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1.
硫化物胁迫对海草影响的研究进展 总被引：1，自引：1，他引：0
硫酸盐的还原作用是沿海海洋沉积物中有机质厌氧矿化的主要终点过程,该过程会生产有毒的硫化物。迄今为止,在所研究的大多数海草中都发现了硫化物侵入植株组织内部的现象,而且在温带和热带区域已经发生过多起因为草床沉积物中硫化物浓度过高而导致海草大面积死亡的事件。本文综述了近三十年来硫化物胁迫对海草影响的相关研究工作,主要内容包括以下四方面：（1）硫化物对海草产生胁迫的环境条件主要有缺氧、缺铁、有机质富集以及高盐;（2）硫化物侵入海草组织的途径是由根部吸收进而转移到地下茎和叶片中,而随着时间的推移,硫化物在海草组织中最终主要以单质硫、硫酸盐以及有机硫的形式存在;（3）硫化物对海草的危害主要是通过直接破坏海草的分生组织并进一步抑制海草的光合作用发生的,对海草的生长带来严重的负面影响;（4）不同海草物种受硫化物的侵入情况不同,主要与海草物种的形态学和内部结构差异有关。最后提出三方面的展望,包括硫化物胁迫下海草组织、细胞层面的深入研究,分子应答机制的研究以及有效的海草床修复手段的探索。本文有助于全面了解海草与硫化物胁迫之间的关系,并为将来开展更深入的研究提供参考。 相似文献
2.
海草床是海岸带最富生产力的生态系统之一,支撑着各种各样的伴生生物。热带的印度和太平洋地区被认为拥有海草植物种类多样性最高,且分布面积最广,然而,这个区域的海草床大型底栖生物我们知之甚少。为了填补认知的空白,我们在该区域开展了一项生态调查,旨在描述该区热带海草床大型底栖生物的丰度和多样性,以及确定大型底栖生物丰度、物种丰富度和群落结构是否明显存在断面内的站间变化和样地间变化。2014年5月和2015年10月我们分别在北苏拉威西省东海岸和西海岸开展野外工作,使用柱状取样器采集海草床大型底栖生物样品。所得样品共计鉴定14大类149种底栖生物,种类最为丰富的类别为多毛类（56种,占26%的总个体数）,十足类（20种,占9%的总个体数）和端足类（18种,占35%的总个体数）。东、西海岸海草床大型底栖生物表现出不同的空间分布模式。在东海岸,同一断面的大型底栖生物和端足类的丰度存在显著的站间差异;而在西海岸,大型底栖生物和多毛类的种类丰富度和丰度都表现出明显的站间变化,这可能归结于同一断面底质不均所造成。单因素ANOSIM以及MDS排序表明了北苏拉威西省东海岸和西海岸海草床大型底栖生物群落结构存在显著不同,正好对应于将海草床分成两大类型的栖息地,即西海岸的红树林-海草床-珊瑚连续体和东海岸的海草床-珊瑚连续体。与在热带海区开展的其他研究相比,本研究的大型底栖生物丰度和多样性处于中等水平。东、西海岸海草床大型底栖生物群落存在显著区别,其原因可能源于多方面,包括了沉积物模式,海草床结构和时间变化。 相似文献
3.
海草床是三大典型的近海海洋生态系统之一,具有极高的生态服务功能。然而,截至2015年我国近海海草资源分布现状尚不明晰,严重制约了我国海草床保护与修复工作的开展。2015～2021年,笔者通过实地调查,借助船只走航、声呐探测、遥感等技术手段,重点对我国近海海草资源的分布面积、种类及主要威胁进行了全面普查,并据此提出我国海草床管理与可持续利用对策。结果表明,我国近海海域海草床面积共为26 495.69hm2,可划分为:温带海域海草分布区和热带-亚热带海域海草分布区;我国现有海草4科9属16种。其中,温带海域海草床面积为17 095.01 hm2,主要分布在辽宁、河北、天津和山东沿海,分布有2科3属5种,以鳗草(Zosteramarina)和日本鳗草(Z.japonica)为优势种,其中唐山乐亭-曹妃甸海草床面积达9 025.56 hm2,是我国面积最大的海草床;热带-亚热带海域海草床面积为9 400.68 hm2,主要分布在福建、广东、广西和海南沿海,分布有4科8属12种,以泰来草(Thalassia hemprichii)、海菖蒲(Enhalus acoroides... 相似文献
4.
文章以海南岛新村湾、黎安港和潭门港海草床为研究区域, 选取褐篮子鱼(Siganus fuscessens)、点斑篮子鱼(Siganus guttatus)、四带牙鯻(Pelates quadrilineatus)和细鳞鯻(Terapon jarbua) 4种代表性鱼类为研究对象, 分析其体长与体质量的关系, 并探讨4种鱼类对海草资源量变化的响应。结果表明, 除栖息于潭门港海草床的4种鱼为负异速生长, 其他区域海草床的鱼类均为正异速或等速生长; 4种鱼的体质量生长速率(即异速生长因子b)和肥满度呈现黎安港>新村湾>潭门港的趋势, 并与3个海草床的海草覆盖率、密度和生物量的变化趋势一致; 推测海草资源量下降可能增加鱼类的被捕食压力和减少食物来源, 从而导致生活于海草床的代表性鱼类生长速率下降。 相似文献
5.
海草床是近岸重要的“蓝碳”生态系统,有机负荷升高导致的硫化物胁迫是海草床衰退的重要诱因;外源铁(Fe)的添加可有效改善高有机负荷沉积物中海草的生存状态。本研究在日光温室内,通过向两种不同类型(钙质和硅质)沉积物中添加淀粉(5 g/kg)模拟海草床高有机负荷,同时添加不同量的Fe(II)(0.00、0.05、0.15、0.50 g/kg),探究了泰来草(Thalassia hemprichii)叶片光合色素(Chl a、Chl b、Cx)含量、叶绿素荧光参数(Fm、Fv/Fm、Fv/F0、ΦPSII、ETR)及抗氧化酶(POD、SOD、CAT)活性对Fe添加的响应特点。结果表明,培养过程(30 d)中,两种类型的沉积物中外源Fe添加均能有效提升泰来草叶片光合色素含量、叶绿素荧光参数水平和抗氧化酶活性,且当Fe(Ⅱ)添加量为0.50 g/kg时效果最优。Fe添加量对间隙水Fe2+浓度、S2-浓度、泰来草叶片光合色素含... 相似文献
6.
海草具有独特的进化地位和重要的生态价值,广泛分布于潮间带和潮下带浅海海域,易遭受多种环境因子变化的威胁,抗氧化系统在海草抵御逆境胁迫的过程中具有非常重要的作用。本文综述了海草抗氧化系统的组成、特征及其对主要逆境胁迫的响应特征研究进展,阐述了海草主要酶促抗氧化机制,并将北半球代表性海草物种——鳗草抗氧化系统相关酶基因归类分析。目前对于海草逆境胁迫的研究主要集中于单一胁迫下主要抗氧化酶(如SOD、CAT、GST)及其转录组的变化,对于多胁迫因子协同作用和非酶抗氧化物及其他抗氧化酶的响应特征研究较少;另外对于逆境胁迫下不同海草种类间抗氧化系统和关键基因的响应差异也有待深入研究。 相似文献
7.
海草床具有重要的生态系统服务功能,可以为海洋生物提供栖息地和食物来源,同时还具有重要的碳储存功能,海草床“蓝碳”功能日益受到学术界的重视,据研究全球每年海草床的碳埋藏量高达(2.7~4.4)×107 MgC。近年来,由于人类活动的影响,世界范围内海草床衰退严重,导致海草床沉积物有机碳储量降低。本文综述了全球海草床沉积物有机碳的来源、组分、储量以及指示作用;从物理、化学和生物三方面讨论了影响海草床碳储量的环境因素。最后提出了未来主要研究方向,主要包括加强海草床碳通量普查,分析全球气候变化背景下海草床沉积物有机碳的变化机制,明确海草床碳储量流失速率,研究海岸带工程对海草床沉积物有机碳的影响。评估海草床沉积物有机碳储量及变化机制可以为全球海洋蓝碳研究提供科学依据。 相似文献
8.
海草是一类生长于海洋环境中的单子叶植物。细菌、真菌、微藻、古生菌和病毒等微生物栖息在海草器官及其周围环境中,对海草生长、营养和健康以及海草床物质循环起着重要作用。本文通过分析与总结国内外参考文献,简要介绍了海草床微生物的一些新的研究进展,并讨论了将来可能进行的研究方向。海草微生物组与沉积物和海水中的微生物群落存在较大差异,其分布在离散且高度异质性的生态位,且该模式在广泛的地理尺度上保持不变,不是受海草种类和沉积物类型控制,而是主要取决于环境驱动与海草代谢。大部分海草核心微生物群落都参与硫循环。今后可采用模拟实验、生态模型、基因组、宏基因组、转录组与代谢组等技术方法研究海草床微生物的多样性、组成、功能、定植与病害等。此外,揭示海草床中微生物、海草和环境之间的相互关系,对保护受威胁的海草床具有重要意义。 相似文献
9.
10.
《海洋学报》2021,(4)
海草是一类生长于海洋环境中的单子叶植物。细菌、真菌、微藻、古生菌和病毒等微生物栖息在海草器官及其周围环境中,对海草生长、营养和健康以及海草床物质循环起着重要作用。本文通过分析与总结国内外参考文献,简要介绍了海草床微生物的一些新的研究进展,并讨论了将来可能进行的研究方向。海草微生物组与沉积物和海水中的微生物群落存在较大差异,其分布在离散且高度异质性的生态位,且该模式在广泛的地理尺度上保持不变,不是受海草种类和沉积物类型控制,而是主要取决于环境驱动与海草代谢。大部分海草核心微生物群落都参与硫循环。今后可采用模拟实验、生态模型、基因组、宏基因组、转录组与代谢组等技术方法研究海草床微生物的多样性、组成、功能、定植与病害等。此外,揭示海草床中微生物、海草和环境之间的相互关系,对保护受威胁的海草床具有重要意义。 相似文献
11.
Toms Vega Fernndez Marco Milazzo Fabio Badalamenti Giovanni D'Anna 《Estuarine, Coastal and Shelf Science》2005,65(4):645-653
An extensive Posidonia oceanica meadow was partially destroyed by excavation, resulting in areas of seagrass habitat of equal complexity (shoot density) but different heterogeneity (degree of fragmentation). The fish assemblages associated with differently fragmented beds were compared from a landscape perspective. Differences in the fish assemblages were detected, with several species showing different patterns: (1) species that increased their abundance along with the degree of bed fragmentation, (2) species that were more abundant in fragmented beds, but did not show differences between more or less fragmented beds, and (3) species that were mostly abundant in large seagrass patches or in the continuous meadow. The fish assemblages were also affected by depth, but further research is needed to determine properly this effect. Some ecological mechanisms are suggested to operate in the interaction between P. oceanica and the held fish assemblage. 相似文献
12.
海草是一类生活在近海区域的高等被子植物,初级生产力高,是全球重要的碳汇之一,具有净化水质、消浪固滩,以及为珍稀濒危海洋生物提供栖息地和保护地的功能。无节制的人类活动和频发的极端气象灾害导致近岸海洋污染加剧、海洋生态系统退化和海草床大面积消失。本文以相关海草床修复生态学基础理论为出发点,在自然因素和人为因素两个方面归纳了海草修复需要考虑的因素,梳理了国内外海草修复实践和技术理论方法,提出了利用营养物质、植物激素和物种共生关系等人为促进海草床生长的技术方法,并从法律角度、技术体系、保护体系和科普宣传等方面提出了促进我国海草床修复的建议,以期为我国海草床保护与修复工作提供理论基础和技术参考。 相似文献
13.
《Marine Chemistry》1987,22(1):71-83
Chemical variables were measured in calcium-carbonate-rich sediments inhabited by the dominant tropical seagrass, Thalassia testudinum, and in adjacent seagrass-free sediments at several locations in the Bahamas Islands. Pore-water alkalinity and pCO2 were consistently greater, while pH was consistently lower in sediment-pore waters within seagrass beds. The ammonium and molybdate-reactive phosphate concentrations in sediment-pore water were variable for vegetated, compared with unvegetated, sample locations.Thalassia testudinum can generate very large amounts of organic matter within calcium-carbonate-rich sediments. However, little of the organic matter is retained in the sediment and the effect of that organic matter on pore water chemical factors appears to be surprisingly small. These observations are markedly different from those for seagrass beds in high latitude clastic sediments and in Syringodium filiforme seagrass beds near San Salvador Island, where major influences of the seagrass beds on sediment chemistry have been observed. The generally coarser grain size of the carbonate sediments may be a primary factor contributing to these differences. 相似文献
14.
近些年来随着生境的破坏其分布面积急遽下降,较大面积连续分布的海草床已经非常少见。本研究首次将声呐探测技术应用到海草床时空分布特征的相关研究中,在河北唐山乐亭-曹妃甸沿海发现目前中国面积最大的鳗草(Zostera marina)海草床,海草床面积高达29.17 km~2,绘制了鳗草分布图和水深分布图,并对鳗草生物量和茎枝高度等基本生物学指标进行了调查。该发现极大丰富了中国海草数据库,并为鳗草的深入研究及保护提供了得天独厚的实验基地,也为周边海洋牧场的构建打下良好的基础。 相似文献
15.
Application of an ecosystem model for the environmental assessment of the reclamation and mitigation plans for seagrass beds in Atsumi Bay 总被引：1，自引：0，他引：1
An ecosystem model was used to evaluate the effects of reclaiming seagrass beds and creating artificial shallows with seagrass beds to mitigate the effects of the reclamation. The applied model can simulate the pelagic and benthic ecosystems including seagrass beds and tidal flats. The objectives of this study were (a) to investigate the likelihood of cultivating and maintaining seagrass beds in artificial shallows (Part 1), and (b) to understand the effects of the reclamation of seagrass beds and the creation of artificial shallows on the water quality in the estuary (Part 2). In Part 1, first, the nutrient turnover rates due to both biochemical and physical processes in the natural seagrass beds where reclamation is proposed were analyzed. Biological processes rather than physical processes were the most significant driving forces of nutrient cycles in seagrass beds. Second, the effects of filter feeding benthic fauna (suspension feeders) in the seagrass beds were analyzed. The scenario with suspension feeders resulted in higher transparency of the water column (8.7% decrease in the light attenuation coefficient) and an increase in nutrient supply (24.9% increase in NH4-N in the water column) contributing to the high specific growth rate of seagrass. Third, the specific growth rate of seagrass on the proposed artificial shallows was measured. The value on the artificial shallows set at a depth of datum line minus 0.8 m (D.L. − 0.8 m) was approximately the same as that of the natural seagrass beds. In Part 2, first, water quality in the estuary was compared among the scenarios with/without natural seagrass beds and artificial shallows. Then, the defined values of the water purification capability of (a) artificial shallows with/without seagrass beds, and (b) natural seagrass beds per unit area were evaluated. The reclamation of the natural seagrass beds resulted in a decrease of the removal of phytoplankton and detritus from the pelagic system (i.e. resulted in a loss in the purification rate). In contrast, the creation of artificial shallows resulted in an increase of the removal of phytoplankton and detritus from the pelagic system (i.e. resulted in a gain in the purification rate). Based on an annual average, approximately twice as much phytoplankton was removed from the artificial shallows at the depth D.L. − 0.8 m, than at the depth, D.L. − 1.5 m, and the artificial shallows with seagrass beds removed pelagic DIN and DIP at a rate 120% higher than that without seagrass beds. 相似文献
16.
Epifaunal invertebrate species, such as amphipods and isopods, have been shown to play key but varying roles in the functioning of seagrass habitats. In this study, we characterized patterns in the poorly known epifaunal communities in eelgrass (Zostera marina) beds in San Francisco Bay as a first step in understanding the individual and collective importance of these species, while testing predictions on spatial patterns derived from previous studies in other regions. Surveys conducted at five beds across multiple time periods (April, June, August and October 2007) showed that San Francisco Bay eelgrass beds varied strongly in epifaunal community composition, total, and relative abundance, and that abundance differed markedly among time periods. In contrast to findings by others, morphologically complex flowering shoots frequently harbored greater numbers of epifauna (>2× and up to 10× more individuals) than vegetative shoots, but not different species assemblages. Similar to previous studies, several abiotic factors did not explain patterns in distribution and abundance among beds. The proportion of introduced species was very high (>90% of all individuals), a finding unique among seagrass epifaunal studies to date. Defining numerical patterns in epifaunal communities will inform related efforts to understand effects of epifaunal species and assemblages on eelgrass growth dynamics, seed production, and higher order trophic interactions over space and time. 相似文献
17.
To investigate whether or not regional–temporal patterns of seagrass habitat use by fishes existed at the Ryukyu Islands (southern Japan), visual surveys were conducted in seagrass beds and adjacent coral reefs in northern, central, and southern Ryukyu Islands, in November 2004, and May, August, and November 2005, the northern region having less extensive seagrass beds compared with the central and southern regions. During the study period, the seagrass beds were utilized primarily by 31 species, the densities of some of the latter differing significantly among regions. With the exception of Apogonidae and Holocentridae, all species were diurnal and could be divided into 6 groups based on seagrass habitat use patterns; (1) permanent residents A (10 species, e.g. Stethojulis strigiventer), juveniles and adults living in seagrass beds as well as other habitats; (2) permanent residents B (5 species, e.g. Calotomus spinidens), juveniles and adults living only or mainly in seagrass beds; (3) seasonal residents A (4 species, e.g. Cheilodipterus quinquelineatus), juveniles living in seagrass beds as well as other habitats; (4) seasonal residents B (6 species, e.g. Lethrinus atkinsoni), juveniles living only or mainly in seagrass beds; (5) transients (5 species, e.g. Parupeneus indicus), occurring in seagrass beds in the course of foraging over a variety of habitats; and (6) casual species (1 species, Acanthurus blochii), occurring only occasionally in seagrass beds. Regarding temporal differences, juvenile densities in each group were high in May and August compared with November in each region, whereas adult densities did not differ drastically in each month. For regional differences, juvenile and adult densities of permanent residents A and B were higher in the southern and central regions than in the northern region. Moreover, some seasonal residents showed possible ontogenetic habitat shift from seagrass beds to coral reefs in each region. These results indicated that seagrass habitat use patterns by fishes changed temporally and regionally and there may be habitat connectivity between seagrass beds and coral reefs via ontogenetic migration in the Ryukyu Islands. 相似文献