Zinc and copper bioaccumulation in fish from Laizhou Bay,the Bohai Sea

Abstract Zinc （Zn） and copper （Cu） concentrations were determined in the tissues （muscle, stomach, liver, gills, skin, and gonads） of five commercial fish species （mullet Liza haematocheilus, flathead Platycephalus indicus, mackerel Scomberomorus niphonius, silver pomfret Pampus argenteus, and sea bass Lateolabrax japonicus） from Laizhou Bay in the Bohai Sea. Metal bioaccumulation was highest in the metabolically active tissues of the gonads and liver. Bioconcentration factors for Zn were higher in all tissues （gonads 44.35, stomach 7.73, gills 7.72, liver 5.61, skin 4.88, and muscle 1.63） than the corresponding values for Cu （gonads 3.50, stomach 3.00, gills 1.60, liver 5.43, skin 1.50, and muscle 0.93）. Mackerel tissues accumulated metal to higher concentrations than did other fish species, but bioaccumulation levels were not significantly correlated with the trophic levels of the fish. Zn and Cu concentrations in the tissues were generally negatively correlated with fish length, except for a few tissues of sea bass. Risk assessment based on national and international permissible limits and provisional tolerances for weekly intake of Zn and Cu revealed that the concentrations of these two metals in muscle were relatively low and would not pose hazards to human health.     

Tissue-specific bioaccumulation and oxidative stress responses in juvenile Japanese flounder (Paralichthys olivaceus) exposed to mercury

To understand mercury (Hg) toxicity in marine fish, we measured Hg accumulation in juvenile Japanese flounder (Paralichthys olivaceus) and assessed the effects on growth and antioxidant responses. After Hg exposure (control, 5, 40, and 160 μg/L Hg) for 28 d, fish growth was significantly reduced. The accumulation of Hg in fish was dose-dependent and tissue-specific, with the maximum accumulation in kidney and liver, followed by gills, bone, and muscle. Different antioxidants responded differently to Hg exposure to cope with the induction of lipid peroxidation (LPO), which was also tissue-specific and dosedependent. As Hg concentration increased, superoxide dismutase (SOD) and catalase (CAT) activities increased significantly, whereas glutathione S-transferase (GST) activity and glutathione (GSH) levels decreased significantly in the gills. SOD and glutathione peroxidase (GPx) activities and the GSH level increased significantly in the liver. SOD activity and GSH levels increased significantly, but CAT activity decreased significantly with an increase in Hg concentration in the kidney. LPO was induced significantly by elevated Hg in the gills and kidney but was least affected in the liver. Therefore, oxidative stress biomarkers in gills were more sensitive than those in the liver and kidney to Hg exposure. Thus, the gills have potential as bioindicators for evaluating Hg toxicity in juvenile flounder.     

Deformities in silver pomfret Pampus argenteus caught from Kuwait waters

During sampling for spawning stock of the silver pomfret, Pampus argenteus in Kuwait waters, a few seriously deformed individuals were captured. These individuals had been attacked and wounded, but had healed and survived. The fish body deformities are believed to be caused by predation attempts on silver pomfret by predators such as sharks, groupers, and croakers.     

Medusa consumption and prey selection of silver pomfret Pampus argenteus juveniles

The current study explored Aurelia aurita and Rhopilema esculent um consumption by silver pomfret juveniles, as well as their prey selection between the two jellyfi sh species. Silver pomfret juveniles weighing 1±0.1 g actively preyed on both the species. Their daily A. aurita consumption was 11.6 times their own body weights regardless of the size of A. aurita medusae. Their daily R. esculent um consumption was 13, 9.1, 5, and 4.1 times their own body weights when the R. esculentum medusae were 10, 20, 30, and 40 mm in bell diameter, respectively. The survival rates of the R. esculent um were higher than those of the A. aurita. When the R. esculent um medusae were more than 30 mm in bell diameter, their survival rate exceeded 92%. Silver pomfrets serve as a type of potential predators on A. aurita in coastal waters, and they have little infl uence on R. esculent um with a size exceeding 30 mm. Besides, A. aurita may be able to be used as fi sh prey in silver pomfret artifi cial breeding.     

A model study on dynamical processes of phytoplankton in Laizhou Bay

A three-dimensional ecosystem model, using a PIC (Particle-In-Cell) method, is developed to reproduce the annual cycle and seasonal variation of nutrients and phytoplankton biomass in Laizhou Bay. Eight state variables, i.e., DIN (dissolved inorganic nitrogen), phosphate, DON (dissolved organic nitrogen), DOP (dissolved organic phosphorus), COD (chemical oxygen demand), chlorophyll-a (Chl-a), detritus and the zooplankton biomass, are included in the model. The model successfully reproduces the observed temporal and spatial variations of nutrients and Chl-a biomass distributions in the bay. The nutrient concentrations are at high level in winter and at low level in summer. Double-peak structure of the phytoplankton (PPT) biomass exists in Laizhou Bay, corresponding to a spring and an autumn bloom respectively. Several numerical experiments are carried out to examine the nutrient limitation, and the importance of the discharges of the Yellow River and Xiaoqinghe River. Both DIN limitation and phosphate limitation exist in some areas of the bay, with the former being more significant than the latter. The Yellow River and Xiaoqinghe River are the main pollution sources of nutrients in Laizhou Bay. During the flood season, the algal growth is inhibited in the bay with the Yellow River discharges being excluded in the experiment, while in spring, the algal growth is enhanced with the Xiaoqinghe River excluded.     

Distribution and accumulation characteristics of heavy metals in sediments in southern sea area of Huludao City, China

The southern sea area of the Huludao City, Liaoning Province might be polluted by heavy metals because it is close to the Jinzhou Bay, one of the heaviest sea area polluted by heavy metals in China. The undisturbed modern sediment core can be used to analyze the accumulation and source of the pollutants using 137 Cs and 210 Pb ex . Thirty-five samples of surface sediment and two core sediments were collected from the southern sea area of Huludao City. The concentrations of copper (Cu), lead (Pb), chrome (Cr), zinc (Zn), arsenic (As) and mercury (Hg) in the surface sediments as well as Cu, Pb, Zn, Cr, 137 Cs and 210 Pb ex in the core sediments were determined to research the spatial distribution and accumulation characteristics, and to analyze the sources and the potential risks of heavy metals. The results show that the pollution levels of Zn and Hg are serious, and 26 stations are at moderate or heavy ecological risks. The concentrations of the heavy metals increase from east to west, as well as from open sea to offshore marine area. The concentrations of heavy metals are not high in the sediments adjacent to the Jinzhou Bay, and the influence caused by the seawater exchange with the Jinzhou Bay is little. The concentrations of the heavy metals in the core sediments show low-high-low characteristic, and it coincides with the pollution history of Huludao City. The atmospheric deposition of heavy metals from the Huludao Zinc Plant is likely to be the main source of pollution without direct discharge of wastewater. The high concentrations of heavy metals appear on the upper sediment of 20 cm. The shallow sediment with high heavy metal contents might be exposed to surface when it was disturbed by the ocean engineering and big storm surge, then cause risk to the safety of aquaculture and human healthy.     

The characteristics of <Emphasis Type="Italic">vasa</Emphasis> gene from Japanese sea bass (<Emphasis Type="Italic">Lateolabrax japoni</Emphasis>cas) and its response to the external hormones

The RNA helicase Vasa is an important regulator of primordial germ cell development. Its function in mature fish, especially the hormone-related differences in maturing male fish has seldom been documented. In this study, a full length cDNA sequence of the vasa gene was cloned from Japanese sea bass, Lateolabrax japonicas, and it was named jsb-vasa. Homology analysis showed that jsb-vasa was closely related to its teleost homologs. The spatial distribution of jsb-vasa indicated that it was only highly expressed in testis, showing its germ cell-specific expression pattern. During the testicular development cycle, jsb-vasa was highly expressed during early period of spermatogenesis, and reduced when spermatogenesis advanced. In addition, the jsb-vasa gene expression was significantly inhibited at 6 h, 12 h and 24 h after injecting hCG (human chorionic gonadotropin) and GnRHa (Gonadotropin-releasing hormone analogue), indicating that jsb-vasa gene may play an important role in spermatogenesis of Japanese sea bass, and be under the regulation of external sex hormones.     

Effects of mercuric chloride on antioxidant system and DNA integrity of the crab Charybdis japonica

Mercury (Hg) is one of the commonly encountered heavy metals, which is widespread in inshore sediments of China. In order to investigate the toxicity of Hg on marine invertebrates, we studied the effects of the divalent mercuricion (Hg²⁺) (at two final concentrations of 0.0025 and 0.0050 mg L⁻¹, prepared with HgCl₂) on metallothionein (MT) content, DNA integrity (DNA strand breaks) and catalase (CAT) in the gills and hepatopancreas, antioxidant enzyme activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), in the hemolymph, gills and hepatopancreas of the portunid crab Charybdis japonica for an experiment period up to 15 d. The results indicated that MT was significantly induced after 3 d, with a positive correlation with Hg²⁺ dose and time in the hepatopancreas and a negative correlation with Hg²⁺ dose and time in the gills. While CAT in the hemolymph was not detected, it increased in the hepatopancreas during the entire experiment; SOD and GPx in the three tissues were stimulated after 12 h, both attained peak value and then reduced during the experimental period. Meanwhile, DNA strand breaks were all induced significantly after 12 h. These results suggested the detoxification strategies against Hg²⁺ in three tissues of C. japonica.     

Localization and dynamic expression of a 27.8 kDa receptor protein for lymphocystis disease virus infection in sea bass (<Emphasis Type="Italic">Lateolabrax japonicus</Emphasis>) tissues

Lymphocystis disease virus (LCDV) infects target cells by attaching to a 27.8 kDa receptor (27.8R) protein in flounder Paralichthys olivaceus, and anti-27.8R monoclonal antibodies (MAbs) have been developed. However, the 27.8R existence in tissues of sea bass (Lateolabrax japonicus) and its role in LCDV infection have remained unclear. In this study, the results of western blotting demonstrated that the same 27.8R was shared by flounder and sea bass. LCDV-free sea bass individuals were intramuscularly injected with LCDV, and viral copies were detected in tissues from 3 h post infection and showed a time-dependent increase during 9 days infection. Distribution and synthesis of 27.8R in sea bass tissues were investigated by using anti-27.8R MAbs as probes. It was found that 27.8R was distributed in all the tested tissues. The levels of 27.8R protein were highest in gill and skin, then a bit lowly in stomach, head kidney and heart, followed by spleen, intestine, blood cells, gonad and liver, and least in kidney and brain in healthy sea bass. Upon LCDV infection, 27.8R synthesis was up-regulated in each tissue, and higher in the tissues with higher LCDV copies. The 27.8R and LCDV were detected in some peripheral blood leukocytes but not in red blood cells. These results suggested that 27.8R was widely distributed in sea bass tissues, and it served as a receptor and correlated with tissue tropism of LCDV infection. Furthermore, leukocytes had the potential of being a LCDV carrier and were responsible for a systemic infection of LCDV in sea bass.     

Risk assessment and zoning of sea level rise in Shandong Province

Sea level rise is a slow-onset disaster. We collected information about the natural and ecological environments, tides and sea levels, and socio-economic aspects to investigate the distribution and zoning of the risks from sea level rise across Shandong Province. The trends in sea level in different counties of Shandong Province were predicted using moving averages and a random dynamic analysis forecasting model, and the model outputs and socio-economic indicators were combined to assess the risks. The results show that the risks of sea level rise along the western coast of Bohai Bay and Laizhou Bay in Shandong Province were sufficiently large to warrant attention.     

The distribution and variation of elements in sediments off the Huanghe (Yellow) River mouth

Surface sediment samples collected off the Huanghe (Yellow) River mouth during the period 2007–2009 were analyzed for major and trace element concentrations. Concentrations of 16 elements were measured using X-ray fluorescence spectrometry. Results demonstrate that sediment grain size is the dominant factor controlling the spatial variations of elemental concentrations. Correlation and cluster analyses allowed classification of the study area into four geochemical regions: Regions I and III are characterized by high concentrations of Al₂O₃, Fe₂O₃, MgO, Na₂O, K₂O, Cr, Cu, Mn, Ni, Pb, V, and Zn, and contain fine-grained sediments with mean grain size (M _z)<22 μm; and; Regions II and IV contain mostly coarse-grained sediments, and are characterized by high concentrations of SiO₂, Na₂O, and Zr. The sediment entering the sea from the Huanghe River and its tributaries is enriched in Ca. Thus, the Ca/Al ratio was used as an indicator of the proportion of sediments in the study area that originated from the Huanghe River. Ca/Al ratios decrease from Regions I and II (located in the nearshore zone of the Huanghe River delta) to Regions III and IV (distributed in the offshore zone of the northern Huanghe River delta, southern and southeastern Laizhou Bay area).     

黄河三角洲高效生态经济区海岸带地貌环境特征及发育模式

黄河三角洲高效生态经济区是具有国家战略地位的重要生态经济区,该地区的海岸带地处海陆交接地带,属于陆缘海海岸带,生态环境脆弱,区域海岸带地形地貌系统性阐述甚少。在开展该区域生态地质环境调查的基础上,结合实际调查情况及以往文献的研读,对该地区海岸带地形地貌、岸滩地貌类型及特征进行了系统性归纳总结。整个黄河三角洲高效生态经济区的海岸带地貌分黄河三角洲粉砂淤泥质海岸、莱州湾南岸潍北平原区粉砂淤泥质海岸、莱州砂质海岸3个部分。岸滩类型分为黄河三角洲岸段冲淤平衡潮滩、侵蚀潮滩、淤积潮滩3种及莱州湾岸段侵蚀潮滩及侵蚀砂质海滩2种。     

Selection of diet for culture of juvenile silver pomfret, Pampus argenteus

Juvenile silver pomfret, Pampus argenteus, was grown in culture tanks for 9 weeks on four different diets, and their effects on fish growth, digestive enzyme activity, and body composition were assessed. The feeding regime was as follows: Diet 1: fish meat; Diet 2: fish meat+artificial feed; Diet 3: fish meat+artificial feed+Agamaki clam meat; Diet 4: fish meat+artificial feed+Agamaki clam+copepods. The greatest weight gain was associated with Diet 4, while the lowest weight gain was associated with Diet 1. No significant difference was observed in weight gain between fish receiving Diet 2 and Diet 3. Specific growth rate followed similar trends as weight gain. The feed conversion ratio (FCR) of fish fed Diet 1 was significantly higher than the other fish groups, but no significant differences were observed in FCRs of fish fed Diet 2, Diet 3 or Diet 4. There was also no significant difference in the hepatosomatic index (HSI) between the four diets. For fish that received Diets 2-4, containing artificial feed, higher protease activities were detected. A higher lipid content of the experimental diets also significantly increased lipase activities and body lipid content. No significant differences in amylase activity or body protein content were found between Diets 1-4. In conclusion, a variety of food components, including copepods and artificial feed, in the diet of silver pomfret significantly increased digestive enzyme activity and could improve growth performance.     

烟台近岸海域表层沉积物重金属污染特征

采取烟台近岸海域150个海底表层沉积物样品进行Hg,Cu,Pb,Zn,Cd,Cr,As,Ni元素分析。结果显示,烟台市近岸海域重金属主要富集在芝罘湾(Cd,Cu)、龙口(As,Cr,Cu)及海阳东部(Ni,Pb)一带,而莱州、招远及牟平近岸海域重金属含量较低。单因子、内梅罗和潜在生态危害指数评价结果显示,研究区88%海域的沉积物达到一类标准,轻污染区主要分布在芝罘岛北部及龙口市西部,龙口、招远及烟台市近岸沉积物潜在风险中等。     

Identification and characterization of a new IgE-binding protein in mackerel (Scomber japonicus) by MALDI-TOF-MS

As fish is one source of the ‘big eight’ food allergens,the prevalence of fish allergy has increased over the past few years.In order to better understand fish allergy,it is necessary to identify fish allergens.Based on the sera from fish-allergenic patients,a 28 kDa protein from local mackerel (Scomber japonicus),which has not been reported as a fish allergen,was found to be reactive with most of the patients’ sera.The 28 kDa protein was analyzed by MALDI-TOF-MS (Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry).Mascot search in NCBI database (Date: 08/07/2010) showed that the top protein matched,i.e.triosephosphate isomerase (TPI) from Xiphophorus maculatus and Poecilia reticulata,had a mowse (molecular weight search) score of 98.In addition,TPI from Epinephelus coioides also matched this mackerel protein with a mowse score of 96.Because TPI is con-sidered as an allergen in other non-fish organisms,such as lychee,wheat,latex,archaeopotamobius (Archaeopotamobius sibiriensis) and crangon (Crangon crangon),we consider that it may also be an allergen in mackerel.     

Microhabitat distribution of metazoan parasites on gills ofSilurus asotus in Jiangkou Reservoir, Jiangxi Province, China

This paper deals with the proportional distribution, niche breadth and niche overlap of two metazoan parasites (copepods species,Ergasilus anchoratus Markewitsch, 1946 andPseudergasilus parasiluri Yamaguti, 1936) and monogeneans (in the genusSilurodiscoides Gussev, 1976) found on gills of the fish,Silurus asotus L. from Jiangkou Reservoir in Jiangxi Province, China.E. anchoratus was the common and dominant metazoan parasite on gills of the fish in this locality as indicated by the higher infection levels, and distributed almost evenly on gill arches without any observed gill-arch preference, as shown by the wide proportional distribution and broad niche breadth.P. parasiluri and monogeneans inSilurodiscoides were found also without any significant gill-arch preference although they had a rather narrow niche breadth. The observed significant overlap betweenP. parasiluri andSilurodiscoides spp. may be simply due to the lower infection levels of the parasites. The observed pattern of unrestricted distributions of the parasitic copepods on gills of the fish may be accounted for, at least in part, by the moving ability of the copepods, and may also indicate that the parasite does not exhibit any feature of gill-arch preference. However, further experimental research is needed to verify the microhabitat distribution of the parasites. Project 39370122 supported by NSFC.     

Biochemical response of the mussel Mytilus coruscus (Mytiloida: Mytilidae) exposed to in vivo sub-lethal copper concentrations

Many aquatic organisms are negatively affected by exposure to high copper concentrations.We investigated the biochemical response of the mussel Mytilus coruscus(Mytiloida:Mytilidae) to copper exposure.In vivo bioassays using M.coruscus and different copper concentrations were conducted.The activity of six biomarkers,namely superoxide dismutase(SOD),catalase(CAT),acid phosphatase(ACP),alkaline phosphatase(AKP),glutamic-oxaloacetic transaminase(GOT) and glutamic-pyruvic transaminase(GPT) were measured.Survival rates decreased with increased copper concentrations and exposure times.The LC50 values at 48,72,and 96 h exposure were 0.48,0.37,and 0.32 mg/L,respectively.Within digestive glands,CAT activity increased with increasing Cu concentrations.The activity of AKP showed no significant change,while the remaining four enzymes showed decreasing activity with increasing Cu concentrations.Within the gills,AKP activity increased when the Cu concentration was 0.05 mg/L,but showed no significant changes at higher concentrations.Activity of CAT and ACP within gills tended to decrease with increasing Cu concentration.The activity of SOD and GPT decreased at an exposure concentration of 0.2 mg/L.GOT activity within gills decreased at 0.1 mg/L and increased at an exposure concentration of 0.2 mg/L.Within the adductor muscle,AKP activity increased at 0.05 mg/L but did not change at higher exposure concentrations.ACP activity within adductor muscle tissue showed no change,while activities of CAT,GOT and GPT decreased with increasing Cu concentrations.SOD activity within the adductor muscle tissue significantly decreased at the 0.02,0.05 and 0.2 mg/L exposure concentrations.Our results show tissue specific differences for the six biomarkers in for M.coruscus.Our findings provide the basis for the establishment of reference activity levels against which biomarker changes can be estimated,and are essential preliminary steps in development of in vivo bioassays.     

莱州湾南岸XZK2钻孔晚更新世以来的沉积环境探讨

通过钻孔岩性特征、沉积构造及沉积物粒度、磁化率与测井曲线对莱州湾南岸XZK2钻孔上部晚更新世以来的松散沉积物进行了沉积相划分,结合14C同位素年龄测定,划分了深海氧同位素阶段,表明该地区沉积物磁化率与砂含量曲线具有明显的正相关关系,结合已有研究,证明该地区晚更新世以来古环境经历了三次冷暖交替,而莱州湾西南海岸所发现的相当于沧州海侵、献县海侵和黄骅海侵的三次海侵事件,钻孔上仅见全新世黄骅海侵,沧州海侵、献县海侵相应层位为滨海沉积。     

Estimates of autumntime benthic secondary production in Laizhou Bay and adjacent Bohai Sea waters

The whole metazoan community inhabiting Laizhou Bay and adjacent Bohai Sea waters were sampled in late autumn,2006.Secondary production estimates for macrofauna and meiofauna were made separately.Total benthic secondary production was as high as 8.38 ± 4.08 g ash-free dry weight(AFDW) m-2 a-1,which represented the autumn production level.In general,macrofaunal secondary production in Laizhou Bay was much lower than that in adjacent Bohai Sea areas.In contrast,meiofaunal secondary production in Laizhou Bay was higher than that in adjacent Bohai Sea areas.Macrofauna contributed 61% to benthic secondary production(5.09 ± 3.26 g AFDW m-2 a-1),lower than the value in previous studies in Bohai Sea.Sediment granulometric characteristics and bottom-water salinity could explain the substantial variability in the macrofauna biomass and production.Meiofaunal production was an important component of benthic production and exceeded macrofauna production under exceptional conditions,e.g.in Laizhou Bay,where macrofauna was restricted.Chlorophyll pigments(Chl-a) concentrations in sediment explained the general meiofaunal biomass and production distribution here.