北部湾北部生态系统结构与功能研究Ⅱ.浮游动物数量分布及优势种

为了解北部湾北部海区浮游动物数量分布规律及优势种组成,2006—2007年对北部湾进行4个航次的综合性调查。根据浮游动物样品分析结果,研究了北部湾北部浮游动物的丰度、生物量和优势种组成,并利用Spearman等级相关法分析丰度与环境因子间的关系。研究结果表明,北部湾北部浮游动物丰度年均值(183.5±142.9)ind/m3,丰度的季节分布由高到低依次为秋季、夏季、冬季、春季;生物量年均值(139.5±116.8)mg/m3,由高到低依次为春季、秋季、冬季、夏季特征。平面分布上,春、秋两季丰度分布呈远岸高近岸低的趋势,而夏、冬两季则在近岸海域形成高丰度区。生物量的平面分布趋势与丰度的分布趋势基本一致。丰度变化与环境因子的相关性显著,水深、温度及叶绿素a浓度是影响丰度分布的主要因素。肥胖软箭虫Flaccisagitta enflata、亚强次真哲水蚤Subeucalanus subcrassus和间型莹虾Lucifer intermedius在北部湾北部的优势地位显著,优势种演替具有明显的季节性。     

Fishing the last frontier: The introduction of the marine aquarium trade and its impact on local fishing communities in Papua New Guinea

Papua New Guinea has sometimes been called the world's last frontier for relatively undamaged coral reefs and their resources. In 2007, the country joined its neighbours in the marine aquarium trade. By licensing a private company, Papua New Guinea tried an alternative approach to the introduction of this activity. Under the so-called SeaSmart Programme, over 100 fishers were trained in sustainable collection techniques and handling of organisms, until the programme was shut down in 2010, and replaced by its successor, EcoAquariums PNG. This article contains the first study on the introduction of the marine aquarium trade into Papua New Guinea. It evaluates the overall outcomes of the SeaSmart Programme, lists targeted species, and their prices. The main focus is on the local collectors, and on the impacts of this new activity on them and their communities. Benefits from collecting marine ornamentals are assessed and their contribution to household income is quantified. Perceptions on non-financial benefits of the SeaSmart Programme are also gathered. The empirical work was carried out between September 2010 and February 2011 in the Central Province of Papua New Guinea. A total of 199 fishers including 44 aquarium fishers were interviewed in eight different communities in the Central Province of Papua New Guinea. The results show that marine aquarium fishing does provide benefits to local resource collectors, but also that this “sustainable” way of collecting of marine ornamentals might lead to some depletion.     

Species distribution modelling to support marine conservation planning: The next steps

Species distribution models (SDMs) offer great potential for inclusion into the toolbox of today's marine environmental manager, especially with regard to marine conservation and planning. The application of SDMs in the marine environment over recent years has been varied but there are still relatively few examples in comparison with terrestrial application, and this is especially true in deep-sea marine ecosystems. This short article builds upon two recent review articles concerning the application of species distribution modelling studies in the marine realm, offering additional practical considerations for discussion. Recommendations for progressing the improved application of SDMs to support marine conservation planning are given, including combining model outputs with other data layers, metadata standards and model error. SDMs have both an urgent and long term contribution to make to marine conservation planning globally, and it is hoped that this article, in combination with developing research on marine SDMs, will contribute to some much needed discussion and inform best practice and new research to enable these models to be of greater use to marine managers.     

The precautionary approach to non-native fisheries—The case of striped bass in Texas

Fisheries managers have long relied on non-native fish to improve, sustain, or create recreational fishing opportunities, often without adequate consideration of potentially negative ecological consequences. There is growing advocacy for using the precautionary approach to avoid potentially serious or irreversible harm to the environment in the face of scientific uncertainty. This paper uses striped bass (Morone saxitilis) in Texas to examine possible effects that might have resulted had the precautionary approach been applied before stocking began in the 1960s when the species was considered non-native to Texas. The current range of reproducing striped bass populations extends from the North Atlantic Ocean to the U.S.–Mexico border. However, the western extent of the species current range beyond Louisiana is probably the result of stocking begun in 1965 that continues today. The historic range is yet unresolved. The best available information suggests that striped bass are not native to Texas, fish stocking has resulted in beneficial economic impacts, and any negative effects (i.e., harm) are currently unknown. It seems unlikely that application of the precautionary approach would have led to different outcomes in Texas than currently exist. However, the complete striped bass story has yet to be written.     

Performance of a northwestern Mediterranean bottom trawl fleet: How the integration of landings and VMS data can contribute to the implementation of ecosystem-based fisheries management

The European Union has established a framework to achieve or maintain good environmental status in the marine environment by 2020. The Marine Strategy Framework Directive requires the application of the ecosystem approach to the management of human activities, covering all sectors having an impact on the marine environment. However, fisheries in the Mediterranean are far from a systematic implementation of an ecosystem-based fisheries management (EBFM). Aiming to address this issue, this study explores the potential of the relationship between daily yield by vessel (landings and income by species) and vessel position (known via vessel monitoring system) as a tool for fleet management. This approach is possible due to the current dynamics of Mediterranean fleets, with vessels returning daily to the harbour where landings are registered as weight and income by vessel. Moreover, vessels of >15 m total length have been compulsory monitored by VMS since 2005. A bottom trawl fleet that operates in the northwestern Mediterranean was chosen to develop this approach. Different groups of trawlers were identified, which could be linked to the strategies displayed by the fishermen that were mainly driven by the target species dynamics. Accurate knowledge of the fishing targets driving the fleet dynamics and of the fishing strategies at the vessel level (i.e. fishing ground habitat where the fishing pressure is exerted and corresponding landings) are shown to be a feasible tool for fleet management.     

New fossil evaniids (Hymenoptera,Evanioidea) from the Yixian Formation of western Liaoning,China

A new species, Procretevania mitis sp. nov., is described from the Early Cretaceous of Yixian Formation at the Huangbanjigou, Beipiao City, western Liaoning, China. Based on new morphological data, a key of Procretevania Zhang and Zhang, 2000 is provided. Forewing venations, body and forewing lengths, localities and horizons of various genera of Evaniidae in amber and compression fossils are summarized for comparison. Evaniidae have a high degree of venational diversity, while more complex forewing venations for Lebanevania and Mesevania suggest that they may represent the stem group of the Evaniidae. High diversity of Evaniidae in the Early Cretaceous implies that Evaniidae might have radiated before the Early Cretaceous. Furthermore, comparison of body and forewing lengths of amber and fossil genera indicate that the amber specimens have relatively smaller size.     

镇江长江豚类省级自然保护区鱼类多样性及年际变化

【目的】调查了解镇江豚类保护区鱼类资源状况,丰富鱼类资源本底数据。【方法】于2013、2016和2019年,分别开展3次渔业资源调查,对该区域鱼类种类组成、优势种、体型大小及群落多样性进行统计分析。【结果】共记录鱼类68种属于7目13科47属;鲤形目(Cypriniformes)鱼类种类占比较为稳定,鲇形目(Siluriformes)鱼类资源量有下降趋势,鲈形目(Siluriformes)鱼类种类占比上升明显;不同年份优势种替代较为明显;2016年的物种丰富度指数和多样性指数最高,分别为6.528、3.026。【结论】保护区鱼类资源较为丰富,但不同年份鱼类群落变化较为明显,渔业资源面临小型化趋势。     

A TAXONOMICAL AND ECOLOGICAL SURVEY OF ROTIFER COMMUNITIES IU KROTTENSEE (AUSTRIA)

The composition and distribution of benthic, periphytic and planktonic rotifers in different habitatsin Krottensee were investigated. Sixty-five rotifer taxa were identified, their relative abundance estimated. Classification of the data set by cluster analysis allowed the recognition of distinct habitat groupe con-fined to acid bog ponds, macrophytes, sediments, and open water. Five groups of rotifer taxa were identifiedon the basis of their habitat preferences and the occurrence of the taxa. Highest diversities were found onmacrophytes and in acid bog ponds.     

模拟厌氧水稻土中氮、砷变化及迁移研究

矿渣和酸性矿山废水的排放会使矿区周围的农田受到污染。为研究厌氧条件下矿区农田中氮和砷之间的联系,本文通过摇瓶实验探究了含砷水铁矿在厌氧含氮农田中释放的砷形态的变化,通过柱实验探究了水稻生长对氮、砷形态和浓度的影响。研究结果发现,在厌氧条件下,外源氮的加入促进了砷污染水稻土中As(Ⅴ)的还原,使生成的As(Ⅲ)浓度最高达396μg/L;在柱实验模拟的厌氧农田不同层位中,水稻的生长过程促进了氮和砷的还原以及砷向下层位的迁移,使装置中的As(Ⅲ)浓度最高达517μg/L;摇瓶实验和柱实验在相近的厌氧条件下,NO^-₃的存在能够直接参与As(Ⅴ)还原。研究结果为农田砷污染的治理提供了一定的参考价值。     

贵州都匀下泥盆统蟒山群Zosterophyllum australianum(澳大利亚工蕨)新材料及其古地理意义*

Zosterophyllum(工蕨属)是早期陆生植物的代表性类群之一,全球广泛分布。Z.australianum(澳大利亚工蕨)产自华南和澳大利亚,是东北冈瓦纳古植物地理区系的典型分子。文中描述了产自贵州都匀包阳剖面蟒山群中的Z.australianum新材料。该标本的孢子囊具短柄,呈椭圆形或扇形,宽2.6~4.1 mm,高可达3.9 mm,加厚带宽约0.6 mm,紧密螺旋排列形成孢子囊穗,与云南文山早泥盆世坡松冲植物群中的Z. australiaunum极为相似。依据目前对Z. australianum时代延限的认识,并结合蟒山群其他植物属种的发现(如Adoketophyton subverticillatum),推断该群下段的时代为早泥盆世布拉格期。Z. australianum在蟒山群中的发现,扩展了该植物的地理分布范围,反映出蟒山群中的植物组合与坡松冲植物群存在一定联系。