Abstract:The species composition, density and seasonal variation of phytoplankton in Sanggou Bay were investigated in April, July and November, 2006 and January, 2007. There were 92 species belonging to 28 genera of phytoplankton collected during the surveys, which were mainly composed of diatoms (74 species) and dinoflagellates (11 species). Dominance index analysis indicated that diatoms were the predominant species. Shannon Wiener index of diversity ranged from 1.91 to 2.74 on seasonal average (Spring > Summer > Autumn > Winter). The phytoplankton densities and their distribution patterns varied in different seasons. The highest density was in winter (188.4×104 cells/m3 on average). The densities were 63.0×104 and 11.7×104 cells/m3 on average in spring and autumn, respectively. The lowest density was in summer (9.2×104 cells/m3 on average). For the horizontal distribution patterns, phytoplankton was more abundant in the coastal shallow waters of the bay in winter and summer, whereas the higher densities were found in the shellfish kelp mixed culture areas which located in the center of the bay. Compared to the historical data, the species quantity and density of the phytoplankton obviously declined in Sanggou Bay after more than 20 years' mariculture. The density of culture species and culture technology had significant influences on the quantity and seasonal distribution of phytoplankton.

Abstract:Mariculture；Biofouling；Scallop Chlamys farreri；Sanggou Bay

Abstract:The distribution of dissolved nutrients in Sanggou Bay was investigated in April,July and November 2006 and January 2007.The concentration and distribution of dissolved inorganic nitrogen (DIN),phosphate (PO43-) and silicate in Sanggou Bay showed obvious seasonal variation.DIN reached the lowest level in spring and the highest level in autumn; PO43- concentration was at the lowest level in summer and the highest level in autumn; while Si concentration reached the lowest point in autumn and the highest point in summer.Limiting nutrients for the growth of phytoplankton were assessed by the method of theoretical half saturation constant (Ks) and stoichiometric ratios among DIN,PO43-and SiO2-3.The results showed that in spring,the percentage of stations with concentration of DIN and PO43-below Ks was 44% and 39%,respectively,suggesting for potential N and P limitation.In summer,the percentage of stations with PO43-concentrations below Ks was 68%,and potential P limitation was at 79% probability,N and Si limitation were at 5% and 0% probability,respectively.In autumn and winter,Si was the major limiting nutrient,and the potential Si limitation was at 94% and 78% probability,respectively.The effect of mariculture activities,land based input,and water exchange with Yellow Sea on the space time distribution of nutrients were discussed.Based on the long term data,more attention should be paid to DIN enrichment in Sanggou Bay.

Abstract:A multi species culture ecosystem model coupled with a dynamic model that takes the culture drag into consideration was established.This three dimensional model involved four variables: phytoplankton biomass, dissolved inorganic nitrogen (DIN), particulate organic matter (POM) and kelp biomass.The model focused on the variation of the drag caused by kelp growth, and the competition of nutrients between kelp and phytoplankton.Finally, sensitivity of the parameters were analyzed.

Abstract:Based on the multi species culture ecosystem model in Sanggou Bay, the annual variation cycles and seasonal distributions of phytoplankton biomass and dissolved inorganic nitrogen (DIN) concentration were simulated. Model results indicated that the seasonal aquaculture activities made seasonal variations of DIN concentration and biomass of phytoplankton more prominent. The distributions of DIN and phytoplankton biomass were mainly influenced by the aquaculture scenarios. During the period of kelp culture, DIN from the open sea is an important source of nutrient supporting the growth of kelp, due to the exchange of water.

Abstract:Based on the multi species culture ecosystem model in Sanggou Bay, numerical experiments were done by altering the kelp culture density. The aim is to probe the kelp culture carrying capacity in Sanggou Bay. Increase of the kelp culture density at the same time enlarged the frictions caused by the culture activities, which inhibited the supply of dissolved inorganic nitrogen (DIN) from the open sea. As a consequence, there is no definite increase in the kelp production. Model results for different kelp culture densities indicated that the kelp production reached the peak when the culture density was 0.9 fold of the present one.

Abstract:The sexual reproductive traits of eelgrass Zostera marina L. in Sanggou Bay was studied during January to August, 2009. Distinguishable flowering shoots were first observed in early April. Spathes with projecting pistils and dehiscence of anthers were found in mid May, when water temperature was 14.8℃. The first visible fruit was observed in early June. Maturation of fruits and release of seeds started at the beginning of July as water temperature reached 20.4℃. Few flowering shoots were found at the beginning of August and seed release was completed by this time. Branches of reproductive shoots initiated development centripetally while spathes matured acropetally. Spathes produced at the beginning and the end of the flowering phase showed fewer pistils and lower seed setting rate. The average density of flowering shoots was 114 ind/m2 with 67.0 fruits on each shoot. The potential seed production was 7 638 ind/m2.

Abstract:In order to understand the ecological function of seagrass in coastal ecosystems in China，fouling organisms on the leaves of eelgrass Zostera marina L. in the area of Chu Island of Sanggou Bay was investigated from September 2008 to August 2009. Twenty nine species of organisms were found and the dominant species were Cocconeis scutellum, C. scutellum var. Pava, Halothrix lumbricalis, Punctaria latifolia, Chlorostoma rustica, Australaba sp. and Stenotis sp. In the spring, 9 diatom species, 7 macroalge species and 8 invertebrate species were found. Phaeophyta dominated the fouling species of eelgrass and the biomass reached the peak in April. Species of epiphytic macroalgae decreased in summer and the dominant fouling organisms were gastropoda. The number of diatom, macroalgae and invertebrate species were 8, 4 and 6, respectively. In autumn，diatom abundance reached the peak, while there were only four species of invertebrates. The number of epiphytic macroalgae species was the same as that of summer while the biomass of marcoalgae and invertebrates were less than that of the summer. No epiphytic macroalgae and invertebrate were found in winter, besides diatoms.

Abstract:The background and themes of dynamic study on mariculture carrying capacity of Sanggou Bay were described. The method used for this study was based on the fine processes observation, using physical oceanography theory and numerical model to examine the interaction between mariculture and hydrodynamics in Sanggou Bay. Design proposal and purposes for two cruises were introduced. Based on the observation we found that the kelp and the raft influenced the current vertical structure greatly, and the maximum velocity was at the lower layer with strong phase delay. It was also found that the damped current was too weak to mix the sediment detritus and nutrients into the upper layer. Based on these discoveries a double drag boundary hydrodynamic model was proposed by adding the aquaculture drag at surface. The mechanism of kelp influence on the current profile was studied numerically by a one dimension model. Considering the kelp drag in the water column besides the boundary drag, a three dimension hydrodynamic model was adopted to quantify the influence of the aquaculture on hydrodynamics and water exchange of Sanggou Bay. A physical biological coupled aquaculture ecosystem model was established using DIN, POM concentration and phytoplankton with kelp biomass as variable. The simulation and numerical experiments showed that polyculture was a useful method for healthy and high efficiency aquaculture. Sanggou Bay has nearly reached its capacity under present aquaculture mode. By cutting down aquaculture density to 0.9 fold of the present density, the total production of kelp will slightly increase and the cost will be reduced. Cutting down the kelp density at the mouth of the bay could greatly enhance the amount of nutrients and biomass in the kelp bivalve culture area in the inner side. Artificial mixing might bring more nutrients from seabed in the bay.

Abstract:从2007年5月~2008年4月，采用悬挂试网和直接从海区采集栉孔扇贝养殖笼样品两种方法，对桑沟湾贝藻养殖区的附着生物群落结构和季节演替规律进行了研究。结果显示，桑沟湾附着生物群落结构复杂，本实验鉴定的大型附着生物23种，玻璃海鞘、柄海鞘和紫贻贝是群落中的优势种。附着生物的生物量呈现明显的季节变化特征，试网上附着生物湿重与温度变化相关，生物量为0.003～1.21 kg/m2，其中2月和8月分别具有最小和最大值。栉孔扇贝养殖笼的附着生物生物量9月为1.94 kg/笼，之后随温度下降而减少，10月为0.99 kg/笼，之后又有所上升，11月份为1.03 kg/笼。生物量变化主要是由于优势种的演替引起的，随温度下降海鞘类逐渐消退，贻贝等成为优势种。

Abstract:Vertical structure of tidal current in a typically coastal raft culture area is discussed by a numerical model. A one dimensional hydrodynamic model was modified to include the tidal surface boundary layer for describing the interaction between aquaculture and tidal flow and parameterized with the field data. It replicated the observed velocity profile and was then used to investigate the impacts of varying culture densities and bottom frictions on the vertical tidal current structure. Modeling results indicate that the surface current velocity was largely damped because culture activities enhanced the frictional effects on flow intensively. The magnitude and vertical structure of tidal current are determined by aquaculture drag and bottom friction. The magnitude damps so rapidly that the vertical double log profile is distorted within a water column when the frictional effect of culture density increases to a certain threshold value. The vertical structure is remarkably deformed by the varying magnitude of bottom friction. In addition, the vertical velocity structure has a nonlinear trend along with culture density and bottom friction. The variation of the vertical structure is a kind of adaptation/adjustment to both surface friction (aquaculture drag) and bottom shear stress under the tidal forcing. This study is a theoretical foundation for optimizing aquaculture configuration through regulating culture density and species distribution. The frictional effect of culture organisms growth and suspended cage on the flow should be considered in further studies.

Abstract:The experiment was carried out under laboratory conditions to study the effects of temperature and body weight on feeding rate of scallop Patinopecten yessoensis. The feeding rate of the scallop of 5 levels of dry tissue weight was determined at temperatures of 5, 10, 15, 20 and 25 ℃. The results showed that the feeding rate of P. yessoensis was affected significantly by temperature and body weight (P<0.05). The relationship between feeding rate and temperature or dry tissue weight can be described as FR=b0＋b1T＋b2T2＋b3T3 and Y=aXb. The assimilation efficiency of P. yessoensis was affected significantly by temperature (P<0.01), but not significantly by dry tissue weight (P>0.05). The maximum feeding rate of P. yessoensis occured at 15 ℃, and the maximum assimilation efficiency was found at 10 ℃.

Abstract:Pacific oyster Crassostrea gigas summer mortality frequently occurs in Sanggou Bay recent years，but the oyster appears low mortality rate in its neighboring region Ailian bay. In this study, two typical Pacific oyster culture areas of these bays have been selected as experimental sites. The environmental factors including water temperature, salinity,pH and DO, superoxide dismutase (SOD) activity and growth situation of oysters have been monitored, and the oyster summer mortalities of two sites have been researched. The reason of Pacific oyster summer mortality in Sanggou bay has been analyzed. The results show that: in experiment period (from May to October), the total mortality rate was 37% in Yatou marine culture region of Sanggou bay (E122.498，N37.151), the highest mortality rate that appeared on August 17 was 51%. The total mortality rate was 2.5% in Ailian bay (E122.582, N37.179), the highest mortality rate that appeared on September 28 was 4.5%. One way ANOVA results show that: the mortality rate has significant positive correlation with water temperature (R=0.804, P<0.01), negative correlation with the dissolved oxygen (R=-0.377, P<0.01), negative correlation with body weight, soft weight and gonad weight and so on (R=-0.690,-0.498,-0.358, respectively), positive correlation with superoxide dismutase activity (R=0.21,P<0.05).

Abstract:A detection method of high-performance liquid chromatography (HPLC) coupled with fluorescence was developed for the determination of residues of three quinolones in seawater.pH of were water samples adjusted with dilute HCl followed by extraction and concentration through hydrophilic-lipophilic balance cartridges, and three antibiotic quinolone compounds were determined using external standard quantification method. The results showed that the detection limits of norfloxacin, ciprofloxacin and enrofloxacin were 2 μg/L, 1 μg/L and 1 μg/L respectively, and the quantitative limits were 6.6 μg/L, 3.3 μg/L and 3.3 μg/L respectively. The recoveries from natural seawater ranged from 71.9% to 85.3% when the three antibiotics were added at the concentration of 10 μg/L, 20 μg/L and 50 μg/L for norfloxacin, ciprofloxacin and enrofloxacin, respectively. The coefficients of variation within batches were equal or less than 10%, while that among batches were equal or less than 7%. The method has been successfully applied to the monitoring of the residues in the sea water samples from the Yellow Sea near Qingdao (from 36°40.303′N,121°8.939′ E to 35°39.36′N,119°52.433′E). Norfloxacin, ciprofloxacin and enrofloxacin were detected at mass concentrations of 6.20~982 μg/L, 55.2 μg/L and 11.6~55.4 μg/L respectively. The results showed that this method posessed high sensitivity and good reproducibility, and can be used for the detection of norfloxacin, ciprofloxacin and enrofloxacin in aquacultural seawater.

Abstract:The characteristics of species composition, quantity distribution and biodiversity of intertidal benthos in Nanpeng islands of Guangdong Province were analyzed in this study. Eighty species were found which belonged to 35 families. Mollusk, Crustacean and algae were the most abundant species, which comprised 84％ of the total species. and some of them were commercial species with high economic value. The average biomass and density of intertidal benthos in Nanpeng islands were 1，83131g/m2 and 21867 ind/m2, respectively. The algae and mollusks were the dominant species in biomass and density, respectively. The Shannon-Winer diversity index (H) was at high levels, distributing between a range of 3.32~3.57 with an average of 3.42; and its evenness (J) was between 0.81~0.87, with the average of 0.84.

Abstract:The effects of aldehydes produced by two algae Skeletonema costatum and Prorocentrum micans on reproduction of Calanus sinicus were investigated in laboratory. Aldehydes produced by these two algae were analyzed qualitatively and quantitatively by HS SPME/GC MS method. Compared with P. micans, S. costatum showed negative effects on female survival, egg production and egg hatching of C. sinicus. Six kinds of aldehydes were detected in S. costatum, while only 2 kinds were detected in P. micans. The content of any single aldehyde or total aldehydes in S. costatum were significantly higher than those in P. micans, indicating that the aldehydes produced by diatom could cause potential negative effects on the reproduction and survival of C. sinicus.

Abstract:Nutrient compositions and meat qualities of turbot Scophthalmus maximus, flounder Paralichthys olivaceus and sole Cynoglossus semilaevis were analyzed and compared in this paper. The results showed that the protein content of turbot and sole were much higher than that in flounder (P<0.05), while no significant difference was found between turbot and sole. There was no significant difference in the lipid and ash content in turbot, flounder and sole (P>0.05). The total amino acid in turbot, flounder and sole were 37.73, 33.32, 32.91 mg/100mg respectively, and the percentage of essential amino acids to the total amino acids (EAA/TAA) were 43.50%, 43.25%, 43.00% respectively. For fatty acids, the C20∶4, C22∶5 and C22∶6 content in turbot was significantly higher than that in flounder and sole, and the C20∶5 content in flounder was significantly higher than that in turbot and sole. For texture, the hardness of turbot was significantly higher than that of flounder and sole (P<0.05), and the springiness of turbot and flounder was significantly higher than that of sole (P<0.05). The content of soluble collagen in turbot was significantly higher than that of flounder and sole (P<0.05), while there was no difference between flounder and sole (P>0.05). The content of insoluble collagen in turbot was significantly higher than that in flounder and sole (P<0.05), and it's significantly higher in sole than that in flounder (P<0.05).

Abstract:Biochemical compositions of flatfish were analyzed,and nutritional value and safety evaluation of flatfish were discussed based on their characteristics of biochemical composition.The results showed that the animo acids of flatfish conformed to the animo acids ideal mode(EAA/TAA about 40% and EAA/NEAA above 60%)published by FAO/WHO,and the contents of heavy metals met the relevant standards home and abroad,indicating that the proteins of flatfish were ideal and quality safe.The ratios of FAA/TAA were close in different sized flatfish,but the contents of EAA,NEAA and FAA in 1~2 kg flatfish were larger than those in 0.5 kg flatfish.

Abstract:Dominant industry areas of sea cucumber Apostichopus japonicus Selenka aquaculture had been constructed in Shandong Province, which is one of the main sea cucumber producing areas in China. Yantai, Weihai and Qingdao constituted the major culture regions in Shandong Province, and they are the leaders in the development of sea cucumber aquaculture industry. Dongying and Binzhou areas are emerging industry belt for introduction and development of sea cucumber aquaculture, which indicated that it is feasible to culture sea cucumber in western area of Shandong Province. Rizhao and Laizhou areas are a new industry belt of sea cucumber culture representing deep water well greenhouse factory culture model, which is the new spotlight in sea cucumber aquaculture industry since 2007. In this paper, the problems and challenges in sea cucumber aquaculture industry are summarized and the corresponding strategies are proposed. It will be helpful for the healthy and sustainable development of sea cucumber aquaculture industry in Shandong Province, and in other areas of China, and it may provide theoretical and technical basis for decision making of relevant authorities.