Quantifying the impact of watershed urbanization on a coral reef: Maunalua Bay,Hawaii

Human activities in the watersheds surrounding Maunalua Bay, Oahu, Hawaii, have lead to the degradation of coastal coral reefs affecting populations of marine organisms of ecological, economic and cultural value. Urbanization, stream channelization, breaching of a peninsula, seawalls, and dredging on the east side of the bay have resulted in increased volumes and residence time of polluted runoff waters, eutrophication, trapping of terrigenous sediments, and the formation of a permanent nepheloid layer. The ecosystem collapse on the east side of the bay and the prevailing westward longshore current have resulted in the collapse of the coral and coralline algae population on the west side of the bay. In turn this has lead to a decrease in carbonate sediment production through bio-erosion as well as a disintegration of the dead coral and coralline algae, leading to sediment starvation and increased wave breaking on the coast and thus increased coastal erosion. The field data and resulting coral reef ecohydrology model presented in this paper demonstrate and quantify the importance of biophysical processes leading to coral reef degradation as the result of urbanization. Coral restoration in Maunalua Bay will require an integrated ecosystem approach.     

海藻叶面附着细菌群落生理特性与荧光原位杂交分析

实验对青岛沿海10月的石莼以及5月的石莼和裙带菜的叶面附着细菌群落进行了Biolog碳源利用实验,结果表明不同海藻表面的细菌群落碳源利用有较大的差异,且同一种海藻不同的采集时间其细菌群落也有较大的差异.荧光原位杂交方法表明采用EUB-fluo探针比SYBR-Green染色的效果要好; γ-Proteobacteria在不同海藻表面占据了较高的比例;裙带表面观察到了一些特异性链珠状细菌;石莼表面的细菌形态展示了较高的多样性.从海藻表面分离的优势菌落中分离到1株细菌,16SrDNA测序表明该序列与已知的Pseudoalteromonas16S rDNA序列的相似性为99.9%.本研究为海洋无环境公害防污材料的研究提供了一些新的思路.     

30株海洋绿藻的总脂含量和脂肪酸组成

对 11属 (小球藻属、绿囊藻属、微绿球藻属、海绿球藻属、卵胞藻属、原球藻属、咸胞藻属、杜氏藻属、裂丝藻属、塔胞藻属和衣藻属 )的 30株海洋绿藻进行特定条件下的一次性培养 ,在指数生长末期收获 ,进行了总脂含量和脂肪酸组成的分析。 2 1株海洋绿藻的总脂含量超过干重的10 % ,达 11.6 1%～ 34.4 9% ,其它 9株在 4 .2 5%～ 9.4 8%之间 ,绿藻的 16碳和 18碳脂肪酸最为丰富 ,有着含量较高的 16∶ 0、16∶ (n- 3)、18∶ 2 (n- 6 )和 18∶ 3(n- 3)脂肪酸。两株小球藻 (C95,C97)的2 0∶ 5(n- 3)脂肪酸含量较高 ,分别为 2 0 .8%和 2 6 .1%。另一株小球藻 (C10 2 )和两株裂丝藻 (C19和C2 0 ) EPA含量居中 ,分别为 8.0 % ,6 .0 %和 8.1%。其它藻株一般只含有少量的 2 0∶ 5(n- 3)和 2 2∶ 6 (n- 3)或不含 2 2∶ 6 (n- 3)     

Production of methyl chloride and methyl bromide in laboratory cultures of marine phytoplankton

Laboratory cultures of three phytoplankton species (Phaeodactylum tricornutum, Phaeocystis sp., Thalassiosira weissflogii) were tested for methyl halide (monohalomethane) production by sparging and cryotrapping coupled with GC-ECD detection. Both axenic and xenic cultures were tested under various nutrient regimens. Production of methyl bromide (CH₃Br) and methyl chloride (CH₃Cl) was observed in all cultures. Methyl iodide (CH₃I) production was also observed but could not be quantified due to Chromatographic interference. No consistent differences in production rates were observed between axenic and xenic cultures or between nutrient regimens. Methyl halide production was not directly dependent on photosynthesis. Within each species, total methyl halide production was most closely correlated with biomass, measured as utilized nitrate (ΔDIN) or Chl a. Among the three species, Phaeocystis sp. had the highest production rates and T. weissflogii the lowest. In all cases, the biomass-normalized production rates were only a fraction of the levels needed for the ocean to constitute a significant global source of either CH₃Cl or CH₃Br. However, it must be noted that these data comprise results from a limited number of species and a limited range of conditions.     

不同磷源对藻类生长及其生化组成的影响

在实验室培养条件下，对ＫＨ２ＰＯ４及多种溶解有机磷化合物对藻灶进行了一次性培养，考察要对ＤＯＰ的利用和不同磷源对藻类生物及其生化组成的影响。结果表明；甘油磷酸钠，６－磷酸葡萄糖，蛋黄卵磷脂和酵母核糖核酸均可被藻类吸收利用，并且培养藻类都生长良好；碱性磷酸酶在大分子ＤＯＰ利用过程中起重要作用。     

青岛小青岛海区底栖海藻研究

本文对青岛的小青岛海区的底栖海藻进行了年周期(1988.4—1989.3)的研究观察,分析了全年藻类的种群结构和季节变化、生物量变化,并对其作了初步分析。全年共采集底栖海藻标本61属、78种。其中红藻34属44种;褐藻16属19种;绿藻9属14种;兰藻1属1种。[见检索表] 全年中不同方位生物量以东面最高,北面最低。     

4种单胞藻同化速率与温度关系的实验研究

本文采用~(14)C示踪法,实验研究了温度对小球藻、牟氏角毛藻、聚生角毛藻和钙质角毛藻同化速率的影响,发现这4种藻类的同化速率随温度呈非线性函数变化,并从理论上阐述了藻类生长过程中对温度的要求和适应,以及这4种藻类光合过程的平均活化能。     

多种糖类添加物对秘鲁鱿鱼(Loliginidae)肌原纤维蛋白抗冻保水效果及构象变化影响研究

为探索海藻糖类对于冷冻水产品的抗冻保水效果,以秘鲁鱿鱼(Loliginidae)鱼糜为研究对象,以焦磷酸钠保水处理为对照,研究海藻糖、海藻胶寡糖及海藻胶对秘鲁鱿鱼鱼糜蛋白质抗冻保水的作用效果。结果表明,–18°C冻藏6周后,1.0%海藻糖和海藻胶寡糖(500—600Da)处理效果最好,可显著降低冷冻鱿鱼鱼糜解冻汁液流失(5.00%—5.54%),其与焦磷酸钠保水效果无显著性差异(5.02%—5.48%,P0.05)。整个冻藏期内,随着冻藏时间延长,不同处理鱿鱼鱼糜盐溶性蛋白、Ca2+-ATPase活性及总巯基均呈逐渐下降趋势,其中海藻糖、海藻胶寡糖对鱿鱼鱼糜蛋白质特性的保护效果,显著优于蒸馏水、焦磷酸钠处理(P0.05)。本研究可为开发一种安全、高效、节能、环保,适用于冷冻鱿鱼的海藻糖类抗冻保水剂提供参考。     

三亚湾珊瑚来源虫黄藻不同株系微环境中微生物群落结构的差异比较分析

虫黄藻、细菌和造礁石珊瑚有着密切的共生关系, 但虫黄藻藻际细菌群落尚未得到广泛研究。本研究对5个属的6株虫黄藻进行了离体培养, 其中2株为悬浮型虫黄藻(E型), 4株为贴壁型虫黄藻(A—D型)。通过采集藻株培养物3种粒径的样本开展细菌群落分析, 分别为0.2~3μm(自由生活)、>3μm(附着于藻体或颗粒物)与Settling(沉底贴壁藻体上)。结果发现, 2种生活方式的藻株藻际细菌群落具有显著差别, 贴壁型藻株细菌群落的物种丰富度显著高于悬浮型藻株。发现7个属的细菌广泛存在于所有的藻株中, 它们代表了A—E型虫黄藻藻际细菌的核心类群。对3种粒径样本的核心细菌群落比较发现, 自由生和颗粒附着生的核心细菌群落十分相似, 但均与沉底贴壁样本差异明显。     

Physical disturbance and subtidal habitat structure on open rocky coasts: Effects of wave exposure, extent and intensity

Canopy-forming algae occur across of range of energy environments (i.e., wave sheltered to exposed coasts) where disturbances are frequent (i.e., gap formation) and benthic patterns largely reflect variation in post-disturbance processes. Disturbances vary in extent (area affected) and intensity (degree of damage), and this may affect recolonisation at local scales. On an open oceanic coast, we tested whether habitat structure (patches of canopy algae) differed between heavy and relatively lighter wave exposure (sheltered vs. exposed sides of islands), and whether wave exposure affected the response of prominent habitat-formers to varying disturbance regimes (different sizes of partial and complete canopy removal). Observations of naturally occurring patterns showed sheltered coasts to be characterised by small patches of fucoids, whereas exposed coasts were characterised by large patches of kelp. Canopy-gaps were larger at exposed than sheltered coasts, and mixed canopies constituted > 24% of the subtidal rocky habitat independently of wave exposure. Experimental disturbances showed the local density of kelps to affect recovery through greater recruitment to partial clearings (80% canopy removal). Fucalean algae, on the other hand, mainly recruited into complete clearings (100% removal), but when their recruits were abundant, they also recruited into partial clearings. The covers of filamentous, turf-forming algae increased in all clearings, and more so at exposed than sheltered sites. Extent of disturbance had no detectable effect on recolonisation by canopy-forming algae across the scales examined (i.e., 1.5 m, 3 m diameter loss of canopy). Recolonisation varied among islands kilometres apart, and correlations (r > 0.85) between cover of canopies and cover of their recruits in clearings at the scale of sites, suggested that differences in propagule supply could account for variation in patterns of recolonisation at scales of kilometres. There was no evidence to suggest that the effect of disturbance depended on wave exposure within the range of exposures tested in this study (i.e. open coasts). We recognise that wave exposure can be fundamental to habitat structure of subtidal rocky coasts, but we suggest that its influence may be mediated by the biological setting (e.g., canopy composition).