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Featured researches published by Waleed Hamza.


Aquatic Ecosystem Health & Management | 2009

Protecting and managing the Arabian Gulf: Past, present and future

Waleed Hamza; M. Munawar

The Arabian Gulf (also known as Persian Gulf and ROPME Sea) represents an extremely important economic, political and strategic aquatic resource. Although the Gulf region is known world wide for its oil-gas deposits and production, very little is known about its ecosystem health, food web dynamics, fisheries, biodiversity and sustainability. The present study reviews and highlights the major anthropogenic stressors which threaten the marine and coastal ecosystems of the Gulf. The Arabian Gulf environment lacks the holistic, ecosystem-based research and monitoring that have been conducted in other marine ecosystems. There is a need for multi-disciplinary, multi-trophic and multi-agency international investigations including the application of emerging technology. Such an integrated strategy is urgently needed to save the rapidly changing marine ecosystems from the impact of rapid and vigorous coastal development across the entire Gulf region. The necessity of developing and implementing ecosystem health agreements between the various riparian countries is emphasized for expeditious protection, conservation and management of this precious but threatened natural heritage.


FEMS Microbiology Ecology | 2008

Lipid biomarkers, pigments and cyanobacterial diversity of microbial mats across intertidal flats of the arid coast of the Arabian Gulf (Abu Dhabi, UAE)

Raeid M. M. Abed; Katharina Kohls; Raphaela Schoon; Ann Kathrin Scherf; Marion Schacht; Katarzyna A. Palinska; Huda Alhassani; Waleed Hamza; Jürgen Rullkötter; Stjepko Golubic

Variations in morphology, fatty acids, pigments and cyanobacterial community composition were studied in microbial mats across intertidal flats of the arid Arabian Gulf coast. These mats experience combined extreme conditions of salinity, temperature, UV radiation and desiccation depending on their tidal position. Different mat forms were observed depending on the topology of the coast and location. The mats contained 63 fatty acids in different proportions. The increased amounts of unsaturated fatty acids (12-39%) and the trans/cis ratio (0.6-1.6%) of the cyanobacterial fatty acid n-18:1omega9 in the higher tidal mats suggested an adaptation of the mat microorganisms to environmental stress. Chlorophyll a concentrations suggested lower cyanobacterial abundance in the higher than in the lower intertidal mats. Scytonemin concentrations were dependent on the increase in solar irradiation, salinity and desiccation. The mats showed richness in cyanobacterial species, with Microcoleus chthonoplastes and Lyngbya aestuarii morphotypes as the dominant cyanobacteria. Denaturing gradient gel electrophoresis patterns suggested shifts in the cyanobacterial community dependent on drainage efficiency and salinity from lower to higher tidal zones. We conclude that the topology of the coast and the variable extreme environmental conditions across the tidal flat determine the distribution of microbial mats as well as the presence or absence of different microorganisms.


Aquatic Ecosystem Health & Management | 2011

Dust storms over the Arabian Gulf: a possible indicator of climate changes consequences

Waleed Hamza; Mohamed Rizk Enan; Huda Al-Hassini; Jan Berend W. Stuut; Dirk deBeer

Dust storm frequencies and strengths were monitored during 2009 at various locations along the coast of the United Arab Emirates (UAE), as representative sites of the Arabian Gulf marine environment. The results have been compared with a pre-2009 five-year data set. Mineralogical components of dust samples collected during the 2009 study period were analyzed using both X-ray diffraction (XRD) and X-ray Fluorescence (XRF) techniques. The comparison of the 2009 and pre-2009 data revealed a shift in the characteristics of dust storms in the Arabian Gulf, which may constitute a sensitive indicator of climate change affecting the region. The range of mineral compositions of the collected dust samples is consistent with temporally and spatially variable dust sources, associated with changing wind patterns over the Arabian Gulf. From a positive perspective, the dust may deliver mineralogical nutrients enhancing microbial productivity in the marine ecosystem. Increasing productivity and liberation of iron from sediments will lead to an increase of Dimethyl Sulfide (DMS) in the atmosphere, which by oxidation will scatter solar radiation effectively with a consequent decrease in global temperature as a climate feedback.


Archive | 2009

The Nile Delta

Waleed Hamza

The first € price and the £ and


Aquatic Ecosystem Health & Management | 2006

Effects of food sources on growth rates and survival of Nile tilapia (Oreochromis niloticus) fry

Latifa Al-Shamsi; Waleed Hamza; Abdel-Fattah M. El-Sayed

price are net prices, subject to local VAT. Prices indicated with * include VAT for books; the €(D) includes 7% for Germany, the €(A) includes 10% for Austria. Prices indicated with ** include VAT for electronic products; 19% for Germany, 20% for Austria. All prices exclusive of carriage charges. Prices and other details are subject to change without notice. All errors and omissions excepted. A.M. Negm (Ed.) The Nile Delta


African Journal of Marine Science | 2016

Biological data from sharks landed within the United Arab Emirates artisanal fishery

Rima W. Jabado; Sm Al Ghais; Waleed Hamza; David P. Robinson; Aaron C. Henderson

The present study was conducted to investigate the effects of live food (Chlorella vulgaris, Artemia fransciscana), artificial feed and combinations of both types (Chlorella + Artemia nauplii; Chlorella + Artificial feed; Artemia nauplii + Artificial feed; and Chlorella + Artemia nauplii + Artificial feed) on the growth, feed utilization efficiency and survival of Nile tilapia (Oreochromis niloticus) fry. Triplicate groups of swim-up fry (0.012 g average body weight) were stocked in 20 l fibreglass tanks, with 6 l of water, in a closed rectangular indoor system, at a density of 24 fry per tank (4 fry l−1). The foods were offered to the fish 3 times a day, for 35 days. The results indicated that the maximum body weight gain and survival were achieved in fry fed on Artemia nauplii and on the combination of the three food types, followed by those fed on Artemia nauplii + Artificial. The lowest growth and survival rates were observed in fry fed on Chlorella suspension alone. The fry fed only with artificial feed showed moderate growth and good survival. In conclusion, Artemia nauplii was the best live food, followed by Artemia nauplii combined with artificial feed, to accelerate the growth rate of the fry.


Aquatic Ecosystem Health & Management | 2008

Simulation of the hydrodynamic regime of Jebel Ali Harbor, Dubai, United Arab Emirates

Munjed A. Maraqa; Ayub Ali; Hassan D. Imran; Waleed Hamza; Saed Al Awadi

Landing site and market surveys of sharks landed along the Arabian Gulf coast of the United Arab Emirates were undertaken between October 2010 and September 2012 to obtain biological data from this artisanal fishery. Data were collected on the size and sex of 12 482 individuals representing 30 species. Maximum sizes of Carcharhinus sorrah, C. amblyrhynchoides and Hemipristis elongata were extended by at least 300 mm total length (TL) compared with published global maxima. The size at 50% maturity was determined for males of five species and this indicated that the males of smaller shark species (<1 000 mm maximum TL) in the fishery were largely mature. For many species, including Loxodon macrorhinus and Mustelus mosis, overall sex ratios were male-biased, indicating that sexual segregation is likely in those species. Furthermore, sex ratios for several species, such as Rhizoprionodon acutus, showed differences across seasons. Overall, the landings contained a high proportion of juveniles, causing concerns about the sustainability of this fishery. Biological parameters of a number of species differed from those recorded earlier for the region, demonstrating a need for additional local data collection to support the development of management measures.


Aquatic Ecosystem Health & Management | 2013

Aquatic Ecosystem Health and Management Society: A global integration of aquatic ecosystems research and development

Waleed Hamza

Jebel Ali Harbor in Dubai is one of the largest man-made ports in the world. Due to its bottle-like nature, it is anticipated that little mixing or wave action occurs within the harbor; however, no study has been conducted to investigate the harbors hydrodynamic regime. In this paper, the circulation pattern in Jebel Ali Harbor is presented. The vertical profile of temperature and salinity shows that the harbor water is fairly well-mixed, justifying the use of a depth-averaged, 2-D model. Modeling the hydrodynamic pattern of Jebel Ali Harbor was carried out using MIKE21 model. Although tide is the main driving force of circulation in the harbor, wind and Coriolis forces were taken into account in the simulation. Simulation results showed that both dead and eddy zones exis. As the harbor receives treated wastewater from several industries located in the area, flushing out of a conservative tracer by the advection-dispersion process was also simulated using MIKE21. Results revealed that the flushing time of a conservative tracer from the harbor varies significantly with the discharge location. Simulated results showed that understanding the hydrodynamic regime of Jebel Ali Harbor is useful for selecting the location and time for discharging tracers into the harbor.


Archive | 2012

Effects of Discharge Characteristics on Aqueous Pollutant Concentration at Jebel Ali Harbor, Dubai-UAE

Munjed A. Maraqa; Ayub Ali; Hassan D. Imran; Waleed Hamza; Saed Al Awadi

It was 1990 when I became acquainted with the newly published Aquatic Ecosystem Health and Management Society journal, Aquatic Ecosystem Health and Management (AEHM) volume (1). At that time, I had just registered for my Ph.D. in Italy and my research was underway at one of the CNRItaly (Consiglio Natizionale delle Richerche) prestigious research institutes in the field of hydrobiology. At that time this institute was known as “Istituto Italiano di Idrobiologia” or “Italian Institute of Hydrobiology,” located in Verbania Pallanza, northern Italy. This Institute has many scientific, social, and cultural traditions. One of its scientific traditions was to expose newly published journals on a special shelf in the reading room for a period of 2 weeks to one month which was very helpful in keeping you updated with new publications in your field of research (no online services at that time). Since I was a fresh student at the VI cycle of the Italian Ph.D. program in environmental science with a special interest in aquatic ecology, I was attracted by the title of the journal . . . oh . . . no, I was firstly attracted by the cover design and the colorful cover page. Since it was my first time seeing a scientific journal with such a colorful cover, I was interested to see the quality of publications and what areas of aquatic ecosystems they were focusing on; I was also interested to see who was the editor and who was on the editorial board of this journal. When I read the name Mohi Munawar, as chief editor, I remembered that I was interested in some of his publications about Indian inland waters and their phytoplankton communities while I was preparing my M.Sc. thesis at Alexandria University in Egypt, and I remembered that I wrote to him asking for some of his publications. He kindly sent two of them to me by normal post and at that time it took six months to receive them! The topics of the first volumes of AEHM were not related to one geographic area and were not specific to certain organisms. Those made me reflect on the cover page design, which consists of the world map outline containing different habitats and ecosystem features within. In fact, that was one of the most important strong points that made the AEHMS journal stand out; also its publisher, Taylor & Francis Group, LLC, is one of the most well-known worldwide and has endorsed the journal editor’s ideas to spotlight specific geographical ecosystems. This needs attention not only from the scientific research point of view, but also from the point of view of administrative, policy development and management programs which need to be established in order to sustain healthy aquatic environments worldwide. Years passed and I referred in many of my publications to several published articles in the AEHMS journal until one day in 2004 when I was in LahtiFinland at the 29th SIL Conference, where I met in


Archive | 2010

Dust Storms over the Arabian Gulf: An optimistic vision toward climate change consequences

Waleed Hamza; Mohamed Rizk; Huda Al-Hassini; Jan Berend W. Stuut; Dirk deBeer

The Arabian Gulf is an important geographical location. The Gulf has been extensively used for transport purposes. Meanwhile, countries in the region benefit from the Gulf’s diverse marine habitats and utilize its water for desalination or some industrial needs. Several pollutants are induced into the Gulf including those resulting from oil spill accidents, offshore exploration processes, ballast water discharge, reject brine discharge, dredging activities, and coastal construction projects. Meanwhile, some of the Gulf countries are developing new coastal industrial facilities or expanding existing ones. These facilities are not without an adverse impact on the marine environment.

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Rima W. Jabado

United Arab Emirates University

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Aaron C. Henderson

The School for Field Studies

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Saif M. Al Ghais

United Arab Emirates University

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Carla Bonacina

National Research Council

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Hassan D. Imran

United Arab Emirates University

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Huda Al-Hassini

United Arab Emirates University

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Munjed A. Maraqa

United Arab Emirates University

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Sm Al Ghais

United Arab Emirates University

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Mahmood S. Shivji

Nova Southeastern University

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