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Mahiko Abe Keigo Yokota Masaki Goto Akira Kurashima Miyuki Maegawa 《Fisheries Science》2008,74(2):299-307
ABSTRACT: This study was designed to identify a sustainable Zostera marina population based on the relationships between the distributional patterns of shoots and light conditions in the population. Population structures and light conditions on 22 April 2003 (season of reducing shoot density), 27 September 2003 (season of the annual minimum density and biomass) and 9 April 2004 (season of the annual maximum density and biomass) were examined. On 22 April 2003, the frequency distribution in shoot length was almost even. The spatial pattern is characterized by small clumps within 2–5 cm radius. On 27 September 2003, the lengths of all shoots were less than 40 cm, and the distributional patterns were similar to 22 April. On 9 April 2004, the spatial pattern is characterized by larger clumps within 25 cm radius. The reproductive shoots had a regular distribution. The relative light intensities on the population floor of the sea surface on 27 September and 9 April were 53.3 and 10.2%, respectively. The light intensity on 9 April 2004 was not sufficient for growth. The results suggest that the competition for harvesting solar radiation is caused by the shoot length and the spatial pattern among shoots in the population. 相似文献
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We investigated strategies to enhance populations of bay scallops,Argopecten irradians irradians (Lamarck, 1819), in a presumablyrecruitment-limited natural habitat. At present, the Niantic Riverestuary supports only a minor bay scallop population that is harvestedrecreationally. Three enhancement strategies were evaluated; (1)collection and redistribution of natural spatfall, (2) introduction andover-wintering of hatchery-reared stock into natural habitat to providenew spawning stock, and (3) over-wintering of hatchery-reared stock insuspension culture for creation of mobile spawner sanctuaries. Anassessment of natural bay scallop recruitment in the Niantic Riverconducted in 1997 indicated that few spat were found, they were widelydispersed within the river, and peak spawning occurred in late July1997. Direct re-seeding was evaluated as an enhancement measure byplanting hatchery-reared scallops ( 38 mm shell height) insmall-scale, 100-m2 plots at different times and densities.Time of planting and the inferred predation intensity were major factorsaffecting survival; whereas, planting density had no significant effect.Approximately 9,000 scallops (35–45 mm shell height), broadcastwithin an eelgrass bed in November 1997, had high over-winter survivaland underwent gametogenesis and spawning during 1998. Of 26,000 bayscallops ( 45 mm shell height) over-wintered in suspensionculture from 1998–1999, approximately 60–80%survived, and these scallops spawned in mobile sanctuaries, during thesummer of 1999. There is good potential for using aquacultural methodsfor enhancement of bay scallop populations when natural recruitment ispoor and habitat and environmental conditions are not limiting. 相似文献
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2008年9月～2009年8月,对桑沟湾楮岛海域大叶藻叶片上的附着生物进行了周年调查,以期为我国浅海生态系中大叶藻等海草生态功能的研究提供基础资料。调查共记录大叶藻附着生物29种。附着的主要种类有盾卵形藻Cocconeis scutellum及其小型变种C.scutel lumvar.pava,褐毛藻Halothrixlumbricalis、点叶藻Punctaria latifolia、锈凹螺Chlorostoma rustica、Australaba sp.、脆螺Stenotis sp.。在春季,大叶藻上的附着硅藻类有9种,大型海藻类7种,动物类8种。其中,褐藻类为主要附着生物,附着高峰出现在4月份。夏季,附着的大型海藻种类明显减少,仅出现4种,而动物类有6种,硅藻类8种。其中,腹足类为夏季附着优势种。硅藻附着高峰出现在秋季,此时的附着动物类减少至4种,大型藻类种数与夏季持平,但附着的生物量较小。冬季未发现附着的大型海藻及动物,仅有微藻类的硅藻附着。 相似文献
14.
考察了烟台玉岱山、担子岛和荣成褚岛海域106个采样点的大叶藻种类的分布及各采样点不同表层底质（深度3 cm以内）、根部底质（深度3～15 cm）和水深等级。对不同底质与水深条件下大叶藻Zostera marina和丛生大叶藻Z.caespitosa的出现频率进行χ2检验。结果表明：不同大叶藻的分布与表层底质、根部底质变化呈极显著相关关系（P〈0.01）,列联系数分别为0.612和0.640;与水深等级变化的相关性虽然显著,但列联系数仅为0.338。在表层底质、根部底质和水深等级3种因素中,两物种的分布与根部底质类型相关性最大,与表层底质类型相关性次之。研究表明,两种大叶藻在不同底质上分布的差异明显,大叶藻偏好泥与泥沙底质,而丛生大叶藻偏好沙与砾石底质。 相似文献
15.
Photosynthetic activities of seedlings of Zostera marina were successively measured using a gas volumeter for 6 days at seven light (0–400 μmol photons/m2 per s) and 11 water temperature conditions (5–35°C). The seedlings were collected from mature plants (Ise Bay, central Japan),
and stored and cultured in incubators accurately controlled at each test temperature. The maximum gross photosynthesis (P
maxg) was recorded at an optimal water temperature of 29°C after 0 days. After 6 days, P
maxg appeared at 25°C and most plants cultured at 29–30°C bleached and withered after the drastic increase of light compensation
point (I
c). On the contrary, at 5–28°C, the photosynthetic activities either changed little (5–25°C) or recovered after a temporal
reduction (26–28°C); seedlings survived and looked healthy after being cultured for 6 days. The recovery was thought to be
an acclimation to tolerate higher water temperature. As a result, the critical upper water temperature for Z. marina seedlings was proposed as 28°C. The temperature was consistent with the previously reported maximum water temperature in
habitats around the southern boundary of Z. marina in the northern hemisphere. 相似文献
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- Seagrasses such as Zostera marina L. play a key role in coastal ecosystems because of the ecological goods and services that they provide, enhancing biodiversity, productivity and carbon sequestration. Despite their ecological relevance, their distribution is, to date, insufficiently documented and it is estimated that only one‐quarter of their global extent is mapped.
- This study aims to develop a new method to accurately detect and map subtidal seagrass meadows, using Irish seagrass populations as a case study. This method consists of four steps: (i) the development of a species distribution model (SDM); (ii) the use of satellite‐derived images to visually appraise the potential presence and extent of seagrass beds; (iii) field surveys to validate the presence or absence of the seagrass; and finally (iv) the construction of an up‐to‐date detailed map of the seagrass distribution for the region under investigation.
- Results indicate that along the Irish coast, and in western regions in particular, the actual distribution of seagrass is considerably greater than is currently reported. Using the proposed method, 16 new regions occupied by seagrass in areas of interest in County Galway (Kilkieran Bay, Bertraghboy Bay, and Chasla Bay) were identified, accounting for a total of 267.92 ha, which increased the previously documented distribution in this area by 44.74%.
- In this study, we demonstrate the potential of this novel method to efficiently identify and map undocumented subtidal seagrass meadows. As seagrass habitats are under threat globally, the development of new mapping strategies is a critical contribution to current international efforts in seagrass monitoring and management.
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鳗草根际固氮菌的分离鉴定及培养条件的筛选 总被引：1，自引：1，他引：0
为了解鳗草(Zostera marina)根际微生物的共生固氮功能,并分离得到对海草有潜在促生效果的功能微生物,以山东荣城天鹅湖鳗草为研究对象,采用选择性固氮培养基从其根际分离得到了两株具较高固氮酶活性的菌株(3A和4G),从形态学、生理生化特性、16S rDNA和固氮基因nifH等方面对菌株进行筛选和鉴定,探讨菌株的最佳培养条件并获得了菌株典型生长曲线。结果表明,菌株3A为海旋菌(Thalassospira),革兰氏阳性菌,菌落圆形桔黄色,可利用的碳源:D-甘露糖,D-松三糖,L-鼠李糖等,最佳培养条件:盐度2.585%,pH 8.18,温度31.49℃;菌株4G为芽孢杆菌(Bacillus),革兰氏阴性菌,菌落圆形乳白色,可利用的碳源:D-纤维二糖,D-葡萄糖,D-麦芽糖,蔗糖,D-甘露醇,D-海藻糖等,最佳培养条件:盐度2.920%,pH 7.99,温度37.27℃。利用乙炔还原法测定二者的固氮酶活性,分别为252.21 nmol C_2H_4/(mL·h)和196.31 nmol C_2H_4/(mL·h)。研究证实两株菌株具有良好的固氮性能,可用于海草固氮肥的研制,在海草床生态系统恢复研究领域具有潜在的应用前景。 相似文献
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本文研究了赤霉素和弱酸对鳗草(Zostera marina)种子萌发和生理特性的影响,监测了鳗草种子的累积萌发率、幼苗建成率以及种子萌发过程中种子干重、水分、呼吸速率、可溶性糖、淀粉、赤霉素、脱落酸含量和α-淀粉酶、β-淀粉酶活性的动态变化,探究了2种外源处理对鳗草种子的促萌作用,分析了鳗草种子应对外源促萌的生理响应过程。结果显示,2种促萌处理均能有效促进鳗草种子萌发和幼苗建成,其中,赤霉素处理组促萌效果最优,其种子萌发率和幼苗建成率为对照组的1.6倍;促萌期间,2个促萌处理组种子α-淀粉酶活性呈先上升后下降的趋势,淀粉含量呈下降趋势,可溶性糖含量呈持续上升趋势;至实验结束时,赤霉素处理组种子可溶性糖含量最高,是促萌前初始值的3.3倍,亦显著高于弱酸处理组和对照组(P<0.05),弱酸处理组种子淀粉含量最低,显著低于其他2组(P<0.05),而各处理组之间种子的α-淀粉酶活性无显著差异(P>0.05);主成分分析显示,种子α-淀粉酶活性、淀粉和可溶性糖含量为种子萌发过程中的关键因子。综合分析认为,外源赤霉素处理是破除鳗草种子休眠的有效方法,其主要通过调节种子淀粉酶活性、提高淀粉分解速率和提高可溶性糖含量为种子萌发提供能量实现破除休眠的作用。本研究结果为鳗草种子快速萌发技术提供了理论依据和科学基础。 相似文献