卵圆卡盾藻香港株过氧化氢产生的影响因素研究

研究了卵圆卡盾藻香港株(Chattonella ovata,Hong Kong strain,COHK)在不同生长期、盐度和营养盐条件下的生长及过氧化氢(H2O2)的产生特点.结果表明,过氧化氢浓度峰值出现在COHK对数生长期(4～8 d),以第6 d达到最大,为2.91×10-4nmol.cell-1.在N∶P为16∶1、32∶1和64∶1的情况下,COHK生长较快,以32∶1时生长速率最快(0.58 div.d-1).COHK产生H2O2的量与藻类生长呈相反趋势,在N∶P为4∶1和8∶1的情况下,藻细胞生长率较低,但单位藻细胞H2O2浓度较高.单位藻细胞H2O2浓度在N∶P为4∶1时最大,达到1.26×10-4nmol.cell-1.COHK在盐度为20和25时生长率较高,在盐度为10、15和30时生长率较低,表明低盐和高盐条件均不利于COHK的生长.低盐度和高盐度均有利于COHK过氧化氢的产生,在盐度为10时,单位藻细胞的H2O2量最高,达到2.2×10-4nmol.cell-1;但盐度在15～25范围内,单位藻细胞H2O2量相差不大(0.7×10-4～0.9×10-4nmol.cell-1).Fe3+可显著影响COHK的生长,Fe3+浓度范围为0.2×10-8～1×10-8mol.L-1时,COHK生长率较高.缺铁条件下(Fe3+浓度为0),COHK生长率最低(0.1 div.d-1),而Fe3+浓度较高时(5×10-8mol.L-1),藻细胞生长率也有所降低.缺铁以及高铁条件下,卵圆卡盾藻的H2O2产量增加,H2O2浓度分别为0.97×10-4和0.95×10-4nmol.cell-1.     

Conservation Objectives and Sea‐Surface Temperature Anomalies in the Great Barrier Reef

Abstract: Spatial and temporal dynamics of ecological processes have long been considered important in marine systems, but seldom have conservation objectives been set for them. Climate change makes the consideration of the dynamics of ecological processes in the design of marine protected areas critical. We analyzed sea‐surface temperature (SST) trends and variability in Great Barrier Reef Marine Park (GBRMP) for 25 years and formulated and tested whether three sets of notional conservation objectives were met to illustrate the potential for planning to address climate change. Given mixed and limited evidence that no‐take areas increase resilience to disturbances such as anomalously high temperatures (i.e., temperatures ≥1 °C above weekly mean temperature), our conservation objectives focused on areas less likely to be affected by such events at extents ranging from the entire Great Barrier Reef to the system of no‐take zones and individual no‐take zones. The objective sets were (1) at least 50% of temperature refugia (i.e., pixels that had high‐temperature anomalies <5% or <7% of the time) within no‐take zones, (2) maximum occurrence of high‐temperature anomalies is <10%,< 20%, or <30% of total no‐take area 90% of the time, and (3) coverage of any single no‐take zone by high‐temperature anomalies occurs <5% or <10% of the time. We used satellite imagery from 1985–2009 to measure SST to determine high‐temperature anomalies. SSTs in the Great Barrier Reef increased significantly in some regions, and some of the conservation objectives were met by the park's current zoning plan. Dialogue between conservation scientists and managers is needed to develop appropriate conservation objectives under climate change and strategies to meet them.     

Biochemical Changes in Decomposing Leaves of Mangroves

Nylon bags containing yellow leaves of Rhizophora apiculata and Avicennia marina, were immersed for 80 days from August to October, 1996. the decomposing leaves were collected every 10 days and analysed for dry weight loss and six biochemical parameters: tannins, total amino acids, total sugars, total nitrogen, total lipids and fatty acid profile. the leaf weight initially decreased very rapidly by about 50% of the start in two species of mangroves within 10 days. Similar changes were observed with tannins, total amino acids and sugars. However, the concentration of nitrogen increased significantly with decomposition. There was no significant change in total lipid and fatty acid profile. the highest concentration of fatty acid in the decomposing leaves was palmitic acid (16:0). Unsaturated fatty acids such as, 18:1 w7c and 18:1 w9c were found to be present in decomposing leaves of both species.     

Use of Population Viability Analysis to Evaluate CITES Trade‐Management Options for Threatened Marine Fishes

Abstract: Achieving multiple conservation objectives can be challenging, particularly under high uncertainty. Having agreed to limit seahorse (Hippocampus) exports to sustainable levels, signatories to the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) were offered the option of a single 10‐cm minimum size limit (MSL) as an interim management measure for all Hippocampus species (≥34). Although diverse stakeholders supported the recommended MSL, its biological and socioeconomic implications were not assessed quantitatively. We combined population viability analysis, model sensitivity analysis, and economic information to evaluate the trade‐off between conservation threat to and long‐term cumulative income from these exploited marine fishes of high conservation concern. We used the European long‐snouted seahorse (Hippocampus guttulatus) as a representative species to compare the performance of MSLs set at alternative biological reference points. Our sensitivity analyses showed that in most of our scenarios, setting the MSL just above size at maturity (9.7 cm in H. guttulatus) would not prevent exploited populations from becoming listed as vulnerable. By contrast, the relative risk of decline and extinction were almost halved—at a cost of only a 5.6% reduction in long‐term catches—by increasing the MSL to the size reached after at least one full reproductive season. On the basis of our analysis, a precautionary increase in the MSL could be compatible with sustaining fishers' livelihoods and international trade. Such management tactics that aid species conservation and have minimal effects on long term catch trends may help bolster the case for CITES trade management of other valuable marine fishes.     

Comparison of Outcomes of Permanently Closed and Periodically Harvested Coral Reef Reserves

Abstract: In many areas of the developing world, the establishment of permanent marine reserves is inhibited by cultural norms or socioeconomic pressures. Community conserved areas that are periodically harvested are increasingly being implemented as fisheries management tools, but few researchers have empirically compared them with permanently closed reserves. We used a hierarchal control‐impact experimental design to compare the abundance and biomass of reef fishes, invertebrates, and substrate composition in periodically harvested and permanent reserves and in openly fished (control sites) of the South Pacific island country of Vanuatu. Fished species had significantly higher biomass in periodically harvested reserves than in adjacent openly fished areas. We did not detect differences in substratum composition between permanent reserves and openly fished areas or between permanent reserves and periodically harvested reserves. Giant clams (tridacnids) and top shells (Trochus niloticus) were vulnerable to periodic harvest, and we suggest that for adequate management of these species, periodically harvested community conservation areas be used in conjunction with other management strategies. Periodic harvest within reserves is an example of adaptive and flexible management that may meet conservation goals and that is suited to the social, economic, and cultural contexts of many coastal communities in the developing world.     

人工污水对白骨壤生长的影响

在模拟潮汐条件下以正常、5倍和10倍浓度的人工污水处理红树林植物白骨壤la生幼苗,测定植株的根长、根径、茎高、茎径、叶片数、生物量以及开花结果等指标。结果表明：正常浓度和5倍浓度组的上述指标显著高于对照组,10倍浓度组的这些指标大于或接近对照组;说明：一定浓度的污水可以促进白骨壤的生长和开花结果。     

海洋卡盾藻日本株过氧化氢产生的影响因素

对海洋卡盾藻日本株(Chattonella marina Japan,CMJP)在不同盐度、营养盐条件及不同生长期的过氧化氢产生特点进行了研究.结果表明:H2O2浓度峰值出现在CMJP对数生长期(4~8d),以第6d达到最大,为0.97×10-4nmol/cell.在N:P为8:1和16:1的情况下,CMJP生长较快,藻细胞在对数生长末期之前一直保持较高密度.CMJP产生的H2O2量与藻类生长呈现出一定的相反趋势,在藻细胞适宜生长的N:P下,产生的H2O2浓度较小.在N:P为16:1时单个藻细胞的H2O2量最低(0.40×10-4nmol/cell),仅是N:P为32:1时(1.17 ×10-4nmol/cell)的1/3,N:P为8:1时,单个藻细胞的H2O2浓度为0.63 ×10-4nmol/cell. CMJP在盐度为20,25psu时生长较好且藻细胞达到较高密度,在盐度为10,15,30psu时藻密度较低,表明低盐和高盐条件均不利于CMJP的生长.盐度对CMJP过氧化氢的产量有一定的影响,在高盐度下单个藻细胞的H2O2产量增加,盐度为30psu时,H202浓度最高(1.1×10-4nmol/cell).     

玉米叶对我国几种典型赤潮藻生长的影响研究

研究了玉米叶对塔玛亚历山大藻(Alexandrium tamarense)、海洋卡盾藻(Chattonella marina)、赤潮异弯藻(Heterosigma akashiwo)、东海原甲藻(Prorocentrum donghaiense Lu)和球形棕囊藻(Phaeocystis globosa)生长的影响,以期为筛选新的、无污染的、廉价高效的除藻剂提供思路,为不同的有害赤潮的治理提供参考.结果表明,玉米叶对塔玛亚历山大藻、海洋卡盾藻、赤潮异弯藻、东海原甲藻和球形棕囊藻生长的影响明显不同.玉米叶可显著抑制塔玛亚历山大藻、海洋卡盾藻和赤潮异弯藻的生长,但对东海原甲藻生长的影响不大,对球形棕囊藻的生长则有显著的促进作用.这些结果表明,玉米叶对赤潮藻生长的抑制作用存在一定的选择性,这种选择性与藻的种属与细胞结构并无明显的相关性.     

Changes of plasma membrane AtPase activity, membrane potential and transmembrane proton gradient in Kandelia candel and Avicennia marina seedlings with various salinities

The salt-secreting mangrove, Avicennia marina, and non-salt-secreting mangrove, Kande/ia candel were cultivated in sand with various salinities(0‰, 100‰, 20‰, 30‰, 40‰) for 60 d. Plasma membrane vesicles of highpurity in leaves and roots of A. marina and K. candel seedlings were obtained by two-phase partitioning. The function of the plasma membranes, the activity of ATPase, membrane potential and transmembrane proton gradient, at various salinities were investigated. The results showed that within a certain range of salinity( A. marina and roots of K. candel: 0-30‰; leaves of K. candel: 0-20‰), the activity of ATPase increased with increasing salinity, while high salinity (above 30‰ or 20‰) inhibited ATPase activity. In comparison with A. marina, K.candel appeared to be more sensitive to salinity. The dynamics of membrane potential and transmembrane proton gradient in leaves and roots of A. marina and K. candel seedlings were similar to that of ATPase. When treated directly by NaCl all the indexes were inhibited markedly: there was a little increase within 0-10‰( K. candel) or 0-20‰( A. marina) followed by sharp declining. It indicated that the structure and function of plasma membrane was damaged severely.     

Applying science to pressing conservation needs for penguins

More than half of the world's 18 penguin species are declining. We, the Steering Committee of the International Union for Conservation of Nature Species Survival Commission Penguin Specialist Group, determined that the penguin species in most critical need of conservation action are African penguin (Spheniscus demersus), Galápagos penguin (Spheniscus mendiculus), and Yellow-eyed penguin (Megadyptes antipodes). Due to small or rapidly declining populations, these species require immediate scientific collaboration and policy intervention. We also used a pairwise-ranking approach to prioritize research and conservation needs for all penguins. Among the 12 cross-taxa research areas we identified, we ranked quantifying population trends, estimating demographic rates, forecasting environmental patterns of change, and improving the knowledge of fisheries interactions as the highest priorities. The highest ranked conservation needs were to enhance marine spatial planning, improve stakeholder engagement, and develop disaster-management and species-specific action plans. We concurred that, to improve the translation of science into effective conservation for penguins, the scientific community and funding bodies must recognize the importance of and support long-term research; research on and conservation of penguins must expand its focus to include the nonbreeding season and juvenile stage; marine reserves must be designed at ecologically appropriate spatial and temporal scales; and communication between scientists and decision makers must be improved with the help of individual scientists and interdisciplinary working groups.