共查询到19条相似文献，搜索用时 52 毫秒
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广丰县位于赣浙闽三省交界处,全县国土总面积1377.79平方公里,有大小河流十五条.其中主干流丰溪河起源于福建省武夷山脉,最终汇人信江,全长117千米,流域面积24.72平方公里,本流域为亚热带季风气候区.气候温热,四季分明,光照充足,雨量充沛.天然鱼类资源丰富,据记载共有90种鱼类,其中鲤科鱼类最多有57种,占总数的63.33%.现存66种,已采集到的标本有49种.近年来由于拦河建坝,截断鱼类洄游通道,加上酷渔滥捕和化肥、农药的大量施放以及工矿企业排放的污水,造成鱼类生境恶化,部分鱼类已消失,如鲢鱼、鳍鱼等.为尽快保护、增殖本流域鱼类资源,维护渔业生态平衡,近年来对全县天然鱼类资源进行全面详细调查,同时对流域内渔业存在的问题进行研究分析,提出合理的保护对策,这对维护生态平衡,促进渔业生产健康、快速发展具有十分重要的意义. 相似文献
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2007年5月-2008年5月,作者对温河水库的鱼类资源进行了调查。调查结果显示,鱼类组成共计12科33属34种,其中以鲤科为主,共18种,占52．9％,与资料比较增加1科2属3种,减少两科,增加种类主要来源于人工放养的品种;渔获物组成呈现低龄化、个体规格小趋势。保护对策：温河水库渔业发展遵循以增殖为主、养殖为辅的原则;通过放流增殖减缓水环境富营养化,发挥水库最大生态功能。 相似文献
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汉江上游中段鱼类资源现状及保护对策 总被引：1，自引：0，他引：1
汉江是长江最大支流，汉江上游中段鱼类资源丰富。对上海鱼类资源现状和存在的问题进行了分析，并提出了上游鱼类资源保护措施和对策。 相似文献
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2019~2021年对大渡河上游鱼类资源状况进行了调查,并对调查数据进行了分析。结果表明,大渡河上游共调查到鱼类3目8科23属41种,其中,鲤形目鱼类30种,占总种数的73.17%,鲤科13种,占鲤形目鱼类的43.33%;土著鱼类29种,占总种数的70.73%,属典型的高原鱼类,其中,珍稀保护及特有鱼类15种,占土著鱼类总种数的51.72%,包括3种国家级保护鱼类、4种省级保护鱼类和15种长江上游特有鱼类;外来物种12种,占总种数的29.27%,主要为鲤科、鳅科和鮰科等鱼类,其中,鲤科种类居多,占50%。大渡河裸裂尻（Schizopygopsis chengi）、齐口裂腹鱼(Schizothorax prenanti)、重口裂腹鱼(S. davidi)是大渡河上游优势种,不同河段优势种有所不同,泸定以上河段比较近似。受水电开发等活动的影响,大渡河上游整体鱼类资源呈衰退趋势,川陕哲罗鲑(Hucho bleereri)、长须裂腹鱼(S. longibarbus)分布范围和资源量在缩减,青石爬鮡(Euchiloglanis davidi)、黄石爬鮡(E. kishinouyei)、中华金沙鳅(Jinshaia sinensis)、西昌华吸鳅(Sinogastromyzon sichuangensis)、软刺裸裂尻鱼(S. malacanthus)等已逐渐退出库区,中华鮡(Pareuchilogiants sinensis)、厚唇裸重唇鱼(Gynmoliptychus pachycheilus)已难采集到;针对目前大渡河上游鱼类资源的变化趋势和面临的问题,文章给出了相应的保护对策与建议。 相似文献
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陆水水库鱼类资源调查 总被引：5，自引：0，他引：5
陆水水库鱼类资源调查胡菊香，洪峰，黄学才（水利部水库渔业研究所）（水利部长江水利委员会库区处）陆水水库位于鄂东南长江一级支流陆水河中游，总库容为７．０６亿立方米，可养水面为３６１０公顷，于１９６７年建成蓄水。二十几年来渔业作为水库一项重要的功能一直未... 相似文献
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2007年2月至2008年1月,对天津八仙山国家级自然保护区鱼类进行为期一年的调查,分析其鱼类资源现状及其受影响的主要因素,最后探讨鱼类资源保护对策。 相似文献
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Patricia Sarai da Silva Leandro Esteban Miranda Sergio Makrakis Lucileine de Assumpo Joo Henrique Pinheiro Dias Maristela Cavicchioli Makrakis 《水产资源保护:海洋与淡水生态系统》2019,29(2):258-269
- Conservation of fish assemblages in severely impounded rivers has often focused on providing longitudinal and lateral connectivity along the main stem. Less attention has been given to tributaries, some of which remain unimpounded.
- This study shows that the biodiversity of ichthyoplankton in tributaries to the largest reservoir in the Paraná River, Brazil, is similar to that of tributaries of the few remaining unimpounded stretches of the Paraná River.
- Annual and seasonal variability in discharge within and among tributaries attracts and supports a diverse mix of species in each spawning season.
- Tributaries enrich the fish biodiversity of the entire system by providing a variety of environmental conditions, access to spawning habitat, refugia for early life stages, and by promoting ecological heterogeneity. Thus, tributaries can mitigate the adverse influence of an impounded main stem.
- Tributaries also support populations of endangered and threatened species. A focus on tributaries offers conservation alternatives that are more feasible given the scale and large number of impoundments constructed on the main stem.
- Conservation in the main stem may focus on maintaining passage through dams and access to large floodplains. Conversely, in tributaries conservation may focus on managing the quality of inflows from catchments, preserving suitable instream habitats and flows, and preserving access to smaller but more numerous floodplains.
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- Publication is an important stage in the research process, but determining the impact of published research on environmental outcomes is a complex challenge that is seldom undertaken. In 2016, a published study used acoustic telemetry techniques and drift sampling to demonstrate that environmental flow releases triggered downstream spawning migrations by a threatened fish species, the Australian grayling (Prototroctes maraena). The study provided support for the use of these types of releases to mitigate some of the effects of river regulation on fishes.
- The impacts of this research and its publication in Aquatic Conservation: Marine and Freshwater Ecosystems were thoroughly reviewed to identify benefits to water managers, researchers, institutes, and the wider community.
- Five areas in which this research, and its publication, had a recognizable impact are enhanced confidence for water managers in undertaking actions; greater acceptance in the wider community of environmental flow releases; enhanced relationships among water managers; the credibility arising from the work being published in a peer‐reviewed journal; and setting a foundation for further evidence‐based management.
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William M. Twardek Chris K. Elvidge Alexander D.M. Wilson Dirk A. Algera Aaron J. Zolderdo Stephen C. Lougheed Steven J. Cooke 《水产资源保护:海洋与淡水生态系统》2017,27(4):789-796
- While the use of aquatic protected areas that exclude angling might be considered an evolutionarily enlightened management approach to dealing with fisheries‐induced evolution (FIE), there is little empirical data on the effectiveness of this approach at maintaining the diversity of phenotypic traits within protected areas.
- In species with paternal care, including largemouth bass (Micropterus salmoides), active nest‐guarding and aggression towards potential brood predators by males may render these individuals particularly vulnerable to capture by angling because of increased propensity to attack fishing lures/bait near their nests. Relative levels of aggression by these males during the parental care period correlates with their vulnerability to angling year round. Selective removal of more aggressive individuals by anglers should drive population‐average phenotypes towards lower levels of aggression.
- To assess the effectiveness of protected areas at mitigating FIE, the parental care behaviours of wild, free‐swimming male bass were compared during the early nesting period for bass within and outside protected areas in a lake in eastern Ontario. Nesting males within long‐standing aquatic protected areas closed to fishing for >70 years were more aggressive towards bluegill sunfish (Lepomis macrochirus), a potential nest predator, and patrolled larger areas around their nests compared with bass outside of sanctuaries. Males within protected areas were also more likely to strike at artificial fishing lures and were more prone to capture during angling events.
- Collectively, the findings suggest that the establishment of protected areas may promote phenotypic diversity such as more attentive and vigorous parental care, relative to areas open to angling. The extent to which this phenomenon occurs in other species and systems is likely to depend on the reproductive strategies of fish and their spatial ecology compared with protected area boundaries, and habitat quality within protected areas.
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1989、1990 两年调查了山东全省有代表性的36座大中型水库的鱼产力性状。根据调查结果用系统聚类法,等级法和回归分析法进行了鱼产力评估。用等级法将这些水库根据鱼产力的高低分成了五级,并以二座经营较好、放养充分的典型水库的多年连续平均鱼产量为基准,根据浮游生物的平均丰度,估计了各级水库的鱼产力依次为 440、370、290、220 和150kg·ha~(-1)。回归分析法的评价结果表明影响这些水库鱼产力相对高低的主要因素是集雨区的土壤肥力、人口密度和植被覆盖率;以及库水的总磷、总氮、电导率、化学耗氧量和浮游生物的丰度,其中又以土壤肥力影响力最强。 相似文献
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Trevor J Kenchington 《Fish and Fisheries》2017,18(1):160-170
The Convention on Biological Diversity calls for networks of ‘representative’ MPAs, the effectiveness of which requires that the protected ecosystems be independent of external anthropogenic pressures. One principal pressure, fishing, severely depletes the oldest age classes of the target fish even if optimally managed. As many fishery resource species had high natural abundance and large individual sizes, while most fish show indeterminate growth and ascend the trophic pyramid as they grow, elimination of older age classes equates to removal of once‐dominant top predators. Because archetypal resource species are also migratory, that loss is transported throughout the range of the exploited populations, including into MPAs, through a lack of large migrants. The ecological implications remain uncertain in marine ecosystems, which are typically under ‘bottom‐up’ control. ‘Top‐down’ effects, such as mesopredator release, species replacement and trophic cascades, have been observed, however, meaning that elimination of top predators may affect ecosystem structure. It follows that, while exceptions doubtless exist, in general ‘representative’ MPAs should not be expected to fulfil their declared purposes, unless they are made so large as to encompass the whole migratory circuits of principal resource species – implying indefinite closure of the fisheries affected. Some compromise may be possible if MPAs were combined with fishing mortality rates far below current ‘optimal’ levels or where fishing can be concentrated on younger adults, while older fish are protected from exploitation. In any case, societies must choose between seafood production and recovery of selected marine areas to near‐pristine conditions. 相似文献
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- Following a shark attack, local governments often rapidly respond by implementing indiscriminate shark culls. These culls have been demonstrated to have substantial localized and adverse effects on a variety of marine organisms, and therefore there is an increasing need for an eco‐friendly alternative that maximizes both beachgoer and marine organismal safety.
- In response to such culls, the novel magnetic barrier technology, the Sharksafe Barrier was developed and rigorously tested on a variety of sharks implicated in shark attacks (e.g. bull sharks – Carcharhinus leucas and white sharks – Carcharodon carcharias). Although these studies exhibited promise in shark swim pattern manipulation and C. leucas exclusion, research was lacking in assessing if the technology could serve as an alternative to shark nets, or more specifically, if it could exclude motivated C. carcharias from bait.
- Using a 13 m × 13 m square exclusion zone, this study aimed to test the C. carcharias exclusion capabilities of the Sharksafe Barrier while additionally assessing the long‐term structural integrity of the system.
- After 34 trials and approximately 255 hours of total video collected over two years, data illustrate that all interacting C. carcharias were successfully excluded from the baited Sharksafe Barrier region, whereas teleosts and other small elasmobranch species were not. In addition, the long‐term deployment potential of this barrier system held promise owing to its ability to withstand harsh environmental conditions.
- Therefore, with the successful exclusion of a second large shark species, C. carcharias, from a baited region, continued long‐term research and implementation of this system at other locations should be considered to assess its viability and overall success as a bather and shark protection system.
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- Mobulid rays are protected in New Zealand, but the spinetail devilray Mobula japanica is caught as bycatch in skipjack tuna purse seine fisheries.
- Between 2005 and 2014, rays were recorded in 8.2% of observed purse seine sets. Rays were caught during summer, with a ‘hotspot’ (24.3% of sets) near the shelf edge off North Island over seabed depths of 150–350 m. Rays were usually brailed aboard with the tuna catch from successful sets, but were often entangled in the bunt of the net during unsuccessful sets.
- Observers tagged nine rays with popup archival tags to obtain preliminary information on their post‐release survival, and spatial and vertical movements. Seven of the nine tags reported data, and four of those rays died within 2–4 days of release. All four rays that died had been brought aboard entangled in the bunt. The three surviving rays were all brailed aboard with the tuna catch.
- One surviving ray remained near New Zealand for 2.7 months during summer, and the other two migrated 1400–1800 km northward to tropical waters near Vanuatu and Fiji at minimum speeds of 47 and 63 km day?1 at the end of summer.
- Archive data from one ray showed that it made regular vertical movements of 25–100 m amplitude, but spent most of its time shallower than 50 m, more so during the night (89.6%) than the day (76.6%), and mainly experienced temperatures of 18?22 °C. Dives deeper than 200 m were usually made during the day or twilight.
- All three surviving rays typically moved between the surface and 200–300 m daily, and reached greatest depths of 649 m, 1000 m and 1112 m, respectively, substantially exceeding the previous depth record for this species of 445 m.
- Recommendations are made for reducing purse seine mortality of mobulid rays by avoiding areas of high ray abundance, avoiding setting on ray‐associated tuna schools, and adopting best‐practice methods of returning rays to the sea from the net or vessel.
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Erin K. Loury Shaara M. Ainsley Shannon D. Bower Ratana Chuenpagdee Tracy Farrell Amanda G. Guthrie Sokrith Heng Zau Lunn Abdullah Al Mamun Rodrigo Oyanedel Steve Rocliffe Suvaluck Satumanatpan Steven J. Cooke 《水产资源保护:海洋与淡水生态系统》2018,28(2):485-500
- Marine protected areas (MPAs) and freshwater protected areas (FPAs), collectively aquatic protected areas (APAs), share many commonalities in their design, establishment, and management, suggesting great potential for sharing lessons learned. However, surprisingly little has been exchanged to date, and both realms of inquiry and practice have progressed mostly independent of each other.
- This paper builds on a session held at the 7th World Fisheries Congress in Busan, South Korea, in May 2016, which explored crossover lessons between marine and freshwater realms, and included case studies of four MPAs and five FPAs (or clusters of FPAs) from nine countries.
- This review uses the case studies to explore similarities, differences, and transferrable lessons between MPAs and FPAs under five themes: (1) ecological system; (2) establishment approaches; (3) effectiveness monitoring; (4) sustaining APAs; and (5) challenges and external threats.
- Ecological differences between marine and freshwater environments may necessitate different approaches for collecting species and habitat data to inform APA design, establishment and monitoring, but once collected, similar spatial ecological tools can be applied in both realms. In contrast, many similarities exist in the human dimension of both MPA and FPA establishment and management, highlighting clear opportunities for exchanging lessons related to stakeholder engagement and support, and for using similar socio‐economic and governance assessment methods to address data gaps in both realms.
- Regions that implement MPAs and FPAs could work together to address shared challenges, such as developing mechanisms for diversified and sustained funding, and employing integrated coastal/watershed management to address system‐level threats. Collaboration across realms could facilitate conservation of diadromous species in both marine and freshwater habitats.
- Continued exchange and increased collaboration would benefit both realms, and may be facilitated by defining shared terminology, holding cross‐disciplinary conferences or sessions, publishing inclusive papers, and proposing joint projects.
