微藻养殖中的新型光生物反应器系统

目前世界上微藻的大规模养殖仍普遍采用开放池式生产系统，该系统具有许多不足之处，开发高效、易于控制的新型生产系统是今后发展的趋势。本文对一些新型光生物反应器系统如优化的浅水道式生产系统、密闭管道式、发酵罐式光生物反应器。

固定化硫酸盐还原菌降低盐藻砷含量研究

为降低养殖盐藻产品的砷含量,作者从日晒盐田中分离耐盐硫酸盐还原菌群/株,制备硫酸盐还原菌固定化小球,分析其厌氧处理盐藻藻泥的除砷效果。结果表明:采用高通量测序技术分析耐盐SRB菌群16S rDNA序列的多样性,发现Thalassobacillus属菌株为菌群中丰度最高的物种。采用16S rDNA序列分析法鉴定生长速度最快的纯菌株SRB-6为表皮葡萄球菌,生理特性分析结果表明菌株SRB-6为pH值敏感型中温性中度嗜盐菌,其最适培养温度、起始pH值、培养盐度和接种量分别为37℃、8、12%和4%。利用耐盐SRB菌群和表皮葡萄球菌SRB-6固定化小球厌氧处理盐藻藻泥,结果表明处理后藻粉中的砷含量降低且β-胡萝卜素含量提高。表皮葡萄球菌SRB-6的砷去除能力较强,砷去除率为16.55%,藻粉的β-胡萝卜素含量提高35.92%。

Construction of an Ecological Ditch Based on Periphyton Reactor

[Objective] This study aimed to make the effluent of constructed wetlands in a pond recirculating aquaculture system satisfy aquaculture requirements. [Method] A 150 m long, 0.5 m wide and 0.6 m deep ecological ditch was constructed on the basis of the periphyton reactor theory, to investigate the reoxygenation and deep purification effect of the ecological ditch on the effluent of constructed wetlands. [Result] Experimental results showed that the level of dissolved oxygen （DO） in the effluent of constructed wetlands increased to a range of 4.41-7.91 mg/L and pH val- ue increased significantly by flowing though the ecological ditch （P〈0.05）. DO level in the water of ecological ditch increased linearly with the increasing length of the ecological ditch within the range of 150 m （P〈0.05）. The ecological ditch showed further removal effect on NH4＋-N, IMn and PO4^3 -P in the effluent of the constructed wetlands, with the removal rate of 19.46%, 13.38% and 31.09%, respectively. The total coliform group was also eliminated with the removal rate ranging between 12.5% and 78.13%. [Conclusion] The ecological ditch based on periphyton reactor could improve DO level and further reduce N and P contents in the effluent of the constructed wetlands, which could be used as a matching water-reuse system of constructed wetlands. Key words Water quality; Purification; Dissolved oxygen; Periphyton; Pond aquaculture

Effect Research of Immobilized Algae-bacteria Removal Ammonia Nitrogen of Aquaculture Wastewater and Proposed Model

Applied Immobilized algae bacteria (ABI) to remove ammonia of freshwater aquaculture wastewater. Temperature (T),PH,light intensity (I),dissolved oxygen (DO) and filling rate five factors plays important role in the process of ammonia nitrogen removal ,related data between ammonia removal and five factors was received through multi-factor orthogonal test,and established relations model between the five factor and nitrogen removal. The results show that five-factors had significant effect on AR,and the best combinations for removing AR was temperature 30 ℃,pH=7.0,light intensity 6 000 lux,dissolved oxygen 5.0 mg/L and the fill rate 10%. According to the experimental data,equation model was proposed and coefficient of determination R2 =0.864 8,P<0.05. Samples T-test was done between the model predictions and the actual measured values.Test results showed that the significant difference of overall mean value sig. (2-tailed) was 0.978 (P>0.05),it Shows that had no significant difference between model predictions and the actual measured value,and model had a high degree of fitting.

天然胡萝卜素产业悄然兴起

β-胡萝卜素健康领域用途广泛β-胡萝卜素是广泛存在于绿色和黄、橙、红色蔬果中的天然类胡萝卜素,是所有类胡萝卜素中含量最大的一种。近年来的研究表明,β-胡萝卜素除了作为维生素A的前体.

Growth performance,digestive enzyme activities and serum nonspecific immunity of the red tilapia(Oreochromis mossambicus×Oreochromis niloticus)feddiets supplemented with ultrafine powder of Enteromopha prolifera

The present study evaluated ef fects of ultrafine powder of the green macroalgae E nteromopha prolifera as dietary supplement on growth performance, digestive enzyme activities and serum nonspecific immune responses of the red tilapia(O reochromis mossambicus × Oreochromis niloticus). The red tilapia were fed five diets supplemented with different levels of E. prolifera ultrafine powder as well as a control diet containing no E. prolifera for seven weeks(Diets 0–6 contained 0(control), 10, 20, 30, 40 and 50 g/kg of E. prolifera ultrafine powder, respectively). The results showed that diets supplemented with E. prolifera ultrafine powder generally improved growth, immunity and digestive enzyme activities of the red tilapia. In particular, the fish fed the diet incorporated 50 g/kg (5%) E. prolifera ultrafine powder(Diet 5) achieved the highest percentage weight gain, specific growth rate and the condition factor(increased by 15.4%, 8.0% and 5.7%, respectively when compared to the control). Feeding the diet also led to significantly increases( P <0.05) in serum nonspecific immune responses, including total superoxide dismutase, acid phosphatase, alkaline phosphatase, lysozyme activities and serum total protein(increased by 19.4%, 48.1%, 29.5%, 30.3% and 8.7%, respectively) as well as digestive enzyme activities of erepsin, gastric amylase, gastric lipase, pepsin, intestinal amylase and gastric lipase(increased by 15.7%, 33.3%, 16.3%, 21.3%, 52.3% and 28.2%, respectively) than those of the control. Based on these results, it is recommended that the inclusion level of E. prolifera ultrafine powder in the diet of the red tilapia should be 50 g/kg(or 5%).

The Seaweed Business Development in Indonesia

In Indonesian marine area about 555 species of seaweed have been identified and of these 55 species are being commercially utilized and have been successesfully cultivated. Three varieties of macro algae have been most successfully cultivated, i.e., Eucheuma cottony, Eucheuma spinosum and Gracilaria verucosa. The global financial crisis has reduced the worldwide demand for carrageenan by 20-30%. Demand continues to be slow and there is little evidence so far that this situation will change in the short term. There are signs, however, that demand might start to pick up on the 1st quarter of next year but is not expected to meet the same level as experienced during 2008. Based on survey data, the is about 1.2 million ha which centered around 15 provinces. In potential area of Indonesian coastal water for seaweed cultivation these areas, the production of Eucheuma cottonii （Kappaphycus alvarezii （Doty）） and Eucheuma spinosum （Eucheuma denticulatum （N. L. Burman） F. S. Collins ＆ Hervey） has amounted to around 42% of the supply. These natural resources provide excellent prospects for future development of the seaweed business in Indonesia.

Development of a Seaweed Species-Selection Index for Successful Culture in a Seaweed-Based Integrated Aquaculture System

Integrated multi-trophic aquaculture (IMTA) has been proposed as a concept that combines the cultivation of fed aquaculture species (e.g., finfish/shrimp) with extractive aquaculture species (e.g., shellfish/seaweed). In seaweed-based integrated aquaculture, seaweeds have the capacity to reduce the environmental impact of nitrogen-rich effluents on coastal ecosystems. Thus, selection of optimal species for such aquaculture is of great importance. The present study aimed to develop a seaweed species-selection index for selecting suitable species in seaweed-based integrated aquaculture system. The index was synthesized using available literature-based information, reference data, and physiological seaweed experiments to identify and prioritize the desired species. Undaria pinnatifida, Porphyra yezoensis and Ulva compressa scored the highest according to a seaweed-based integrated aquaculture suitability index (SASI). Seaweed species with the highest scores were adjudged to fit the integrated aquaculture systems. Despite the application of this model limited by local aquaculture environment, it is considered to be a useful tool for selecting seaweed species in IMTA.

De-eutrophication of effluent wastewater from fish aquaculture by using marine green alga Ulva pertusa

The de-eutrophication abilities and characteristics of Ulva pertusa, a marine green alga, were investigated in Qingdao Yihai Hatchery Center from spring to summer in 2005 by analyzing the dynamic changes in NH4-, NO3-, NO2- as well as the total dissolved inorganic nitrogen （DIN）. The results show that the effluent wastewater produced by fish aquaculture had typical eutrophication levels with an average of 34.3 ~mol L-1 DIN. This level far exceeded the level IV quality of the national seawater standard and could easily lead to phytoplankton blooms in nature if discarded with no treatment. The de-eutrophication abilities of U. pertusa varied greatly and depended mainly on the original eutrophic level the U. pertusa material was derived from. U. pertusa used to living in low DIN conditions had poor DIN removal abilities, while materials cultured in DIN-enriched seawater showed strong de-eutrophication abilities. In other words, the de-eutrophication ability of U. pertusa was evidently induced by high DIN levels. The de-eutrophication capacity of U. pertusa seemed to also be light dependent, because it was weaker in darkness than under illumination. However, no further improvement in the de-eutrophication capacity of U. pertusa was observed once the light intensity exceeded 300 pmolM2 S1. Results of semi-continuous wastewater replacement experiments showed that U. pertusa permanently absorbed nutrients from eutrophicated wastewater at a mean rate of 299 mg/kg fresh weight per day （126 mg/kg DIN during the night, 173 mg/kg in daytime）. Based on the above results, engineered de-eutrophication of wastewater by using a U. pertusa filter system seems feasible. The algal quantity required to purify all the eutrophicated outflow wastewater from the Qingdao Yihai Hatchery Center into oligotrophic level I dean seawater was also estimated using the daily discharged wastewater, the average DIN concentration released and the de-eutrophication capacity of U. pertusa.

Succession and seasonal variation in epilithic biofilms on artificial reefs in culture waters of the sea cucumber Apostichopus japonicus

Periphytic biofilms in aquaculture waters are thought to improve water quality, provide an additional food source, and improve the survival and growth of some reared animals. In the AsiaPacific region, particularly in China, artificial reefs are commonly used in the commercial farming of sea cucumbers. However, few studies have examined the epilithic biofilms on the artificial reefs. To gain a better understanding of the succession of epilithic biofilms and their ecological processes in sea cucumber culture waters, two experiments were conducted in culture waters of the sea cucumber Apostichopus japonicus in Rongcheng, China, using artificial test panels. On the test panels of succession experiment, more than 67 species were identified in the biofilms. On the test panels of seasonal variation experiment, more than 46 species were recorded in the biofilms. In both experiments, communities of epilithic biofilms were dominated by diatoms, green algae and the annelid Spirorbis sp. In the initial colonization, the dominant diatoms were Cocconeis sp., Amphora spp. and Nitzschia closterium in June, which were succeeded by species of Navicula, Cocconeis and Nitzschia(July to September), and then by Licmophora abbreviata, Nitzschia closterium and Synedra spp. in the following months. A diatom bloom in the autumn and filamentous green algae burst in the summer were also observed. Ecological indices well annotated the succession and seasonal changes in epilithic communities. Multidimensional scaling(MDS) analysis found significant differences in diatom community composition among months and seasons. Fast growth of biofilms was observed in the summer and autumn, whereas the biomass of summer biofilms was largely made up of filamentous green algae. Present results show that the components of epilithic biofilms are mostly optimal foods of A. japonicus, suggesting that biofilms on artificial reefs may contribute important nutritional sources for sea cucumbers during their growth seasons. Future works should include quantitative determination of the contribution of epilithic biofilms to the diet of A. japonicus, potential roles of epilithic biofilms in regulating the water quality of sea cucumber ponds, and the regulation of epilithic biofilms in sea cucumber culture ponds.

Comparative study of brine shrimp bioassay-based toxic activities of three harmful microalgal species that frequently blooming in aquaculture ponds

Typical harmful micro-algal species constantly occurred in high density in marine aquaculture ponds in Xiangshan and Sanmen Bay, Zhejiang Province. Fates of the microalgal cells influenced by activity of the cultured animals largely determined the ef fects of the harmful microalgae. However, it is difficult to detect the in situ process. In this paper, toxic activities of three harmful microalga, namely P rymnesium parvum, Pleurochrysis elongata, Karlodinium veneficum, which were isolated from the local ponds, were comparatively studied based on brine shrimp toxic bioassays. Diff erent lethal activities of live cells, cell debris, cellular extracts, and cell free mediums prepared by different process were analyzed. The results showed that,(1) all of the three microalgal species had density and time dependent lethal ef fects on A rtermia nauplii, while P. parvum was the most toxic one and had acute lethal eff ects in 5 h. No such acute lethal eff ects were observed in P. elongata or K. veneficum;(2) live cells, cell debris and cellular extracts of P. parvum had the same lethal pattern. Prymnesins, toxin from P. parvum, is probably not exotoxic active; For P. elongata, toxic activity mainly came from live cells and cell debris; For K. veneficum, toxic activity was relatively lower compared with the other two species. However, Karlotoxin, toxin from K. veneficum, is exotoxic active. Physical disturbance triggered K. veneficum cells actively releasing toxins, which made it an active predator.

Culture techniques and growth characteristics of Dinophysis acuminata and its prey

The dinoflagellate Dinophysis acurninata Claparede ＆ Lachrnann is a toxic alga that causes diarrhetic shellfish poisoning. No Dinophysis species were maintained in culture for a long period of time until 2006 when Park successfully established D. acuminata in culture using a three-step feeding protocol in which the cryptophyte, Geminigera cryophila, is fed to Myrionecta rubra （=Mesodinium rubrum）, a ciliate that is in turn fed to D. acuminata. In this paper, we present the details of culturing D. acuminata from the Northeastern United States. The protocols described herein can be adopted for laboratory studies of this species. The effects of temperature on the growth and ingestion rates of D. acuminata were also examined. The results show that D. acuminata growth rate was 0.23/d at 10℃ and 0.11/d at 4℃when fed M. rubra prey. The maximum prey ingestion rate was 2.80 Dinophysis cell/d at 10℃, although the rate decreased slightly at 4℃. In overall, temperature showed a greater influence on growth rate of D. acuminata than on the ingestion rate under the study conditions, and the quantity of available food was also an important regulator to D. acurninata growth.

The benthic diatom community of Xiangshan Bay

The samples collected from the surface sediments in Xiangshan Bay,Zhejiang province in May and November 2005 were analyzed under a light microscope.The species composition,abundance,community structure and diversity were investigated.A total of 179 taxa belonging to 46 genera of diatom were identified.The result showed that the ecotypes of diatom were mostly eurytopic species,followed by warm water species and temperate species.The most dominant species were Cyclotella stylorum and Coscinodiscus jonesianus.The seasonal variation of diatom abundance was remarkable.The cell abundance of diatoms was higher in spring(2.974×10^3 cells/g)than that in autumn(0.071×10^3 cells/g).The number of species varies with change of season,demonstrating the adaptability of diatoms to the temperature of water.The species diversity of benthic diatom was lower in autumn than that in spring.

Macroalgae Blooms and their Effects on Seagrass Ecosystems

Seagrass decline caused by the macroalgae blooms is becoming a common phenomenon throughout temperate and tropical regions. We summarized the incidence of macroalgae blooms throughout the world and their impact on seagrass beds by direct and indirect ways. The competition for living space and using resources is the most direct effect on seagrass beds when macroalgae are blooming in an aquatic ecosystem. The consequence of macroalgae blooms(e.g., light reduction, hypoxia, and decomposition) can produce significant indirect effects on seagrass beds. Light reduction by the macroalgae can decrease the growth and recruitment of seagrasses, and decomposition of macroalgae mats can increase the anoxic and eutrophic conditions, which can further constrict the seagrass growth. Meanwhile, the presence of seagrass shoots can provide substrate for the macroalgae blooms. Controlling nutrient sources from the land to coastal waters is a general efficient way for coastal management. Researching into the synergistical effect of climate change and anthropognic nutrient loads on the interaction between searsasses and macroalgae can provide valuable information to decrease the negative effects of macroalgae blooms on seagrasses in eutrophic areas.

Pond culture of seaweed Sargassum hemiphyllum in southern China

The seaweed Sargassum hemiphyllum is widely distributed throughout the coastal waters of Asia and has high commercial value. In recent years, its natural biomass has declined due to over-exploitation and environmental pollution. To seek for a feasible way to culture this seaweed efficiently, we designed a simple long-line system in a shrimp pond for the culture during winter, and the growth and nutritional composition of the seaweed were examined. Results show that the cul^re system was durable and flexible allowing S. hemiphyllum to grow vertically offthe muddy bottom of the pond. Although the length of pond- cultured S. hemiphyllum was inhibited by water depth, the weight-specific growth rate （（1.65±0.17）%/d） was nearly three times higher than that of wild plants （（0.62±0.19）%/d）. The crude protein （6.92%±0.88%） and ash content （21.52%±0.07%） of the pond-cultured seaweed were significantly lower than those of the wild plants （9.38%±-0.43% and 26.93%±0.07%, respectively）; however, crude fat （1.01%±0.04%） was significantly higher than that of the wild plants （0.87%±0.02%）. In addition, the nutritional composition of both pond-cultured and wild S. hemiphyllum was comparable to or even higher than those of other common seaweeds being used as food and/or aquaculture fodder. Future studies shall be focused on the impact of environmental parameters on its growth and nutritional composition.

Temporal population dynamics of dinoflagellate Prorocentrum minimum in a semi-enclosed mariculture pond and its relationship to environmental factors and protozoan grazers

The ecological processes and interrelationships between protists,either autotrophic or heterotrophic,and environmental factors in mariculture ponds are largely unknown.This study investigated the temporal dynamics of potentially harmful dinoflagellate,Prorocentrum minimum (Pavillard) Schiller,and its relationship to physico-chemical factors and protozoan grazers over a complete cycle in a semi-enclosed shrimp-farming pond near Qingdao,Northern China.P.minimum occurred frequently in low numbers from June to August,followed by a sharp increase from the middle of August,reaching a single maximum peak value of 2.2×105 cells L-1 in October.Temporal variation in abundance was positively correlated with dissolved nitrogen,but showed a significant inverse relationship to abundance of the dominant ciliates,Tintinnopsis lohmanni and Askenasia stellaris.The results provide statistical evidence that the number of P.minimum increased with increasing nitrogen,and the suppression or shortening of algal bloom may be associated with protozoan grazers,such as Tintinnopsis lohmanni,in mariculture ponds.