Distribution and habitat characteristics of three sympatric cetacean species in the coastal waters of Matang,Perak, Peninsular Malaysia

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我国渔业水域环境保护面临的问题与对策探讨

本文简要介绍了我国渔业水域环境监测体系的状况；分析了我国业水域环境保护面临的问题，如渔业水域环境损害严重，渔业水域的监督管理分散和渔业水域环境保护法规不完善；介绍了国外在渔业水域环境控制方面的经验，就如何解决我国渔业水域环境保护存在的问题，本文从建立集中的海洋环境监督,完善渔业水域环境保护的法律法规，健全渔业水域环境监测网络及加强水污染监测治理的科学技术研究等方面提出了一些建议。     

基于分位数回归的大西洋中部公海大眼金枪鱼(Thunnus obesus)栖息环境综合指数

摘要：2001年7月4日-10月27日，中国水产总公司所属的3艘大洋性超低温金枪鱼延绳钓渔船对大西洋中部公海海域进行金枪鱼渔业调查。本文根据所获得的渔场环境、作业参数、渔获统计等数据，应用栖息地适应性指数（habitat suitability index, HSI）模型并结合分位数回归分析方法分别对有关水层（60m为一层）及总渔获率与温度、盐度和相对流速等环境因素的关系并考虑其不同的影响权重及交互作用建立了数值模型，根据该模型计算大眼金枪鱼的栖息环境综合指数(HEII)，利用MarineExplore4.0绘制大眼金枪鱼HEII指数等值线分布图。结果显示：（1）180～240m水层中，中部海区的 指数分布较高（高于0.6），其他海区分布较低（小于0.6）；（2）240～300m水层中，6ºN以南的海区 分布较高（高于0.6），以北的海区分布较低；（3）300～360m水层中，仅南部部分海区（4ºS，23ºW附近） 分布较高，其他大部分海区分布很低（低于0.3）；（4）7ºN以南的大部分海区 指数分布较高（高于0.6），仅在部分较小海区（5ºN，22ºW、2ºS，17ºW和2ºS，23ºW的附近）内 指数分布低于0.5。 关键词：大眼金枪鱼；栖息环境综合指数；分位数回归；大西洋中部公海     

Growth and production of Pacific ocean perch (Sebastes alutus) in nursery habitats of the Gulf of Alaska

Nursery areas for juvenile fishes are often important for determining recruitment in marine populations by providing habitats that can maximize growth and thereby minimize mortality. Pacific ocean perch (POP, Sebastes alutus) have an extended juvenile period where they inhabit rocky nursery habitats. We examined POP nursery areas to link growth potential to recruitment. Juvenile POP were captured from nursery areas in 2004 and 2008, and estimated growth rates ranged from ?0.19 to 0.60 g day^?1 based on differences in size between June and August. Predicted growth rates from a bioenergetics model ranged from 0.05 to 0.49 g day^?1 and were not significantly different than observed. Substrate preferences and the distribution of their preferred habitats were utilized to predict the extent of juvenile POP nursery habitat in the Gulf of Alaska. Based on densities of fish observed on underwater video transects and the spatial extent of nursery areas, we predicted 278 and 290 million juvenile POP were produced in 2004 and 2008. Growth potential for juvenile POP was reconstructed using the bioenergetics model, spring zooplankton bloom timing and duration and bottom water temperature for 1982–2008. When a single outlying recruitment year in 1986 was removed, growth potential experienced by juvenile POP in nursery areas was significantly correlated to the recruitment time‐series from the stock assessment, explaining ～30% of the variability. This research highlights the potential to predict recruitment using habitat‐based methods and provides a potential mechanism for explaining some of the POP recruitment variability observed for this population.     

电子鼻在中华绒螯蟹产地鉴别及等级评定上的应用

采用电子鼻对阳澄湖、松江、崇明的不同等级中华绒螯蟹(Eriocheir sinensis)各可食部位香气轮廓进行了检测。特级、1级、2级阳澄湖中华绒螯蟹体肉、钳肉、足肉、性腺4部位香气轮廓区分显著。采用软独立建模的方法, 分别建立了基于单部位及联合多部位的阳澄湖中华绒螯蟹产地鉴别模型, 结果表明应用联合多部位模型, 对非阳澄湖蟹的识别率达到100%。采用偏最小二乘回归法建立了电子鼻响应信号与中华绒螯蟹等级评分的回归模型, 相关系数为0.96, 表明基于此模型可判定中华绒螯蟹蟹样等级。

     

Mesohabitat associations of the threatened San Marcos salamander (Eurycea nana) across its geographic range

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Difference in factors explaining growth rate variability in European eel subpopulations: the possible role of habitat carrying capacity

As a key parameter in the management of fish populations, individual growth rate (GR) variations were examined in the European eel (Anguilla anguilla; > 150 mm) using extensive mark–recapture surveys in the lotic habitats of two small rivers of western France: the Frémur, supposed to be saturated, and at the same latitude, the Oir with densities fivefold lower than those of the Frémur. In both systems, generalised linear models were used to test whether spatiotemporal factors such as dominant habitat type or local density affect GR variability. In the presumed unsaturated system, the Oir, GR variability is mainly explained by a set of habitat suitability drivers (density, dominant habitat type). In the Frémur, GRs appear independent of differences in habitat density or productivity. Below saturation, an increase in density will decrease the GR through intraspecific competition. At saturation, intraspecific competition reaches such high levels that regardless of eel density and productivity, the resources available by individual are similar throughout the system. In these circumstances, the effect of density on growth was presumed undetectable. Despite these contrasted results, mean GRs observed in both catchments were closed (~20 mm·year^?1). This is an unexpected result as GR is expected to be higher in unsaturated systems. This similarity could be explained by the difference between the two systems in terms of: (i) sex ratio (the Frémur is dominated by male, whereas the female is dominant in the Oir), (ii) habitat type distribution or (iii) possible interspecific competition (important salmonid populations in the Oir).     

Salinity and geomorphology drive long‐term changes to local and regional fish assemblage attributes in the lower Pecos River,Texas

River systems throughout arid regions worldwide have been heavily impacted by human activities, resulting in long‐term ecological consequences. The lower Pecos River in the Trans‐Pecos region of Texas is no exception, having undergone anthropogenic changes that include decreased flow, elevated salinity, species loss and species invasion. We compared historical and contemporary fish assemblage attributes from the Pecos River at local (site‐specific) and regional (Trans‐Pecos region) scales across a 24‐year time period. Fish assemblage data were collected in October 1987 and 2011, by seining at 15 sites spanning 430 km of the river in Texas. Additionally, we examined contemporary environmental conditions to determine species–environment relationships. We found that fish assemblages were significantly different between time periods, likely due to increased salinisation in the upper half of the study region. Decreased species richness, species replacement and increases in euryhaline species were documented in the upstream sites. Freshwater springs lower the salinity and maintain flows in the downstream reach, allowing for maintenance of the native fish fauna. Careful management of regional aquifers, irrigation practices and petroleum waste water will be necessary for protecting biodiversity and environmental flows in the lower Pecos River.