耳石生长轮的观察和基础生物学测定,研究了鲐鱼的年龄和生长。结果表明叉长与体重的关系雌雄间没有显著性差异;所鉴定鲐鱼年龄组成为1～3龄鱼,共3个年龄序列,并补充20世纪80年代4～5龄鱼对鲐鱼的生长规律进行研究,采用Walford方法拟合,其生长参数K、L∞、t0分别为0.31993、451.3514和-1.20307;鲐鱼的生长拐点年龄为2.7yr,拐点体重为450g,拐点叉长为320mm。比较分析东海群系鲐鱼的渔业生物学历史状况,在目前所能观察得到的鲐鱼年龄段内(1～3龄),东海区鲐鱼个体平均叉长比20世纪80年代的都要小;与闽南、粤东近海地方群系的相比,东海群系的平均叉长在鲐鱼的整个生长阶段都明显的大。     

黄海北部发现的中华白海豚Ⅰ.外形和内脏器官的测定结果

中华白海豚(SousaChinensis)属于国家Ⅰ级重点保护野生动物,在中国主要分布于广西、海南、广东、香港、澳门、台湾、福建、浙江沿岸,向北可达长江口。2003年5月9日在黄海北部(北纬39°35′01″,东经122°51′50″),由于渔业生产误捕的中华白海豚,是迄今为止该种发现的最北记录,笔者报告了对该海豚的外形和内脏器官测定结果。     

Modelling annual cycles of primary production in different regions of the Bohai Sea

The Bohai Sea is a typical shallow sea in which the average depth of water is about 18 m, and which has a rich biodiversity and abundance of marine life. The values of primary production differ among the four different regions of the Bohai Sea. A biological model consisting of nutrients, phytoplankton, zooplankton and detritus is used to simulate the annual cycles of plankton and primary production in these four regions. The simulation is forced by monthly observational data. Water transparency, nutrient concentrations, temperature and incident irradiance influence the amount and variation of plankton and primary production. The model simulations indicate that transparency and nutrient concentration are the principal causes of the differences in primary production among the four regions of the Bohai Sea.     

Modelling the transport of particles in the North Sea with reference to sandeel larvae

The transport of particles representing sandeel larvae in the North Sea is simulated with a three-dimensional circulation model for the years 1976 to 1990. A great year-to-year variability in drift patterns is demonstrated. The results may explain some of the observed differences in recruitment between the main sandeel areas in the North Sea. In the northern sandeel area it seems that strong year classes are unlikely if the retention due to unfavourable currents is poor, and that a high retention in the summer may favour a good year class. In the southern sandeel area no clear coupling between year class strength and larval drift is found, possibly because the retention always seems large enough for a potentially good year class. For more quantitative use of such models in relation to sandeel recruitment, more biological knowledge is obviously needed on larval vertical distribution and timing of sandeel hatching and settling.     

黄海北部虾夷扇贝吊耳养殖技术研究

2010年进行了虾夷扇贝吊耳养殖试验研究。吊耳养殖分为一针四贝及一针二贝2种模式,经过6个月的对比试验,结果显示,与笼养方式相比,吊耳养殖扇贝的壳高增长率、单贝质量、贝柱质量、台产量、台产值等指标具有较大优势,存活率、肥满度、出丁率等指标互有优劣。在吊耳养殖模式下,虾夷扇贝壳高的生长优势明显,其中一针四贝模式的生长优势最大。本试验中吊耳养殖扇贝的总体生长情况优于传统的笼养方式;综合对比2种吊耳养殖模式,一针四贝模式的养殖效果好于一针二贝模式。     

北方地区斑点叉尾鮰人工繁殖技术

2000年进行斑点叉尾鱼回人工繁殖技术试验,选择我国1997年从美国引进培育的美国密西西比品系斑点叉尾鱼回原种3龄鱼为亲体,经60d池塘暂养培育,获受精卵12 5×105粒,经28d室内孵化培育,共出池全长约2 5cm的鱼苗10 1×105尾,出苗率为80 6%。试验结果表明,斑点叉尾鱼回可以在北方地区进行人工繁殖。     

福建海区单拖渔业现状浅析

本文根据1998-2003年福建海区拖网渔业资源监测以及1995-1997年间闽南台湾浅渔场单拖渔业资源调查、1998年和2000-2001年福建海区拖网定点调查的资料,论述和分析福建海区单拖渔业的现状。结果表明:目前整个单拖渔业虽然船数削减,实际却加大渔船功率,作业时间延长,促使年产量、单位产量不断提高,导致渔获组成发生很大变化,由低质小型鱼类、生命周期短的头足类、虾蟹类支撑,渔获鱼类质量较差,经济效益下降;另一方面头足类、虾蟹类资源量年间波动性较大,易受捕捞过渡影响,很难长时间承担目前捕捞压力。为此,文中提出加强严格实行"双控制度"及控制网目规格等管理建议和意见,为有关渔业管理和生产部门提供参考依据。     

福建海区张网渔业状况分析

本文根据历年福建省张网渔业调查及闽东、闽南海区张网监测船渔获物组成分析资料,阐述张网作业生产规模、渔业地位以及对近海渔业资源利用的情况,围绕张网作业盲目发展,造成对近海渔业资源损害日趋严重的问题进行讨论,提出加强和完善张网作业管理的看法和建议.     

The abundance of juvenile yellowtail (Seriola quinqueradiata) near the Kuroshio: the roles of drifting seaweed and regional hydrography

We assess the effect of drifting seaweed (Sargassum sp.) biomass, geography and hydrography on juvenile yellowtail (Seriola quinqueradiata) abundance variation off the southeast coast of Japan, near the Kuroshio Current. The amount of drifting seaweed mats progressively increased northeastward into the cooler, coastal waters. Frontal structure indexed using a station‐to‐station ΔSST did not explain spatial variation in the seaweed mat distribution, although the western extent of the Kuroshio Current appeared to act as a boundary. Juvenile yellowtail constituted 51–62% of the fish collected in association with drifting seaweed mats in April 1996 and 1997 and 29% in June 1996. The abundance of juvenile yellowtail was positively correlated with seaweed biomass. The geographic distribution of juvenile yellowtail associated with drifting mats varied among sampling periods, being more southwesterly in April and more northeasterly in June. Simple multiple regression models based on seaweed biomass and geographic distribution (latitude) explained between 35% and 43% of the variation in juvenile yellowtail abundance in spring. Associations with spatial and temporal variations in hydrographic conditions did not contribute to explained variation in a meaningful manner. The results presented here indicate that, off the southeast coast of Japan during April, yellowtail juveniles are likely to be most abundant when seaweed biomass is high, occur offshore, and are bounded by the western extent of the Kuroshio Current near the 19–20°C SST isotherm.     

加强我国海洋渔业资源管理的思考

目前我国近海捕捞能力大大超过了渔业资源的再生能力,海洋渔业资源面临枯竭的严峻形势。加强渔业资源管理,保持海洋渔业资源的再生能力,实现可持续发展已经刻不容缓。在对我国海洋渔业资源管理现状深入分析的基础上,从改善和健全管理体制、建立健全法规体系、加强管理执法能力建设、完善各项管理措施等方面提出了一些具体建议。     

中国海带养殖向离岸深水区发展的初步探讨

海带(Saccharina japonica)是我国重要的经济海藻之一,我国海带养殖业已形成了完整的技术链条和产业链条。近年来,在内外因素双重驱动下,我国海带养殖业呈现出向离岸深水区发展的趋势。本文围绕海带离岸养殖,介绍海带近岸养殖和离岸养殖的概念,对比分析海带近岸养殖和离岸养殖的优劣势,探讨海带离岸养殖发展的动因,总结海带离岸养殖发展的现状与问题,为海带离岸养殖发展提出建议和对策,以期为海带养殖产业的健康、可持续发展提供新思路、新理念。     

Climate fluctuations and the spring invasion of the North Sea by Calanus finmarchicus

The population of Calanus finmarchicus in the North Sea is replenished each spring by invasion from an overwintering stock located beyond the shelf edge. A combination of field observations, statistical analysis of Continuous Plankton Recorder (CPR) data, and particle tracking model simulations, was used to investigate the processes involved in the cross-shelf invasion. The results showed that the main source of overwintering animals entering the North Sea in the spring is at depths of greater than 600 m in the Faroe–Shetland Channel, where concentrations of up to 620 m⁻³ are found in association with the overflow of Norwegian Sea Deep Water (NSDW) across the Iceland–Scotland Ridge. The input of this water mass to the Faroe–Shetland Channel, and hence the supply of overwintering C. finmarchicus , has declined since the late 1960s due to changes in convective processes in the Greenland Sea. Beginning in February, animals start to emerge from the overwintering state and migrate to the surface waters, where their transport into the North Sea is mainly determined by the incidence of north-westerly winds that have declined since the 1960s. Together, these two factors explain a high proportion of the 30-year trends in spring abundance in the North Sea as measured by the CPR survey. Both the regional winds and the NSDW overflow are connected to the North Atlantic Oscillation Index (NAO), which is an atmospheric climate index, but with different time scales of response. Thus, interannual fluctuations in the NAO can cause immediate changes in the incidence of north-westerly winds without leading to corresponding changes in C. finmarchicus abundance in the North Sea, because the NSDW overflow responds over longer (decadal) time scales.     

2003年东海及部分黄海海域表面水温状况分析

本文分析了2003年东海及部分黄海海域的表面温度状况。研究表明,不同的水团具有不同的温度年变化特点。大陆水系的均极差远大干多年平均的水平,说明沿岸海域的表面温度年变化比常年更大,但黑潮主干区的均极差却和多年平均值差不多。虽然各海域的温度季节变化因海区的不同略有不同,但各种水团的年平均温度比多年平均都要高一些,说明这一年是比较温暖的一年。