Distribution and Risk Assessment of Polycyclic Aromatic Hydrocarbons in Mussels from the Middle and Lower Main Stream of Huaihe River

[ Object] The aim was to discuss the pollution status of polycyclic aromatic hydrocarbons （PAHs） in mussels from the middle and lower main stream of Huaihe River, which will provide a scientific basis for dietary safety of mussels. [ Method] Suspended matter, sediment, and mussel samples were collected from Wuxiaojie and Fushanji in middle and lower reaches of Huaihe River. All samples were extracted with Soxhlet, separated through Silica GeI-Al2O3 column, and determined by GC-MS, and then 16 typical PAHs contents in the prior table listed by American EPA were obtained. [ Result] The results indicated that total PAHs concentrations in suspended matters and sediments of Wuxiaojie were significantly higher than those in Fushanji respectively. However, PAHs concentrations in mussels of the two samplings showed little difference; as for single PAH component, low-ring PAHs were more advantaged in suspended matters of two sampling sites, while high-ring PAHs were more advantaged in mussels. PAHs in sediments of Wuxiaojie assumed low-ring aspect, though PAHs in sediments of Fushanji assumed high-ring aspect. [ Conclusion] In spite of that sediments and mussels were not yet contaminated according to the ecological risk assessment of PAHs, its potential hazards couldn＇t be ignored any more.

Organochlorines in sediments and mussels collected from coastal sites along the Pearl River Delta, South China

The level and pattern of residues of organochlorine pesticide and polychlorinated biphenyls(PCBs) were analyzed in sediment and mussel(Perna viridis) samples from ten coastal sites along the Pearl River Delta, South China. The range of total HCH was <0 01 to 0 29 ng/g freeze-dried weight in sediment, and <0 0 1 to 1 35 ng/g lipid weight in mussels. Average total DDTs concentrations ranged from <0 01 to 1 04 ng/g in sediment, and <0 01 to 148 5 ng/g in mussels . Average total PCB concentrations ranged from 16 4 to 198 6 ng/g in sediment, and from 41 to 729.2 ng/g in mussels. Organochlorine pesticide and PCBs in mussels and sediments presented similar distribution patterns. The regression analysis indicated that PCBs concentrations in mussels were significantly correlated(p<0 01) with concentrations in sediments. However, their concentrations in mussels were several times higher than the concentration detected in surrounding sediments. The major fraction of DDT related compounds measured in mussels and sediments was DDD. Based on average PCB concentrations, penta-, hexa-, and tetrachlorobiphenyls were preferentially accumulated by mussels as compared to the average sediment composition. According to the present results,three organochlorine polluted “hot spot' sites, including Victoria Harbour, Lingding Yang and Huangmao Sea, were found in the Pearl River estuarine zone. HCHs, DDTs and PCBs in all mussel samples were below the limits of 2, 0 2 and 5 0 μg/g wet weight recommended by the Technical Group of Guangdong Coastal Zone Resource Comprehensive Survey and U. S. Food and Drug Administration.

Fauna and standing crop of freshwater mussels in Poyang Lake, China

Freshwater mussels are a major component of the zoobenthos and they therefore play an important role in freshwater ecosystems. The community composition and the standing crop of freshwater mussels in Poyang Lake, the largest freshwater lake in China and one of two lakes connected to the Changjiang （Yangtze） River, were investigated from February 2008 to May 2009. Mussels were sampled in hydrologically and geographically distinct sampling areas. A total of 42 species and 13 genera were identified, of which 32 species were endemic to China. Two species, Unio douglasiae and Lamprotula caveata, dominated all sampling areas. The number of genera and species, and the number of species within each genus, differed significantly among sampling areas. Freshwater mussels were very abundant, with an overall density of 0.28±0.22 ind./m-＇ and biomass of 4.08±3.96 g/m^2. Significant variation observed among sampling areas and among genera was probably due to the variety of habitats among the areas sampled and to the adaptability of different freshwater mussels to environments. This study suggests that Poyang Lake and other freshwater lakes in the region are important sites of freshwater mussel biodiversity and conservation.

Effect of Salinity-Changing Rates on Filtration Activity of Mussels from Two Sites within the Baltic Mytilus Hybrid Zone:The Brackish Great Belt(Denmark)and the Low Saline Central Baltic Sea

Mussels from two sites within the Baltic mussel (Mytilus edulis × M. trossulus) hybrid zone were used in a comparative study on the effects of salinity-changing rates on filtration activity. The acute effect of varying salinity-changing rates was found to be similar in M. edulis from the brackish Great Belt and in M. trossulus from the low saline Central Baltic Sea, and the relationships could be described by linear regression lines through 0.0 indicating that the acute effect of deteriorating conditions at decreasing salinities is the opposite as for improving conditions when the salinity is subsequently increased. Further, both M. edulis and M. trossulus acclimatized to 20 psu reacted to an acute salinity change to 6.5 psu by immediately closing their valves whereupon the filtration rate gradually increased during the following days, but only M. trossulus had completely acclimatized to 6.5 psu within 5 days which may be explained by different genotypes of M. edulis and M. trossulus which probably reflected an evolutionary adaptation of the latter to survive in the stable low-salinity Baltic Sea.

Effect of Salinity on Growth of Mussels,Mytilus edulis,with Special Reference to Great Belt(Denmark)

The effects of salinities between 10 and 30 psu on the growth of blue mussels, Mytilus edulis, were studied in laboratory feeding experiments and compared to the growth of mussels suspended in net-bags in the brackish water Great Belt, Denmark. In the laboratory, 3 series of growth experiments were conducted: in Series #1, groups of mussels were exposed to 10, 15, 25 and 30 psu, in Series #2, two groups of mussels were exposed to 10 and 30 psu, respectively, for 15 days (first period) where upon the mussels were exposed to the reversed salinities for another 15 days (second period). In Series #3, two groups of mussels were initially exposed to 15 and 25 psu for 22 days whereupon the mussel groups were exposed to the reversed salinities for another 17 days. In the laboratory experiments there was a tendency towards reduced growth with decreasing salinity, reflected as reduced shell growth rate and decreasing weight specific growth rate with falling salinity. The shell growth rate was relatively low in the first feeding period compared to the second period, and mussels that were initially exposed to 10 psu, where the growth was low, exhibited fast growth when subsequently exposed to 30 psu, and reversed when 30 psu mussels were exposed to 10 psu. The study showed that mussels are able to adjust growth at changing salinities, and the observed effect of salinity could partly be explained by a temporary shell valve closure after a sudden change in salinity. The specific growth rate of mussels measured in laboratory experiments at salinities between 15 to 25 psu (4.2% to 4.8% d–1) were comparable to the growth of mussels in the field experiment (3.2% to 4.0% d–1) where the salinity varied between 24 and 13 psu during the growth period.

Thermal processing induced release and degradation of paralytic shellfish toxin from mussels Mytilus edulis

Understanding the risk factors associated with shellfish consumption is a relevant public health concern because of the potential adverse ef fects of paralytic shellfish toxins(PSTs).This work aims to study the effects of the five most common heating treatments(steaming,boiling,frying,water-bath heating,and microwaving),for different processing times and temperature/power settings,on the content of PSTs in mussels(Mytilus edulis)collected in Qinhuangdao,China.The toxin concentration,removal percentages,and toxin distribution in the cooking liquor and meat were examined.The five processing modes effectively accelerated toxin release into the cooking liquor.The average percentage removal was 73.53%±16.50%from tissues.Microwaving led to the most significant toxin degradation among the methods tested.These findings should facilitate risk assessment of PSTs in mussels.

Heavy metals in oysters, mussels and clams collected from coastal sites along the Pearl River Delta,South China

Concentrations of 8 heavy metals: cadmium (Cd), copper (Cu), zinc (Zn), lead (Pb), nickel (Ni), chromium (Cr), antimony (Sb) and tin (Sn) were examined in 3 species of bivalves (Perna viridis, Crassostrea rivularis and Ruditapes philippinarum) collected from 25 sites along the Pearl River Delta coastal waters in the South China Sea from July to August 1996. In general, Cd, Cu, Zn and Sn concentrations in the three bivalve species collected from the Estuarine Zone were significantly higher than those collected from the Western and Eastern Zones of the Pearl River Delta, which are related to the existence of various anthropogenic activities in the catchment of the Pearl River Delta. The Western Estuarine Zone is mainly impacted by Cr, Ni and Cu contamination. In Victoria Harbor, heavy metal contamination is mainly due to Cu and Pb. Cd, Cu and Zn concentrations in oysters were significantly higher than those in mussels and clams. This could be explained by the fact that oysters live mainly in the Estuarine Zone of the Pearl River Delta which receives most of the polluting discharges from the catchment of the Delta. During turbid condition, heavy metals(soluble or adsorbed on suspended particulates) discharged from the Delta are filtered from the water column and subsequently accumulated into the soft body tissues of oysters. Heavy metal concentrations in the three bivalve species were compared with the maximum permissible levels of heavy metals in seafood regulated by the Public Health and Municipal Services Ordinance, Laws of Hong Kong, and it was revealed that Cd and Cr concentrations in the three bivalve species exceeded the upper limits. At certain hotspots in the Delta, the maximum acceptable daily load for Cd was also exceeded.

The effects of co-cultivation of pearl mussels and fishes on water pollution control in middle or small sized water

Our field experiments showed that the cultivation of pearl mussels formed a new biocoene composed of filamentous algae, protozoa, porifera and coelenterate. It effectively reduced nitrogen, phosphorus, chemical oxygen demand and biochemical oxygen demand in the water by 67.3%, 73.2%, 38.1% and 15.5%, respectively, during May to September 1998 when the water eutrophication was developing. This could control water eutrophication and produce pearls, shellfish meat and shells. This is an economical and effective way to control water eutrophication by using the ultra strong filtering capability of freshwater pearl mussels.

Evaluation of Total and Faecal Coliforms and Salmonella spp. in Irradiated Mussels from Brazil

Ilha Grande Bay is one of the biggest producers of bivalves of Rio de Janeiro State. Statistics reports of foodborne diseases are quite low in Brazil, however, this fact is a matter of Public Health. In their majority concerning consumption of bivalves meat, the availability of safe products requires the use of technology as food irradiation. The objective of this paper was to evaluate the presence of bacteria resulting from the environmental contamination and epidemiological importance, Salmonella spp., total and faecal coliforms of mussel （Perna perna） from that region and the use of irradiation on the product in natura. Fifteen indicative samples of mussel were collected from five gr owing points in Ilha Grande Bay. A sample of each point was irradiated with doses of 1.0 and 1.5 kGy. The bacteriological analysis followed the instructions of the Brazilian legislation. The samples presented irregularities in relation to Salmonella spp. and faecal coliforms, the latter for the control group. The control group was noticed as not appropriate for consumption. The dose of 1.0 kGy was effective for the reduction of faecal coliforms, but ineffective for the extinction of Salmonella spp.

Annual Component Analysis of Pacific Oysters （Crassostrea gigas） and Mussels （Mytilus gallopro vincialis）

To study the change in components of Pacific oysters （Crassostrea gigas） and mussels （Mytilus galloprovincialis） over a year, their annual obesity ratio, umami components （glutamic acid and glycogen）, functional components （Zn, Mn, Cu, and vitamin B12）, and Cd and noroviruses （NoVs） contents were quantified. In oysters, the obesity ratio and chemical components showed seasonal changes depending on the spawning season. Glutamic acid content increased from November to March. In contrast, glycogen content peaked in May and November. Mineral content markedly increased during spawning. From the comparison of NoVs GI and GII strains, oyster predominately infected by the GI. A remarkable difference in NoVs contents was observed depending on the oyster farms. In mussels, glutamic acid, Zn and Cu contents were stable throughout the year. Mussels＇ Cd content was about one-fifths times lower than that found in oysters. Although the NoVs strain was affected by the collection area, mussels from both areas showed decreased NoVs contents in summer, corresponding with the consumption season of mussels in Japan. Our comparative study on the seasonal variability in the chemical components and NoVs contents in pacific oysters （C. gigas） and mussels （M. galloprovincialis） clearly showed an association with physiological and environmental factors.

Integrated biomarker response to assess toxic impacts of iron and manganese on deep-sea mussel Gigantidas platifrons under a deep-sea mining activity scenario

Deep-sea mining activities can potentially release metals,which pose a toxicological threat to deep-sea ecosystems.Nevertheless,due to the remoteness and inaccessibility of the deep-sea biosphere,there is insufficient knowledge about the impact of metal exposure on its inhabitants.In this study,deep-sea mussel Gigantidas platifrons,a commonly used deep-sea toxicology model organism,was exposed to manganese(100,1000μg/L)or iron(500,5000μg/L)for 7 d,respectively.Manganese and iron were chosen for their high levels of occurrence within deep-sea deposits.Metal accumulation and a battery of biochemical biomarkers related to antioxidative stress in superoxide dismutase(SOD),catalase(CAT),malondialdehyde(MDA);immune function in alkaline phosphatase(AKP),acid phosphatase(ACP);and energy metabolism in pyruvate kinase(PK)and hexokinase(HK)were assessed in mussel gills.Results showed that deep-sea mussel G.platifrons exhibited a high capacity to accumulate Mn/Fe.In addition,most tested biochemical parameters were altered by metal exposure,demonstrating that metals could induce oxidative stress,suppress the immune system,and affect energy metabolism of deep-sea mussels.The integrated biomarker response(IBR)approach indicated that the exposure to Mn/Fe had a negative impact on deep-sea mussels,and Mn demonstrated a more harmful impact on deep-sea mussels than Fe.Additionally,SOD and CAT biomarkers had the greatest impact on IBR values in Mn treatments,while ACP and HK were most influential for the low-and high-dose Fe groups,respectively.This study represents the first application of the IBR approach to evaluate the toxicity of metals on deep-sea fauna and serves as a crucial framework for risk assessment of deep-sea mining-associated metal exposure.

In situ visualization of the cellular uptake and sub-cellular distribution of mussel oligosaccharides

Unlike chemosynthetic drugs designed for specific molecular and disease targets,active small-molecule natural products typically have a wide range of bioactivities and multiple targets,necessitating extensive screening and development.To address this issue,we propose a strategy for the direct in situ microdynamic examination of potential drug candidates to rapidly identify their effects and mechanisms of action.As a proof-of-concept,we investigated the behavior of mussel oligosaccharide(MOS-1)by tracking the subcellular dynamics of fluorescently labeled MOS-1 in cultured cells.We recorded the entire dynamic process of the localization of fluorescein isothiocyanate(FITC)-MOS-1 to the lysosomes and visualized the distribution of the drug within the cell.Remarkably,lysosomes containing FITC-MOS-1 actively recruited lipid droplets,leading to fusion events and increased cellular lipid consumption.These drug behaviors confirmed MOS-1 is a candidate for the treatment of lipid-related diseases.Furthermore,in a high-fat HepG2 cell model and in high-fat diet-fed apolipoprotein E(ApoE)^(-/-)mice,MOS-1 significantly promoted triglyceride degradation,reduced lipid droplet accumulation,lowered serum triglyceride levels,and mitigated liver damage and steatosis.Overall,our work supports the prioritization of in situ visual monitoring of drug location and distribution in subcellular compartments during the drug development phase,as this methodology contributes to the rapid identification of drug indications.Collectively,this methodology is significant for the screening and development of selective small-molecule drugs,and is expected to expedite the identification of candidate molecules with medicinal effects.

The environmental analysis and site selection of mussel and large yellow croaker aquaculture areas based on high resolution remote sensing

Mussel aquaculture and large yellow croaker aquaculture areas and their environmental characteristics in Zhoushan were analyzed using satellite data and in-situ surveys.A new two-step remote sensing method was proposed and applied to determine the basic environmental characteristics of the best mussel and large yellow croaker aquaculture areas.This methodology includes the first step of extraction of the location distribution and the second step of the extraction of internal environmental factors.The fishery ranching index(FRI1,FRI2)was established to extract the mussel and the large yellow croaker aquaculture area in Zhoushan,using Gaofen-1(GF-1)and Gaofen-6(GF-6)satellite data with a special resolution of 2 m.In the second step,the environmental factors such as sea surface temperature(SST),chlorophyll a(Chl-a)concentration,current and tide,suspended sediment concentration(SSC)in mussel aquaculture area and large yellow croaker aquaculture area were extracted and analyzed in detail.The results show the following three points.(1)For the extraction of the mussel aquaculture area,FRI1 and FRI2 are complementary,and the combination of FRI1 and FRI2 is suitable to extract the mussel aquaculture area.As for the large yellow croaker aquaculture area extraction,FRI2 is suitable.(2)Mussel aquaculture and the large yellow croaker aquaculture area in Zhoushan are mainly located on the side near the islands that are away from the eastern open waters.The water environment factor template suitable for mussel and large yellow croaker aquaculture was determined.(3)This two-step remote sensing method can be used for the preliminary screening of potential site selection for the mussels and large yellow croaker aquaculture area in the future.the fishery ranching index(FRI1,FRI2)in this paper can be applied to extract the mussel and large yellow croaker aquaculture areas in coastal waters around the world.

Study on Adsorption Removal of Polycyclic Aromatic Hydrocarbons by Modified Mussel Shells

Polycyclic aromatic hydrocarbons(PAHs)are typical persistent organic pollutants(POPs)that are commonly found in the environment.They are carcinogenic,teratogenic,mutagenic and biodegradable obviously.In this paper,the modified mussel shells were used to adsorb and remove anthracene.The results show that the adsorption removal rate of the mussel shells was higher after calcination at 600℃.5%H_(3)PO_(4) solution was more suitable for shell treatment than 3 mol/L ZnCl_(2) solution.As the dosage of the modified shells was 0.5 g/L,the adsorption reached a stable state,and the removal rate of PAHs was about 69.44%;the adsorption efficiency rose with the increase of time.It can be seen that as a new and cheap biological adsorbent,the modified shells can be used to remove PAHs from wastewater.

Happy together？ Avoidance of conspecifics by gregarious mussels

Zebra mussel Dreissena polymorpha is a Ponto-Caspian species invasive in Europe and North America, with great environmental impact. It lives byssally attached to hard substrata in large aggregations, which is often explained by its preferences for conspecifics, though direct evidence for such preferences has been rather limited so far. We studied the reactions of zebra mussels to con- specifics, hypothesizing that they may either be attracted to one another or form aggregations only in the absence of alternative attachment sites, in Experiment 1, we tested mussel tendency to detach from existing druses depending on druse size （2-25 individuals） and substratum type （soft： sand; hard： glass）. Mussels detached significantly more often on the hard substratum and from larger druses compared to soft substratum and smaller druses, respectively. This indicates that mussels tended to avoid conspecifics at high density, particularly when alternative substratum was available. In Experiment 2, we tested the responses of single mussels to distant （3 or 15cm） conspecifics （0, 3, 15 individuals per 2.51 tank） on the sandy substratum. The presence of conspecifics, regardless of their distance and density, resulted in single unattached mussels staying more often in their initial positions. Mussels did not move preferentially towards or away from the conspecifics. Thus, even on unsuitable substratum mussels were not attracted by conspecifics and probably exhibited an avoidance reaction by reducing their movement. This suggests that dense mussel aggregations are formed due to the lack of available alternative attachment sites rather than due to their preferences for conspecifics.

Proximate composition and elemental analysis in soft tissues of freshwater mussels （Anodonta anatina） from the Chashma Lake, River Indus Pakistan

BACKGROUND： Aquatic invertebrates are playing an important role in assessment of the water contaminants and also serve as a major component of food chain. Freshwater mussels are considered to be the good bioindicator species of aquatic environment and widely used to determine the metals load. METHODS： Proximate composition and elemental analysis were carried out in edible （foot, mantle） and non-edible portion （gills） of freshwater mussels （Anodonta anatina） harvested from various site of Chashma Lake, River Indus Pakistan. RESULTS： The nutritional components were varied among the studied portion and muscular foot found to be the best part for consumption. Protein and fat contents were significantly higher in foot （15.90±0.88%, 1.19 ±0.26%） as compared to mantle （10.78±2.24%, 0.27±0.09%） and gills （6.44± 1.22%, 0.53 4-0.15%） respectively. For the macro minerals mantle had high concentration of Ca （46838±984 mg/kg）, Na （2706±343 mg/kg）, P （6921± 1063 mg/kg） and Mn （7207± 1046 mg/kg） as compared to foot. CONCLUSIONS： Heavy metals （Cd, Cu, Cr） concentration in edible portions were lower than the permissible limit by WHO whereas the concentration of Pb was slightly higher than the recommended value that might be the risk for the consumers. Being filter feeder gills accumulated the high concentration of all the metals and found to be the key portion for biomonitoring studies. Freshwater mussels of Chashma Lake Indus River are the rich source of protein and all the other micro and macro minerals therefore could be used as an excellent source of food.

Mussel meat protein: Extraction, processing, nutrition value, and application in food products

The rapidly increasing global population has resulted in an increased demand for proteins in the human diet.The mussel meat protein is an affordable,abundant,sustainable,and environmentally friendly source of proteins suitable for human consumption.This review described the composition and characteristics of mussel meat proteins,as well as methods for sufficiently isolating and extracting these proteins.Several non-thermal processing technologies including high-pressure homogenization and ultrasonication are introduced for the mussel meat protein modification,and the impact of these processing treatments on the structure and functional properties of mussel meat proteins is also discussed.Moreover,the production of bioactive peptides with various kinds of biological activities from mussel meat proteins is highlighted.Finally,industrial and commercial applications of mussel meat proteins and their derived bioactive peptides in food formulations are discussed.The research findings demonstrated that homogenization and ultrasonication treatments could induce the change in protein conformation and significantly improve the functionality of mussel meat proteins.Enzymatic hydrolysis and fermentation are effective approaches to produce bioactive peptides with multiple biological activities from mussels.Mussel meat proteins exhibit considerable nutritional and functional values compared to other widely used protein sources.Therefore,mussel meat protein could be used as a sustainable alternative protein resource in food applications.

Phylogenetic Relationships of Japanese Unionoida (Mollusca: Bivalvia) Based on Mitochondrial 16S rDNA Sequences

Japanese unionoid mussels are classified into 2 families (Margaritiferidae and Unionidae), 12 genera, and 18 species based on the morphological characteristics of both adults and larvae;however, there are some debates regarding their systematics. In this study, we determined mitochondrial 16S ribosomal DNA sequences (347-bp) for 60 specimens belonging to 18 species and constructed trees to elucidate phylogenetic relationships and evaluate the current systematics of Japanese unionoid mussels. Almost all species formed clades, except for Inversiunio yanagawensis, Sinanodonta lauta, S. japonica, and Margaritifera laevis, even though two or more specimens were collected from distant localities. All genera formed highly supported clades with the exception of the genus Sinanodonta. Phylogenetic relationships obtained in this study supported systematics based on morphological and larval traits. Therefore, the current phylogenetic relationships and systematics of Japanese unionoid mussels are stronger than they were before;now that they are corroborated by genetic data.

Assessment of Marine Pollution at Bay of Oran, Algeria

This work aims to the assessment of marine pollution in the Bay of Oran, including zinc, copper, iron and lead. These toxic elements represent a real danger to living organisms. Many factors have increased the marine pollution and marine traffic including the transport of hydrocarbons, industrial and domestic discharges and fishing activities, etc. This study shows essentially the bioconcentration of heavy metals in the species Mytilus galloprovincialis, these filter bivalves have a broad geographical distribution in our study area, so they allow us to better estimate the degree of pollution at the Bay of Oran. The study of changes in metal concentrations has marked some important points for, the four metallic elements are present in the flesh of mussels analyzed at the port of Oran. This study is part of assessment of pollution at the coast of western Algeria to protect the marine environment.

The Asian Green Mussel <i>Perna viridis</i>(Linnaeus 1758): 20 Years after Its Introduction in Trinidad and Tobago

Invasive species are often characterised by the introduction of low numbers of individuals and a small genetic pool which could give rise to a population with a lower genetic diversity than the original population. Perna viridis was first reported on the west coast of Trinidadin1990 inthe Point Lisas Industrial estate. They may have been first introduced either as juvenile free floating mussels (spat) or as adults attached to the hulls of ships. This gregarious species spread rapidly throughout the Caribbean toVenezuela,KingstonHarbor(Jamaica) and by 1999 was reported inTampaBay(Florida). Genetic analysis was done on tissue samples fromTrinidadto determine the genetic similarity of newly collected specimens (2009) with archived specimens (collected 1994). Results suggest that there may not be any genetic variation in the population of Perna viridis, even approximately 20 years after initial colonization. These results suggest that there was no evidence of genetic bottlenecks in the population of P. viridis fromTrinidad.