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41.
粤东柘林湾溜牛人工鱼礁建设选址生态基础评价   总被引:1,自引:0,他引:1  
采用层次分析法,构建了基于生态系统效应的资源保护型人工鱼礁建设选址评价方法,通过选择水文、水质、底质和浮游生物、鱼卵仔鱼、大型底栖动物、游泳动物、初级生产力、潮间带大型底栖动物等30个海洋环境与海洋生物因子,建立了人工鱼礁建设选址生态评估模型;以柘林湾溜牛人工鱼礁区选址区域为例,对所选因子进行了春、夏、秋、冬4个季度的跟踪监测,探讨了该海区进行人工鱼礁建设的适宜性,根据该模型计算得出各季度人工鱼礁建设选址生态基础评价指数分别为0.65、0.71、0.63、0.64,平均为0.66,计算结果表明,该区域建礁生态基础良好,适宜选址开展人工鱼礁建设,其中生态基础最优的季节为夏季。  相似文献   
42.
Abstract

Australia's reef water quality protection plan has a key objective: “reduce the load of pollutants from diffuse sources in the water entering the Reef.” This article reports on a survey to assess the contemporary phosphorus (P) status of fertilized cropping soils across 21 catchments in coastal Queensland, Australia. The survey focused on surface soils from cane farms, vegetable and subtropical/tropical fruit tree sites. There were sampling depth effects on P levels in sugar and fruit tree sites (lower with depth). Importantly, 84% of 105 sugarcane sites were excessively fertile and only 3% rated low (P deficient). Some 75% of 16 vegetable sites and 38% of 8 fruit tree sites had excess ratings for extractable soil P fertility. Highest total P levels (0–10 cm) occurred in fruit tree sites, followed by vegetable and sugarcane soils. There are regional differences in P soil fertility, and the recycling of mill by‐products needs attention. Part 2 (Bloesch and Rayment 2006 Bloesch, P. M. and Rayment, G. E. 2006. “Phosphorus fertility assessment of intensively farmed areas of catchments draining to the Great Barrier Reef World Heritage Area, 2: Potential of soils to release soluble phosphorus”. In Communications in Soil Science and Plant Analysis 37 [Google Scholar]) examines the potential of these soils to release soluble P in a nutrient‐sensitive area.  相似文献   
43.
珊瑚对环境要求较高,温度、盐度、pH、重金属、悬浮泥沙、紫外线等因素都可能造成珊瑚的退化.又因为造礁石珊瑚是现代珊瑚礁的框架,本研究首先基于造礁石珊瑚的生存状况及其与珊瑚礁生态系统的密切关系,分析了其退化原因及可能产生的后果,进而从珊瑚礁生物增殖放流、人工养殖移植技术、相关功能基因研究、科学有效的监测管理等多个角度,综...  相似文献   
44.
在水槽内观测了许氏平鲉Sebastes schlegeli与大泷六线鱼Hexagrammos otakii幼鱼对两种不同结构PVC材料模型礁的行为反应,并对模型礁的集鱼效果进行了统计分析.结果表明:水槽内无论有礁还是无礁,两种鱼均喜欢栖息在水槽两端的角落或侧壁,在水槽的Ⅰ区和Ⅱ区的平均出现率为20%左右;大泷六线鱼与许氏平鲉的对礁接近行动指数,在方形礁角形格底板试验B1组中分别为1.12和1.03,在十字礁角形格底板试验B2组中分别为1.16和1.05,大泷六线鱼高于许氏平鲉,两种鱼对十字礁的接近行动指数和平均出现率要略高于方形礁.  相似文献   
45.
The worldwide market for ornamental saltwater invertebrates supplies the needs of millions of aquarium hobbyists, as well as for public exhibition (zoos, aquaria), universities, and research institutions. The large-scale continuous collection of marine organisms is responsible, in many places, for the destruction of habitats, including coral reefs. The perceived expansion of the animal trade further threatens these fragile habitats. In the present paper, several concepts for the domestication of marine ornamental invertebrates (mainly colonial species) are discussed, offering an alternative commercial approach. The major rationale is based on future ex situ propagation, not field collections; a strategy aimed to circumvent the need for wild-harvested animals. This strategy is based on: (1) collection, settlement and metamorphosis of large numbers of larvae from marine organisms or of naturally shed germ cells under aquarium conditions, where survivorship exceeds several orders of magnitude than that in nature; (2) fragmentation of very small pieces (such as the size of a single polyp in colonial corals or blood vessel ampullae in tunicates) for the production of new colonies; (3) the development of replicates and inbred-lines from chosen ornamental species; (4) the use of cryopreservation of larvae and germ cells which will support the supply of material year-round; (5) several concepts for husbandry methods. Some benefits and deficiencies associated with the strategy for ex situ cultures are discussed, revealing its importance to the future of the trade.  相似文献   
46.
采用行为学方法,对体长2~7 cm、体质量2~30 g的刺参(Apostichopus japonicus)在实验室水槽中自然光照下的行为特性进行观察,分别记录了刺参在水槽中无礁(对照组)和有礁区域的分布情况,并分析了不同形状、材料及距水槽底部不同空隙的人工参礁对刺参的诱集效果.实验观察发现,刺参在水槽中有明显的爬壁现...  相似文献   
47.
为研究崂山湾人工鱼礁区浮游植物群落结构与环境因子的关系,于2011年3、6、9、12月对崂山湾3个人工鱼礁区(峰山区、仰口区、港东区)进行取样调查。4次采样共鉴定浮游植物69种,其中3、9、12月优势种都为甲藻门中的中肋骨条藻(Skeletonema costatum),并且9月鱼礁区浮游植物密度远大于其他月份浮游植物密度。应用Canoco for Windows 4.5软件对获得的浮游植物数据和环境因子数据进行典范对应分析(Canonical correspondence analysis),作出物种与环境因子关系的二维排序图。结果表明,影响礁区浮游植物分布的主要环境因子依次为磷酸盐、温度、硅酸盐。  相似文献   
48.
研究人工鱼礁在波流作用下的水动力特性,对于人工鱼礁的设计具有重要的意义。基于有限体积法,采用边界造波,利用自由表面捕捉法(VOF)捕捉自由水面,建立了可以分别模拟纯波、均匀流以及波流共同作用下人工鱼礁水动力特性的多功能三维数值波流水槽。基于该数值模型对不同波流工况作用下圆柱型镂空人工鱼礁水动力特性进行数值模拟,并与物理模型试验结果进行比较。结果显示,人工鱼礁数值模拟受力与模型试验结果吻合良好,人工鱼礁所受的波流力最大值随着波高、周期和水流流速的增大而增大;人工鱼礁处于波流场波峰正下方时,背涡流的面积随着水流流速的增大而增大,随着波高、周期增大而减小。对单独均匀流作用、单独波浪作用和波流联合作用下人工鱼礁的水动力特性对比研究表明,人工鱼礁所受的最大波流力比最大波浪力、水流力都大,波流联合作用下的流场效应最显著,在礁体的后部形成了较大规模的漩涡结构。  相似文献   
49.
Since Pre-Columbian times, humans have exploited Jamaican marine ecosystems with significant consequences for flora and fauna. This study focuses on the history of reef fish exploitation in Jamaica, from first human occupation to the present day, to determine how past fishing activities contributed to subsequent declines in the coral reef ecosystem. The pattern of declining reef fish populations was nonlinear. Reef fish first declined in prehistoric times but then potentially recovered, following genocide of the native human population. Reduced fishing pressure lasted until the mid-19th century. At that time, depletion of reef fish populations again occurred with a precipitous decline from the 1850s to the 1940s. The final shift from relatively abundant to overfished marine fauna corresponded to subtle changes in fish trap design as well as development of recreational fishing. Government subsidies throughout the second half of the 20th century exacerbated the declines. This analysis shows that local artisanal fisheries with relatively low levels of effort and seemingly subtle shifts in technology can significantly impact the coral reef ecosystem and that declines occurred decades to centuries before modern ecological studies began. This research shows how historical analysis can be a powerful tool to minimize shifted baselines and establish realistic targets for recovery and sustainable management of marine ecosystems.  相似文献   
50.
1. The case is made for recognition of the marine bivalve Limaria hians as a reef‐forming species, which plays a key architectural role in certain benthic communities around the United Kingdom and Ireland. 2. This species uses byssal threads to construct nests that can coalesce to form reefs that cover hectares of seabed, contain multiple conspecifics and bind sediment. In so doing, L. hians modifies physical, chemical and biological processes at the sediment–water interface. 3. Such nests support a high diversity of associated organisms in coarse‐grade sediments (19 species of algae and 265 species of invertebrates from six discrete nests in Loch Fyne are reported on), although the biological interactions between species both inside and outside this assemblage (e.g. predatory cod) are unknown. 4. Being insubstantial, labyrinthine structures situated on the sediment surface, Limaria nests are sensitive to mechanical impacts, such as those caused by moorings, hydraulic dredging for infaunal bivalves and scallop dredging. 5. At appropriate sites, the status of L. hians can contribute a useful indication of disturbance on coarse‐grade sediments. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   
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