南海北部渔场表层沉积物中的硫化物

为了给南海北部渔场的资源和环境保护提供基础数据,用碘量法测定了南海北部陆架区表层沉积物中硫化物含量.结果表明,全部28份样品中硫化物含量为3.3～42.2mg/kg(干重,下同),平均为12.1mg/kg,符合外海含量低的一般规律,明显低于沿岸海湾的含量,远低于日本渔业环境质量标准(200mg/kg)和安全下限值(400mg/kg).硫化物含量在测站间和不同区域间存在一定差异,南北方向呈近岸(13.1mg/kg)略高于离岸(12.1mg/kg)、离岸略高于远岸(11.1mg/kg)的梯度分布,但梯度差异不显著(p＞0.10);东西方向的分布特点是粤西海域(23.7mg/kg)＞海南岛以东(15.3mg/kg)＞台湾浅滩(9.4mg/kg)≈粤东海域(8.7mg/kg)≈珠江口外海域(8.6mg/kg).空间分布不太均匀主要是受沉积物类型的影响,与陆源硫化物输入的关系不大.     

Comparing effects of land reclamation techniques on water pollution and fishery loss for a large-scale offshore airport island in Jinzhou Bay,Bohai Sea,China

Plans are being made to construct Dalian Offshore Airport in Jinzhou Bay with a reclamation area of 21 km². The large-scale reclamation can be expected to have negative effects on the marine environment, and these effects vary depending on the reclamation techniques used. Water quality mathematical models were developed and biology resource investigations were conducted to compare effects of an underwater explosion sediment removal and rock dumping technique and a silt dredging and rock dumping technique on water pollution and fishery loss. The findings show that creation of the artificial island with the underwater explosion sediment removal technique would greatly impact the marine environment. However, the impact for the silt dredging technique would be less. The conclusions from this study provide an important foundation for the planning of Dalian Offshore Airport and can be used as a reference for similar coastal reclamation and marine environment protection.     

南沙群岛北部海域鸢乌贼(Sthenoteuthis oualaniensis)夏季渔业生物学研究

采用自动鱿钓(AJ)和灯光罩网(LAFN)定点采样,对南沙群岛北部海域(12—16°N,112—116°E)鸢乌贼生长、繁殖、摄食及资源分布等进行研究。结果表明:灯光罩网渔获中鸢乌贼的胴长范围为65—231mm,体质量范围为6—580g;自动鱿钓鸢乌贼胴长范围为108—215mm,体质量范围为38—400g。自动鱿钓和灯光罩网鸢乌贼雌雄性比分别为32.0和1.4。南沙鸢乌贼雌性个体出现两个性腺发育高峰期,即101—120mm与161mm以上胴长组,4—7月为繁殖高峰期。鸢乌贼以大眼标灯鱼、尖头燕鳐等中上层鱼类为主,还摄食同类以及钩腕乌贼属等其它头足类及少数蟹类,雌雄个体摄食强度随胴长增加而增加。自动鱿钓CPUE(单位捕捞努力量渔获量)为1—38pc/(line·h),平均值为12pc/(line·h);而灯光罩网CPUE为15—50kg/net,平均值为35.7kg/net。南沙群岛北部海域鸢乌贼具有重要的经济学和营养生态学研究价值,灯光罩网是开展南海鸢乌贼渔业资源研究的较佳采样方式。     

Individual transferable quotas versus auctioned seasonal quotas: An experimental investigation

Fishery policies have largely developed in response to revealed problems with existing policy instruments. The last major innovation is the introduction of individual transferable quotas, ITQs. Experience thus far is promising. However, if history repeats itself, it is pertinent to start exploring further improvements. Among other things, concerns may be raised about the efficiency of ITQs, financial risks to owners of quotas and fishing vessels, and problems with fairness and collection of resource rent. These issues are studied with a laboratory experiment. Different from previous experiments it allows for trade of both quotas and vessels. In addition, the experiment tests an alternative institutional arrangement, namely auctioned seasonal quotas, ASQs. Neither of the two systems turns out to be as perfect as economic theory predicts. While the two systems are similar in some respects, the ASQ system allows for taxation of resource rent, and surprisingly, it may be the system with the lowest financial risk for fishing firms.     

The incorporation of traditional knowledge into Alaska federal fisheries management

Fisheries policy and management processes for federal waters off western Alaska currently lack consistent and considered integration of traditional knowledge (TK), TK holders, social science of TK, and subsistence information. The incorporation of these into fisheries work can lead to more informed, equitable and effective policy and management practices. This paper includes information and recommendations derived from previous work by the authors as well as from two community workshops with indigenous TK holders and fisheries experts. Discussions of TK and related concepts, TK research in the Bering Strait and Yukon River regions, and Alaska federal fisheries management-related institutions and processes as pertains to TK are presented. Substantive recommendations are provided for improving processes, increasing tribal representation, capacity building, effective communication, outreach and relationship-building, the incorporation of indigenous concerns and values, and regarding the development of a Fisheries Ecosystem Plan for the Bering Sea.     

Participatory assessment of management measures for octopus vulgaris pot and trap fishery from southern Portugal

Co-management has shown promising results for the sustainable use of fishery resources. The common octopus (Octopus vulgaris) pot and trap fishery in the Algarve (Portugal) holds the potential for implementation of a co-management system. To explore this potential, seven participatory workshops took place between 2014–2015, bringing together 60 participants from 10 fishing associations and 16 fisheries management and research institutions. The exercise resulted in promising outcomes with regards to the possible implementation of a co-management system for the fishery. In the present work an overview of the outcomes of the participatory workshops is given and compared with initiatives worldwide. Among the management actions identified, some have direct impacts on the octopus’ life cycle, while all target the same overall objective: to regulate fishing effort. In the informal setting of the workshops, a formal request was developed: the establishment of an annual closed season in the Algarve. This request was taken into consideration by the responsible management institution.     

Population biology of coral trout species in eastern Torres Strait: Implications for fishery management

Coral trout (Plectropomus spp.) are the main target species for commercial fishers in the eastern Torres Strait Reef Line Fishery (ETS RLF). The four species of coral trout known to occur in Torres Strait: Plectropomus leopardus, Plectropomus maculatus, Plectropomus areolatus and Plectropomus laevis are currently managed as a single species in Torres Strait, as there is no species-specific biological information available for the region which could be used to assess whether species differ in their response to fishing pressure. The aim of our study was to determine whether it is appropriate (biologically) to manage coral trout in the ETS RLF as a single species group or whether different management arrangements are required for some species. We used catch data and biological data from samples collected by commercial fishers to examine the distribution within Torres Strait and estimate a range of biological parameters for P. leopardus, P. maculatus and P. areolatus. Insufficient P. laevis samples were collected to reliably examine this species. Results indicated that the population biology, particularly the reproductive biology, of P. areolatus was substantially different to both P. leopardus and P. maculatus. Although it is difficult to predict the response to fishing, P. areolatus may be more vulnerable to fishing than P. leopardus and P. maculatus, due to the larger size at sex change observed for this species and the very low proportion of males protected by the current minimum size limit. Therefore, while the common management arrangements for P. leopardus and P. maculatus appear to be adequate for these species, separate management arrangements are needed for the sustainable harvest of P. areolatus populations in the ETS. Specifically, we recommend the introduction of a maximum size limit for P. areolatus, in addition to the current minimum size limit, which may allow a proportion of males some protection from fishing.     

厦门沿岸海域渔业资源变化和最适捕捞力量的估算

本文以厦门沿岸海域历次渔业资源和生物调查及１９８４－１９９５年渔业统计资料为背景,分析了该海域渔业资源的变动,重点对文昌鱼、真鲷、鳓鱼、大黄鱼、蓝点斑马鲛、长毛对、中国鲎等重要经济种类资源变动的原因进行探讨,针对目前资源的变动趋向,指出了近期重点的保护对象和有开发潜力的种类,并以三种标准捕捞力量,应用了Ｓｃｈａｅｆｅｒ和Ｆｏｘ两种剩余产量模式估算最大持续产量（ＭＳＹ）和最知捕捞力量。估算结果ＭＳＹ     

A direction-sensitive underwater blast detector and its application for managing blast fishing

Little is known about the spatial and temporal distribution of blast fishing which hampers enforcement against this activity. We have demonstrated that a triangular array of hydrophones 1 m apart is capable of detecting blast events whilst effectively rejecting other sources of underwater noise such as snapping shrimp and nearby boat propellers. A total of 13 blasts were recorded in Sepangor bay, North of Kota Kinabalu, Sabah, Malaysia from 7th to 15th July 2002 at distances estimated to be up to 20 km, with a directional uncertainty of 0.2 degrees . With such precision, a network of similar hydrophone arrays has potential to locate individual blast events by triangulation to within 30 m at a range of 10 km.     

黄海、渤海底层盐度预报方法的研究

根据二维流体动力学方程和深度平均盐度扩散方程在河口径流量以及蒸发和降水之差为已知情况下构成的闭合方程组，预报出深度平均盐度，然后利用底层盐度与深度平均盐度、水深和时间（月）之间的经验关系，给出底层盐度的二维预报。为了检验试报结果的可靠性，文中将黄渤海底层盐度的试报结果（１９７年７月１１日，时效为３ｄ）与标准断面观测资料（７月１１日观测，１２４．５°Ｅ以西，共１０４站）作一粗略比较。比较表明，试报结果与实测值的相关系数为０．９６，均方误差为σ＝０．２６，绝对误差小于０．２和０．３的站数分别占总站数的６３．５×１０－２和７７．０×１０－２，而总均绝差为０．１９。由此可见，试报的效果是令人满意的。