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1.
为了查清铜藻空间分布格局与影响因子之间的关系,采用水下采样方法对不同生境条件下铜藻分布和生长情况进行了调查,并从大小两个尺度(站点间和站点内)分析了铜藻空间分布与影响因子之间的关系。结果发现,在站点尺度上,铜藻多集中分布于隐蔽的内湾处,分布密度和株高显著高于暴波站点(P<0.05),暴波站点的波浪和水流运动大小以及浊度显著高于隐蔽站点(P<0.05),说明暴波强度是影响铜藻水平分布和生长的主要因子之一;在站点内,铜藻垂直分布特征明显,潮间带低潮区铜藻分布密度和株高显著高于潮下带(P<0.05),且分布在潮间带低潮区的藻苗平均株高最高;铜藻分布密度和株高与附着基粗糙度、坡度、坡向表现出一定的相关性,但经相关性分析表明,水深与铜藻分布密度最相关(r=-0.337,P=0.001),粗糙度次之(r=0.175,P=0.092),与坡度和坡向相关性不高,说明了与水深相关的光照条件可能是影响铜藻垂直分布和生长的另一个主要因子。研究表明,附着基物理特征不是影响铜藻分布的主导因子,由波浪和水流运动引起的沉积物再悬浮影响到铜藻所需的光照条件,进而影响到铜藻的分布与生长,以此推断出沉积物可能是影响铜藻空间分布格局的主导因子。  相似文献   

2.
研究了不同质量浓度锰离子、铜离子、锌离子和铁离子对抑食金球藻细胞密度、相对生长率和叶绿素含量的影响,试验结果表明,当锰离子、铜离子和铁离子质量浓度分别为0~25μg/L、0~5μg/L和0~12 500μg/L时,抑食金球藻的细胞密度、相对生长率和叶绿素含量均随质量浓度的升高而增加,随着3种重金属离子质量浓度的继续升高,抑食金球藻生长受到不同程度的抑制。不同质量浓度锌离子对抑食金球藻生长均产生抑制作用。选取锰离子、铜离子和铁离子进行正交试验,分析其综合效应。试验结果显示,3种重金属离子对抑食金球藻细胞密度影响程度为铁铜锰。对抑食金球藻细胞密度影响最大的组合为62 500μg/L铁离子、1μg/L铜离子和5μg/L锰离子,但铜离子和锰离子所对应的细胞密度的■值间差异不显著(P0.05)。分析抑食金球藻细胞密度、相对生长率和叶绿素含量与3种重金属离子吸收量的相关性得出,铁离子与上述参数均呈极显著正相关(P0.01),相关系数分别为0.745、0.577和0.870;铜离子和锰离子吸收量与上述3个参数相关性均不显著(P0.05)。因此,铁离子是影响抑食金球藻生长最大的因素。  相似文献   

3.
设置氮质量浓度和硅质量浓度双因子试验,探讨其对三角褐指藻生长的影响及对藻细胞增殖的交互作用,结果发现,氮质量浓度对三角褐指藻生长有极显著的影响.不论是在低硅质量浓度,还是高硅质量浓度下,与高氮处理相比较,缺氰处理下藻细胞不能存活,低氮处理下藻细胞生长受严重抑制.试验结束时,低硅质量浓度下缺氮、低氮和高氮处理的藻细胞密度分别为0、5.0×105个/mL和7.37×106个/mL.硅质量浓度同样对三角褐指藻的细胞密度产生显著性影响,高硅质量浓度下的藻细胞密度显著高于低硅质量浓度下的藻细胞密度.双因素方差分析结果表明,试验前期,氮和硅对三角褐指藻细胞密度的交互作用不明显(P>0.05);但试验后期,氮和硅对三角褐指藻细胞密度有显著性的交互作用(P<0.05).  相似文献   

4.
2006年9月与2007年7月对浙江中街山列岛岩相潮间带底栖海藻进行了调查,初步查明底栖海藻的种类组成、分布特征和温度属性。结果表明,采集到的34种海藻隶属于3门24属,其中褐藻门3属3种,绿藻门4属5种,红藻门17属26种。在波浪和潮汐作用下,潮间带出现局限分布种和选择性分布种,鼠尾藻(Sargas-sum thunbergii)、珊瑚藻(Corallina officinalis)和石莼(Ulva lactuca)等在调查的岛礁广有分布;红藻门种类在调查海域的出现频率为67.8%,为优势门类,褐藻门种类在该海域的总体水平分布基本呈均匀状态;91.2%的调查种类分布在低潮带,种类数垂直分布均为低潮带〉中潮带〉高潮带,具有明显的垂直分带现象,且温度属性以亚热带区系种类占绝对优势。  相似文献   

5.
补充CO2对光生物反应器培养新月菱形藻的影响   总被引:1,自引:0,他引:1       下载免费PDF全文
为了优化光生物反应器培养微藻的条件,研究了在充空气的基础补充CO2对光生物反应器培养新月菱形藻(Nitzschiaceae closterium)生长和光合作用的影响.实验表明,补充CO2(含1 000μL/L CO2的空气)促进新月菱形藻的生长,藻细胞密度和生物量显著高于对照组(CO2含量350μL/L)(P<0.05).补充CO2也能够提高藻细胞叶绿素a和类胡萝卜素的含量(P<0.05),但是对叶绿素b没有显著影响(P>0.05).补充CO2能够显著提高指数生长期的最大光合速率(Pm)、光合作用效率(α)和光合作用饱和光强(Ik)(P<0.05).结果表明,CO2是光生物反应器培养微藻的限制因子之一,补充CO2能够提高微藻的生物量.  相似文献   

6.
温度、光照度、盐度和pH对颤藻生长的限制条件研究   总被引:1,自引:0,他引:1  
颤藻(Oscillatoria sp.)是对虾养殖池塘中的常见蓝藻,其大量繁殖直接危害对虾养殖.实验旨在通过研究不同温度、光照度、盐度和pH对颤藻生长的影响,得出颤藻生长的限制条件.单因子实验结果显示:实验条件范围内,温度、光照度、盐度和pH对颤藻叶绿素a含量和干重影响显著(P<0.05),温度<10℃和>30℃、光照度<50 lx和>1100 lx、盐度<15和>30、pH <5.2和>8.0是颤藻生长的限制条件;颤藻生长的阈值为温度10℃,光照度50 lx,盐度15.0,pH5.2;正交实验结果显示,颤藻生长的最低条件为温度15℃、光照度600 lx、盐度17.5、pH 5.5,温度对颤藻叶绿素a含量和干重影响最大,其次是盐度和pH.对虾养殖池可以通过调节盐度来控制颤藻生长.  相似文献   

7.
研究了水深、底质、密度和饲料原料对刺参(Apostichopus japonicus)稚幼参生长和存活率的影响,以期明确最适的养殖条件.水深试验在野外海区进行,试验网箱用锚与重物固定于海底,其它试验在室内玻璃钢水槽或塑料桶中进行.结果表明:体质量(2.13±0.12)g刺参在5 m和10 m水深的体质量(Wt)和特定生长率(SGR)显著大于20 m水深(P<0.05),(6.19±0.24)g刺参在20 m的Wt显著大于其它深度(P<0.05),(9.49±0.09)g刺参在各水深的生长差异及同规格刺参在不同水深存活率的差异均不显著(P>0.05).砾岩、沙质和泥质底刺参Wt和SGR显著小于沙泥和泥沙底(P<0.05).(1.73±0.03)g、(0.40±0.07)g和(0.13±0.02)g刺参低密度下的生长状况优于较高密度.(1.53±0.08)g和(0.68±0.05)g刺参摄食孔石莼饲料组的Wt与SGR同摄食鼠尾藻组和海蒿子组之间差异不显著(P>0.05).  相似文献   

8.
中国蛤蜊隶属于软体动物们、瓣鳃纲、帘蛤目、蛤蜊科、蛤蜊属,栖息于潮流畅通、饵料丰富的近河口区潮间带的中、低潮区,在沙质滩涂中营埋栖生活,埋栖深度1~3厘米,栖息水深以2~5米分布最多,水深60米处也有发现。中国蛤蜊在我国主要分布于山东、辽宁沿海,在日本、朝鲜也有分布。中国蛤蜊具有对环境适应性强、生长速度快、养殖  相似文献   

9.
海藻场是近岸海洋生态系统的重要组成部分,发挥着海洋生物资源保育,净化海洋水体环境,进行大气二氧化碳碳汇等生态作用。为了恢复这种珍贵的海洋栖息地资源,以及通过研究其自然种群群落特征的分布特点,来指导河北省海藻场修复与重建的相关工作,笔者研究了浙江省枸杞岛海域的底栖海藻群落结构、底栖海藻生物量及其变化规律。在浙江省枸杞岛选择海藻场3个潮间带、潮下带的调查点,在选取100cm×100cm的样方后,估算出覆盖度。潮下带调查是潜水员潜于水下采样,测量海藻场外缘到岸边的距离。同时,我们在海藻场内外取了两处站点的水样,测量海水中营养盐的浓度,包括三氮、活性磷酸盐、活性硅酸盐。调查结果显示,铜藻生物量占到总生物量的93.9%,为优势种。5月份铜藻样本平均长度为80cm,6月份的平均长度为75cm。潮间带区域底栖海藻从4月份开始旺盛生长,在5月份达到最高,6月份气温升高藻体开始腐烂,慢慢进入衰退期。氨氮浓度对于铜藻生长具有重要影响。  相似文献   

10.
根据2011年5-7月对秦皇岛附近海域夜光藻及相关环境因子的调查结果,采用灰关联度分析方法,以各调查站位夜光藻的密度(ind/L)X0={x0(k)︱k=1,2…,24}为参考序列,以溶解无机氮DIN(NO2-N、NH4-N、NO3-N)、磷酸盐(PO4-P)、硅酸盐(SiO2-Si)、叶绿素(Chl-a)、COD、BOD5、石油烃、水温、盐度、透明度、pH、浮游植物丰度、浮游植物密度等Xi={xi(k|k=1,2…,24;i=1,2…,16)}为比较序列,对秦皇岛近岸海域理化因子和夜光藻密度的相关性进行了分析。结果表明,5-7月期间,秦皇岛近岸海域浮游植物分布密度、COD和海水温度是影响夜光藻种群数量变动的主要因子,这些环境因子在监测和预报秦皇岛海域夜光藻赤潮时应作为主要指标予以关注。  相似文献   

11.
12.
Anguilla luzonensis and A. huangi were each described in 2009 using eels obtained from northern Luzon Island. We examined the taxonomic status of these two groups of eels using morphological and molecular genetic characters. There were no significant differences in two vertebrae counts between eels of A. luzonensis and A. huangi. Mitochondrial 16S ribosomal RNA and cytochrome b genes sequences were obtained and compared among 28 specimens of A. luzonensis, the holotypes of A. luzonensis and A. huangi, and one specimen of the other 15 anguillid species. The specimens of A. luzonensis exhibited almost identical sequences, including the holotype, with only a few site differences, and the genetic difference between the holotypes of A. luzonensis and A. huangi was within the range of differences of specimens of A. luzonensis. The other anguillid species were genetically very different from A. luzonensis and A. huangi, although A. interioris is a closely related species. It is clear that A. luzonensis and A. huangi are the same species, and according to the principle of priority in zoological nomenclature, A. luzonensis Watanabe, Aoyama, and Tsukamoto, 2009 is the valid species name, and A. huangi Teng, Lin, and Tzeng, 2009 is a junior synonym of A. luzonensis.  相似文献   

13.
The effects of exposing the eggs of Pacific threadfin and amberjack eggs (AEs) to different concentrations of hydrogen peroxide for 5 min on hatch rate and survival were assessed in a series of experiments using a petri dish model rearing system. Despite significant inter‐batch variation in hatch rate, it was shown that eggs of both species could be safely exposed to up to 11 340 mg L−1 H2O2 for 5 min. Exposure to 34 230 mg L−1 H2O2 for 5 min was shown to be lethal to AEs at a late stage of development. In two further experiments, it was demonstrated that Pacific threadfin eggs were resistant to all tested concentrations of a range of polyvinylpyrrolidone iodine (PVP‐I) concentrations and contact times (up to 1000 mg L−1 PVP‐I for 10 min). The level of bacteria adhering to the eggs of both species was highly variable. Where eggs were heavily colonized (>104 cfu egg−1), hydrogen peroxide concentrations of at least 11 340 mg L−1, or PVP‐I concentrations higher than 500 mg L−1 for 10 min, were required for effective sterilization. In less colonized batches, rinsing in sterile seawater or exposure to lower (550 mg L−1) concentrations of H2O2 was sufficient to result in high apparent levels of surface sterility (<1 cfu egg−1).  相似文献   

14.
Mulloway (Argyrosomus japonicus) occur in estuarine and coastal waters surrounding Australia, Africa, India, Pakistan, China, Korea and Japan, where they are important in fisheries. This study identified that mulloway in south-eastern Australia had similar growth rates, but matured at smaller lengths and younger ages, to those in South Africa and Western Australia. Growth of both sexes was similar to about 5 years, after which females grew faster and attained a greater maximum length than males. Female mulloway matured at 4–5 years of age with a L50 of 68 cm, whereas males matured at 2–3 years of age with a L50 of 51 cm. The commercial fishery in New South Wales was characterised by declining catches and a reduction in the proportion of mulloway of mature lengths in landings. During 2002–2005 commercial landings were dominated (83%) by fish within 15 cm of the current minimum legal total length of 45 cm and aged 2 and 3 years (>80%), even though mulloway can attain lengths of 200 cm and live >30 years. Estimates of the rates of instantaneous total mortality ranged between 0.34 and 0.45, whilst the rate of instantaneous natural mortality (M) was estimated to be approximately 0.12. Yield-per-recruit analyses indicated that mulloway in New South Wales are being growth overfished and substantial increases in yield could be achieved by increasing the length at first harvest. Values of the spawning potential ratio were below 0.2 under a range of mortality estimates, suggesting that mulloway are at risk of recruitment overfishing. These results suggest that the spawning stock of mulloway in south-eastern Australia has been depleted and that remedial management action is required to protect this iconic species.  相似文献   

15.
对驼背鲈(Chromileptes altivelis)的胚胎发育及仔、稚、幼鱼的形态特征进行了详细的观察与研究,描述了从受精卵到仔、稚、幼鱼各发育期的时间和形态特征变化。结果表明,在水温25-26℃、盐度30的海水中,受精卵历时27 h 25 min完成整个胚胎发育过程,经历从卵裂、囊胚、原肠、神经胚到肌节形成、各器官的逐渐形成、变化、完善等一系列的胚胎发育和变化过程;根据其卵黄囊消长情况、鳞片的覆盖状态、体色发生的不同变化以及第二背鳍和腹鳍的消长,将胚后发育分为仔、稚、幼鱼3个阶段。在水温22-26℃、盐度29-31、DO≥5 mg/L的条件下,2-3 d仔鱼卵黄囊消失,开口摄食;生长发育至31 d,仔鱼已变态进入稚鱼期;培育至57 d,稚鱼完成变态,成为幼鱼。第二背鳍棘和腹鳍棘的生长与收缩等石斑鱼类早期发育的共性生长特征及其体表特性体色变化特征为驼背鲈胚后发育过程中最明显的特征。  相似文献   

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Adult common bullies, Gobiomorphus cotidianus McDowall, are small (total length =  30–120 mm), benthic fish commonly found in the littoral zones of New Zealand lakes where they are a major prey species for trout and eels. Differences in their relative abundance (CPUE) were determined between 21 shallow North Island lakes. Mean CPUE ranged from 2 to >  1000 fish net− 1 night− 1 and was inversely related to water transparency. The abundance of bullies was not reduced in lakes containing rainbow trout, Oncorhynchus mykiss (Walbaum), but was reduced in all lakes containing self-recruiting populations of eels, Anguilla spp. Mean densities of planktonic larval bullies in the limnetic zone were also inversely related to water transparency. Since low water transparency is related to increased trophic status for these lakes, the abundance of bullies is likely to be related to lake productivity, rather than turbidity.  相似文献   

18.
Mosquitofish, Gambusia sp., have been spread throughout the world to biologically control mosquitoes. However, the fish has gained a reputation as an invasive species and has been implicated in displacing native aquatic species. Gambusia affinis are native to the southeastern United States and commonly occur in commercial channel catfish, Ictalurus punctatus, production ponds. We investigated effects of mosquitofish presence on zooplankton populations, water quality, disease occurrence, and fish production in experimental ponds. There were no differences between ponds with or without mosquitofish in numbers of calanoid copepods, cyclopoid copepods, total copepods, Bosmina sp., Ceriodaphnia sp., Moina sp., Daphnia sp., or total cladocerans. There were also no differences in copepod and cladoceran sizes. Copepod nauplii were more numerous during the summer months in ponds with mosquitofish. There were no differences in water quality variables (soluble reactive phosphorus, nitrate, nitrite, ammonia, total nitrogen, total phosphorus, pH) or phytoplankton density between ponds stocked with and without mosquitofish. Catfish production and disease occurrence were also similar between ponds with and without mosquitofish. Although mosquitofish may cause problems when stocked outside their native range, there does not appear to be any adverse effects of mosquitofish presence in catfish production ponds.  相似文献   

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  1. In the last two decades, Brazil has advanced significantly with the expansion and improvement of its national system of protected areas. Until recently most of the expansion was concentrated in the Amazon region (with useful lessons). It also had an uneven ecological representation of coastal and marine ecosystems, concentrated in coastal waters. Despite significant advances, the levels of funding, staff and stakeholders' engagement remain relatively low for such a vast system.
  2. Within the past few years, key elements of a new strategy for protection of coastal and marine areas have started to emerge, combined with some participatory processes and a focus on expansion of the total area protected (from <1.5% protection of the country's marine area). These included: a renewed focus on priority areas for conservation; attention to national and international commitments and targets; clarity about the need for partnerships and funding; better engagement of Brazilian society and stakeholders; new, and more collaborative, models of protected areas management and conservation; and openness in the relationships with wider society.
  3. Significant results of this effort have started to appear: new large mosaics of oceanic protected areas were created; Amazon mangroves were recognized by the Ramsar Convention; new mangrove protected areas were created, besides other ones proposed; project proposals are under development with partners for better funding and sharing of responsibility; and there is a better engagement with stakeholders. The building of the Brazilian Blue Initiative is underway.
  4. The implementation of the proposed 15‐year marine strategy is at its onset: partnerships need to be strengthened and substantial funding is required. It will only be possible to manage the larger system of protected areas if there are more collaborative and innovative models for protected areas and conservation management. These should include partnerships with civil society, local and traditional communities and the private sector, as well as greater engagement of scientists and research institutions, stronger and more qualified tourism, volunteer work, etc. Further innovative funding mechanisms will also be needed along the way.
  相似文献   

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