不同盐度、温度及光照对漂浮浒苔生理生态的影响

为研究不同盐度、温度及光照对漂浮浒苔生理生态的影响,我们将实验室内培养的浒苔置于不同盐度、不同温度及不同光照强度条件下培养,测定藻体光合参数。不同盐度条件下,对浒苔叶绿素荧光参数测定结果表明,在盐度为0的条件下,浒苔样品实际量子效率Fv/Fm快速降低,随后Fv/Fm维持在较低水平,在盐度10‰~40‰范围内,在前5天各处理样品Fv/Fm没有明显变化,之后样品Fv/Fm有不同程度的降低。不同实验温度条件下,对浒苔叶绿素荧光参数测定结果表明,在5℃~25℃,浒苔Fv/Fm呈现先上升后下降趋势。不同光照条件下,对浒苔叶绿素荧光参数Fv/Fm进行测定,其数值都在第一天发生了显著降低,之后稍有波动。藻体Fv/Fm变化有所不同,处理的前2天中,所有条件下样品都有相同幅度的降低,处理第三天时,光强400μmol/(m²·s)下比其他光强下的要显著低14%~16%;到培养后期,则以160μmol/(m²·s)下要明显较高,即160μmol/(m²·s)下藻体Fv/Fm的降低总体较为平缓。光照实验表明,浒苔在低光照条件下的实际量子效率要高于高光照条件,且最大量子效率的测定也进一步证实了该结果,表明高光照条件会引起浒苔光合作用能力下降。     

Physiological energetics of the fourth instar of Chinese horseshoe crabs (Tachypleus tridentatus) in response to hypoxic stress and re-oxygenation

Hypoxia associated with eutrophication is a potential threat to the Chinese horseshoe crab Tachypleus tridentatus which inhabits intertidal sand flats in Asia. This study investigated the effect of dissolved oxygen level (DO) (6, 4 and 2 mg O₂ l⁻¹) on the physiological energetics in the juvenile T. tridentatus. They were exposed to various oxygen levels for three days and then transferred to normoxia for three days to examine the recovery from low oxygen stress. Feeding rate, respiration rate and scope for growth were reduced at lower DO levels while absorption efficiency and excretion rate were independent of DO levels. Although full recovery of the physiological responses and scope for growth from hypoxis stress was observed when normoxia resumed, their long term survival in suboptimal habitats with frequent occurrence of hypoxia deserves a close monitoring as hypoxia may be even more common in future in a warming world.     

紫外光对有毒甲藻塔玛亚历山大藻的生态学效应

对1991年分离自南海大鹏湾海域的塔玛亚历山大藻单克隆培养林在不同光照条件、辐射强度（9.5，5．9W／m2）（辐射剂量为：95，190，380,760,1520J/m2）和营养盐（N，P）浓度下，进行紫外辐射敏感性的研究。结果表明，紫外辐射可以导致细胞变形、增大和死亡。不论在什么条件下，低剂量的紫外辐射（95J／m2）就能使该藻的存活率和生长率大幅下降。此后，随着辐射剂量的增加，虽然存活率和生长率继续下降，但下降幅度渐缓。充足的营养盐和辐射处理后的连续光照对藻群的恢复有益，但在缺氮和缺磷条件下培养的藻群，可能由于生理活性减弱而导致对紫外辐射敏感性的迟钝。辐射强度对该藻的紫外辐射敏感性的影响十分显著，而且与辐射剂量具有明显的双重效应。     

Advances in Coccolithophore laboratory culture and their application research

This paper summarizes previous studies of coccolithophores laboratory culture with emphasis on the application of cultured coccolithophores in the ecology, paleoceanography and petroleum. Because of the particular biology and physiology characteristics, coccolithophorid bloom can influence marine and atmosphere environment deeply , play an important roal in global carbon cycle and geological evolution. In the aspect of culture, we introduce the cultural method, the influence of cocolithophores growth by setting different environment parameters, the principle of suitable culture meduim depending on different research purpose. In the aspect of application, firstly, this paper discusses the physiological responses of coccolithophorids about ocean acidification. Then, coccolithophorid is high producer of DMSP(dimethylsulphoniopropionate)which can be divides into gas DMS, which can influence marine and atmosphere environment deeply through some chemical course. Further, another important application is the element geochemistry of coccoliths which is very meaningful in paleoceanography and paleoclimatology study. Finally, this paper also discusses the application of coccolithophores hydrocarbon generation to petroleum geology.     

Growth and Heterozygosity in a 12-Month-Old Cohort of Ostrea chilensis Obtained by Mass Spawning in the Laboratory

Abstract. Oysters Ostrea chilensis P hilippi 1845. from a 40-month-old cohort which came from the natural population of the Quempillen River Estuary Southern Chile, were used as parental stock n = 600 for a hatchery-produced cohort. At 12 months of age this cohort was analysed physiologically filtration rate, organic ingestion rate, absorption rate, assimilation efficiency, excretion rate, respiration rate and electrophoretically multilocus heterozygosity MLH using four loci: LAP, GPI, PGM, CA. Most physiological variables were positively correlated with dry weight P < 0.05. with the exception of assimilation efficiency, excretion size and net growth efficiency P > 0.05. Also. there was a positive correlation between body size, ingestion rate, absorption rate and net growth efficiency with MLH. Respiration rate and consequently energy losses were negatively correlated with MLH. The energetic efficiency product of a lower metabolic cost in the heterozygous individuals in this cohort is reflected in a higher net growth efficiency and a positive correlation between growth and MLH. The genetic basis for the relationship between metabolic parameters and heterozygosity can be due to an overdominance in this 12-month-old cohort.     

三十烷醇对几种单细胞藻生长影响的研究

于1988－1990年，在大连凌水养殖二场，用0．01×10－6－1．00×10－6三十烷醇处理亚心形良藻、盐藻、微球藻、球等鞭金藻、新月菱形康，观察其对漠的生长影响。结果表明，在各种浓度下以上5种藻均提早进人指数生长期。对前3种藻的最佳处理浓度为0．10×10－6；后2种藻为0．05×10－6；其中对亚心形扁藻，促生长效果尤为明显，可视为海产经济动物人工育苗阶段的优质饵料。     

The effects of plant density of Melastoma malabathricum on the erosion rate of slope soil at different slope orientations

Malaysia’s cut slopes,especially for road lines accommodation,are prone to erosions and landslides.These problems mainly occur due to lack of vegetation cover and strong erosive forces.In addition,the topography factors have also become a major factor affecting soil degradation.Thus,this study is aimed at determining the effects of planting density of a selected species,namely Melastoma malabathricum;one,two,and three seedlings per box,on the erosion rate at selected slopes of different orientation(morning and evening sun) at the Guthrie Corridor Expressway,Selangor.In six months of observation,treatment with three seedlings/box on the morning sun slope showed a lower erosion rate by 69.2%than those with the same treatment on the evening sun slope.In addition,the treatment of the three seedlings recorded at month six(final observation) had the highest reduction of soil saturation level(STL),by 23.6%.Furthermore,the physiological values of the species studied,grown on the morning sun slope,were higher in terms of stomatal conductance and photosynthetic rate by 12.1%and 15.8%(three seedlings/box),respectively.The overall results showed that plant density was inversely related to the STL and erosion rate on the slope.In conclusion,a planting density of three seedlings/box and morning sun orientation gave positive effects on the plant’s physiological performance of the slope,reducing the STL,as well as alleviating the erosion rate of slope soils.     

Responses of the green-lipped mussel Perna viridis (L.) to suspended solids

Laboratory experiments were conducted to investigate the lethal and sublethal effects of suspended solids on the survival and physiological, behavourial and morphological changes of the green-lipped mussel Perna viridis collected from Tolo Harbour, Hong Kong. Results showed that P. viridis survived in all test conditions of suspended solids from 0 to 1200 mg/l over a period of 96 h. Physiological responses of the green-lipped mussel under 14-d exposure of suspended solids from 0 to 600 mg/l, followed by 14-d recovery in natural seawater, revealed no significant changes (p>0.05) in oxygen consumption and dry gonosomatic index for treatments in different concentrations of suspended solids and exposure time. Changes in clearance rate were only found to be significant (p<0.001) with exposure time. Responses in behavourial and morphological changes of the green-lipped mussel were also studied under similar experimental treatments and exposure time. Byssus production was significantly (p<0.001) related to exposure time. Gill damage, however, was significantly greater in treatments (p<0.001). Present findings suggested that P. viridis could tolerate a high level of suspended solids in the laboratory. There were dose-dependent effects of suspended solids on morphology of gill filaments. Implications of survival and responses of the green-lipped mussel to suspended solids in the marine environment are discussed.     

Photosynthetic community responses to upwelling in mesoscale eddies in the subtropical North Atlantic and Pacific Oceans

In this paper we summarise the photo-physiological responses of phytoplankton to upwelling of macronutrients in mesoscale eddies in the subtropical North Atlantic (EDDIES project, Sargasso Sea) and subtropical North Pacific (E-FLUX project, Hawaii). The observations, obtained on two sets of cruises over 2 years, occupied six cyclonic eddies and two mode-water eddies. The photosynthetic physiological parameters were measured using a bench-top fluorescence induction and relaxation (FIRe) system and a submersible in situ fast repetition rate fluorometer (FRRF) deployed on an undulating towed vehicle. Both of these instruments were used to provide highly sensitive and well-resolved data on community responses. The responses are dependent on both the type of eddy and its stage of development. Our results indicate that, while cyclonic eddies in the Atlantic and Pacific can increase primary photosynthetic production early in their development, mode-water eddies in the subtropical North Atlantic can support patchy blooms of large diatoms for long periods of time (more than 3 months).