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Qatar University Life Science Symposium-QULSS 2015 Global Changes: The Arabian Gulf Ecosystem
- Conference date: 15-16 Dec 2015
- Location: Qatar University, Doha, Qatar
- Volume number: 2015
- Published: 07 December 2015
21 - 38 of 38 results
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Geochemical composition of dust from Qatar peninsula
Atmospheric dust samples have been collected from different areas in Qatar and analyzed for major and trace element composition. This region of the Arabian Gulf represents an area largely affected by dust from natural and anthropogenic sources. Twenty one samples were collected during 2014 and 2015 from Al-Khor, Katara, Sealine, Al-Waab, and Qatar University by passive and active sampling techniques. Some bulk samples were collected during the massive megastorm that occurred in April 2015. Back trajectories were determined for each sample set using the NOAA HYSPLIT model over a 50 hour time interval. Samples were equally divided between northerly (n=12; northern Saudi Arabia, Kuwait or Iraq) and southerly (n=8; SE Saudi Arabia, United Arab Emirates and Oman) sources. One sample is expected to originate from westward, in Saudi Arabia. There is more variability noticed in source locations throughout the winter months (October to March), with more of them coming from the south (9 times) compared to summer months (April to September) for twice only. Dust samples were microwave-assisted, total acid digested (HF+HCl+HNO3) and oxidized with H2O2 before analyses were conducted by ICP-OES. Only 12 out of 23 elements (Al, Ca, Fe, K, Mg, Na, Ag, As, Ba, Be, Cd, Co, Cr, Cu, Li, Mn, Mo, Ni, Pb, Sr, V, Zn, P) of the Qatari dust samples were enriched relative to Upper Continental Crust (UCC). Calcium was especially enriched to a level of 400% relative to UCC. About 33% of the total sample mass was CaCO3, reflecting the composition of surface rocks in the source areas. Of the elements typically associated with anthropogenic activity, Ag, Ni, and Zn were the most enriched relative to UCC, with enrichment factors of 182%, 233%, and 209%, respectively. Other metals like Pb and V were not significantly enriched, with enrichment factors not exceeding 25% and 3%, respectively. Major elements (Al, Mn and Fe) were depleted relative to UCC due to the strong enrichment of CaCO3, with enrichment factors of -58%, -35% and -5%, respectively. Samples with northern and southern origins were separated to investigate if the elemental composition could be used to identify source/origin. Only three elements were observed to have a statistical difference. Pb and Na were higher in the samples collected from the south while Cr was higher in those from the north. This study aims to investigate present-day geochemistry of dust particles and its effect on the marine environment of the Arabian Gulf. The geochemical composition of dust is essential component for correcting lithogenic input to water column suspended matter samples. Acknowledgement This study was made possible by a grant from the Qatar National Research Fund under the National Priorities Research Program award number NPRP 6-1457-1-272. The abstract contents are solely the responsibility of the authors and do not necessarily represent the official views of the Qatar National Research Fund.
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Marine collection in Qatar - basis for biodiversity management
Authors: Bruno Welter Giraldes, Ibrahim Al-Maslamani, Mark Chatting and David SmythBiological Collections, which deal directly with identifying and documenting biodiversity, have a major role in assisting biodiversity management. They form the basis for research, documenting flora and fauna and creating repositories of biological information. Without taxonomic research the biological collections would be merely a collection of curious objects, of limited value to our understanding of the natural world. The Environmental Scientific Centre of Qatar University has created a Marine Collection to house the species collected in the region. The species are being identified by taxonomists and deposited in the Marine Collection with a Collection Number and accompanied by descriptive characteristics. The Specify Software Project, a database platform for museum and herbarium research data, is being used concomitantly for registration of each species. The collection includes marine animals from coastal and offshore waters of Qatar, such as invertebrates (poriferas, cnidarians, crustaceans, gastropods, molluscs, echinoderms and others) and vertebrate specimens (urochordata, cephalochordate, Condrictyes, Osteicties and Reptiles). A total of 4830 specimens was collected and are being deposited in the Collection, as well as subsequent samples from new projects, including species for articles in preparation which are currently listed as a new occurrence in Qatar such as; Coeloplana (Benthoplan) meteoris,Branchyostoma arabia, Paranchystus pictodontaeamong several other species. Furthermore the collection houses a new systematic ofPortunus segnis, and the biodiversity of benthic organisms from offshore oyster beds and crabs from the mangrove ecosystem. It is well recognized for any impending assessment of biodiversity indices a baseline of existing data is required and the marine collection at the ESC will be a crucial tool in any future research or environmental monitoring programs that might be undertaken in not only Qatar but the Arabian Gulf.
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Biodiversity and distribution of benthic macro-fauna community from mangrove swamps and saltmarshes, Qatar
Authors: Jassim Al Khayat and Maryam A. AbdullaMangroves with its aerial roots provide a complex structure of microhabitats and refuge for an array of organisms that contributes to the biodiversity of this ecosystem. The present study aims to investigate and compare the distribution and biodiversity of the macro-benthic fauna living within the natural mangrove Avicennia marina, saltmarsh and replanted mangle. The study also compares relevant features of the abiotic and biotic environments of these habitats, during the period of study (October 2013 – March 2014). Results showed that TOC content was significantly higher in the sediments of the mangrove compared with salt marshes. The percent silt was also higher in the natural mangrove ecosystem compared to the planted and salt marshes locations. There was significant differences in community structures in terms of species composition and abundance between the natural mangrove, saltmarsh and planted mangrove sites. Shannon diversity index (H’) was generally higher for natural mangrove compared to the other two sites. Multivariate statistical analyses, including cluster analysis and non-multidimensional scales plot were employed to show similarity percent between sites. The higher organic matter content and the finer grain size in the natural mangrove site indicated the higher productivity and organic carbon flux from the mangrove. This result indicated that the three ecosystems have different biotic and abiotic settings that impacts the macrofaunal communities.
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Investigating the biodiversity and current status of the historically renowned oyster beds of Qatar
Authors: David Smyth, Ibrahim Al-Maslamani, Bruno Giraldes and Mark ChattingThe “Pearl Oyster” Pinctada radiata has long been associated with the nation of Qatar. Historically pearl oysters were harvested in huge quantities in the Arabian Gulf with Qatari pearls making up a large percentage of the fishery. However, following the discovery of oil in Qatar, combined with the emergence of Japanese cultured pearls onto the market, the Qatari pearl fishing industry diminished considerably. Oyster beds are recognized globally as hotspots of species diversity. The beds provide numerous primary ecosystem services such as nursery habitat for juvenile fish, major pelagic benthic coupling, water filtration and substrate stabilizing eco-engineers. It was therefore important that the demise in interest of this once iconic mollusk, such a rich part of Qatar’s culture and heritage, was addressed. It was the lack of information on the current status of the oyster beds in Qatar’s marine waters, and their associated biodiversity, that prompted the start of a targeted research program at the Environmental Science Center (ESC) at Qatar University. The current research project is focused on three key components: • The current ecosystem health, biodiversity, population structure and demographics of the “Pearl Oyster” Pinctatda radiata within the Qatari Exclusive Economic Zone. • The current status of the standing stock of Pinctada radiata. • The potential for oyster reef restoration using applied stock enhancement strategies and habitat expansion. The research was undertaken with a biogeochemical and biological cruise onboard the ESC’s marine research vessel, the R/V Janan, when ten offshore oyster sites were visited. Sampling was carried out on historically productive oyster beds as well as the periphery of the bed. This allowed for inter and intra comparison of biodiversity of the oyster beds. Preliminary results have shown a dramatic decline in “Pearl Oyster” densities with inter and intra bed biodiversity now displaying similar indices. This is undoubtedly a matter of concern that will need urgent remedial action.
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First report on the identification of species known to produce PSP, DSP, ASP, and NSP toxins in Qatari waters (Arabian Gulf)
Authors: Abdulrahman Al-Mufta and Mete YilmazHarmful algae bloom (HAB) is a natural phenomenon that occurs due to increase of algae cell density in water column that subsequently causes deleterious effects to natural environments as well as mankind. HABs in the Qatari waters occurred when a particular group of Phytoplankton cells proliferate in the eutrophied semi-enclosed water body. In this study, HABs composition in the Qatari waters was determined by light and scanning electron microscope (SEM) . Plankton samples were collected by a 20-micron plankton net haul in the Qatari waters during Oct. 2012 and Nov. 2013. The samples collected were divided into two Jars, one for culture, mainly toxicity test, and the other for identification. Samples were undergone fixation, several serial dehydration and observation under SEM. A total of 20 HABs was identified with 15 species known to be associated with HABs events and a total of 15 toxic species was identified with PSP dominancy. The occurrence of fish-killing armored dinoflagellate, Vulcanodinium rugosum, was reported for the first time in the Arabian Gulf and first report of noval pinnatoxin and portimine toxins. The presence of 12 major algal toxins and other potentially HABs in the Qatari Waters should be further investigated by the respective authorities in the future.
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Chlorophyll and phaeo-pigments in mangrove sediments in an arid environment in the Arabian Gulf, east coast of Qatar
Authors: Baraa Tayeh and Yousria SolimanMangroves are one of the most important ecosystems in Qatar, Arabian Gulf. They support complex, yet poorly studied food chain. Microphytobenthos are known to have better nutritional values and more palatable than mangrove leaves. There are very few studies on the standing stock of the sediment microphytobenthos in the mangroves of the Arabian Gulf. It is important to quantify the micophytobenthos in the mangrove ecosystem in order to understand their role in the food web and in the carbon cycle. Sediments’ chlorophyll and phaeo-pigments were measured in three locations representing three different ecosystems (natural mangrove, planted mangrove, and sand flat), in the east coast of Qatar. Biweekly samples were collected in the period between Fall 2013 and Spring of 2014. The present study used the chlorophyll concentration as a proxy to quantify the biomass of the microphytobenthos in sediments in the three ecosystems selected. Chlorophyll A, B, C, and phaeopigments were analyzed using the method of Lorenzen and Jeffery (1980). The study compared the biomass of benthic chlorophyll in intertidal and subtidal sediments in three habitats; natural mangrove (Dakhira), planted mangrove (Semisma) as well as a sand flat (the pearl). Chlorophyll-A concentrations were significantly different between mangrove habitats and sand flat (P<0.05). The average concentrations of sediment chlorophyll in natural mangrove was about five times (4.7 μg g−1) compared to that of non-mangrove sand flat (0.98 μg g−1). Chlorophyll B was most abundant in Al-Dakhira mangrove with average concentration of 2.5 μg g−1 that was significantly different from the concentrations determined in the sand flat (P>0.05). High concentrations of phaeopigments were found in Al-Dakhira (6-35 μg g−1 ) indicating higher grazing and biodegradation activities compared with the sand flat (2-11 μg g−1). Natural and planted mangrove ecosystem constituted higher sediment microphytobenthic biomass than sandy beach as hypothesized.
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Environmental contamination in mangrove crustaceans inhabiting Qatari waters
Authors: Hassan Hassan and Ibrahim Al-MaslamaniThe increasing level of pollutants in the marine environment is a major concern in all countries, in particular where the main diet is seafood. The major goal of this project was to assess the level of pollution and their effects in three local species, namely blue crab (Portunus pelagicus), barnacle (Balanus amphitrite), and shrimp (Palaemon khori). Samples were collected from intertidal and subtidal zones at Al-Khor Bay.The levels of pollutants such as poly chlorinated biphenyls (PCBs), heavy metals, and methylmercury in tissues and water samples were determined by Gas Chromatography (GC) , Cold vapor atomic fluorescence spectrometer (CVAFS), and inductively coupled plasma optical emission spectrometry (ICP-OES).The results show that the concentrations of the contaminants were very low in the water (mostly below detection limits), but PCB congeners (2,2,3,5-Tetrachlorobiphenyl and 2,2,4,5,5-Pentachlorobiphenyl) in shrimp and crab tissues was at the detectable levels. Methylmercury was measured (1 ppb approximately) in all three species’ tissues. The order of heavy metal concentrations in the tissues was Zn>Al>As>Mn>Cd>Mn>Ni>Cu>Mo>V>Pb>Co for barnacles; Zn>Al>Ni>Mo>Mn>As for blue crab, and Zn>Fe>Ni>Mn>Cr>As>Cd>Pb>Co>V for shrimp. The data presented in this study reports the first ever estimated baseline of contaminants both in the marine environment (water) and in animal tissues from this particular study area of Qatar.
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Characterization of microalgae species from Qatar coastal waters for animal feed production
Authors: Asmaa M. Raees and Radhouane Ben-HamadouMicroalgae have a great potential to be used in animal feeding due to its significant amount of protein and essential fatty acids secreted in their cells. Two strains of microalgae were selected from Qatar University Culture Collection of Cyanobacteria and Microalgae (QUCCCM) isolated from the Qatari coasts and subjected to different cultural conditions (salinities and CO2) and the biomass produced is further analyzed for protein, lipids, and mineral composition. Result shows that Tetraselmis sp. under optimum condition of 35 psu and 5% CO2 enriched air is a promising candidate for feedstock production containing higher amount of calcium. Additionally, Nannochloris sp. isolate contains high amount of fatty acids, especially PUFA and contains high amount of potassium. We suggest using a blend of Tetraselmis sp. and Nannochloris sp. to provide adjustable diet for animals depending on their dietary requirements.
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Phylogenetic diversity of cyanobacteria from Qatar coastal waters
Authors: Fatima Al-Khelaifi, Mete Yilmaz, Imen Saadaoui and Radhouan Ben-HamadouA major consequence of the sustained degradation of the coastal environment is the progressive eutrophication, which makes Harmful Algal Blooms (e.g. cyanobacteria) more likely to happen and with potential production of cyanotoxins which may create health hazards. Qatar concerns have been rising following the observations of blooms in the last years. Identifying relevant cyanobacteria species that grow in the extreme environment of Qatar would help in keeping records of their diversity as well as finding the strains that have several positive biotechnological applications or negative effects such as harmful algal blooms (HABs) where environmental mitigation and/or adaptation measures are needed. We aimed in this work to better understand the diversity of the cyanobacterial natural communities found in Qatari marine environment through a genotypic characterization (phylogenetic analysis) with the objectives to a) assess the local diversity, and b) provide consistent reference for future comparative analysis, biotechnological applications, and monitoring. In this study, Qatar University Culture Collection of Cyanobacteria and Microalgae (QUCCCM) strains collected from Qatar’s coastal regions were used to amplify fragments of the 16S rRNA gene followed by phylogenetic analysis. The obtained phylogenetic trees helped in branching the isolates by computing the differences (distances) among the isolates and compared them to known (published) cyanobacteria. This allowed the accurate identification and detection of the relevant Qatari cyanobacteria diversity and evolutionary relationship. Qatari marine cyanobacteria populations showed a high species richness. Indeed, we identified 28 taxa among them Geitlerinema sp., Euhalothece sp., and Geminocystis sp. have never been reported from Qatari waters. Additionally several isolates are potentially newly identified strains with low relationship to known cyanobacteria species. We were able to distinguish between populations in geographically separate regions along the Qatari coasts identifying where potentially toxic cyanobacteria may occur. Within the identified 28 species, we conducted a bibliographic analysis about their potential toxicity or toxin production. Eighteen strains are belonging to potentially toxic marine cyanobacteria. A regular monitoring of the occurrence and potential toxicity of the cyanobacteria in the coastal zone is recommended to timely identify potential environmental and human health hazards. Indeed, six isolates belonged to the potentially toxic marine cyanobacteria Geitlerinema sp., producer of a cytotoxic response to human lung tumor cells and other six isolates belonged to the marine cyanobacteria Chroococcidiopsis sp. and are known to produce a neurotoxic amino acid.
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Seasonal patterns of zooplankton in the Qatari coast (Arabian Gulf) and their relationship to environmental changes
Authors: Mariem A. Safi, Pedro Range, DM Estremadura and Radhouane Ben HamadouZooplanktons are marine animal members of the planktonic community. They play a key role in marine ecosystem, by linking primary production to higher trophic levels. The spatial and temporal dynamics of zooplankton communities were studied in 4 station along a transect offshore of Doha Bay, Qatar, from June 2014 to March 2015. Zooplankton samples were collected by means of horizontal tows using 120 and 500μm mesh size plankton nets. Two methods of examination were used and intercalibrated: optical microscopy and the automated identification and counting equipment FlowCAM. No spatial variability was observed among the locations sampled, while temporal variability was detected. The faunistic groups contributing most to these temporal variations were Cladocera, Oikopleura, crab larvae, Lucifer typus, fish eggs, and jellyfish. Our results showed no significant differences between the use of either the automated (FlowCAM) or the optical identification and counting suggesting the possible use of both methodologies as they provide complementary information (accurate identification capabilities and size spectra or population structure data).
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Extending the application of Arabian Gulf killifish embryo test for risk assessment of heavy metals in Qatari waters
Authors: Suhur Saeed, Nandita Deb and Jennifer M. DupontFish embryos are excellent models for studies aimed at the understanding of toxic mechanisms and the indication of possible acute and chronic effects. For the past 3 years, an Arabian killifish fish embryo test (FET) has been developed in our laboratory as a routine ecotoxicological test for risk assessment of potential contaminants in the Arabian Gulf around Qatar. To further explore the applicability of the killifish embryos as a model for the Arabian Gulf conditions, we tested the toxicity of heavy metals such as zinc and copper using Arabian seawater conditions. A breeding stock of sexually mature killifish, variable in age, was used for egg production. Eggs from several females were pooled and placed in salt water for fertilization. Embryos were examined under a dissecting microscope and viable embryos that were less than 6 h were selected. Eggs were distributed in replicates by stratified random assortment into 24 well plates. Observation was performed in 48-hour increments (± 2 hours). Endpoints included: coagulated eggs, absence of heartbeat, tail deformity and delayed hatching. Literature review was compiled for fish species that have been recommended for ELS toxicity testing. The data collected was then used for comparison to the current findings and the sensitivity was then extrapolated for the killifish embryos. Past findings indicate that toxicity is reduced in high salinity waters. This was confirmed in this study where at salinity 40 psu there were no apparent effects on embryos for any concentration tested and all embryos hatched at expected duration. When salinity was reduced from 40 to 20 psu, metal toxicity increased significantly (P > 0.05). Examination of the existing literature on acute Zn and Cu toxicity to fish and larvae showed similar results to the findings in this study using killifish embryos. The findings further support the use of killifish embryos as indicator organisms for environmental risk assessments of Qatari waters. Benefits include; sensitivity to wide range of substances and conditions, animal alternative, ease of fish breeding, clarity of the embryos, reduced sample size, reduced waste generation and shorter study duration. By expanding this test to evaluate its sensitivity towards other potential contaminants in the Arabian Gulf, we will further enhance the potential of killifish embryos to be adopted as a model species in marine ecotoxicology and risk assessment in this region.
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Observations of hydrographic properties, dissolved oxygen (DO) and chlorophyll-A (Chl-a) (phytoplankton biomass) within the exclusive economic zone (EEZ) of Qatar (central Arabian Gulf)
Authors: Mohammad Fazle Rakib and Ibrahim A. M. Saleh Al-AnsariIn situ observations of physical, chemical, and biological parameters of the Qatari water column were conducted to understand the temporal (seasonal) and spatial (regional) variability in the vertical and horizontal distribution of oceanographic properties within the exclusive economic zone (EEZ) of Qatar. Samples were collected from 5 different offshore shallow and deep stations covering the northern and eastern marine regions of the Qatar EEZ during two seasons: late summer (September 2014) and winter (January 2015). Eighteen (18) water samples were analyzed for temperature, salinity, density, dissolved oxygen concentration, dissolved oxygen saturation (DO%), and chlorophyll-a concentration (Chl-a). These data reveal several interesting and unique features that are related to surface warming that give rise to a large excess of evaporation over precipitation, resulting in the formation of several high salinity water masses. The deep offshore EEZ of Qatar was characterized by stratification (seasonal thermocline and pycnocline) during summer when deep water temperature was about 23.5°C (colder than the surface 32.6°C) where reduced stratification appeared to dominate in winter. Well-oxygenated water exists within the surface layer (0-23 m) during both summer and winter. Oxygen saturation layer (concentration 4.53 ml/l; saturation 94.49%) in the deep water extends to bottom (63 m) in winter however oxygen level falls below the summer thermocline (1.35 ml/l corresponding to 28.95% saturation) at Station 5 (63 m depth). Chl-a concentration was high in summer due to high primary productivity but remained sustained at moderate levels in winter. The procedures and methods were carefully applied to ensure the accuracy of the study results. In-situ measurements have high reliability in detecting hydrographic properties; however, it is costly, time consuming, requires ship time and as well as large number of scientific personnel and resources.
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Northeastern Qatari coast hydrodynamic modeling for assessment of sensitive ecosystems under anthropogenic and natural stressors
The Northeastern Qatari coast, comprising diverse and sensitive flora and fauna communities (e.g. coral reefs and patches, seagrass meadows and turtles), is expected to undergo changes imposed by anthropogenic stressors (coastal development projects) in the near future. Ecohydrological models are theoretical, mathematical representations of a natural system, made to understand the functionalities of the real ecological system under physical forcing. These model systems are then used in order to assist the impact assessment of future scenarios on real systems. The aim of this study was to create hydrodynamic simulation along with a sediment transport model for a stretch of coastline off of Jabal Fuwairat. This aim was achieved using GEMSS modeler software, which requires the following data for a proper model (1) spatial data (that is included as shape files imported from ArcGIS), primarily the water body shoreline and bathymetry, additionally the locations, altitudes, and formations of man-made structures; (2) time-based data, that are varying in time (i.e. tidal changes, influx rate and temperature and meteorological data) and (3) Sediment composition. These data were collected and gathered into time varying data files and incorporated in the GEMSS modelling tool.Results from both hydrodynamic model (HDM) and sediment transport models (STM) demonstrated that the study area is highly dynamic, being mainly controlled by tides and with relatively high shear stress (potential for erosion) in the northern and east-western boundaries. Three scenarios of future development that might take place in the area were assessed and results showed the alteration of the dynamics of water and sediments accordingly. A sensitive analysis was conducted and recommendations to decision makers for a better management of the considered coastal zone are developed.
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Nitrous oxide (N2O) in the north-eastern Arabian Sea and its formation pathways, a stable isotope and isotopomeric perspective
Authors: M. Nayeem Mullungal, R. Van Hale, R. D. Frew and C. S. LawNitrous oxide (N2O) is a biogenic trace gas in the atmosphere having significant role in global climate change and stratospheric chemistry. Its concentration in the ambient air has increased to the current value of 325 ppbv from 275ppbv in last hundred years. Oceans account for 25-30 % of global N2O emissions. Tropical and coastal regions contributes to more than 50 % of oceanic emissions; however, the biogeochemical pathways leading to its formations are poorly constrained. Nitrification and denitrification dominates N2O production with their N2O source product varying with oxygen availability. This paper describes the dissolved nitrous oxide concentration and its changes with apparent oxygen utilisation (AOU) along the Northeast Arabian Sea waters during South West Monsoon. Stable isotopic study of N2O including d15Nbulk, d18O, d15Nα and its site preference (SP) which is the difference between d15N α and d15N β were also conducted for the first time in this oceanic regions. The N2O were highly concentrated at the surface as compared to the other oceanic waters especially in the upwelling regions and the concentration increased to a maximum value in the oxygen less bottom waters. From sea to air N2O flux measurements these water masses appeared as a source for N2O with an average flux of 0.001-0.5 Tg N2O per year. The N2O vs AOU and Nitrate relationship suggested the importance of nitrification in the formation of N2O. The dual isotopic signatures of d 15Nbulk-N2O and d 18O were suggestive of more than one mechanism responsible for production with a nitrification dominated pathway in N2O cycling. The d18O of O2 confirms that mostly N2O is derived through nitrification process through the oxidation of NH2OH/NO. The SP values confirmed the existence of nitrification and nitrifier denitrification throughout the stations along the depth. This results suggest the need for more detailed study in the Gulf waters from where the highest N2O emissions were reported in 1991 for the first time.
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Investigation of spatiotemporal variability of microplastics in Qatar's coastal environment
Microplastics have recently been reported in the most pristine region of the world’s oceans. Microplastics are easily mistaken for food by filter-feeders and planktivorous fish, and can also adsorb large quantities of recalcitrant organic pollutants (OPs) which biomagnify up the marine food web, hence, explains the need for their investigation. In this study, the spatial and temporal distribution of microplastics were investigated for the first time in Qatar; both in sediments and seawater. Eight beaches across Qatar and four sea surface stations were surveyed between the months of December 2014 and March 2015. Microplastics were discovered in all samples and their abundance varied both in intertidal sandy beaches and sea surface. Two-factor ANOVA revealed that the spatial variability of microplastics in sea surface stations was statistically significant however, there was no observable temporal variability. The average concentration of microplastics in all 8 beaches was not significantly different. Results from the present study indicate the pervasiveness of microplastics in Qatar’s coastal environment.
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Prevalence of microplastics in the marine environment of Qatar's exclusive economic zone
Authors: Azenith Castillo and Jeffrey Philip ObbardMicroplastics are now firmly recognized as a ubiquitous and growing global threat to marine biota, as well as their associated ecology and habitats. The prevalence of microplastics in the marine waters within Qatar’s Exclusive Economic Zone (EEZ) was investigated. Following sample extraction, microplastics were characterized using Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy, and the polymer type then verified using OMNIC Spectra Library. Synthetic polymer microplastics were identified in seawater sampled from ten out of twelve marine monitoring stations, with varying shapes and sizes. Granular shaped microplastics present ranged from 120µm to 1.2mm in size, and fibrous microplastic ranged from 150µm to 10mm. Polypropylene (PP), low density polyethylene (LDPE), polyethylene (PE), polystyrene (PS), polyamide (PA), acrylonitrile butadiene styrene (ABS), polymethyl methacrylate (PMMA) and cellophane microplastic particles were identified. Copolymers were also identified from the collected samples, including poly(styrene:vinylidene chloride), poly(ethylene:propylene:diene) and alkyd resin e.g. paint debris. The most numerous type of synthetic polymer microplastic identified was polypropylene, with the greatest concentration found near Halul Island in the north east of the Qatar EEZ, where nearby anthropogenic activities include oil-rig installations and shipping operations. In addition, as par to the investigation, an optimized method was also developed for the extraction of microplastics from seawater samples rich in phytoplankton. The use of 1M NaOH proved to be more efficient digestion treatment than 10M NaOH and 22.5M HNO3 solutions, as the latter two solutions resulted in structural damage and discoloration of the reference polymers: polyvinyl alcohol (PVA), polyvinyl chloride (PVC), polystyrene (PS), polyethylene (PE), and nylon.
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Remotely sensed empirical modeling of bathymetry in the east coast of Qatar
Authors: P. Balakrishnan and Abdullah Ahmad HalimiRemotely sensed imagery is proving to be a useful tool in estimating water depths in coastal zones. On the other hand, many coastal zone studies in Qatar are only concerned with areas of shallow water and would easily benefit from updated bathymetric estimates. In this study, there are three significant satellites (Landsat TM, Landsat8 and Worldview3) that have been used to extract the bathymetric data from their images. We tested two different methods (1) single band algorithm and (2) principal components analysis (PCA) for extracting bathymetry information from satellite data. The location of the study area was chosen to be the east of State of Qatar. This area is called "AlGhariya" and the size of it is 62 km2. The best band in Landsat TM that can be used to extract the data as the correlation coefficient (r) value obtained by regression between the known depth and the extracted depth was the green band with a r2 value of -0.909.. The blue band and the red band were not hugely different when single band algorithm (SBA) method was used. On the another hand, the results obtained using the second method of principal components analysis (PCA) exhibited a better r2 value (0.914), which was the best result between the three satellites . The best band using the first method for Landsat 8 was found to be the red band with a r2 of -0.837. Near IR band also had a good result and relation with the known depth with -0.834. The other bands did not have a high correlation coefficient (r) value by regression between the extracted depth from the bands and the known depth. In the second method two different components of images were used. In this, the highest correlation coefficient (r) was -0.816 using blue, green and red bands. For the third satellite Worldview-3, the result was not as good as the other satellites using both methods. Using the first method, the best band was the coastal band with -0.654. The correlation coefficient (r) value was less in the blue, green, red and the other bands. The second method also was not as good for the other satellites. The highest correlation coefficient (r) was -0.641 using coastal, blue and green bands. Furthermore, the shallow waters have negative influences on the accuracy of bathymetric modeling; thus, the correction of data in these shallow waters is challenged by the presence of continental aerosols, bottom reflectance, and adjacency of land.
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Ecosystem services and mangroves in Qatar: preservation issues
Mangroves are halophyte trees, able to survive in intertidal areas, an interaction zone between land and sea. In Qatar, the only mangrove species able to survive the very high levels of salinity and the extreme climatic conditions is Avicennia marina. Creating a space of green that highly contrasts with the surrounding barren landscapes, mangroves bring many ecological and environmental benefits to Qatar. Firstly by being essential for many living species, who may find there shelter, food and breading areas. They also benefit to neighboring ecosystems to which they are closely linked. Secondly, they bring many ecosystem services to human societies, as they help in stabilizing and protecting coastlines, acting as strategic greenbelts and buffer areas against diverse environmental threats, as well as reducing the negative effects of greenhouse gases. Mangroves are crucial for human societies as they hold a major socioeconomic part, mostly because they are shelters and breeding areas of many commercial species. They may as well be used in daily life for different uses such as charcoal, firewood, construction or farming. Mangroves can also be used more indirectly for ecotourism, recreational activities or just for spiritual decompression. This study’s aim is to find out the reasons and the ways to ensure the survival of Qatari mangroves along with the current development of the country. The study was based on available literature, several field visits, GIS maps, interviews and personal communications with specialists and/or governmental people. Yet, Qatar has recently witnessed a significant development. Anthropic pressures as well as demographic and urban explosion are a global threat for the country’s mangroves, directly or indirectly, as they know an important decrease for most of them henceforth. Mangroves are therefore being cut down and destroyed, beside many hydrodynamic and coastal changes, which have also led to the disappearance of many wetlands that used to be found along the coasts and in the intertidal zone. The reported direct threats are mainly due to urban development, industrialization and the growth of the population. In certain areas mangroves are being replaced by diverse constructions such as hotels, residential areas, coastal projects, ports, airports, corniche, roads or industries. One of the most important irresponsible human activities is made by off-road cars that go on the shores or even directly through the trees, damaging the plants as well as the pneumatophores and seedlings in addition to disturb the fauna living there and alter the forest’s hydrology and nutrient status. Activities such as scuba diving, yachting, cruising and anchoring causes direct degradation of mangrove ecosystems. It is a common activity in Qatar to journey among the mangrove trees by foot, boats or canoes. However, this uncontrolled flow of people may harm the mangroves by trampling and breaking the sites, disturbing the species, or leaving waste around. A good example can be found in the mangrove of Purple Island (North East of Al-Khor). Another important threat is due to waste disposal and the inefficient management to collect it, dispose of it or recycle it. Eutrophication due to sewage runoff or pipe leaks was encountered in many locations of Mangrove ecosystems. This eutrophication may lead to the spread of toxic algae which may spread into mangrove areas, or at least exhaust O2 and create anaerobic environment killing many forms of life including mangrove seedlings. However, Qatar is committing itself more and more to environmental issues and many protection and conservation measures have been taken, especially these last few years. But there are still many gaps and agreement measures do not always seem effective on field. The main problem in Qatar remains the lack of will due to a deficiency in environmental awareness and interest towards the mangroves by the local population as well as by the authorities.
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