首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 171 毫秒
1.
基于大型底栖动物的桑沟湾不同养殖区底栖生境健康评价   总被引:1,自引:1,他引:0  
为了解桑沟湾养殖区大型底栖动物的动态变化以及底栖生境的健康状况,于2019年5-9月采集了中国北方典型养殖海湾桑沟湾不同养殖区(藻类、贝类和网箱养殖区)大型底栖动物样品,分析了不同养殖区大型底栖动物的种类、组成、数量分布、群落结构及生物多样性等群落特征,运用多样性指数、AMBI和M-AMBI指数法评价了不同养殖区底栖生境健康状况的时空变化。调查共鉴定出大型底栖动物56种,其中多毛类31种,甲壳类10种,软体动物9种,棘皮动物4种,其他类2种,大型底栖动物的优势种主要为多毛类,以污染耐受种为主;调查期间,贝类养殖区和网箱养殖区的群落多样性指数H''呈现下降趋势,表明贝类养殖活动和网箱养殖活动已经造成沉积物中有机物颗粒过度积累。ABC曲线显示,7月桑沟湾养殖区开始受到干扰,8月和9月受到中等程度的干扰。AMBI和M-AMBI指数评价显示桑沟湾养殖区域底栖生态系统处于轻度或中度干扰状态,底栖生境健康状况处于高等或者良好的状态。  相似文献   

2.
研究了采用蓝网、白纱、绿纱、编布、瓦片、石头制成的各种人工参礁对刺参池塘生态系统中底栖藻类种类组成及生物量、底层溶氧和营养盐等生态因子的影响。结果表明,颜色较深的蓝网与绿纱附着底栖藻类的生物量较大;水深小于150cm时附着生物量较大;小型底栖藻类在编布、瓦片上的生物量较大;大型底栖硅藻在蓝网、绿纱、白纱等有孔网片上的生物量较大。NO3--N远远大于NH4+-N并与底栖藻类生物量的相关系数极小;而底层NH4+-N与底栖藻类生物量的相关系数较大,为0.7176;PO43--P与底栖藻类生物量的相关系数介于二者之间。人工参礁的材料、设置方式与水深是刺参池塘养殖生态系统的关键技术和条件,并具有显著的生态效应。  相似文献   

3.
全面梳理溪流大型底栖无脊椎动物群落的研究热点和演化路径,以期为溪流生态系统研究提供有价值的参考及对未来研究方向的启示。以Web of Science核心合集数据库中2009-2018年的2416篇文献为原始数据,基于文献计量学分析方法,探索溪流大型底栖无脊椎动物群落研究热点,归纳研究主题。研究发现:(1)溪流大型底栖无脊椎动物群落研究的论文数量总体上呈上升趋势,主要研究力量来自美国;(2)土地利用、水质和生物多样性等为溪流大型底栖无脊椎动物群落主要研究热点;(3)近10年来溪流大型底栖无脊椎动物群落研究主题为以下6大类:以水质为代表的环境因子与大型底栖无脊椎动物群落关系研究、以比较分析为手段的β生物多样性研究、多重环境压力对大型底栖无脊椎动物群落的影响研究、大型底栖无脊椎动物群落长期响应研究、季节性河流研究和大型底栖无脊椎动物群落生物特征研究等。  相似文献   

4.
枸杞岛海藻场小型无脊椎动物的食物来源   总被引:5,自引:2,他引:3  
摘 要 枸杞岛近岸海藻场生态系统内浮游动物、端足类、多毛类和棘皮动物等小型无脊椎动物是海藻场食物网的重要组成部分,承担了将初级生产者的能量产出向高级消费者传递转移的功能。为了探明桡足类、太平洋磷虾、中国毛虾、短毛海鳞虫、厚壳贻贝、角蝾螺、紫海胆、钩虾、麦秆虫、海绵和钩虾幼体等海藻场内主要小型无脊椎动物的能量来源,本研究应用稳定同位素技术分析海藻场食物网内这些小型无脊椎动物及其潜在食源浮游植物、大型海藻、底栖微藻等初级生产者的碳、氮稳定同位素组成,并用IsoSource多源线性混合模型来估算不同的初级生产者对小型无脊椎动物的食源贡献率。结果表明,初级生产者的δ13C值介于-21.7‰~-13.8‰之间,δ15N值介于2.3‰~11.6‰之间。初级生产者SOM、浮游植物、POM、铜藻的δ13C值无显著的季节差异(P>0.05),附生生物、孔石莼和底栖微藻的δ13C值有明显的季节变化(P<0.05)。在所有的初级生产者中,仅附生生物的δ15N值有极显著的季节差异,其余种类的季节变化不显著。小型无脊椎动物的δ13C值介于-20.3‰~-15.4‰之间,δ15N值介于2.5‰~8.1‰之间。在所有的小型无脊椎动物中,仅桡足类的δ13C、δ15N值有显著的季节变化(P<0.05),其余的小型无脊椎动物的δ13C、δ15N值都无显著的季节变化(P>0.05)。基于IsoSource模型分析发现,浮游植物和POM等是桡足类、太平洋磷虾和中国毛虾等浮游动物以及海绵的主要食源;钩虾幼体和麦秆虫等啃食性端足类主要以附着微藻为食;大型海藻和底栖微藻是钩虾、紫海胆和角蝾螺等底栖生物的主要能量来源。  相似文献   

5.
研究河口潮间带底栖生境(intertidal benthic habitat)变化,能为河口湿地生物的保护、底栖环境质量的评价、受损生境的生态恢复提供的科学依据和管理建议。本文从关注空间和时间尺度的研究出发,对河口潮间带栖息地监测、分类与评价方面的研究进展进行了归纳总结,分为以下六个方面进行论述:河口潮间带底栖生境的时空新特征、河口潮间带底栖生境特征参数、河口潮间带底栖生境特征获取方式、数据处理、河口潮间带底栖生境分类模型选择、多时空尺度分析。河口潮间带底栖生境特征的分类方式由于考虑生态过程和格局中所涉及的空间生态学问题(边界分割、尺度效应、分类精度、动态变化等),模拟底栖物种及群落分布更为便捷,最终使物种/群落栖息地分类结果更加精确、真实、全面。最后,本文提出利用SIT对河口潮间带底栖生境进行分类将对底栖生态系统评价及研究生态功能机制带来新的视角,同时也需注意一些问题。例如,潮间带生境特征参数需要选择合适的统计方法在不同的尺度上进行甄别和筛选,以期有效提高指示参数在研究尺度上的解释度。  相似文献   

6.
研究高黎贡山南段河流生态系统健康状况,以更好地开展生物多样性与生态系统保护工作。2018年11月,调查了高黎贡山南段6条河流22个样点的物理生境、水质和大型底栖无脊椎动物,采用河流水文指标、形态指标、河岸带指标、水质指标和大型底栖无脊椎动物指标对河流生态系统健康状况进行单因子评价,并基于多项指标构建评价体系进行综合评价。结果显示:研究区域内共采集到大型底栖无脊椎动物95个分类单元、33 725头,稀有种(单个物种数量少于338头)81种、占比85.26%,EPT指数高于5的样点19个、占比86.36%,生物多样性处于较高水平;水质状况整体较好,68.18%的样点水质为Ⅱ类水标准,其余样点水质均为Ⅲ类水标准;栖息地环境质量良好,QHEI平均得分为180.36分;综合评价结果表明研究区域内达到健康等级的样点占比为90.9%,河流生态系统整体处于健康状态,老窝河2个样点处于亚健康状态。人类活动已对少数河段的健康状况造成了影响,主要是农牧业活动、河岸河床硬化、筑坝、取水等。建议对相关河段定期开展河流健康评价,根据评价结果调整河流及河岸带的生产和开发活动,减少非必要的渠道化,针对易受干扰河段建立缓冲区,保护河流水生生物多样性。  相似文献   

7.
首次针对香格里拉保护区水生生态系统状况进行调查.河源到河口共设置16个采样河段,采集到的大型底栖动物共计9目39科(亚科)61种(属),划分为34个不同敏感类群(科或属),并给出不同种类所指示的水质状况.采用香农生物多样性指数(Shannon-Wiener Diversity Index)和MBI生物指标(Macroinvertebrate Biotic Index)对大型底栖无脊椎动物群落进行计算、评价和分类,对岗曲河的水质状况进行快速生物评价.研究表明:除了一些靠近矿山和村庄下游河段,香格里拉保护区水生生态系统生物种类组成丰富、水质状况良好,其调查数据和研究结果是进一步开展保护区水生生态系统研究的基础,也可作为同类型河流生态系统评价的参照.  相似文献   

8.
供水型水库底栖动物完整性指数的构建   总被引:1,自引:0,他引:1  
为给水源地水库的生态风险评估提供科学依据和决策支持,根据浙江省和湖北省几个典型水库的调查数据,构建了底栖动物完整性指数(B-IBI)。参考相关文献及调研选取了32个备选参数,经统计分析筛选出8个指示能力较强的参数,构建B-IBI指标体系,分别为香侬-维纳多样性指数(Shan2)、捕食者类群数量百分比(Pred-Pct)、寡毛类物种数百分比(%OligoTax)、非水生昆虫数量百分比(NonInPct)、Hilsenhoff生物指数(HBI)、收集者物种数百分比(%CllctTax)、收集者数量百分比(CllctPct)和平均物种数量(RichnessPerTaxon)。确立了水库生态系统健康评价标准,并与潜在环境梯度进行了相关性分析。结果表明,该指数很好地反映了潜在环境梯度,用于供水型水库的水生态系统健康评估较为合适。  相似文献   

9.
准确描述北运河流域水生态状况,为北运河流域水生态管理决策提供支持。在北运河流域26个采样点进行采样,对河流栖境打分,采用层次分析法对河流栖境各参数得分进行加权,计算大型底栖动物BMWP值,分析北运河栖境得分与BMWP值相关性。结果表明,加权前栖境得分与BMWP值的Pearson相关系数为0.346,相伴概率为0.086,两者无显著相关性;层次分析法将河流栖境一级指标河道水量状况、河道变化状况、河滨带状况、河堤岸稳定状况分别加权为0.1466、0.1623、0.6040、0.0872,加权后栖境得分与BMWP值的Pearson相关系数为0.413,相伴概率为0.036,两者显著相关。后续研究需要进一步优化一级、二级指标的加权值,以使栖境得分值既可以有效指示不同河段的生物状况,也可以有效反映水生生物栖息地质量。  相似文献   

10.
应用底栖动物完整性指数评价水源地水库溪流健康状态   总被引:2,自引:0,他引:2  
及时了解水源地水库入库溪流的水生态健康状态对保障供水安全十分重要。依据2010-2011年对浙江省水源地汤浦水库的环境和底栖动物观测资料建立了底栖动物完整性指数(B-IBI)。根据Shannon-Wiener指数、百分比模式相似性指数(PMA)和多元统计分析结果对参照条件进行量化并确立参照点群。从60个候选参数中筛选出6个核心参数参与构建B-IBI指标体系,采用四分法进行量纲的统一,以参照点群25%分位值作为水生态系统健康与否的阈值,并对小于25%的分位值分布范围进行2等分,确立了水源地汤浦水库入库溪流健康评价标准:B-IBI>25.50,健康;B-IBI 12.75~25.50,亚健康;B-IBI<12.75,差。B-IBI分值与溶氧水平和pH显著正相关(P<0.05)。  相似文献   

11.
Two techniques for preparing samples of Coryphaena hippurus fish eggs for fatty acid analysis were compared. The first technique involved direct methylation of samples containing either 50 or 100 fresh eggs. The second involved methylation of the solvent-extracted fat from samples containing 1000 eggs each that had either been freeze dried or oven dried. The fatty acid profiles of small samples of fresh eggs were similar to profiles obtained from the solvent-extracted fat of much larger samples of dried eggs. In addition, the fatty acid profiles of 100 fresh egg samples were higher in both saturated and unsaturated fatty acids than the profiles obtained from 100 freeze-dried or oven-dried eggs. The technique of using direct methylation of fresh egg samples without solvent extraction has three main advantages: it requires less preparatory and analytical work, it can be used with much smaller samples, and it is less destructive to the material being analyzed. Direct methylation can also be used to prepare samples of small organisms such as algae, rotifers (Brachionus sp.), and brine shrimp (Artemia sp.) for fatty acid analysis.  相似文献   

12.
Fatty acids of three cultured unicellular algae wldely used in aquaculture ( Isochrysis galbana , clone T-iso, Chaetoceros calcitrans , and Chaetoceros gracilis ) were analyzed in detail by gas-liquid chromatography and mass spectrometry. Fatty acid compositions of the individual species, harvested at monthly intervals during a four month period, showed a very consistent pattern. Shorter chain (C16) fatty acids accounted for more than 70% of total fatty acids in the diatoms but less than 20% in I. galbana . Medium chain (C18) and the long chain 22:6w3 unsaturated fatty acids represented more than 50% of the total fatty acids in I. galbana but less than 10% of the total In the Chaetoceros spp. However, in the latter, 20:5w3 replaced 22:6w3 at an equivalent level. Fatty acid profiles of c. calcitrans and c. gracilis were similar, except that the latter contained lower levels of 16:2w4, 16:3w4 and 16:4w1, and higher levels of 18:2w6 and 18:3w6. In particular C. gracilis contained a higher proportion of the biochemically important fatty acid 20:4w6 (arachldonic acid). One of the salient features of I. galbana lipids was the presence of the fatty acid 18:5w3. This fatty acid is not generally reported in algae or invertebrate lipid analyses, but is a typical component of I. galbana and of other marine photosynthetic flagellates. Its potential for utilization by aquatic organisms is unknown.  相似文献   

13.
茎柔鱼(Dosidicus gigas)是一种广泛分布在东太平洋的大洋性头足类,具有重要的经济价值。本研究以捕获自3个作业海区的茎柔鱼为研究对象,对其肌肉脂肪酸含量进行测定、分析和比较。结果显示,各海区茎柔鱼肌肉脂肪酸种类和组成存在显著差异。秘鲁外海样品所含脂肪酸种类最多(共28种),中东太平洋赤道海域样品含有脂肪酸27种,而智利外海样品所含脂肪酸种类最少,只检测出24种。脂肪酸均以多不饱和脂肪酸为主(59.68%~69.28%),其次是饱和脂肪酸(20.71%~27.28%)和单不饱和脂肪酸(10.01%~13.04%)。各海区茎柔鱼肌肉中C16:0、C18:0、C20:1n9、C18:2n6、EPA和DHA含量较高,均占脂肪酸总含量的81%以上。脂肪酸组成的空间异质性主要是由各海区C16:0、C18:2n6、C20:4n6和DHA的含量不同造成的,这种差异可能与各海区海洋环境、食物来源和个体能量需求的差别有关。本研究说明了脂肪酸分析在茎柔鱼食性研究中的潜在作用,对分析不同海区茎柔鱼营养成分和资源合理利用有一定的应用价值。  相似文献   

14.
SUMMARY: When long-chain saturated and unsaturated fatty acids were incubated with crude enzyme of marine green alga Ulva pertusa , the corresponding ( R )-2-hydroperoxy acids were found to have high enantiomeric excess (> 99%). In a similar administration experiment, the ( R )-2-hydroperoxy acid was obtained from the incubation of palmitic acid with crude enzymes of a variety of marine algae. Thus, we found that not only green algae but also brown and red algae are capable of enantioselective 2-hydroperoxylation of palmitic acid.  相似文献   

15.
This study examined the effects of storage time on the fatty acid composition of freshwater Selenastrum capricornutum algal paste under 4 C refrigeration, the fatty acid composition of rotifers fed the fresh and stored algal paste, and the toxicological properties of the algal paste. Microalgae were produced in a hydraulically integrated serial turbidostat algal reactor (HIS-TAR), harvested as a paste, refrigerated and analyzed every 2 wk. Fresh Selenastrum capricornutum paste had almost three times greater concentration of unsaturated fatty acids than saturated fatty acids. Over 50% of the unsaturated fatty acids were made up of n-3 and n-6 fatty acids. Total unsaturated, n-3 group and n-6 group fatty acids decreased ( P 0.05) during storage, including the nutritionally important fatty acids (C20:4n6, C20:5n3, C22: 6n3). Rotifers fed 2– and 4-wk-old algal paste had a significantly lower ( P 0.05) total unsaturated fatty acid percentage and significantly greater ( P 0.05) total saturated fatty acids than those fed fresh algae. There were no significant changes in the n-6 group fatty acid level in the 4-wk-old paste feeding study or for the n-3 or n-6 groups in the 2-wk-old paste feeding study as compared to fresh algae. The levels of the three nutritionally important fatty acids (C20:4n6, C20:5n3, C22:6n3) did not differ between rotifers fed fresh and stored algae. Stored algae did not present toxicity to rotifers and Daphnia at the normal feeding concentration. These results indicated that the use of refrigerated freshwater algal paste for production of rotifers results in live feed with adequate nutritional properties for marine larviculture. This could eliminate the costs associated with production of marine algae, which could be replaced with freshwater algae, and may provide an alternative to cryopreservation.  相似文献   

16.
Three different groups of cod larvae Gadus morhua L ., feeding on natural plankton in two large enclosures, were analyzed for fatty acid composition through development. Unfed control groups and different size-fractions of plankton were also analyzed. Consistency in changes of fatty acid composition suggests three developmental periods during early larval development. The periods corresponded with dietary shifts in the larvae, but a metabolic origin for changes in certain fatty acids was also evident. In the first period, relative amounts of n-9 monounsaturates decreased, while n-3 polyunsaturates together with certain fatty acids abundant in the small-sized phytoplankton fraction increased. In the second and third periods, relative amounts of the longer n-3 PUFA decreased, while fatty acids of calanoid copepod origin occurred in one group. The consistency in changes of larval fatty acid profiles in cod suggests development in both lipid absorption and lipid metabolism during ontogenesis.  相似文献   

17.
研究了低温烘干、真空冻干和微波干燥3种干燥方式对蛋白核小球藻粗脂肪、脂肪酸含量和种类组成的影响及不同保存条件下脂肪酸的变化规律。试验结果表明,低温烘干藻粉的粗脂肪含量明显低于真空冻干藻粉和微波干燥藻粉。3种干燥方式对小球藻脂肪酸含量无显著影响,但藻粉颜色明显不同。藻粉脂肪酸含量与鲜藻之间无显著差异。在小球藻粉保存过程中,脂肪酸种类组成保持不变。藻粉在常温(14.5~18.5℃)下保存半年、4℃下保存1年时,多不饱和脂肪酸含量显著减少,饱和脂肪酸和单不饱和脂肪酸含量显著增加。在-24℃下保存1年时,各脂肪酸含量无明显变化。  相似文献   

18.
  • 1. Rapid assessment protocols for determining and monitoring the status of any given coral reef are provided and include measuring: (a) standing stocks of functional indicator groups, (b) herbivore populations, (c) water‐column nutrient levels, (d) tissue C:N:P ratios, (e) algal physiological‐response assays, and (f) herbivory assays. These measurements can reveal quantitative tipping‐point levels beyond which resilience to undesirable phase shifts begins to become critically reduced. Universal tipping‐point approximations are reviewed for inorganic nutrients, and posited for the first time for herbivory.
  • 2. The relative roles of top‐down and bottom‐up controls in determining benthic community structure and the health of coral reefs are especially important management concerns. This paper specifically addresses the top‐down effects of herbivory and bottom‐up effects of nutrient enrichment on critical indicator groups, i.e. reef‐building corals, crustose coralline algae, dense turf algae and frondose macroalgae.
  • 3. A predominance of (a) massive corals and calcareous coralline algae relative to frondose macroalgae and algal turfs indicates a healthy spatially heterogeneous condition reflecting low nutrients and high herbivory. An abundance of (b) frondose macroalgae illustrates the least desirable condition of elevated nutrient levels and reduced herbivory, possibly reflecting pollution in concert with destructive herbivore fishing practices. High coverage of (c) coralline algae suggests healthy high herbivory levels, but problems with elevated nutrients that are inhibitory to some corals. Domination by (d) dense turf algae indicates desirably low nutrient levels, but an inadequate herbivory component.
  • 4. The fast growth and turnover rates of fleshy algae compared to other reef organisms highlight their value as early warning indicators of reef degradation.
  • 5. From a management perspective, levels of herbivory and nutrients rank among the most useful quantitative indicators of coral reef resilience; whereas, the degree of degradation and mortality are inferred from the above functional indicator groups of benthic primary producers.
Published in 2006 by John Wiley & Sons, Ltd.  相似文献   

19.
贝类壳色常呈现出多态性,壳色可以作为优良性状的标记色,用于贝类良种选育研究。为了探究青蛤壳色性状与其生长和营养成分之间的关系,本研究对青蛤不同壳色个体的生长指标及营养组分进行了测定分析。结果显示,青蛤紫壳个体(整体)的湿重、壳长、水管和鳃组织湿重占比显著高于白壳个体(p<0.05),青蛤紫壳个体(整体)的壳宽和外套膜组织湿重占比极显著高于白壳个体(p<0.01)。青蛤紫壳个体可食部分的粗脂肪和粗蛋白含量极显著高于白壳个体(p<0.01)。紫/白壳个体的必需氨基酸与总氨基酸比值分别为37.46%和37.02%,且紫壳个体显著高于白壳个体(p<0.05);必需氨基酸与非必需氨基酸比值分别为67.72%和66.60%,且紫壳个体显著高于白壳个体(p<0.05),表明紫壳个体氨基酸平衡效果优于白壳个体,且均属于优质蛋白。紫/白壳个体的单不饱和脂肪酸主要以棕榈酸为主,分别占可食部分脂肪酸总量的9.97%和9.85%,多不饱和脂肪酸主要以EPA和DHA为主,其中EPA分别占脂肪酸总量的6.64%和6.54%,DHA分别占脂肪酸总量的8.00%和8.51%。研究表明,紫/白壳个体间在生长和营养上均存在一定差异,且紫壳性状与其生长和营养存在一定正向关联关系,为利用紫壳性状作为遗传标记进行青蛤良种选育提供理论依据。  相似文献   

20.
大型水库实施生态调度是修复河流水文情势、维持河流生态系统健康的重要手段。江垭水库位于溇水干流下游的张家界慈利县,是澧水流域具有重要防洪意义的大型水库。本研究通过环境DNA采样、IHA水文指标变动分析和文献资料总结等方法,开展了江垭坝下水文情势及鱼类繁殖需求的关系研究,提出了江垭水库生态调度需求及建议。2021年9月在溇水干支流综合调查到鱼类55种,与上世纪90年代相比,流水性种类在干流江段显著减少了51.35%;按照生态调度优先等级评估原则,确定江垭水库生态调度的主要目标物种为产漂流性卵的银鲴、银鮈、贝氏?和产粘沉性卵的鲤、鲫;江垭建坝前后下游水文情势变化较大,发生高度改变且对鱼类洄游产卵及鱼卵发育有重要作用的水文指标包括:年最大1日、3日平均流量指标,年出现高流量脉冲事件的次数和持续时间,以及连续日流量上涨率。以促进坝下不同产卵类型的鱼类繁殖为目标,江垭水库生态调度一方面需要恢复一定的高流量脉冲次数和历时,另一方面需要控制下游的水位日降幅,通过泄放合理的生态流量来维持下游鱼类的生物多样性。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号