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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
38 results
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Global change: The Arabian Gulf ecosystem – An introduction
More LessThe Arabian Gulf is a main source of wealth and food for the people of the Gulf countries. For hundreds of years, the Gulf used to be the main source for some of the finest pearls in the world. It harbors highly diverse and productive habitats including coral reefs, mangroves, intertidal marshes, and seagrass. Another feature of the Arabian Gulf is that it hosts the second largest population of dugongs in the world’s oceans. The Gulf is a shallow basin (avg. depth = 35 m) that has some of the most radical environmental conditions in the world’s oceans including extreme temperature, high UV irradiance, high evaporations and limited fresh water influx, resulting in salinities that ranges from 40 up to 70 psu in some bays. On the top of the aforementioned extreme natural hydrographic conditions, there are tremendous environmental stresses exerted by the unprecedented industrialization, fossil hydrocarbon exploration and production, shipping tankers introducing non-indigenous species, power and desalination plants, and coastal development activities as well as any remnants from the largest oil spills in history, during the Gulf war in 1991. Qatar University Life Science Symposium (QULSS) is an annual event where local and world leader academics address the research priorities for the state of Qatar and the Gulf region. As headlines worldwide emphasize climatic changes, ocean acidification, eutrophication, loss of habitats, marine pollution, and toxic algal blooms as the top environmental issues threatening the health of the world’s oceans and the Gulf, the QULSS of 2015 is tackling the effects of the local and global changes on the Arabian Gulf ecosystem. In QULSS-2015, marine scientists in Qatar University, along with collaborators from local, regional and international leading institutes, communicate and exchange their most recent research findings on impacts of different stressors including extreme natural conditions on the structures and functions of different species and habitats in the Gulf, to the fellow scientists, public, and policymakers. Objectives of the symposium are to increase the awareness on the ecological value of the Arabian Gulf, to initiate activities that foster marine science education, to promote interests in marine and environmental sciences among young people, to encourage young generations to pursue a career in marine environmental science/research, and to provide opportunities for networking and collaboration among scientists at the national, regional and international level as well as to strengthen scientific and research collaboration between academia, industry, and decision makers.
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Global change in marine ecosystems: implications for semi-enclosed Arabian seas
More LessGlobal Change has been defined as the impact of human activities on the key processes that determine the functioning of the Biosphere. Global Change is a major threat for marine ecosystems and includes climate change as well as other global impacts such as inputs of pollutants, overfishing and coastal sprawl. The Semi-enclosed Arabian Seas, including the Arabian Gulf and the Red Sea, have supported human livelihoods in the Arabian Peninsula over centuries and continue to do so, but are also threatened by Global Change. These threats are particularly severe as Semi-enclosed Arabian Seas already present rather extreme conditions, in terms of temperature, salinity and oxygen concentration. The vulnerability of the unique marine ecosystems of the Semi-enclosed Arabian Seas to Global Change vectors is largely unknown, but predictions based on first principles suggest that they may be at or near the tipping point for many pressures, such as warming and hypoxia. There is an urgent need to implement international collaborative research programs to accelerate our understanding of the vulnerability of Semi-enclosed Arabian Seas to Global Change vectors in order to inform conservation and management plans to ensure these Seas continue to support the livelihoods and well-being of the Arab nations.
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The dynamics of the coastal food webs in the Central Arabian Sea
The dynamics of the lower-level components of the coastal food web of Qatar are presented as an 'organic carbon' budget that summarizes comprehensive sampling of the phytoplankton, zooplankton and benthos at standard, repeated locations seasonally over a two year period. Moderate levels of phytoplankton biomass and primary production support diverse, healthy assemblages of zooplankton and benthos that are typical of sub-tropical ecosystems. The primary production however must be supported by sources of new or regenerated inorganic nutrients, such as rate-limiting nitrate, but no clear sources (such as freshwater runoff or upwelling) can be identified in this ecosystem, surrounded as it is by desert. A coupled carbon/nitrogen numerical simulation of the phytoplankton, zooplankton and benthos is used to test the hypotheses that 'new' or regenerated nutrients are supplied by i. export from coastal mangroves forests, ii. nitrogen fixation in the plankton, iii. benthic-pelagic coupling, or iv. the annual (summer) low-salinity, nutrient-rich current from the Sea of Oman. While the potential that high temperatures, high salinities and low oxygen affect metabolic rates, a general limitation of available inorganic nutrients at the bottom of the food web appears to limit sustainable recruitment and biomass.
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What Arabian coral reefs can teach us about the past, the future, and the management of the world's coral reefs
More LessArabian coral reefs are a window into the past and the future. Absence of well-developed frameworks in the southern Arabian Gulf indicates a long-term stressful, historical environmental regime. This contrasts with the northern Arabian Gulf, where better environmental conditions allowed reefs to progress further in geological succession. Since the late 1990s, thermal bleaching of corals has occurred with the highest frequency observed anywhere in the world. The Arabian Gulf now has a thermal regime that is predicted to occur across the tropical oceans in 2100 and studies of Gulf reefs today allow us to draw inferences on future pathways of stress and changes in coral assemblages across the world. Arabian Gulf coral communities are made up by three major groups of competitors (Acropora-merulinids-poritids) that converge upon a stable equilibrium, where they co-exist but Acropora dominates. Less tolerance to temperature and greater susceptibility to diseases makes Acropora vulnerable to dieback in extreme years, which allows slower-growing massive corals (faviids, poritids) to persist and even expand. Over the past two decades, dieback episodes occurred five times as frequently as in the early 20th century, causing significant changes in coral communities. Acropora death and availability as settlement substratum changes a competitive network from stable into unstable. But during very frequent and severe annually recurring disturbances, also poritids and merulinids die back, and now can positively influence populations via settling space on denuded colonies, therefore the competitive network is unstable. Trajectories are hard to predict and depend on local fertility or connectivity. Therefore, Gulf coral communities are not arranged orderly along environmental gradients, but are patchy and variable. Global change will continue to cause mortality and stability of competitive networks in many other regions will be degraded with hardly predictable outcomes. Lessons for the management of Gulf coral reefs, however, are clear: - No species must be lost. Otherwise trajectories of even the best-managed reefs will be unpredictable. - Threatened Acropora should be given special protection to safeguard remaining populations. - Maximum connectivity must be maintained between different reef regions, to allow recolonization of degraded reefs. - Networks of large marine protected areas are required - Impacts in the coastal zone must be reduced since coral larvae must traverse also reef-free zones.
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The puzzling existence of arid mangroves - what sustains Qatar mangroves?
Ecological dogma holds that mangroves are predominantly exporting and are sources for production of offshore systems including fisheries (the ‘outwelling hypothesis’). Yet, the amount of export, and thereby the economic benefits to fisheries, varies greatly between locations. Mangrove functional research has focused on tropical and subtropical areas, where rainfall-driven transport of terrestrial nutrients into mangroves makes forests productive and runoff flow makes export likely. It remains unclear to what degree the outwelling hypothesis applies to arid mangroves; and, at a more basic level, in the absence of rainfall-driven runoff, what are the sources of nutrients that sustain arid mangrove production? This presentation will address these fundamental questions and review the sources for contextual variation in mangrove outwelling; it will detail the findings of several recent multi-disciplinary ecological and oceanographic research projects on Qatar mangroves. Our research explored the notion that the extent of outwelling globally depends on interactions of coastal geomorphology, tidal regime and mangrove production. Findings show that outwelling is less prevalent than previously thought, particularly in areas where in-house herbivory is intense. In mangroves with low freshwater through-flow the net balance between import and export might well be lead to net inwelling: a net import of organic material from subtidal habitats. Thus, seagrass beds are source of inwelling at Al-Khor mangrove in Qatar. At Al-Khor, limited export of mangrove-derived carbon to adjacent food webs has been attributed to the arid environment where the lack of rainfall eliminates a significant flushing mechanism, reducing the opportunity for outwelling of particulate organic material. This presentation concludes that mangroves in the western Arabian Gulf are nutrient limited and dependent on localized retention and cycling of nutrients and inwelling of nutrients from adjacent habitats, partially driven by tidal asymmetry. We suggest that inwelling of particulate material from down-stream habitats, such as seagrass beds, makes a significant contribution in supporting mangrove resident fauna and sustains mangroves in arid countries.
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Multiple stressors for oceanic primary production
Marine ecosystems are increasingly exposed to stress factors of anthropogenic origin that change their function, structure and services they deliver society. Climate change occurs simultaneously with other changes in the environment acting jointly in a context of global environmental change. For oceanic phytoplankton communities, the research conducted so far has identified stress factors associated with global change and their impact individually (warming, acidification, increased UVB radiation, pollutants). But when several stressors act simultaneously interactions and responses are not equal to the sum of individual impacts, but may have synergistic effects (the effects are multiplied) or antagonistic (cancel out the effects) that hinder predictions of the vulnerability of ecosystems to global change. Here we will examine the vulnerability of oceanic primary producers to the accumulation of different stressors associated with global change. The trend for autotrophic picoplankton to increase with temperature in the ocean has led to predictions that autotrophic picoplankton abundance will increase with warming. However, it is documented a trend towards a decline in productivity, due to declined autotroph biomass and production with warming and the associated stratification in the subtropical ocean. Models predicting an increase in abundance are in contradiction with the reported decrease in productivity in several oceanic areas, and associate oligotrophication. Here we perform a global study to analyze the relationships of autotrophic picoplankton with oceanic temperature, nutrients, underwater light and ultraviolet B (UVB) radiation, and productivity. We built a model to project the future changes of autotrophic picoplankton considering multiple environmental changes in future climate scenarios for the subtropical gyres. We considered increased water temperature, and associated changes in productivity and underwater light and UVB. The model show that warming and the decrease in water productivity, with the associated increase in photosynthetic active radiation and UV-B radiation at depth, are expected to result in a decline by 18 to 42 % in the abundance of autotrophic picoplankton. We also predict an increase in the importance of deep blooms at moderate warming, that models based solely in temperature changes failed to predict. We will examine also the vulnerability of oceanic primary producers to the accumulation of different stressors associated with global change as warming, increased UVB radiation and persistent organic pollutants, and explore whether there are synergistic and antagonistic responses of due to join stresses impacting them.
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Marine giants in extreme environments - why the Arabian Gulf hosts one of the largest aggregations of whale sharks in the world
Authors: Steffen Sanvig Bach, Mohammed Al-Jeidah and David RobinsonThe Al Shaheen oil field is located approximately 80 km north-east of Qatar in the Arabian Gulf. The area hosts a highly productive marine environment due to a combination of complex currents. Despite sea surface temepratures exeeding 35 degress Celcius in the summer images taken by Remote Operated Vehicles demonstrate extensive and diverse marine growth on the subsea structures of the production platforms. Over the last twenty years the platforms have turned into artificial reefs that attracts numerous pelagic species. More than 30 fish species have been identified so far including top predators such as Scalloped hammerhead(Sphyrna lewini), Blacktip shark (Carcharhinus limbatus), and Zebra shark (Stegostoma fasciatum). The diverse marine fauna is however best known for one of the world largest aggregations of whale sharks (Rhincodon typus) that return to this area every summer from May to September. The research has demonstrated that whale sharks come here to feed on the high concentration of tuna mackerel spawn (Euthynnus affinis) (Robinson, et. al , 2013). Over the past four years the Qatar Whale Shark Research project (www.qatarwhalesharkproject.com) has used novel acoustic and telemetric technologies to describe the behaviour of the Arabian Gulf whale shark population. More than 100 whale sharks have been fitted with acoustic tags to be able to identify the hot spots within the Al Shaheen oil field. Photo identification of more than 300 individuals and satellite telemetry tracking has confirmed the Al Shaheen Oil field as a highly important feeding habitat in the region. Detailed hydrological modelling has been initiated in order to better describe the currents that may influence the spawning location of the tuna mackerel and the movements of the whale sharks in the Arabian Gulf. The data will make it possible for relevant authorities and industry operators to take appropriate action in order to secure the protection of whale sharks in the Arabian Gulf. Robinson DP, Jaidah MY, Jabado RW, Lee-Brooks K, Nour El-Din NM, Malki AAA, et al. (2013) Whale Sharks, Rhincodon typus, Aggregate around Offshore Platforms in Qatari Waters of the Arabian Gulf to Feed on Fish Spawn. PLoS ONE 8(3): e58255. doi:10.1371/journal.pone.0058255
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Acoustic detection discovers hotspot for dolphins in the Arabian Gulf and records undocumented species
Authors: Balle Jeppe Dalgaard, Steffen Sanvig Bach and Jonas TeilmanGaining knowledge about the biodiversity of an area is a prerequisite to understanding and protecting the inhabiting species. Very little is known about cetacean species and their distribution in Qatar marine waters. The Al Shaheen offshore oil extraction platforms situated in the Arabian Gulf 85 km NE of Qatar mainland have been identified as a hotspot for plankton feeding whale sharks and cetacean species have been sighted consistently in the area during whale shark surveys. Several different species of cetaceans have been sighted but no official records have been published nor has any monitoring been carried out so far. It is important for conservation and management to understand the ecological consequences of human utilisation of marine habitats. Anthropogenic noise in the marine environment is increasing as a consequence of such utilisation and may have a great impact on the behaviour and overall fitness of marine mammals in the vicinity of noise sources (Richardson et al. 1995). A 2 year monitoring project around a Danish Maersk gas production platform initiated in 2013 has indicated that production platforms potentially act as a hotspot for harbour porpoises regardless of the increased noise levels from the ongoing human activities (Balle et al. 2014). It is possible that a similar positive effect is seen with the cetacean species sighted in the Al Shaheen area. Alternatively, Al Shaheen may have a high natural productivity, attracting large fish and cetaceans. Using state of the art marine acoustic technology, 2 passive acoustic monitoring (PAM) stations using Wildlife Acoustic SM3M+ broadband loggers (384 kHz sample rate, 16 bit, -165dB re 1V/µPa single hydrophones) with Sub Sea Sonic AR-60-E acoustic releasers were deployed in August 2014. One station (AlShaheen800) was deployed within 800 m of an operating production platform and a reference station (Alshaheen12800) at 12 kilometres distance within the Al Shaheen area. Here, we will present preliminary diurnal and seasonal variation from the first three deployment periods (Aug-Oct 2014, Feb-Apr 2015 and May-July 2015) and visual identification of 3 species (dwarf spinner dolphin, long-beaked common dolphin and indo-pacific bottlenose dolphin) encountered in the Al Shaheen area. To our knowledge, this is the first time the dwarf spinner dolphin has been sighted in the Arabian Gulf. We also wish to stress the requirement for an ongoing monitoring effort (visually and acoustically) to further understand and document the distribution of cetacean species inhabiting the Al Shaheen area. Balle, Jeppe Dalgaard, Clausen, Karin Tubbert, Mikkelsen, Lonnie, Wisniewska, Danuta Maria & Teilmann, Jonas 2014. Harbour Porpoises and noise around an operating oil and gas production platform in the North Sea – Status report. Nature Agency, Danish Ministry of Environment. Richardson, W.J., Malme, C.I., Green Jr., C.R., Thomson, D.H., 1995. Marine Mammals and Noise. Academic Press, San Diego, CA, USA.
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How do the Arabian Gulf's fish assemblages respond to multiple stressors?
About 50 species of elasmobranchs and 460 species of bony fishes are currently known from the Arabian Gulf. They are key components of the region’s marine biodiversity, contributing to ecosystem functions and services, such as food security. Addressing natural and human-induced threats and the absence of adequate species-specific information, bony fishes were recently assessed against the criteria of the International Union for the Conservation of Nature (IUCN) Red List of Threatened Species, which assigns species to extinction risk categories, based on objectively verifiable criteria. Two Red List Assessment workshops were held by the IUCN Global Marine Species Assessment team, Qatar University, and Qatar Museums, funded by the Qatar National Research Fund. Regional and international experts on fish taxonomy, fisheries, and Arabian Gulf environmental issues participated. Preliminary results indicate that 7% of the fish species, including several of high commercial importance, were at an elevated risk of extinction (5% Vulnerable and 2% Endangered); another 2% were designated as Near Threatened. Most species (71%) were listed as Least Concern. For 20% of all species adequate information was unavailable and they were listed as Data Deficient. Naturally stressful environmental conditions such as high salinities and temperature extremes prevail in the semi-enclosed, shallow Gulf. In addition, degradation resulting from urban and industrial developments, pollution, and unsustainable fisheries is increasing rapidly, aggravated by climate change. The findings of the regional Red List Assessment are attributed to these multiple stressors. While in general, overfishing is the dominant threat, coral-associated species are mainly impacted by habitat loss. Fish assemblages recovered from major oil spills within a few years, but climate change resulted in permanent shifts in species compositions. The high percentage of Data Deficient species underlines the need for more research. Improved scientific knowledge will be the basis for region-specific conservation measures. Most international scientists participating in the assessments have a museum background, underlining the importance of Natural History Museums in research and conservation. There is an urgent need to establish regional research collections, which will provide Qatar with prime sources of objectively verifiable, species-specific information for management and conservation purposes.
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Arabian Gulf reef fishes: a valuable but vulnerable asset for climate change research
By John BurtThe Arabian Gulf is one of the most thermally extreme marine environments on earth, representing a unique ‘natural laboratory’ in which to develop an understanding of how reef fishes may respond to future climate change. Recent research comparing fish in the southern Arabian Gulf with those on reefs in the more benign Gulf of Oman and Arabian Sea has provided insights into how reef fish communities, populations and individuals may respond to increasingly extreme temperatures in other regions. Reef fish communities in the southern Arabian Gulf were shown to be low in species diversity, abundance, and biomass compared with those on reefs in less extreme environments. Arabian Gulf reef fish communities were also functionally distinct, with coral-dependent fishes and important functional groups such as parrotfish being relatively rare. Demographic studies of several species have shown that the extreme thermal environment of the southern Gulf is associated with faster growth rates than conspecifics outside of the Gulf, but that these fish mature at significantly smaller sizes, which may have implications for reproduction and population replenishment. Such studies can provide insight into how populations and communities in other regions may respond as sea temperatures increase in the future. While Arabian Gulf reef fish represent a valuable asset for understanding biological responses to extreme temperatures, they are not immune to the growing pressure of climate change in the region itself. Recent experiments have shown that while Arabian Gulf reef fishes may have the capacity to survive higher temperatures than conspecifics in surrounding seas fish in the Gulf are living very near their physiological limits, suggesting that they are likely to be highly susceptible to even modest increases in seawater temperature. Climate change is also likely to have indirect effects on reef fishes in the Gulf through increased habitat loss, with all coral dependent fishes known for the Gulf already classified as vulnerable to extinction as a result of reef degradation in recent decades. There are also considerable gaps in knowledge of how ocean acidification may affect reef fishes, particularly the more vulnerable larval stages, and how this may synergize with thermal and other anthropogenic stressors.
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Distribution of yeasts in the Arabian Gulf surrounding Qatar
The Arabian Gulf surrounding Qatar is distinct from other marine ecosystems due to its high salinity (39-57 psu) and extreme water temperature fluctuations (15-39°C). Furthermore in the last decade, Qatar has been witnessing an industrial boom as well as extensive infrastructure construction activities. During the first year of a 3-year study, we investigated the diversity of marine yeasts in Qatar. Water samples were collected during two seasons, from 14 different sites along the coastal waters of the Arabian Gulf surrounding Qatar. Yeast species were isolated and identified by sequence analyses of the internal transcribed spacers (ITS1/ITS2) and the D1/D2 domains of the large subunit (LSU) of the ribosomal DNA (rDNA). A total of 360 yeast isolates belonging to 37 genera of Ascomycetes and Basidiomycetes were identified during the two sampling campaigns. Species distribution depicted seasonal and geographical differences. Candida spp. (24%), Rhodotorula spp. (16 %), Kondoa aeria (8%), Aureobasidium spp. (7%), and Hortaea spp. (7%) were among the most frequently identified yeast species. High prevalence of Kondoa spp. (34%), Knufia spp. (24%), and Hypocrea spp. (13%) was observed during summer season, whereas Debaryomyces spp. (37%), Clavispora spp. (23%), Issatchenkia spp. (17%) were the most common species during the winter season. The highest number of yeast isolates was recovered from sites impacted by land-based activities, especially fishing harbors along the Eastern coast of Qatar. This report is the first study on the distribution of yeasts from the marine environment surrounding Qatar.
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Global and regional oceanography - the role of IOC
More LessThe Intergovernmental Oceanographic Commission (IOC) of UNESCO was established in 1960 to coordinate ocean research, observations and services. Today the IOC is perhaps most known for its role in tsunami warning and sea level related hazards, but the IOC also covers many other issues including ocean data exchange, development of standards and systems, climate research and capacity development. The IOC has worked closely with the Scientific Committee on Oceanic Research (SCOR) of ICSU from the start. The International Indian Ocean Expedition (IIOE) in the 1960s was the first large joint experiment of its kind providing improved scientific understanding of the Indian Ocean and related capacity development. 50 years later, the IIOE-2 to be officially launched in December 2015 will be directed towards a series of scientific and societally relevant goals including improvement of the Indian Ocean component of the Global Ocean Observing System (GOOS). Due to limited resources, it is not possible for IOC Officers or the Secretariat to be heavily involved in specifics of all regional and marginal seas of the world ocean. Yet we recognize that the increasing pressure on the coastal zone from human activities and the possibilities for utilizing coastal ocean resources are high priorities for IOC Member States. The IOC therefore aims to stimulate regional cooperation, sharing of scientific expertise and data, and the development of standards, tools and best practices to underpin sustainable regional and coastal marine management including marine spatial planning. In a region hosting a large fraction of the worlds seawater desalination plants, environmental aspects of associated brine release are in focus, in particular since this occurs in a shallow marginal sea of high background salinity due to natural evaporation. While these features may be unique to the region and seem to be driven mainly by local forcing, external drivers from larger scale ocean and climate variability should also be considered. Study of similarities and differences to other marginal seas including inverse estuaries may be useful for scientific understanding of the dynamics and resilience of the regional oceanographic system.
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The status of harmful algae in the Arabian Gulf
More LessIn the ocean, microscopic plankton algae constitute a crucial food supply for filter- feeding bivalves, shellfish (oyster, mussels, scallop and clams), as well as larvae of commercially important crustaceans and finfish. In most areas, the proliferation of plankton algae (so called "algal blooms"; consisting of millions of cells per liter) is beneficial for aquaculture, recreational and commercial fisheries. However, sometimes algal blooms may have a negative impact. Mass occurrences of harmful microalgae, harmful algal blooms (HABs), are a globally growing concern. Most HAB species cause harm due to their production of toxins. HAB species may kill marine wildlife directly, or the algal toxins may accumulate in the food web, causing illness and mortality of fish, seabirds, marine mammals and humans consuming the toxic seafood products. There is scientific consensus that the HAB problem is increasing globally, with increasing numbers of toxic blooms and associated economical loss. The most significant reasons for the increased occurrence of HABs are increased eutrophication of marine coastal areas and spreading of harmful species to new areas. During the last three decades, the Arabian Gulf area has experienced massive marine mortalities, resulting in serious economic losses (Kuwait, Saudi Arabia, Iran, U A E, Oman, Bahrain and Qatar). A documented example is an eight-month-bloom during 2008-2009 of the dinoflagellate Cochlodinium polykrikoides, killing thousands of tons of fish, hampering traditional fisheries, impacting tourism, forcing closure of desalination plants, and damaging coral reefs. The frequency and severity of HAB events are increasing in the Arabian Gulf, and the distribution of harmful species within the region appears to be expanding. In this situation, exchange of information and cooperative research has become obvious to scientists working in the Gulf region. To date, only a small number of studies have been conducted on diversity, distribution and toxicity of HABs in the Arabian Gulf, including Qatari waters. A project on harmful algae is needed here, focusing on biodiversity and ecology based on state of the art techniques, and involving capacity building of local Qatari staff.
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Toward the development of a remote sensing and field data framework to aid management decisions in the state of Qatar coastal environment
The benthic habitat of the Qatari nearshore marine environment plays a significant ecological role and environmental service. Areas of coral help provide protection and sustenance for a vast array of fish species and marine invertebrates, and represent a significant proportion of biodiversity in the region. Seagrass meadows which are prominent in northern Qatari waters are important to charismatic species such as the Hawksbill turtle and dugongs. Stands of macroalgae and even areas of coral rubble provide additional habitat for many marine species. These features, particularly the coral structures, also provide shoreline protection from high energy wave events and storm surges. As such, improving our understanding of these habitats as well as the need to protect and conserve the nearshore Qatari environment is a focus area for local researchers and regulatory authorities. Traditionally, the nearshore marine environment has been studied through intensive field measurement and monitoring. While valuable for collecting detailed site-specific information, this approach can be very resource intensive and also limiting in the scale at which habitats can be quantified and monitored for change. One way to address this is through remote sensing, which has been widely used around the globe to study and monitor benthic habitat cover. For example, data obtained from satellite imagery has been used to classify benthic habitats and in various coral reef remote sensing applications. In this paper, a framework is discussed for the remote sensing mapping of sensitive habitats in the Qatari nearshore marine environment, including field data collection and analysis. A case study from northeastern Qatar is highlighted, focusing on spring 2015 efforts to test the framework particularly for the purposes of mapping coral and seagrass habitats. Results suggest this approach may be a viable option for identifying sensitive areas in the region and monitoring longer-term ecosystem health under natural and anthropogenic stressors in a more safe and cost-effective manner. Limitations and lessons learned will be discussed as well as recommendations on the application of this approach to coastal environmental risk assessment and management planning in the State of Qatar.
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If it is possible to create and manage marine ecosystem in a desert, why is the whole gulf ecosystem under threat?
Authors: David A Jones and Manickam NithyanandanOver the last 14 years a mega project, Sea City, Kuwait, has been developed for over 100,000 inhabitants in a saline desert, most dwellings having access to the sea via waterways. These are designed to circulate high quality seawater throughout the city using only wind and tidal power. Virtually all the intertidal and subtidal open sea Gulf marine habitats have been replicated artificially in Sea City following strict environmental guide lines. Long term monitoring demonstrates that most of these habitats now contain a higher diversity and abundance in comparison to similar habitats, including fisheries, in the open Gulf. In contrast there is now abundant evidence that the open Gulf ecosystem is in serious decline, particularly with regard to key habitats such as mangrove, seagrass, coral reefs and fisheries. Climate change cannot yet be responsible, as both Sea City and the open Gulf are subject to the same effects. Hence decline in the open Gulf is likely to be due to a lack of adherence to environmental guide lines and management practises which have been strictly observed in the development of Sea City. These include absence of pollution; monitoring of water quality and ecosystem development; control of dredging; minimal habitat destruction, only protective infill; lack of sedimentation; enhancement of mangrove, seagrass and corals by cultivation and transplantation and regulation of fisheries. Similar strict environmental regulation needs to be applied throughout the Gulf to save a fragile ecosystem before it is too late.
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The elemental composition of plankton and dust in the Qatari EEZ (Arabian Gulf)
We present data on elemental concentrations of plankton net tow samples from the Exclusive Economic Zone (EEZ) of Qatar in the Arabian Gulf as part of a broader study of biogenic and lithogenic influences on particulate trace metal concentrations in the surface ocean. There are relatively few analyses of planktonic trace metals and their associated role in the biogeochemical system. We had the opportunity to investigate the composition of plankton in a region heavily affected by dust, a significant factor for phytoplankton growth. Our samples were collected from 2012 to 2015 using trace metal clean net tows with mesh sizes of 50 and 200 microns for measurements of phytoplankton and zooplankton, respectively. Samples were totally digested and analyzed by inductively coupled plasma-mass spectroscopy (ICP-MS). The biogenic portion was determined by subtracting the lithogenic portion from the total concentration. The lithogenic fraction was defined as the concentration of aluminum in the sample multiplied by a [Me]/Al ratio. Using average Qatari dust for these ratios generated a significant amount of overcorrection, so ratios were established using average continental crust (UCC). This method still caused some overcorrection for the lithogenic portion resulting in negative excess values for barium, molybdenum, and lead. These same elements showed the least consistency between measurements. For the other elements, a relative stoichiometry for plankton was determined as Fe > Cu ≈ Zn > As ≈ Cr ≈ Mn ≈ Ni ≈ V > Cd ≈ Co. We also found a significant near shore enrichment for 9 out of 13 elements analyzed, indicative of a possible influence of pollution. 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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Bioaccumulation of mercury in pearl oyster (Pinctada radiata) from the coastal waters of Qatar (Arabian Gulf)
Mercury (HgT) and Methylmercury (MeHg) contents were determined in the soft edible tissue of the pearl oyster Pinctada radiata (family Pteriidae) collected by scuba diving from the coastal waters of Qatar during April-May 2011. Samples were gathered from Doha and Al-Edd Al-Gharbi representing highly productive sites. Samples were immediately transferred to a closed laboratory on board the research vessel and/or semi-closed section of the speed boat and processed without encountering sample contamination. Oysters were carefully placed in clean plastic zip-lock bags, and stored at -18 °C until freeze dried at QU and/or MoE labs. Trace metal clean techniques were applied for all steps in the sampling, preparation, preservation and analysis. Duplicate samples, spiked samples and Certified Reference Materials (TORT-2, DORM-2) were digested and analyzed multiple times with each batch of samples. The prepared samples were then analyzed in accordance with US-EPA Method 1630 and 1631 within 48 hours of digestion via ethylation, purge and trap (Tenax) pre-concentration, GC separation and AFS detection. HgT analyses were conducted by AULA 254 Automatic Mercury Analyzer (Gold Trap System) with Automatic Sample Digester in QU-ESC laboratories. MeHg analysis was conducted utilizing the BROOKS RAND MERX System with Hg Speciation GC & Pyrolysis. The maximum MeHg concentration detected was 0.284 μg/kg with the average of 0.016 μg/kg showing a 93% recovery for 80 individuals. The maximum HgT concentration was 0.014 μg/g with an average of 0.008 µg/g for the same set of samples with 87% spike recovery. These values were lower than those reported by FDA (average of 0.02 mg/kg) for oysters and mussels for MeHg contents and within the safe chronic exposure limits of 0.3 μg/kg/day for MeHg via oral ingestion. Values of MeHg and HgT concentrations were correlated with the biometric body parameters (length, width, thickness, total and wet weight) of oysters to detect the relation between mercury bioaccumulation in soft edible tissue and organisms age using its size as a proxy. Correlations between Hg concentrations in predator (e.g. Fish) and prey (e.g. Oyster) is useful in determining pathways of mercury transfer in coastal waters. Long-term monitoring of mercury tissue residue in Qatar’s coastal water is crucial in ecological risk assessment. It is recommended that monitoring for Hg should be extended to cover more stations especially near industrial activities. Acknowledgement This study was made possible by a grant from the Qatar National Research Fund under its National Priorities Research Program award number NPRP 09-505-1-081. 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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Acute orthogonal stress driven by temperature, salinity and light intensity on Qatari Porites photosynthesis and growth
Authors: Nayla Al-Naema, Nandita Deb, Suhur Saeed, Jennifer Dupont and Radhouane Ben-HamadouCoral reefs are very important as they provide a foundation habitat for many aquatic species. Corals are marine invertebrates that exist as communities of polyps. Occasionally when corals experience physical stresses, the polyps expel their symbiotic zooxanthellae resulting in a white appearance. This is commonly described as “coral bleaching”. The Arabian Gulf is well known as one of the most extreme environments in which zooxanthellate coral reef communities occur. A combination of both extremely high and low temperatures as well as high salinities, combined with shallow profile of the coastal waters (high luminosity) imply high stress for coral physiology that may explain much of the coral bleaching and mortality events observed during the last decade. We initiated a series of laboratory experiments (microcosms: ecosystems under controlled conditions) to understand the impact of specific environmental parameters on Qatari coral health under controlled lab conditions. To draw a conclusion about optimum conditions and tolerance range for corals in Qatari waters, Porites sp. nubbins, collected from natural coral reefs North of Qatar, were cultured in pre-acclimatized laboratory aquaria. Orthogonal experiments were conducted to test the physiological response of corals under 3 stress stimuli: salinity, light intensity and temperature. Imaging-Pulse Amplitude Modulation Fluorometry (Imaging-PAM) and buoyant weight were utilized during experiment to measure photosynthetic performance and growth of the corals. Results revealed that elevated levels of temperature and salinity have a statistically significant effect on Symbiodinium photosynthetic activity; while light intensity did not. High level of salinity (50 psu) affected the corals’ photosynthetic efficiency. As a result, corals’ weight dropped down causing partial bleaching which was noticed at day 10 of the experiment with faded spots that covered the corals’ body and allowing other algae to overgrow. The decrease in photosynthetic activities of the in-hospite Symbiodinium under acute salinities and temperature levels were effectively observed through Imaging-PAM only after the 6th day of exposure. This suggests that in-hospite Symbiodinium of Porites sp. are affected only in relatively prolonged extreme conditions. A fast and comprehensive recovery of Porites sp. health could; therefore, be possible for short exposure to extreme temperature or salinity conditions. These results are very important to address the coral mortality and bleaching events occurring in Qatari coastal waters and may help establish guidelines for coral relocation efforts in Qatar marine environment or the identification of potential impacts of thermal pollution on coral reefs in Qatari waters due to industrial discharges from power or desalination plants.
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Sediments quality assessment using sediment chemistry and community structure in the natural mangrove habitats in the east coast of Qatar, Arabian Gulf
Authors: Yousria Soliman and Jassim Al KhayatMangroves in the east coast of Qatar is one of the most productive ecosystems that supports complex communities of invertebrates and fishes. These habitats are exposed to impacts associated with the rapid industrial developments in the region and in the eastern coast of Qatar, where the natural mangrove reserve resides, making its biodiversity at risk of impacts of pollution from different sources. In order to assess the quality of the sediments of the mangrove and to assess the associated biodiversity of benthic macrofauna, integrative assessment was performed using chemical, biological and toxicological measurements. The quality of the sediments and the structure of the associated benthic community were examined in three locations (Al Dakhira, Al-Khor and the Port), that are located at different distances to potential sources of pollution. The first location while the latter is near a harbor. Sediment concentrations and tissue residues of organic contaminants (PAHs, PCBs, Dioxin and Furan) and trace metals (Hg, Pb, As and Cu) were determined in order to assess levels and bioavailability of contaminants. Biodiversity of benthic macrofaunal community where also estimated in the sediments bi-annually during 2013-2014. Sediments analysis showed that both trace metals and organic contaminants were impacted by proximity to potential sources of pollution with higher levels of contaminants in Al Dakhira and the port. Some contaminants like dioxin and furan were not detected in the study area. Species richness seemed to be impacted by the sediment quality where the highest number of species of benthic macrofaunal species (46 species) where reported from Al Khor. The number of species decreased by about 15% near the industrial city while it is reduced by over 60% near the harbor. Long term monitoring of these habitats is highly recommended for effective management and conservations. Long term monitoring of these habitats is highly recommended for effective management and conservations.
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Contaminant metals in costal marine sediment along the Doha Bay, Qatar
Heavy metals pollution in marine environments has become a worldwide problem with the fast industrial development in the east coastal region of Qatar, especially in the Doha bay area. Heavy metals are expected to be presented into the coastal environment and be combined within sediments together with organic matters, clay, oxides, and sulfides. The concentration of heavy metals in the marine environment depends on many factors such as the source of pollution, input, and its speciation, sediment characteristics, adsorptive properties of clay minerals, and others. This study aimed at providing knowledge on the environmental characteristics and properties in the location where many developments are constructed such as residences, marinas, and other facilities within the coast of Doha Bay. The study analysed the concentrations of 25 metals around Doha Bay to evaluate the pollution loading and the magnitude of the impact that the contaminants had on the sediment samples within the area on two sampling durations. Significant differences were observed in metal concentrations between the sampling locations and durations. Higher concentrations were observed in areas where there are a lot of anthropological activities. The distribution of selected metals was presented in contour maps showing the variation between the two periods. In order to further study particle size effect on metals uptake, two different grinding times were administered on four randomly selected samples and the results showed no significant difference on the analysis in the ICP-OES instrument. The overall results of metal analyses were within the international standards criteria and the results were comparable to the previous studies conducted around Qatar.
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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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