A5021202272- Marine and coastal ecosystems
- Marine Biology and Ecology Research
- Aquatic Ecosystems and Phytoplankton Dynamics
- Atmospheric chemistry and aerosols
- Soil and Water Nutrient Dynamics
- Isotope Analysis in Ecology
- Geology and Paleoclimatology Research
- Heavy metals in environment
- Marine and environmental studies
- Groundwater and Isotope Geochemistry
- Geochemistry and Elemental Analysis
- Microbial Community Ecology and Physiology
- Water Quality and Pollution Assessment
- Marine Bivalve and Aquaculture Studies
- Fish Ecology and Management Studies
- Fish Biology and Ecology Studies
- Marine and fisheries research
- Coastal wetland ecosystem dynamics
- Mine drainage and remediation techniques
- Aquaculture Nutrition and Growth
- Iron oxide chemistry and applications
- Coal and Its By-products
- Aeolian processes and effects
- Wastewater Treatment and Nitrogen Removal
- Mercury impact and mitigation studies
University of Leeds
2014-2024
University of Haifa
2015-2024
Carmel (Israel)
2013-2023
University of Waterloo
2016-2018
UK Centre for Ecology & Hydrology
2010
Laboratoire de Biologie du Développement de Villefranche-sur-Mer
2006
Plymouth Marine Laboratory
2005-2006
Hellenic Centre for Marine Research
2006
Israel Oceanographic and Limnological Research
1985-2005
International University of Monaco
2005
Although NO 3 is generally considered to limit primary productivity in most of the world’s oceans, previous studies have suggested Mediterranean Sea may be an exception. In this study southeastern Mediterranean, we found that all PO 4 3− was removed from upper water column during winter phytoplankton bloom core and boundary a warm‐core eddy, while measurable (0.3–0.6 µ M) − remained. The N : P (NO :PO ) ratio Cyprus eddy 27.4 slope linear portion vs. scattergram 25.5 with positive intercept...
A reaction scheme for the spectrophotometric determination of ammonia by means a modified Berthelot is proposed, in which salicylate, dichloroisocyanurate and complex cyanides are principal reagents. The experimental results presented consistent with, support, proposed. It suggested that act on two stages reaction, firstly to stabilise monochloramine at pH values (12–13) it normally unstable hence facilitate formation 5-aminosalicylate from salicylate (this step rate determining reaction),...
Phosphate addition to surface waters of the ultraoligotrophic, phosphorus-starved eastern Mediterranean in a Lagrangian experiment caused unexpected ecosystem responses. The system exhibited decline chlorophyll and an increase bacterial production copepod egg abundance. Although nitrogen phosphorus colimitation hindered phytoplankton growth, phosphorous may have been transferred through microbial food web copepods via two, not mutually exclusive, pathways: (i) bypass compartment by uptake...
The adsorption of dissolved phosphate in anoxic marine sediments has been investigated samples mud from two locations Long Island Sound kept under strictly conditions. Kinetic experiments showed that desorption is more rapid than adsorption, but both reach equilibrium within 24 h. process can be described by a simple linear isotherm: the dimensionless situ coefficient ( K ) determined four separate runs on FOAM site was 1.7 ± 0.2; for sediment NWC it 1.9. Diffusion measurements provide...
The eastern Mediterranean has a high nitrate to phosphate (N : P) ratio (~28 1) in the deep water and highly unusual P limitation of primary productivity. We present detailed nutrient budget inputs basin, which shows that there is N: (>16 all input sources, particularly from atmospheric source, where was 117 1. retained within system because no significant denitrification either sediments or intermediate water. This extreme oligotrophic nature system, caused by anti‐estuarine flow at...
The diffusion coefficients of sulfate, ammonium, and phosphate ions were determined directly in the laboratory by placing two samples homogenized, anoxic mud from Long Island Sound contact with one another across a planar interface. After 141 h concentration profiles them, values effective (which incorporate effects adsorption) calculated. Correction these for adsorption, using independently linear adsorption constants same sediments, gave following (× 10 −6 cm 2 · s −1 , 20°C, errors ±2σ):...
Abstract Strontium isotopic and petrologic information, obtained from sediment cores collected in the Nile delta of Egypt, indicate that paleoclimatic baseflow conditions changed considerably about 4200 to 4000 cal yr B.P. basin. Our study records a higher proportion White transported during annual floods at ca. 6100 than towards B.P., which time suspended Blue formed significantly larger fraction total load. This resulted decrease vegetative cover an increase erosion rate accompanying...
Research Article| January 01, 2002 Nile River sediment fluctuations over the past 7000 yr and their key role in sapropel development Michael D. Krom; Krom 1School of Earth Sciences, University Leeds, Leeds LS2 9JT, UK Search for other works by this author on: GSW Google Scholar J. Daniel Stanley; Stanley 2Deltas-Global Change Program, Smithsonian Institution, Washington, D.C. 20560, USA Robert A. Cliff; Cliff 3School Jamie C. Woodward 4School Geography, Author Article Information Publisher:...
Estimates of the sources and wet deposition fluxes inorganic nutrients (PO 4 3− , NO 3 − 2 NH + ) have been made using a long‐term atmospheric measurement at three sites along Mediterranean coast Israel. The nutrient composition in rainwater indicated dominant anthropogenic source for continental, natural, anthropogenic, rock/soil PO . calculated dissolved N (IN) P (IP) were 0.28 0.009 g m −2 yr −1 to coastal zone estimated as 0.24 0.008 Southeast (SE) Mediterranean, with possible increasing...
The formation of iron (Fe) nanoparticles and increase in Fe reactivity mineral dust during simulated cloud processing was investigated using high-resolution microscopy chemical extraction methods. Cloud experimentally via an alternation acidic (pH 2) circumneutral conditions 5−6) over periods 24 h each on presieved (<20 μm) Saharan soil goethite suspensions. Microscopic analyses the processed samples reveal neo-formation Fe-rich nanoparticle aggregates, which were not found initially....
Abstract. Primary productivity of continental and marine ecosystems is often limited or co-limited by phosphorus. Deposition atmospheric aerosols provides the major external source phosphorus to surface waters. However, only a fraction deposited aerosol water soluble available for uptake phytoplankton. We propose that acidification prime mechanism producing from soil-derived minerals. Acid mobilization expected be pronounced where polluted dust-laden air masses mix. Our hypothesis supported...
<strong class="journal-contentHeaderColor">Abstract.</strong> We investigated the iron (Fe) dissolution kinetics of African (Tibesti) and Asian (Beijing) dust samples at acidic pH with aim reproducing low conditions in atmospheric aerosols. The Beijing three size fractions Tibesti (<20 μm: PM<sub>20</sub>; <10 PM<sub>10</sub>; <2.5 PM<sub>2.5</sub>) were dissolved 1, 2 and/or 3 for up to 1000 h. In first 10 min, all underwent an extremely fast Fe solubilisation. Subsequently,...
Augite, hypersthene, diopside, and hornblende all undergo dissolution during weathering by means of the formation, growth, coalescence distinctive, parallel, lens-shaped etch pits. Similar features can be produced if these minerals are treated in laboratory with concentrated hydrofluoric acid plus hydrochloric acid. These pits most likely form at dislocation outcrops, their shape orientation controlled primarily crystallography underlying mineral. The results similar to those found for soil...
[1] The flux of bioavailable Fe from mineral dust to the surface ocean is controlled not only by processes in atmosphere but also nature and source dust. In this study, we investigated how minerals affects its potential solubility (Fepsol) employing traditional modern geochemical, mineralogical, microscopic techniques. chemical mineralogical compositions, particularly mineralogy, soil samples as precursors collected North African regions were determined. Fepsol was measured after 3 days...
Phosphorus (P) in water and sediment the Yellow River was measured for 21 stations from source to Bohai Sea 2006–2007. The average total particulate matter (TPM) increased 40 mg/L (upper reaches) 520 (middle 950 lower reaches of river. dissolved PO4 concentration (0.43 μmol/L) significantly higher than that 1980's but world level despite high nutrient input system. Much P removed by adsorption, which due TPM rather surface activity particles since they had low labile Fe affinity P. a sink...