Environmental Drivers of Habitat Use by Hawksbill Turtles (Eretmochelys imbricata) in the Arabian Gulf (Qatar)

Understanding the environmental drivers of movement patterns are critical to the protection, management and recovery of endangered species. The Arabian Gulf is considered to be the hottest marine system in the world and is known for its extreme environmental conditions that pose substantial physiological stress on marine organisms living there. Satellite tags were deployed on hawksbill turtles in the Arabian Gulf and quantitative ecological modeling (i.e., Bayesian state-space models and GAMMs) was used to provide new insights into the ecological basis of observed hawksbill movement and behavior. Hawksbills used a relatively large core area in the southeast Arabian Gulf when transit and area-restricted search behaviors were included. The numerous hotspots identified suggest that important habitat occurs along a large area of the Qatari eastern coastline and into Saudi Arabia. Offshore islands with fringing reef habitat and deep-water habitats near the 30–50 m isobaths were intensely used. Hawksbills made seasonal migrations to deep-water habitat during summer months, typically once SST reached ∼33°C and bottom temperature reached ∼32°C. These data provide valuable information to managers seeking to conserve hawksbills in the region. Our data also provide a context to understand the underlying physiological, energetic and behavioral drivers of hawksbill movement in the Arabian Gulf. Future studies should include the use of biologging devices, benthic surveys, and dietary biomarkers to better understand the seasonal migrations of Arabian Gulf hawksbills to this deep-water region.This work was funded by the Qatar National Research Fund, National Priorities Research Program 5-642-1-110. The open access publishing fees for this article have been covered by the Texas A&M University Open Access to Knowledge Fund (OAKFund), supported by the University Libraries

Improving management of future coastal development in Qatar through ecosystem-based management approaches

The coastline of Qatar is a rich mosaic of productive and diverse ecosystems including mangrove forests, intertidal mudflats (sabkha), seagrass beds, and coral reefs. These ecologically interconnected ecosystems contain a substantial proportion of Qatar's total biodiversity, and support an estimated 97% of the >US$ 67 million in annual commercial fisheries, the highest value resource sector after petroleum. The extreme environmental conditions that characterize Qatar has led to fauna that are robust compared with other regions, but makes them highly sensitive to further pressure from anthropogenic stress. These vulnerable ecosystems have come under increasing pressure in recent decades as a result of dramatic expansion of coastal development, and threats to these ecosystems are likely to accelerate in the coming years as Qatar's economy and population continue to grow. Although environmental regulation had historically lagged behind the rapid pace of development, in recent years Qatar's leadership has aggressively expanded environmental management as a result of the growing awareness of the importance of coastal ecosystems. While these improvements are encouraging, management remains challenged by its current sectorial, project-driven focus. Ecosystem-based management (EBM) offers an opportunity to overcome these challenges by integrating impacts from across all major activities in multiple sectors and considering their cumulative effects on ecosystem services and products. While an EBM approach would require modest reprioritizing of existing processes and attention to addressing deficiencies in data needed to support decision making, it has the potential to greatly enhance the efficiency and effectiveness of coastal zone management. The article closes by summarizing a recently initiated research project on coral reefs and seagrass beds in Qatar which can serve as a model for development of the EBM approach for other coastal ecosystems in Qatar.This publication was made possible by the NPRP award [NPRP8-952-1-186] from the Qatar National Research Fund (a member of The Qatar Foundation) through the National Priority Research Program. The statements made herein are solely the responsibility of the authors. Appendix AScopu

Nutritive effect of dust on microbial biodiversity and productivity of the Arabian Gulf

The Arabian Gulf is exposed to intensive dust storms during summer until early winter. We investigated the nutritive effect of the dust on microbial biodiversity of the water column and the productivity of the Gulf. We collected samples from three sites in a transect perpendicular to the shore in March (before the strong dust storms) and in October (after the dust season) in 2013. At the three sites, we sampled the water column at three depths, and see-floor sediments using a HAPS corer. We also sampled the sand dunes that are the source of the dust. We analyzed the samples for pigments, microbial community composition using a 16S rRNA analysis, and nutrients. Our results showed that species richness and biodiversity were higher in October than in March. The relative abundances of key-player microorganisms were strongly pronounced in October. We assume that the dust rapidly sinks to the seafloor where the nutrients Fe and P are liberated through iron reduction. Assuming that all phosphate diffusing from the seafloor originates from the dust particles after deposition, we estimated a contribution of minimum 30,000 tons of fish produced every year in the Gulf. We found no close temporal coupling between dust storms and productivity. This is because nutrient liberation from the seafloor is slow and its transport from the seafloor to the photic zone by circulation processes is irregular. This study highlights the importance of dust as a source of nutrients in the Gulf ecosystem

Mercury accumulation in Lethrinus nebulosus from the marine waters of the Qatar EEZ

Total mercury (THg) and methylmercury (MeHg) were recorded in the commercial demersal fish Lethrinus nebulosus, caught from six locations in Qatar EEZ (Exclusive Economic Zone). Concentrations of THg decreased in the order: liver ˃ muscle ˃ gonad. THg concentrations in fish tissue ranged from 0.016 ppm in gonad to 0.855 ppm (mg kg−1 w/w) in liver tissues, while concentrations in muscle tissue ranged from 0.24 to 0.49 ppm (mg kg−1 w/w) among sampling sites. MeHg concentrations were used to validate food web transfer rate calculations. Intake rates were calculated to assess the potential health impact of the fish consumption. There is no major threat to human health from the presence of Hg in L. nebulosus, based upon reasonable consumption patterns, limited to no more than three meals of L. nebulosus per week.Qatar National Research Fund (QNRF) under the National Priorities Research Program (NPRP) award number NPRP 09-505-1-08