Qatar University Life Science Symposium-QULSS 2015 Global Changes: The Arabian Gulf Ecosystem

Global 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.

Arabian 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.

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.

Gaining 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.

The 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.

The 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.

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.

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.

Coral 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.

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.