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Internal bioerosion in dead and live hard corals in intertidal zone of Hormuz Island (Persian Gulf)
2016
Jafari, Mohammad Ali | Seyfabadi, Jafar | Shokri, Mohammad Reza
Internal macrobioeroders and their erosion rate in three live and dead coral genera (Favia, Platygyra and Porites) from the intertidal zone of the Hormuz Island were studied by collecting five live and five dead colonies from each genus, from which 4mm cross-sections were cut and photographed. Photos were analyzed using the Coral Point Count with Excel extensions. Totally, 9 taxa were identified: four bivalve species, one sponge, three polychaetes, and one barnacle. Bioerosion rate did not significantly differ among the three live corals, but among the dead ones only Porites was significantly more eroded than Favia. Sponge had the highest role in the erosion of the dead Platygyra, while barnacles were the most effective eroding organism in the live Platygyra. Polychaetes, followed by bivalves, were the most destructive bioeroders on the dead and live Porites. Further, none of the bioeroding organisms had selectively chosen either the dead or live Favia.
Show more [+] Less [-]Small-scale temporal and spatial variability in the abundance of plastic pellets on sandy beaches: Methodological considerations for estimating the input of microplastics
2016
Moreira, Fabiana Tavares | Prantoni, Alessandro Lívio | Martini, Bruno | de Abreu, Michelle Alves | Stoiev, Sérgio Biato | Turra, Alexander
Microplastics such as pellets have been reported for many years on sandy beaches around the globe. Nevertheless, high variability is observed in their estimates and distribution patterns across the beach environment are still to be unravelled. Here, we investigate the small-scale temporal and spatial variability in the abundance of pellets in the intertidal zone of a sandy beach and evaluate factors that can increase the variability in data sets. The abundance of pellets was estimated during twelve consecutive tidal cycles, identifying the position of the high tide between cycles and sampling drift-lines across the intertidal zone. We demonstrate that beach dynamic processes such as the overlap of strandlines and artefacts of the methods can increase the small-scale variability. The results obtained are discussed in terms of the methodological considerations needed to understand the distribution of pellets in the beach environment, with special implications for studies focused on patterns of input.
Show more [+] Less [-]Assessing pollution-related effects of oil spills from ships in the Chinese Bohai Sea
2016
Liu, Xin | Guo, Mingxian | Wang, Yebao | Yu, Xiang | Guo, Jie | Tang, Cheng | Hu, Xiaoke | Wang, Chuanyuan | Li, Baoquan
An analysis of the effects of potential oil spills will provide data in support of decisions related to improving the response to oil spills and its emergency management. We selected the Chinese Bohai Sea, especially the Bohai Strait, as our investigation region to provide an assessment of the effects of pollution from ship-related oil spills on adjacent coastal zones. Ship-related accidents are one of the major factors causing potential oil spills in this area. A three dimensional oil transport and transformation model was developed using the Estuary, Coastal, and Ocean Model. This proposed model was run 90 times and each run lasted for 15days to simulate the spread and weathering processes of oil for each of four potential spill sites, which represented potential sites of ship collisions along heavy traffic lanes in the Bohai Sea. Ten neighboring coastal areas were also considered as target zones that potentially could receive pollutants once oil spilled in the study areas. The statistical simulations showed that spills in winter were much worse than those in summer; they resulted in very negative effects on several specific target zones coded Z7, Z8, Z9, and Z10 in this paper. In addition, sites S3 (near the Penglai city) and S4 (near the Yantai city) were the two most at-risk sites with a significantly high probability of pollution if spills occurred nearby during winter. The results thus provided practical guidelines for local oil spill prevention, as well as an emergency preparedness and response program.
Show more [+] Less [-]Dynamics of phytoplankton communities in eutrophying tropical shrimp ponds affected by vibriosis
2016
Lemonnier, Hugues | Lantoine, François | Courties, Claude | Guillebault, Delphine | Nézan, Elizabeth | Chomérat, Nicolas | Escoubeyrou, Karine | Galinié, Christian | Blockmans, Bernard | Laugier, Thierry
Tropical shrimp aquaculture systems in New Caledonia regularly face major crises resulting from outbreaks of Vibrio infections. Ponds are highly dynamic and challenging environments and display a wide range of trophic conditions. In farms affected by vibriosis, phytoplankton biomass and composition are highly variable. These conditions may promote the development of harmful algae increasing shrimp susceptibility to bacterial infections. Phytoplankton compartment before and during mortality outbreaks was monitored at a shrimp farm that has been regularly and highly impacted by these diseases. Combining information from flow cytometry, microscopy, pigment and phylogenetic analysis, the presence of Picocyanobacteria, Prasinophyceae and Diatomophyceae were detected as dominant phytoplankton groups and Cryptophyceae, Prymnesiophyceae and Dinophyceae as minor components. At the onset of the first shrimp mortalities, Bacillariophyceae increased while Cyanobacteria, Prymnesiophyceae and Dinophyceae decreased in the water column, followed by proliferation of Prasinophyceae. Several taxa were identified as potential harmful algae (Cyanobacteria, dinoflagellates and Phaeocystis).
Show more [+] Less [-]The role of transport processes of particulate mercury in modifying marine anthropogenic secondary sources, the case of Haifa bay, Israel
2016
Bareket, Merav M. | Bookman, Revital | Katsman, Regina | de Stigter, Henko | Herut, Barak
We have assessed the redistribution of a secondary source of sedimentary anthropogenic mercury in the Haifa bay (HB) area (SE Levantine basin), which is the northern sink for Nile-driven sand. A long-term (30years) ~80% decrease of the total sedimentary mercury concentrations (THg) was recorded in the inner bay, while an up to 3-fold increase was recorded in the top sediments of the outer bay. Sedimentary THg depth profiles and their temporal variability were used to model the main re-distribution processes, mainly resuspension associated with winter storm-derived transport. This mechanism transforms a secondary, sandy and well-aerated sink into a tertiary, more silty and hypoxic source at adjacent peripheral areas, affecting mercury bioavailability. We revisited the concept of environmental relaxation, i.e. the rate of return of a polluted environment to an acceptable state, showing that sedimentary transport processes may affect the associated ecological risks, mainly at shallow-water coastal sites.
Show more [+] Less [-]Tolerance to stress differs between Asian green mussels Perna viridis from the impacted Jakarta Bay and from natural habitats along the coast of West Java
2016
Huhn, Mareike | Hattich, Giannina S.I. | Zamani, Neviaty P. | von Juterzenka, Karen | Lenz, Mark
It is an open question whether adverse habitat conditions, characteristic for many anthropogenically impacted coastal habitats, can determine resistance to abiotic stress in populations of residing invertebrates. We tested experimentally for differences in stress tolerance between individuals of the Asian green mussel Perna viridis stemming from the heavily impacted Jakarta Bay and from two natural sites, Lada Bay and Pelabuhan Ratu, West Java. Mussel performance under hyposalinity and hypoxia was assessed in laboratory assays by measuring fitness-related response variables, e.g. body condition index, relative shell weight, byssus production, respiration rates and survival. We found stress-specific and population-specific differences in mussel resistance to adverse conditions: Individuals from the impacted Jakarta Bay performed better under hypoxia than their conspecifics from the natural sites, whereas the latter were more resistant to hyposalinity. We explain these differences by differential acclimation to environmental conditions in the respective habitats and by diverging degrees of food supply.
Show more [+] Less [-]Potential human health risk assessment of trace metals via the consumption of marine fish in Persian Gulf
2016
Naji, Abolfazl | Khan, Farhan R. | Hashemi, Seyed Hassan
This study was carried out to evaluate the concentration of trace metals (Cd, Cu, Ni, Pb and Zn) in the muscle of four fish species from the Persian Gulf. Trace metals were analyzed using atomic absorption spectroscopy and consumption rates advisory for minimizing chronic systemic effects in children and adults were estimated. The metals concentrations in analyzed fish samples were lower than legal limits. Cadmium target hazard quotient values suggested that the threshold to avoid the potential risk for children health is an exposure level lower than 3 meals per week. Hazard index values based on four metals (not including Pb) for the child age class were higher than those of the adult age class, suggesting that children may suffer from a higher health risk. This study provides information about the consumption limits of certain metals, in particular Cd, necessary for minimizing potential health risks resulting from human consumption.
Show more [+] Less [-]Seasonal variations of phytoplankton assemblages and its relation to environmental variables in a scallop culture sea area of Bohai Bay, China
2016
Chen, Yang-hang | Gao, Ya-hui | Chen, Chang-ping | Liang, Jun-rong | Sun, Lin | Zhen, Yu | Qiao, Ling
Seasonal variations of phytoplankton assemblages were examined in a scallop culture sea area of Bohai Bay (China) with regard to some major physical and chemical variables. Samples were collected at three stations from July 2011 to September 2013. A total of 134 species belong to 4 phyla were identified, of which 104 were diatoms, 27 were dinoflagellates, 1 was euglenophyte and 2 were chrysophytes. The cells abundance in autumn (55.44×103cells/L) was higher than that in summer (6.99×103cells/L), spring (3.46×103cells/L) and winter (2.69×103cells/L). The Shannon-Wiener diversity index was higher in summer (3.06), followed by spring (3.02) and winter (2.91), and low in autumn (1.40). Results of canonical correspondence analysis showed that phosphate, salinity, temperature, silicate and DIN/SiO2 ratio were the most important environmental factors influencing the variation of phytoplankton community structure. It is suggested that eutrophication resulted from scallop culture would cause a potential red tide risk.
Show more [+] Less [-]Characteristics of haze weather in Chongqing, China and its determinants analysis based on automatic monitoring stations
2016
Li, Mingsheng | Jia, Lin | Zhang, Fengying | Hu, Maogui | Shi, Yu | Chen, Xi
Statistical analyses were carried out on the characteristics of haze weather and their relation with air quality and meteorological factors using data recorded by the national air quality and meteorological monitoring network of Chongqing, China in 2013. The results showed that the hourly occurrence rate of haze in Chongqing was 81.3% and that 67.2% of the total number of haze hours was at the level of mild to light haze. Haze was more likely to occur in autumn and winter (67.2% of the total number of hours; occurrence rate 97.5%) and was more likely to occur between 22:00 and 10:00. Haze mainly occurred when the wind speed was <1.2 m s−1 and the relative humidity was >50%. Haze rarely occurred when the wind speed was >3.0 m s−1 and the relative humidity was <30%. There was a positive correlation between temperature and visibility. The occurrence rate was higher with positive variations in the 24-h temperature records. The main factor affecting haze was the level of PM2.5 pollution. Haze mainly occurred when ρ(PM2.5) was between 35 and 250 μg m−3, accounting for 86.4% of the total number of hours of haze. When ρ(PM2.5) was >75 μg m−3, the occurrence rate of haze was 100.0%. The mean value of ρ(PM2.5)/ρ(PM10) during the hours of haze was 72.9%, 17.7% higher than that at other times. The number of hours with air pollution accounted for 48.8% of the total number of hours, far less than the occurrence of haze. When the ambient air quality was excellent or good, haze was present in 65.4% of hours. We suggest that there are differences between the assessment of air quality and the definition of haze used in China. The relationship between haze and air quality would be better matched if we used the World Meteorological Organization's definition of haze (visibility < 5.0 km).
Show more [+] Less [-]Plastic litter in sediments from a marine area likely to become protected (Aeolian Archipelago's islands, Tyrrhenian sea)
2016
Fastelli, Paolo | Blašković, Andrea | Bernardi, Giulia | Romeo, Teresa | Čižmek, Hrvoje | Andaloro, Franco | Russo, Giovanni F. | Guerranti, Cristiana | Renzi, Monia
This research aims to define for the first time levels and patterns of different litter groups (macro, meso and microplastics) in sediments from a marine area designed for the institution of a new marine protected area (Aeolian Archipelago, Italy). Microplastics resulted the principal group and found in all samples analyzed, with shape and colours variable between different sampling sites. MPs levels measured in this study are similar to values recorded in harbour sites and lower than reported in Adriatic Sea, while macroplastics levels are notably lower than in harbor sites. Sediment grain-size and island extent resulted not significant in determining levels and distribution of plastic debris among islands. In the future, following the establishment of the MPA in the study area, these basic data will be useful to check for potential protective effects on the levels and distribution of plastic debris.
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