Influence of a breakwater on nearby rocky intertidal community structure

It is widely recognised that coastal-defence structures generally affect the structure of the assemblages they support, yet their impact on adjacent systems has been largely ignored. Breakwaters modify the nearby physical environment (e.g. wave action) suggesting a local impact on biological parameters. In the present study, an ACI (After-Control-Impact) design was used to test the general hypothesis that the artificial sheltering of an exposed coast has a strong effect on the structure and functioning of adjacent systems. The effects of a reduction in hydrodynamics were clear for a number of taxa and included the replacement of barnacles, limpets and frondose algae by an increasing cover of ephemeral algae. These effects were evident both at early and late successional stages. Results suggest that the artificial sheltering of naturally exposed coasts can have a strong impact promoting a shift from consumer- to producer-dominated communities, which has important ecological and energetic consequences for the ecosystem.     

Strategic priorities for assessing ecological impacts of marine renewable energy devices in the Pentland Firth (Scotland,UK)

The Pentland Firth, located between the north coast of mainland Scotland (UK) and the Orkney Islands, is recognised as an excellent location for the utilisation of tidal stream technology. Potential ecological impacts associated with tidal stream technology may ultimately depend on device design, array size and deployment location. Available ecological data for the Pentland Firth is summarised and strategic priorities for assessing ecological impacts are provided. Baseline data on marine species and habitats in the Pentland Firth is severely lacking and consequently the integrity of any environmental impact assessment could be compromised by this lack of data.     

Abundance and growth of larval and early juvenile cod (Gadus morhua) in relation to variable environmental conditions west of Iceland

Around Iceland, the west- and north-flowing coastal current, induced by freshwater runoff, provides a transport mechanism for pelagic eggs and larvae derived from the main spawning grounds off the southwest coast to the main nursery grounds off the north coast. In the present study, abundance and growth of larval and juvenile cod were recorded during a series of cruises conducted in June/July of 1998–2001 along the drift route southwest and west of Iceland. The cruises provided information on approximately 2–8-week-old individuals. Hatch dates and abundance varied greatly between years. Hatch dates ranged from Julian Day 92 to 167. Growth rate differed also between the years studied. Relative abundance was generally greatest in temperatures above 7.5 °C and in low-salinity waters, characteristic for the coastal current. The study demonstrates the link between the coastal current and larval/juvenile distribution, thus providing evidence for its importance in promoting successful recruitment of the Icelandic cod stock.     

Recruitment of shrimp (Pandalus borealis) in the Barents Sea related to spawning stock and environment

The shrimp spawn in autumn, and the females carry their eggs as out roe until spring when the larvae hatch. Within a period of 2 months the shrimp larvae settle to the bottom. It has been claimed that the year-class strength probably is determined during the larval phase. Today's assessment and forecast of the shrimp stock productivity and potential fishing yields are weak. This is partly due to poor knowledge on population dynamics from hatching until the shrimp are caught in the fishery at the age of 3 or 4 years. We, therefore, here identify the most important abiotic and biotic factors that affect recruitment in addition to spawning stock biomass. Since 1995, a net attached to the underbelly of the survey trawl used at the annual cruise in the Barents Sea has caught juvenile shrimp. The abundance of settled shrimp larvae varies in time and space. The recruitment to the fishery has been quite stable with the exception of the 1996 year-class, which was observed as 1-year-olds but has not been registered since. The temporal pattern of the three youngest year-classes is studied in relation to abiotic factors such as sea temperature, ice index and North Atlantic Oscillation, as well as biotic factors such as spawning stock biomass and presence of copepods, euphausiids and predating cod. Recruitment indices and factors identified by the Spearmann correlation to be significantly correlated with recruitment were used as input in a principal component analysis (PCA) and a generalized additive model (GAM) was applied. Abundance of 1-year-old shrimp is positively correlated to spawning stock biomass the previous year and to temperature of the previous winter, and negatively correlated with the number of 1-year-old cod. Two-year-old shrimp show significant correlation with temperature, whereas there is a strong negative correlation with euphausiids. Three-year-old shrimp are significantly correlated with the number of 2-year-old shrimp the previous year but negatively correlated to temperature at sampling time. This is probably due to less overlap with the main predator cod when cold. Ricker functions indicate an increased density-dependent mortality with age. When predicting the recruitment of shrimp to the fishery, the spawning stock biomass, the abundance of cod and euphausiids, as well as the temperature should be included.     

国际海底区域环境保护制度分析与中国实践

为促进国际海底区域资源开发和环境保护的协调可持续发展,提高我国在相关领域的话语权和执行力,文章系统分析国际海底区域环境保护制度的发展特征及其存在的问题,总结我国对国际海底区域环境保护的实践和展望,并提出对策建议。研究结果表明:国际海底区域环境保护制度经历萌芽、成形、发展和充实4个阶段,发展特征主要包括理念的更新、原则的完善以及义务和责任的明确,然而至今在规章环境保护条款、《联合国海洋法公约》非缔约国的环境保护权责和相关利益平衡等方面仍存在问题;我国从参与制定相关制度和开展国内法探索等方面积极实践国际海底区域环境保护;未来应从制定环境保护标准、探索政策环境和平衡各方利益等方面完善国际海底区域环境保护制度,我国应继续参与相关国际法律制度的制定以及完善国内海洋环境保护制度。     

广东沿海经济带海洋环境与经济增长的协调关系实证研究

环境与经济的关系是社会发展中不可忽视的重要问题。文章基于环境库茨涅兹理论构建广东沿海经济带主要海洋污染物排放量与人均GDP的线性回归模型,探索海洋环境随经济增长的变化规律,并采用熵变方程法进一步描述海洋环境与经济增长的协调关系。研究结果表明:广东沿海经济带以第二和第三产业为主导,经济增长速度快,但海洋污染物排放量逐年增加,其中珠三角是海洋污染物排放的主体区域;广东沿海经济带海洋环境与经济增长的EKC曲线因主要海洋污染物类别和地区的差异而呈现线型、"倒U"型、"N"型和"倒N"型等不同形式,整体海洋环境污染与人均GDP的拟合趋势表现为单调递增的线性变化,海洋环境污染程度随经济增长而显著加剧;广东沿海经济带海洋环境与经济增长处于严重不协调状态,经济增长与海洋环境质量的变化方向相反;亟须优化调整广东沿海经济带的产业分工布局,强化海洋环境保护制度保障,构建和完善海洋环境与经济增长的协调机制。     

深海采矿潜在环境影响因素及监测技术体系研究

目前深海采矿潜在的生态环境影响引起来了广泛关注,文章针对工业化深海金属矿产资源开采潜在的环境影响监测评估需要,系统地总结了深海铁锰多金属结核、铁锰富钴结壳以多金属硫化物等主要深海资源的基本产状,分析了“物质迁移-羽流产生-声光电磁噪声-耗氧-有毒物质释放”等主流采矿工艺潜在的环境影响因素,基于深海采矿生态环境影响评估调查研究的技术需求,从实施深海采矿环境监测实验工程、建立深海重大装备系统、发展原位监测传感器等方面提出了深海采矿环境监测技术体系建设构架,以期为我国深海采矿生态环境监测保护技术发展提供借鉴。     

Chemical degradation characteristics of reinforced concrete reefs in South Korea

The chemical degradation characteristics of reinforced concrete reefs, which had been fully immersed in Tongyeong waters of South Korea for 18–25 years, were studied. In order to investigate the marine environmental impact on the concrete reefs, environmental factors, for example pH, have been observed between 1997 and 2002. Then, four reinforced concrete reefs recovered from different sites in Tongyeong waters were nondestructively tested. Finally, those test results were analyzed to determine the chemical deterioration. Based on the test results, it is shown that the reinforced concrete reefs have sound chemical properties and their originally estimated service life is secure enough for a further service period in water depths of 28–32 m. A concrete cover depth of 40 mm is recommended for the design of reinforced concrete reefs to achieve safety in marine environments and special events occurring during installation and construction.     

International fisheries agreement: Review of the International Commission for the Conservation of Atlantic Tunas: Case study—Shark management

To properly manage world fisheries, especially highly migratory species, there are numerous treaties that have been implemented by specialized international fishery commissions. One of the oldest organizations is the International Commission for the Conservation of Atlantic Tunas (ICCAT). The main focus of this review was to summarize the history, roles and responsibilities of ICCAT, and to evaluate ICCAT's management of sharks in general and specifically for shortfin mako (Isurus oxyrinchus) shark. This review found that the Convention was established 40 years ago, but it was not until 2004 that the commission conducted its first population assessment on pelagic sharks.