Swedish coastal fisheries—From conflict mitigation to participatory management

Several research projects have studied Swedish coastal fishery to investigate the conflict between seals and fishery. In recent years, a strategy of participation by means of co-management has been unfolding. Realising that maintaining the coastal fishery requires societal support and knowledge integration, attempts have been made to introduce the principle of participatory management into the centralised Swedish fisheries management system. However, this co-management approach, presently implemented in six pilot projects, will take a long time to develop through a sustained process of experimentation and improvement.     

An overview of socio-economic and ecological perspectives of Fiji's inshore reef fisheries

This paper reviews the socio-economic and ecological context of Fijian reef fisheries. This review is deemed necessary because improved understanding of the state and trends of Fiji's coral reef fisheries on a national level is required for designing an effective management plan for Fiji's inshore reef fisheries. The most important point that emerges from our review is that despite numerous studies of Fiji's reef fisheries, the current status of reef-associated fisheries at the national level is still uncertain due, mainly, to the lack of dependable data on the subsistence fisheries. This in turn leads to uncertainty about how the continuation of fishing, in particular, fishing focused on target species for the coral reef resources trade, will affect fishing communities and the ecosystem.     

Estimating the economic impact of the Prestige oil spill on the Death Coast (NW Spain) fisheries

This paper presents an estimation of the economic effects of the Prestige oil spill in Galicia, focusing on the Death Coast fisheries and using fish landings as a market technique. Examining the evolution of landings in the Death Coast before and after the accident, the analysis reveals two opposing trends, with landings of some species increasing and those of other species diminishing.     

Small-scale marine fisheries policy in Vietnam

Vietnam's marine fisheries are considered to be small scale and are concentrated in coastal near-shore waters. This has resulted in heavy pressure on near-shore fisheries resources. Near-shore fisheries are considered by fishers and the government to be over-exploited, causing hardship for many coastal communities. This paper reviews and analyzes changes in policy towards small-scale fisheries in Vietnam over the last two decades. The primary issues facing the small-scale fisheries in Vietnam are to restructure the near-shore fisheries and to address over-capacity. Recommended actions include improved fisheries statistics, resources for provincial fisheries staff, and a coordinated and integrated approach involving a mixed strategy of resource management; resource restoration; economic and community development; and new governance arrangements.     

Economic gains of liberalising access to fishing quotas within the European Union

This paper analyses the extent to which specialisation gains can be achieved by liberalising access to fishing quotas within the European Union (EU). Fishing quotas are today exchanged between EU member states at a rate of 4% of total turnover in EU fisheries. Germany, Belgium, Denmark and the Netherlands are the most active. Only one fourth of these exchanges are permanent. With the management systems in EU fisheries differing among countries, comparative advantages in fisheries exist in member states with the best management practices. Hence, although positive but small specialisation gains exist in EU fisheries today, these gains might potentially be increased by liberalising access to fishing quotas and allowing transferability of quotas between individuals from different countries on a permanent basis. Increasing the gains might, however, affect relative stability.     

Describing and generating facies models for reservoir characterisation: 2D map view

This paper documents a new method for describing channel-related sedimentary deposits based on formal language theory. Using this method an analogue model of a sedimentary deposit can be encoded as a grammar. A program, called a parser, has been developed which can generate stochastic maps of these sedimentary deposits based on information in a specified grammar. The maps of sedimentary deposits generated by the parser have the same type, spatial arrangement, shape and size distribution as the analogue model. The successful generation of depositional maps represents a crucial step in the ongoing development of a new technique designed to generate 3D static geological models of sedimentary successions. The maps can be conditioned to match sparse hard data in the form of channel segments interpreted from seismic horizon maps.     

Impacts of trawling on benthic macro-fauna and -flora of the Spencer Gulf prawn fishing grounds

The overall effects of trawling on benthic habitats and their assemblages are dependent on the distribution and intensity of trawl effort. The benthic habitats of the Spencer Gulf prawn trawling grounds are subjected to known variable levels of trawling disturbance recorded from fisher's logbooks. These habitats have not been quantitatively investigated. The aim of the study was firstly to characterise the macro-faunal and -floral assemblages and secondly, to comparatively assess trawl impact by testing the null hypothesis of no differences between five sites exposed to different intensity of trawl effort. The distribution and abundance of benthic macro-fauna and -flora were studied at two sampling resolutions by using beam trawl sampling (10,000 m²) and underwater stereophotography (4.5 m²) at five sites with different levels of trawl disturbance (effort). The results showed that the Spencer Gulf prawn trawling grounds are characterised by sandy sediments with a low content of silt and clay, with the exception of one site with very fine gravel. Biomass, abundance and cover of macro-fauna and -flora were generally low throughout, but with large differences among sites. Biomass, abundance and cover were found to be negatively correlated to both trawl hours from 1994–1998 and during the period of study. ANOSIM and SIMPER analyses using biomass, abundance and percentage cover as variables showed significant differences between sites with eight species or taxonomic groups contributing more than 10% to the observed similarity within sites. The two northern sites were dominated by sponges and the bearded mussel, Trichomya hirsutus, and the southern hammer oyster, Malleus meridianus. Other species that contributed to the similarity within sites were the ascidian, Polycarpa viridis, mobile epifauna (the blue swimmer crab, Portunus pelagicus, and the western king prawn, Penaeus (Melicertus) latisulcatus) and demersal fish species (Degens leatherjacket, Thamnaconus degeni, and the Melbourne silver belly, Parequula melbournensis). Simpson's Index of Diversity (1 − λ) and species richness in the beam trawl samples were fairly even across all sites, but a significant effect of site was found in the stereophotographic transect samples. It was concluded that prawn trawling has a strong influence on the structure of the benthic habitats of the Spencer Gulf prawn fishing grounds highlighted by the magnitude of change and the strength of the gradient of effects. Confounding factors linked to the biophysical attributes of the sites are believed to be minor.     

Provenance of deep-water reservoir sandstones from the Jubarte oil field,Campos Basin,Eastern Brazilian Margin

The provenance of the Maastrichtian deep-water reservoir sandstones from the Jubarte oil field (Campos Basin, eastern Brazil), was studied using an integrated approach that included quantitative petrography, conventional heavy mineral analysis, garnet mineral chemistry and zircon geochronology. The reservoirs are predominantly coarse, poorly-sorted sandstones with feldspathic composition derived from uplifted basement terrains. The fourth- and fifth-order depositional sequences analyzed show no major variations in composition or in provenance through time. However, variations in apatite:tourmaline presents potential to be used as a parameter for sandstone correlation within the field. The composition of heavy minerals indicates derivation from high temperature and low-to-medium pressure aluminous metapelitic rocks, from granites and subordinate mafic rocks, derived from the Cabo Frio Tectonic Domain and the Oriental terrain of Ribeira orogen, characterizing a supply route from SW to NE. The low ZTR index, as well as the absence of low-grade stable heavy minerals and of metasedimentary rock fragments, suggest that by the end of Cretaceous all supracrustal, low-grade terrains had already been totally eroded, and that plutonic, infracrustal rocks were exposed, similarly to the present situation.     

Honey, I cooled the cods: Modelling the effect of temperature on the structure of Boreal/Arctic fish ecosystems

Historically colder regions of the North Atlantic had fisheries dominated by only a few fish species; principally cod and capelin. Possible population dynamic mechanisms that lead to such dominance are investigated by considering how a charmingly simple published multispecies model of the North Sea would react if the system operated at a lower temperature. The existing model equations were modified to describe temperature effects on growth, fecundity and recruitment and the model was rerun based on typical temperatures for the North Sea and a colder system. The results suggest that total fish biomass in the colder system increases but the community is more vulnerable to a given rate of fishing mortality. In the colder system, within species density dependence is reduced but relative predation rates are higher. Consequently, intermediate-sized species are vulnerable to relatively high levels of predation throughout their life history and tend to be excluded, leading to a system dominated by small and large species. The model helps to explain how temperature may govern coexistence and competitive exclusion in fish communities and accounts for the observed dominance of small and large species in Boreal/Arctic ecosystems.     

长江口及邻近海域表层沉积物中重金属元素含量分布及其影响因素

根据2003和2006年长江口及邻近海域表层沉积物样品的粒度组成和元素铬、铜、镍、铅、锌、铝、钙和锶的含量,分析了重金属元素含量的分布特征,探讨了含量的变化趋势及其对人类活动的响应。自2003年三峡工程一期蓄水完成到2006年6月,长江输沙量逐年减少,长江口海域沉积物中黏土的百分含量明显增加,但是沉积物分布的总体格局并没有发生明显的变化。重金属元素大多在泥质区沉积物中富集,高值区沿岸线呈带状分布,在最大浑浊带和口外羽状锋处达到峰值。在长江大量物质输入的背景下,研究区沉积物中重金属元素含量相对其他类似河口较低。河流的陆源颗粒输入、水动力条件、细颗粒物质的吸附以及絮凝作用是控制沉积物中重金属元素含量分布的主要因素,氧化还原条件也对重金属元素含量变化有一定的影响。人类活动(重大工程的建设和人为污染)对长江口外泥质区中重金属元素含量有重要影响,尤其对铅和锌的含量及其分布的影响显著。自2003年三峡工程一期蓄水以来,长江口海域表层沉积物中重金属元素沉积机制未有明显的变化,但是重金属元素含量有逐渐降低的趋势。