共查询到18条相似文献，搜索用时 128 毫秒
1.
网箱养殖对海南新村澙湖海菖蒲生物学与生态学特征的影响 总被引：1，自引：0，他引：1
以海南新村澙湖海草床优势种之一的海菖蒲（Enhalus acoroides）为研究对象,于2005年4月至2006年1月间,分4个季节对海菖蒲的茎枝生物量、叶长、叶宽、叶单位面积附着藻类生物量、茎枝密度及生物量等进行了研究,初步探讨了网箱养殖对海菖蒲生物学和生态学特征的影响.其结果表明：（1）在春、夏、秋3个季节里,海菖蒲叶长、叶宽和茎枝生物量等均显示了与其所在样区海水和沉积物间隙水D IN含量呈负相关关系.（2）随着水体N负荷的增加,海菖蒲叶单位面积附着藻类生物量剧增.（3）网箱养殖区海菖蒲较小的地上生物量、茎枝密度及地上生物量与地下生物量比,均表明网箱养殖区海菖蒲受人为干扰的影响明显大于其他2个样区. 相似文献
2.
海草的种内差异是它在特定环境中形成生长策略的关键因素。本研究通过将现场实测数据和文献记录进行类比以探讨新村湾海黾草（Thalassia hemprichii）的生长策略。研究结果表明海黾草地下茎伸长速率的差异可以解释该海草生物量和生长的大部分种内差异；新村湾海黾草垂直地下茎和水平地下茎的伸长速率在夏季分别为2．38cm／yr和24．4cm／yr，在冬季分别为1．87cm／yr和29．2cm／yr。海黾草茎枝密度的变化范围是822shootsm^-2至941shoots m^-2，最大值出现在夏季而最小值出现在冬季，生物量的季节变化与此类似。新村湾海黾草通过交替调节垂直地下茎和水平地下茎的伸长速率以适应光照强度和温度的季节变化，从而导致茎枝密度和地上生物量的相应变化。通过这样的生长策略，海黾草可以把夏季干旱和冬季光照强度下降对其生长造成的消极影响降低到最小程度。 相似文献
3.
近几十年来,受到人类活动和气候变化的影响,全球海草床呈现退化趋势,海草床的恢复备受关注。其中,海草种子或幼苗移植由于其对供体海草床破坏和影响较小,并能保证海草的遗传多样性而备受重视。移植区的底质类型是决定海草种子或幼苗移植存活率的重要因子,然而,目前关于热带海草种子萌发和幼苗生长对不同底质类型响应的研究很有限。本研究以热带海草海菖蒲(Enhalus acoroides)种子为研究对象,利用室内模拟实验,分别设置细砂和砂砾底质的处理,探讨不同底质类型对海菖蒲种子萌发和幼苗生长的影响。研究发现,细砂组和砂砾组的萌发率和萌发历期的平均值分别96.3%、3.6 d和95.0%、3.4 d,两个处理组之间差异不显著。萌发后的细砂组海菖蒲幼苗的存活率为97.37%,而砂砾组的幼苗存活率仅为81.58%;另外,海菖蒲幼苗的叶片长度、根长度、叶片生长速率和根生长速率在细砂组均显著高于砂砾组。因此,沉积物粒径的差异对海草种子的萌发率和萌发时间没有显著性影响,但沉积物粒径增大会显著降低萌发后海菖蒲幼苗的存活率和生长速率。因此,未来开展海菖蒲种子或幼苗的野外移植,应选取沉积物粒径较小细砂质区域进行移植,可促进海菖蒲种子或幼苗移植的成活率,提高海菖蒲生态修复的成功率。 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.
《中国海洋大学学报(自然科学版)》2016,(5)
海草组织碳氮含量可快速响应外界环境影响,已经广泛用于海草生态系统健康评估的指示因子。2011—2012年对东楮岛大叶藻海草床进行4次采样调查,研究了不同季节海草组织碳氮含量特征,分析了环境因素对大叶藻组织碳氮含量的影响。结果表明:海草组织碳、氮含量有明显季节性变化。海草叶碳含量最大值出现在5月,为36.4%,最小值出现在12月,为30.8%;而海草叶氮含量最大值和最小值分别出现在2和5月,为2.73%和2.02%。环境因素的相关性分析表明,海水温度对海草叶碳含量和根氮含量具有显著影响,海水及沉积物间隙水中的氮营养盐对海草茎、叶中的碳含量和根、叶中的氮含量有显著影响。调查表明东楮岛海域海草组织氮含量高于世界平均水平,营养盐增加可能对大叶藻产生负面影响,为了保护东楮岛海草床,应严格控制该海域养殖海带过程中营养盐的使用,加强对海草床健康状况的野外监测以及环境因素对海草影响的室内模拟实验研究。 相似文献
6.
海南黎安港海草床分布特征、健康状况及影响因素分析 总被引：2，自引：0，他引：2
通过对黎安港海草资源进行调查，并采用《近岸海洋生态健康评价指南》（HY∕T087-2005）对海草床生态系统健康进行评价。结果表明，黎安港海草种类主要有2科3亚科4属4种，分别为圆叶丝粉草、泰来草、海菖蒲及卵叶喜盐草；海菖蒲分布广泛，其次为圆叶丝粉草及泰来草，海草床分布面积约为0.93 km2，黎安南岸海草分布面积最大，西岸次之，东岸最小。海草平均覆盖度为37.80%。圆叶丝粉草平均密度872.00株/m2，平均生物量150.34 g/m2，泰来草平均密度405.00株/m2，平均生物量62.45 g/m2；海菖蒲平均密度251.00株/m2，平均生物量778.50 g/m2，卵叶喜盐草平均密度6 768.00株/m2，平均生物量70.63 g/m2，2015年黎安港海草床处于健康状态；2018年处于健康状态边缘；2016年、2017年及2019年均处于亚健康状态，主要体现在沉积物环境、栖息地健康以及生物指标存在亚健康，2015年至2019年期间，黎安港海草床的健康状况总体呈现为健康转为亚健康的趋势，主要影响因素有水体交换能力较差、水产养殖活动影响、沿岸围填海工程及其他人为活动影响等。 相似文献
7.
威海荣成桑沟湾海域海草床分布现状及其生态特征 总被引：1，自引：0，他引：1
海草床是生物圈最高产的生态系统之一，在氮捕获、碳封存、水质净化及维持生物多样性等方面发挥关键作用。2016年8月通过对威海荣成桑沟湾海域的现场调查，发现分布总面积约为471.72 ha的海草床，种类为鳗草（Zostera marina）、红纤维虾形草（Phyllospadix iwatensis）、日本鳗草（Zostera japonica）和丛生鳗草（Zostera caespitosa），分布面积分别为395.33 ha、37.28 ha、32.74 ha和6.37 ha。鳗草分布范围较广，平均茎枝密度817.0±27.6 shoots/m2，平均生物量646.6±41.8 g DW/m2；红纤维虾形草主要分布于桑沟湾北部养殖池和南部楮岛海域，平均茎枝密度2 649.0±29.8 shoots/m2，平均生物量2 381.3±27.3 g DW/m2；日本鳗草主要分布于桑沟湾西部八亩地海域，平均茎枝密度506.0±26.2 shoots/m2，平均生物量118.3±12.5 g DW/m2；丛生鳗草主要分布于桑沟湾南部楮岛海域，其平均密度为513.0±17.9 shoots/m2，平均生物量为479.1±28.1 g DW/m2。结合历史资料，发现桑沟湾海域海草床严重退化，分析了海草床的退化原因并提出了相应的建议和对策，以期为海草资源及滨海生境修复提供参考。 相似文献
8.
海草床是滨海三大典型生态系统之一,具有极其重要的环境改善、资源养护和减灾防灾等生态功能,亦是全球重要的碳库。2016年8月,通过对荣成马山里海域的现场调查,发现了面积为58.26 hm2的海草床,其海草的种类为红纤维虾形草（Phyllospadix iwatensis）和丛生鳗草（Zostera caespitosa）。红纤维虾形草分布面积为54.50 hm2,占该海域海草床总面积的93.5%,分为北部和南部2个带状区域,平均茎枝密度为（368.0±18.2）shoots/m2,平均生物量（干重,下同）为（297.0±41.5）g/m2。丛生鳗草分布面积为3.76 hm2,占海草床总面积的6.5%,呈现斑块状分布,与红纤维虾形草交错而生,平均茎枝密度为（691.2±17.1）shoots/m2,平均生物量为（534.0±70.7）g/m2。马山里海域海草床主要分布在平均水深为（2.8±0.3） m的以岩礁为主的底质上。海草的生长状况存在显著的空间差异,与水温呈现显著的正相关,与水深和陆源污染物存在显著的负相关。结合历史资料,发现该海域海草床退化现象较严重,其主要威胁因素是人为干扰,主要包括渔业生产、养殖活动和陆源污染输入。建议合理规划周边海域的养殖规模和密度、加强陆源污染物管控和开展海草床生态修复工程,以期为温带海草床的有效保护和科学管理提供参考。 相似文献
9.
通过对广东沿海水域的现场调查, 新发现8个海草床, 主要分布在柘林湾、汕尾白沙湖、惠东考洲洋、大亚湾、珠海唐家湾、上川岛、下川岛和雷州企水湾。海草种类主要包括喜盐草(Halophila ovalis)、贝克喜盐草(Halophila beccarii)和矮大叶藻(Zostera japonica)等3种。海草覆盖率为6.67%—53.33%, 茎枝密度为3 428.57— 10 542.00shoots.m-2, 生物量为12.86—118.24g.m-2。海草床底上生物密度为16.67—734.67ind.m-2, 生物量为15.39—426.88g.m-2, 多样性指数为0.46—1.98, 均匀度指数为0.28—0.89。海草床生境受到的严重威胁主要来自围海养殖(养蚝、养螺)、污水排放、渔民作业方式(电鱼、电虾、扒螺、挖贝类)、自然灾害(台风和洪水)等。 相似文献
10.
为缓解海南岛东海岸海草床的持续退化,在高隆湾光滩区采用单株定距移植法移植泰来草(Thalassia hemprichii)及海菖蒲(Enhalus acoroides)进行海草床修复研究,修复面积约为1 000 m~2。结果表明,采用铁架加网的修复方式,泰来草1 a后平均成活率为56.39%,其成活率在移植7个月后下降比较明显,容易被掩埋;由于其植株高大,受风浪影响较小,海菖蒲移植1 a后其成活率为88.75%。泰来草比海菖蒲明显容易生根出芽,其新分枝率比海菖蒲高很多,移植1 a后,其斑块平均新分枝率达到22.64%,海菖蒲仅为3.13%;由于海菖蒲植株高大,且不易死亡,其平均盖度为21.90%,远远高于泰来草(4.25%)。由椰子壳、竹筐及泥框作为移植固定修复方式,其修复成活率、新分枝率、盖度及美观程度远远低于铁架加网的修复方式。修复效果优劣为:铁架加网竹筐泥框椰子壳。高隆湾海草床修复的主要影响因素为水动力及悬沙、修复品种、人工岛及人为活动(捕鱼)等的影响。为确保修复效果,本研究提出在我国南方底质为珊瑚礁碎屑及潮汐动能较大的开放水域,宜选用海菖蒲及泰来草相互间隔单株移植,并竖立警示及标识牌,雇佣当地渔民看护,定期监测及管理,加强海草床群落结构及生物功能提升方面的研究等建议,可为今后其他开放水域海草床修复提供基础数据及理论支撑。 相似文献
11.
《Oceanologica Acta》1999,22(1):109-117
The effects of fish farming on a seagrass (Posidonia oceanica) meadow at Fornells Bay, Minorca (Balearic Islands) were studied. Changes in plant and meadow features (e.g. shoot morphology, shoot density, biomass, rhizome growth, nutrient and soluble sugars concentrations…) in three stations along a transect from a disturbed (organic pollution due to fish cultures) to an undisturbed site were assessed. The fish culture had ceased in 1991; however, seagrass decline, already reported in a previous study for the period 1988–1990, was still taking place at the time of sampling (July 1994). Differences between stations were very clear; the station closest to the fish cages showed reduced shoot density, shoot size, underground biomass, sucrose concentration and photosynthetic capacities. In contrast, shoots from the most polluted station showed higher P-concentration in tissues and higher epiphyte biomass than the other two. Since water conditions had recovered completely by the time of the sampling mission, it is proposed that the persistence of the seagrass decline was due to the excess organic matter remaining in the sediment. 相似文献
12.
海南岛南部海草资源分布现状调查分析 总被引：3，自引：1，他引：2
结合2008年和2014年的调查数据,对海南岛南部海草分布现状进行分析探讨。结果显示,海南岛南部海草种类有2科3亚科5属5种,即海神草Cymodocea rotunda、泰莱藻Thalassia hemprichii、海菖蒲Enhalus acoroides、喜盐草Halophila ovalis以及二药藻Enhalus acoroides,泰莱藻广泛分布;海草分布面积从2008年的1.64km2减少到2014年0.50km2,减少幅度较大区域为铁炉港和小东海;平均盖度从2008年35.67%下降到2014年26.40%;受人为活动及无人管理因素影响程度不同,海南岛南部不同海域海草平均密度及平均生物量各有不同,后海湾与鹿回头海草平均密度和平均生物量呈增长趋势,铁炉港、西瑁洲岛及小东海海草平均密度和平均生物量呈下降趋势。鉴于海南岛南部海草资源已出现退化,希望社会各界重视海草的保护,在海草资源丰富区域设海草保护区,在海草破坏严重区域加大政府科研扶持力度,对海草进行保护与修复。 相似文献
13.
为了解胶州湾水体和表层沉积物营养环境状况及其主要影响因素,于2019年8月在胶州湾30个站位点采集了海水和表层沉积物样品,并于2021年5月在胶州湾沿岸采集了18个站位点的水样,对水体溶解无机态营养盐浓度和组成以及表层沉积物中总有机碳、总氮、总磷及生物硅含量和碳、氮稳定同位素（δ13C、δ15N）进行了分析。结果表明,胶州湾内水体和沿岸水体中溶解无机氮、溶解无机磷和溶解硅酸盐浓度空间分布相近,高值均位于湾东北部,主要受到河流输入和沿岸污水排放的影响,低值主要出现在湾中部和湾口处。结合近30年来的历史数据分析发现,胶州湾夏季营养盐浓度在1990?2008年期间呈持续上升的趋势,政府实施的污染物总量控制措施以及河流径流量下降使得2006年以来营养盐浓度呈现下降的趋势,该变化在空间上主要体现为大沽河氮、磷输入量的减少及其对应的湾西部营养盐高值的消失。胶州湾氮、磷营养盐输入的不平衡使得“磷限制”在2000年后逐渐加剧。胶州湾表层沉积物中总有机碳、总氮、总磷含量高值均集中于东北部和东部沿岸,结合生物硅和水体营养盐含量分析显示,这主要是河流与排污输入及其带来的高初级生产力造成的,沉积物生源要素与水体营养盐在空间分布上存在较好的耦合关系。沉积物粒度较粗对有机质保存的不利影响以及湾口较强的水动力作用共同导致了湾西部、中部以及湾口的生源要素含量较低。δ13C以及二端元混合模型显示,胶州湾表层沉积物有机质来源总体以海源为主,平均占比为64%,东部沿岸受陆源输入影响较明显。δ15N的空间分布显示,胶州湾表层沉积物中氮元素受到了海水养殖与污水排放的共同影响。水体和沉积物营养环境现状共同表明,对东北部河流和沿岸污水排放的控制是后期胶州湾污染治理的关键。 相似文献
14.
Impacts of Typhoons Tianying and Dawei on seagrass distribution in Xincun Bay, Hainan Province, China 总被引：1，自引：0，他引：1
More than 50% of the typhoons landing in China have landed on the southeast coast, where they have caused great pressure on the coastal environment. Seagrass, one of the most important constituents of coastal ecosystems, is also greatly affected by typhoons. In order to clarify how seagrass distribution variation is affected by typhoons in coastal areas in southeast China, data of Typhoons Dawei and Tianying (category 4 and category 2 respectively, which just ran through the southern part of Hainan province) have been studied. In situ observation and satellite remote sensing data (CBERS-China Brazil Earth Resources Satellite) in 2004 and 2006 were used to retrieve seagrass distribution in Xincun Bay, Hainan province. In situ observations showed that leaf length, stem biomass and above ground biomass on average showed evidence of reduction after Typhoons Tianying and Dawei. However, seagrass density showed no evidence of reduction after typhoon Tianying and Dawei passed by and increased rapidly in January 2006. From results of satellite remote sensing data, seagrass distribution can be detected with high accuracy, and the area of seagrass distribution on the south coast of Xincun Bay in 2006 after the typhoon passed by was smaller than that in 2004 in region A and B. However, in region C, area of seagrass coverage under 20% increased. These results demonstrated that typhoons Tianying and Dawei damaged seagrass bed and helped seagrass to get rid of aged and dead leaves, and this correspondingly facilitated seagrass growth. 相似文献
15.
《African Journal of Marine Science》2013,35(3):323-330
Heavy nutrient loads in coastal waters often lead to excessive growth of microalgal and macroalgal epiphytes on seagrass leaves, with varying effects on the underlying seagrasses. This study evaluates the photosynthetic performance, epiphytic biomass and tissue nutrient content of two tropical seagrasses, Cymodocea serrulata and Thalassia hemprichii, in two intertidal areas along the Dar es Salaam coast in the Indian Ocean, a nutrient-rich region at Ocean Road (near the city centre), and a nutrient-poor region at Mjimwema (south of the city centre). Epiphyte biomass was significantly higher at the nutrient-rich site, and epiphytes were associated with reduced photosynthetic performance in both seagrass species at both sites. Likewise, nitrogen and phosphorus tissue content was higher in both species at the nutrient-rich site than at the nutrient-poor site. Epiphytic species composition on the seagrass leaves varied between seagrass species and between sites. Cymodocea serrulata had a higher number of epiphytic species at Mjimwema than at Ocean Road, whereas Thalassia hemprichii had more epiphytic species at Ocean Road than at Mjimwema. Seagrass photosynthetic performance, epiphytic biomass and nutrient content of the seagrasses were shown to be affected by nutrient concentration in the water column. Thus, for the future monitoring of the seagrass meadow, we recommend the use of combined measures such as seagrass performance, epiphytic biomass, nutrient contents and nutrient concentration levels in the water column. 相似文献
16.
F.T. Short M.W. Davis R.A. Gibson C.F. Zimmermann 《Estuarine, Coastal and Shelf Science》1985,20(4):419-430
The seagrass Syringodium filiforme was examined in an ecological analysis of plant nutrient requirements and nutrient resource availability. Assessment of the sediment geochemistry in a San Salvador Island seagrass bed indicated that phosphorus was not readily accessible to the plants. Ammonium regeneration in the fine-grained carbonate sediments was high, and interstitial concentrations averaged ca. 100 μM while phosphate replenishment to interstitial water was low, and concentrations were generally less than 2 μM. Analysis of the seagrass leaf tissue content (C : N : P = 1390 : 47 : 1, atomic wt) suggested that nitrogen and phosphorus were both depleted relative to carbon. However, this high N : P for S. filiforme and the low concentration of phosphate available in the interstitial water established the likelihood that plant acquisition of phosphorus was limited. The finding of high root biomass relative to leaf biomass in these seagrass beds corroborates this evidence by depicting a method of plant adaptation that increases nutrient absorptive root surface area. 相似文献
17.
We examined the contribution of submarine groundwater discharge (SGD) to nutrient budgets in Hwasun Bay, Jeju Island, Korea in August 2009, October 2014, and May 2015. The concentrations of dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphorus (DIP) in fresh groundwater were in the range of 285?716 μM and 2.3?3.2 μM, respectively, which were each 1?2 orders of magnitude higher than those in the bay seawater. The outer-bay seawater flowing into the bay was oligotrophic (2.9 ± 1.9 μM for DIN and 0.2 ± 0.3 μM for DIP). Nutrient budget calculations were performed for each season by accounting for submarine fresh groundwater discharge (SFGD) and water residence times. In August 2009 (DIN = 1.8 μM and DIN:DIP ratio = 4.6 for the outerbay water), DIN inputs from SFGD accounted for approximately 40% of the DIN inventory in the bay seawater. In October 2014 (DIN = 1.1 μM and DIP < 0.05 μM for the outer-bay water), DIP from SFGD accounted for approximately 100% of the DIP inventory in the bay seawater. In May 2015, mean concentrations of DIN and DIP in the bay seawater were 8.6 ± 12 μM and 0.11 ± 0.04 μM, respectively, with conservative behaviors in the bay seawater in association with excessive groundwater inputs. These results imply that SGD plays a critical but different role in nutrient budgets and stoichiometry in coastal waters off a volcanic island depending on open-ocean nutrient conditions. 相似文献
18.
海草凋落叶的溶解有机物的释放及其生物地球化学意义 总被引：1，自引：0，他引：1
Dissolved organic matter(DOM) represents a significant source of nutrients that supports the microbial-based food web in seagrass ecosystems. However, there is little information on how the various fractions of DOM from seagrass leaves contributed to the coastal biogeochemical cycles. To address this gap, we carried out a 30-day laboratory chamber experiment on tropical seagrasses Thalassia hemprichii and Enhalus acoroides. After 30 days of incubation, on average 22% carbon(C), 70% nitrogen(N) and 38% phosphorus(P) of these two species of seagrass leaf litter was released. The average leached dissolved organic carbon(DOC), dissolved organic nitrogen(DON) and dissolved organic phosphorus(DOP) of these two species of seagrass leaf litter accounted for 55%, 95% and 65% of the total C, N and P lost, respectively. In the absence of microbes, about 75% of the total amount of DOC, monosaccharides(MCHO), DON and DOP were quickly released via leaching from both seagrass species in the first 9 days. Subsequently, little DOM was released during the remainder of the experiment. The leaching rates of DOC, DON and DOP were approximately 110, 40 and 0.70 μmol/(g·d). Leaching rates of DOM were attributed to the nonstructural carbohydrates and other labile organic matter within the seagrass leaf. Thalassia hemprichii leached more DOC, DOP and MCHO than E. acoroides. In contrast, E. acoroides leached higher concentrations of DON than T. hemprichii, with the overall leachate also having a higher DON: DOP ratio. These results indicate that there is an overall higher amount of DOM leachate from T. hemprichii than that of E. acoroides that is available to the seagrass ecosystem. According to the logarithmic model for DOM release and the in situ leaf litter production(the Xincun Bay, South China Sea), the seagrass leaf litter of these two seagrass species could release approximately 4×10~3 mol/d DOC, 1.4×10~3 mol/d DON and 25 mol/d DOP into the seawater. In addition to providing readily available nutrients for the microbial food web, the remaining particulate organic matter(POM)from the litter would also enter microbial remineralization processes. What is not remineralized from either DOM or POM fractions has potential to contribute to the permanent carbon stocks. 相似文献