Tropical shrimp trawl fisheries: Fishers’ knowledge of and attitudes about a doomed fishery

Tropical shrimp trawl fisheries are unsustainable, and similar sets of management measures are used globally to address the direct and indirect costs of their practices. Yet little is known about shrimp fishers’ perceptions, despite the clear importance of human behaviour in determining the success of fisheries management. This article presents the results of interviews with industrial shrimp trawl fishers from the southern Gulf of California, Mexico, and reveals fishers’ knowledge and attitudes that should be considered when developing management plans for industrial shrimp trawl fisheries. Fishers were asked to comment on problems facing the fishery, management options to address the issues, and the future of the fishery in general. The interviews also elicited new knowledge on effort and valuable components of bycatch, useful to the management process. Among the problems facing the Gulf of California fishery, fishers tended to identify those generated externally—fluctuations in shrimp populations, increases in fishing effort, decreases in shrimp prices and increasing overheads—and thus distance themselves from responsibility for management options. The successes of any mitigation measures for the fishery are likely to depend on proper enforcement and reliable governance, as our study indicates. Should strong enforcement be put in place, then trawl free areas seem to be the most pragmatic way to alleviate problems associated with the fishery; our effort data point to areas that might have greatest acceptance among fishers. A reduction in capacity would clearly complement marine zoning for trawl free areas. In the long run, however, it may be economic extinction of the fishery that reduces pressure on the marine ecosystem.     

Multi-stakeholder perspectives on the use and influence of “grey” scientific information in fisheries management

Scientific information on the shrimp and groundfish resources of the Brazil–Guianas continental shelf has been produced by the United Nations Food and Agriculture Organization (FAO) and the Caribbean Regional Fisheries Mechanism (CRFM), in collaboration with the national governments exploiting the resources, since the early 1970s. In spite of the availability of such information, largely as grey literature, there is limited evidence as to the extent it is being used in fisheries management in Trinidad and Tobago. The flow of information between multiple stakeholders − fishing industry, scientists, fisheries managers, policy makers, and fisheries advisory bodies − was studied based on responses to a survey of key individuals to document each of their roles in the creation, distribution, and use of fisheries information. Content analysis of responses was completed to determine the opportunities and barriers for using scientific information in fisheries management. Salience, credibility, and legitimacy of the information were shadowed by barriers that decreased these attributes. Knowledge about the fishery has increased and technical capabilities have been strengthened through research. At the same time, advances in digital technology have made information more accessible. Yet, the high technical content of fisheries information reduced its usefulness to some stakeholders and formal systems do not exist for distributing or measuring the use and influence of such information in decision making. Communication strategies to promote awareness of the scientific information and aligning scientific information with fisheries policy could increase its use and influence. Institutional support for partnerships and education to encourage stakeholder involvement could also facilitate increased influence of scientific information.     

Age constraints on the evolution of the Austroalpine basement to the south of the Tauern Window

The Austroalpine basement to the south of the Tauern Window once was part of the northern margin of Gondwana. It includes the “Altkristallin” and the phyllitic Thurntaler Complex. In the Altkristallin (AMU, MPU), suites of arc-related metamafic sequences occur together with calc-alkaline metagranite. SHRIMP U–Pb dating of zircon from calc-alkaline metagranite associated with an eclogitic amphibolite give an age of 470 ± 3 Ma interpreted as the age of protolith emplacement. In the Thurntaler Complex, metaporphyroids occur together with tholeiitic as well as alkaline within-plate basalt-type metabasite. The metaryholites of this association give a crystallization SHRIMP age of 477 ± 4 Ma, which suggests contemporaneity of arc-related and extensional settings in the Austroalpine basement units. The age data demonstrate widespread magmatic activity associated with the Early-Ordovician amalgamation at the end of the 550–470 Ma subduction–accretion–collision cycle. The Pb–Pb and U–Pb systematics of step-wise leached staurolite and kyanite from the peak-metamorphic assemblage of the Altkristallin indicate that (1) step-wise leaching of staurolite and kyanite yields the age of inclusions rather than the host; (2) zircon inclusions in staurolite suggest an Ordovician or older age for the precursor of the staurolite-schists; (3) the weighted average of the ²⁰⁶Pb/²³⁸U data of the various leaching steps yields a Variscan age for the inclusions (ilmenite, biotite, and andesine). Since these inclusions are part of the metamorphic mineral assemblage, this age provides a minimum estimate for staurolite growth, i.e., metamorphism. Thus, the Pb–Pb and U–Pb systematics of staurolite provide evidence for a Variscan metamorphism of the Austroalpine basement, e.g., MPU, AMU and Thurntaler Complex, to the south of the Tauern Window.     

对虾病毒病与化学需氧量相关关系研究

通过对虾池内主要环境因子与对虾病毒病相关关系的研究,发现虾池内化学需氧量（COD）太高是诱发对虾病毒病暴发流行的主要环境因子之一。利用多级S型净化池可以大幅度消除水体中的COD,有效预防对虾病毒病的暴发流行。     

中国对虾配合饵料添加维生素的效果

将维生素作为一个综合指标加以试验,配备5个不同维生素水平(0,0.27,0.54,1.1,2.1％)的饵料试验组,经较长期的室内饲养试验以考察混合维生素对对虾生长和成活率的影响。结果表明,在试验范围内,随着添加维生素份量的增加,对虾的成活率也增高,增重倍数也提高。这就表明,维生素(在试验范围内)有降低对虾死亡率、促进生长的作用。维生素促进生长的效应最敏感区间是0～0.54％,在此范围内,维生素的少量增加也能明显地提高其生长效果,而维生素在1.1～1.2％范围内,增重曲线就逐渐趋向平坦,表示2.1％的添加量接近维生素的最适添加量。 维生素还有降低饵料系数的作用,在试验范围内,随着维生素的增加,饵料系数也降低,最低可达2.48。     

Evaluating ecosystem-based management options: Effects of trawling in Torres Strait,Australia

A suite of management options for a prawn trawl fishery in Torres Strait, Australia was assessed for impacts on the benthic fauna using a dynamic management strategy evaluation approach. The specification of the management options was gained through consultation with stakeholders. Data for the model was drawn from several sources: the fleet data from fishery logbooks and satellite vessel monitoring systems, benthic depletion rates from trawl-down experiments, benthic recovery rates from post-experiment recovery monitoring studies, and benthic distribution from large-scale benthic surveys. Although there were large uncertainties in the resulting indicators, robust measures relevant to management were obtained by taking ratios relative to the status quo. The management control with the biggest effect was total effort; reducing trawl effort always led to increases in benthic faunal density of up to 10%. Spatial closures had a smaller benefit of up to 2%. The effect of closing a set of buffer zones around reefs to trawling was indistinguishable from the status quo option. Closing a larger area, however, was largely beneficial especially for sea cucumbers. When the spatial distributions of fauna prior to fishing were accounted for, fauna with distributions positively correlated with effort improved relative to those negatively correlated. The reduction in prawn catch under effort reduction scenarios could be ameliorated by introducing temporal closures over the full-moon period.     

The IVQ regime in Norway: A stable alternative to an ITQ regime?

Since the introduction of quotas and licences as important management tools, Norway has insisted on an individual vessel quota regime (IVQ). The main argument has been to avoid market-based transactions of quotas and vessels and secure stability in regard to a diverse fleet structure and decentralized ownership of scarce cod resources. Thus, an individual transferable quota system (ITQ) with a high degree of transactions and the potential for a heavy concentration of quota ownership and fewer vessels has never been an alternative. However, since the late 80s, the trawler fleet has been trapped within a web of unprofitable overcapacity. Within the frame of a closed management regime and a path-dependent IVQ system, the quota regime has been forced towards a market-orientated system for transactions. In this article, we analyze the Norwegian IVQ system and discuss whether the aggregate effects of the IVQ regime are congruent with the models’ profound ideals.     

HPLC法同步检测鲤鱼、对虾中喹乙醇与MQCA残留

建立了一种高效液相色谱法同时检测鲤鱼、对虾肌肉组织中喹乙醇（OLA）及其代谢物3-甲基-喹啉-2-羧酸（MQCA）的残留。采用0.3 mol/L 盐酸提取鲤鱼、对虾中的残留物, C18 固相萃取柱净化, 氮气吹干及流动相定容后, Waters2695 高效液相色谱仪在320 nm（MQCA）和372 nm（QLA）双波...     

日本对虾(Penaeus japonicus)虾苗杀虾微杆菌(Microbacterium shrimpcida sp.nov.)感染及病原菌检验

用平板划线分离方法,从呈群体死亡的日本对虾溞状幼体中分离到同种细菌,经对从分离做纯培养的6株菌(HL010406-1至HL010406-6)进行形态特征、理化特性、代表菌株(HL010406-1)的16S rRNA基因序列测定及系统发育学等方面的鉴定,初步表明其为微杆菌属(Microbacterium Orla-Jensen 1919)细菌的一个新种;选择代表菌株(HL010406-1)送中国典型培养物保藏中心(CCTCC)进行了复核鉴定,将其暂定名为杀虾微杆菌(Microbacterium shrimpcida sp.nov.)。根据用HL010406-1为代表菌株对健康虾及牙鲆做感染试验,初步认为该菌可能是造成所检虾苗死亡的病原菌。经用37种抗菌类药物对3株菌所做的药敏试验,结果发现对供试的青霉素G等30种药物呈敏感或高度敏感、对诺氟沙星低度敏感、对苯唑青霉素等6种具有耐药性。