Papers by Abed El Rahman Hassoun
Frontiers in marine science, Mar 27, 2024
Frontiers in Marine Science, 2024
The interdisciplinary community of ocean and coastal observers and modelers in Europe is driven b... more The interdisciplinary community of ocean and coastal observers and modelers in Europe is driven by national observing needs for prediction and management of intricate processes shaping Europe's Seas. Not all observing needs can be addressed by nations alone and various coordination activities exist to overcome fragmentation and create cross benefit within the European Ocean Observing Community (EOOC). This way critical insights into impacts of climate change on European Waters and cross border marine resources management can be achieved. Based on a large number of published material, this article is identifying and addressing the current state of activities of the EOOC and states gaps that potentially prevent efficacy. Key challenges include spatial and temporal coverage in observations, data integration, accessibility, uncertainties in projections, technological hurdles, and engagement and communication gaps. Detailed recommendations are provided for identified gaps, offering valuable insights for stakeholders, funders, and supporters of the EOOC. These recommendations, extending beyond academic interest, carry significant implications for climate change mitigation, marine resource management efficiency, ecosystem resilience, disaster preparedness, economic benefits, and the broader scientific advancements in European marine science, thereby benefiting society at large. As the world undergoes transformative changes impacting all facets of European life, substantial investment and support for the EOOC are crucial for precise information, accurate predictions, supporting sustained services that contribute to business growth and community resilience, and a sustainable ocean.
The pH of coastal seawater varies based on several local forcings, such as water circulation, ter... more The pH of coastal seawater varies based on several local forcings, such as water circulation, terrestrial inputs, and biological processes, and these forcings can change along with global climate change. Understanding the mechanism of pH variation in each coastal area is thus important for a realistic future projection that considers changes in these forcings. From 2020 to 2021, we performed parallel year-round observations of pH and related ocean parameters at five stations around the Japanese coast (Miyako Bay, Shizugawa Bay, Kashiwazaki Coast, Hinase Archipelago, and Ohno Strait) to understand the characteristics of short-term pH variations and their forcings. Annual variability (~1 standard deviation) of pH and aragonite saturation state (Wara) were 0.05-0.09 and 0.25-0.29, respectively, for three areas with low anthropogenic loadings (Miyako Bay, Kashiwazaki Coast, and Shizugawa Bay), while it increased to 0.16-0.21 and 0.52-0.58, respectively, in two areas with medium anthropogenic loadings (Hinase Archipelago and Ohno Strait in Seto Inland Sea). Statistical assessment of temporal variability at various timescales revealed that most of the annual variabilities in both pH and Wara were derived by short-term variation at a timescale of < 10 days, rather than seasonal-scale variation. Our analyses further illustrated that most of the shortterm pH variation was caused by biological processes, while both thermodynamic and biological processes equally contributed to the temporal variation in Wara. The observed results showed that short-term acidification with Wara < 1.5 occurred occasionally in Miyako and Shizugawa Bays, while it occurred frequently in the Hinase Archipelago and Ohno Strait. Most of such short-term acidified events were related to short-term low-salinity events. Our analyses showed that the amplitude of short-term pH variation was linearly correlated with that of short-term salinity variation, and its regression coefficient at the
Zenodo (CERN European Organization for Nuclear Research), Oct 1, 2022
Zitierweise für dieses Dokument: MedECC-Zusammenfassung für politische Entscheidungsträger 2020 I... more Zitierweise für dieses Dokument: MedECC-Zusammenfassung für politische Entscheidungsträger 2020 In: Klima-und Umweltveränderungen im Mittelmeerbecken-Aktuelle Situation und Risiken für die Zukunft (Climate and Environmental Change in the Mediterranean Basin-Current Situation and Risks for the Future). Erster Sachstandsbericht für den Mittelmeerraum
The First Mediterranean Assessment Report (MAR1) prepared by the independent network of Mediterra... more The First Mediterranean Assessment Report (MAR1) prepared by the independent network of Mediterranean Experts on Climate and environmental Change (MedECC) founded in 2015, is now published. MAR1 assesses the best available scientific knowledge on climate and environmental change and associated risks in the Mediterranean Basin in order to render it accessible to policymakers, stakeholders and citizens. The report includes a Summary for Policymakers (SPM), which comprises the key messages of the MAR1. The report has been written by 190 scientists from 25 countries, all contributing in individual capacity and without financial compensation. The UNEP/MAP – Barcelona Convention Secretariat, through its Plan Bleu Regional Activity Center, and the Secretariat of the Union for the Mediterranean work in partnership to support MedECC, and to contribute to establish a sound and transparent scientific assessment process.
Frontiers in Marine Science, 2024
Cô te d'Ivoire We carried out measurements of the CO 2 system parameters to evaluate the impact o... more Cô te d'Ivoire We carried out measurements of the CO 2 system parameters to evaluate the impact of carbonate and nutrients' chemistry on phytoplankton populations in the Gulf of Guinea (GoG). The seasonal variations of the CO 2 system parameters (fCO 2 , DIC, pH and TA) along with nitrates and phosphates were quantified weekly at surface (between 0 and 5 m depth) (5.57°N-4.57°W) in the GoG from May to December 2020. Seawater pH varied widely during the study period, ranging between 8.10-8.35 pH units; DIC and TA varied between 1810 and 2094 mmol kg-1 , and between 2051 and 2216 mmol-1 respectively. DIC peaks coincided with the high upwelling period (August and September). For phytoplankton, a total of 60 species were found belonging to four taxonomic phyla: Bacillariophyta, Dinophyta, Chlorophyta and Dictyochophyta. The highest number of phytoplanktonic species were recorded for Bacillariophyta phylum with 36 species (60%). The phylum Dinophyta comprised 22 taxa (36%) and Chlorophyta and Dictyochophyta recorded only one species (2%). The highest specific diversities were observed in August and September with 29 and 26 taxa respectively and the lowest was found in October-November (5 taxa) and December (one taxa). Bacillariophyta and Dinophyta appeared throughout the entire study period. The only species for Chlorophyta phylum appeared in June and July and the Dictyochophyta's one in May, July and August. In general, the physical (SST, SSS) and chemical (TA, DIC, pH) parameters influenced less than 50% of the phytoplankton population in the coastal area of the GoG. Our study shows that Bacillariophyta population grows up when the physicochemical parameters' variability increase.
Zenodo (CERN European Organization for Nuclear Research), Jan 25, 2023
Oceanography of the Mediterranean Sea
Oceanography, 2021
Time-series stations in the Mediterranean Sea are still scarce and not equally distributed within... more Time-series stations in the Mediterranean Sea are still scarce and not equally distributed within its sub-basins, a significant obstacle in characterizing physical, chemical, and biological trends with good temporal and geographic coverage in a sea undergoing multiple changes due to climate change. We discuss two time-series stations located offshore Lebanon in the southeast Mediterranean Sea, an understudied area (Figure 1). Since 1999, stations B1 and B2, 5 km off the coast, have been sampled monthly in the upper 80 m for temperature, salinity, nitrates, nitrites, phosphates, plankton, and chlorophyll-a. Chemical variables added in 2012 include total alkalinity, total dissolved inorganic carbon, pH, dissolved oxygen, and silicates. In addition, since 2012, research vessel CANA has sampled station A3, located 10 km off the coast, seasonally for the parameters listed above down to ~900 m depth.
2022 IEEE International Workshop on Metrology for the Sea; Learning to Measure Sea Health Parameters (MetroSea)
Frontiers in Marine Science
Ocean acidification (OA) is a serious consequence of climate change with complex organism-to-ecos... more Ocean acidification (OA) is a serious consequence of climate change with complex organism-to-ecosystem effects that have been observed through field observations but are mainly derived from experimental studies. Although OA trends and the resulting biological impacts are likely exacerbated in the semi-enclosed and highly populated Mediterranean Sea, some fundamental knowledge gaps still exist. These gaps are at tributed to both the uneven capacity for OA research that exists between Mediterranean countries, as well as to the subtle and long-term biological, physical and chemical interactions that define OA impacts. In this paper, we systematically analyzed the different aspects of OA research in the Mediterranean region based on two sources: the United Nation’s International Atomic Energy Agency’s (IAEA) Ocean Acidification International Coordination Center (OA-ICC) database, and an extensive survey. Our analysis shows that 1) there is an uneven geographic capacity in OA research, a...
Environmental Science and Technology, 2022
The spectrophotometric methodology for carbonate ion determination in seawater was first publishe... more The spectrophotometric methodology for carbonate ion determination in seawater was first published in 2008 and has been continuously evolving in terms of reagents and formulations. Although being fast, relatively simple, affordable, and potentially easy to implement in different platforms and facilities for discrete and autonomous observations, its use is not widespread in the ocean acidification community. This study uses a merged overdetermined CO2 system data set (carbonate ion, pH, and alkalinity) obtained from 2009 to 2020 to assess the differences among the five current approaches of the methodology through an internal consistency analysis and discussing the sources of uncertainty. Overall, the results show that none of the approaches meet the climate goal (± 1 % standard uncertainty) for ocean acidification studies for the whole carbonate ion content range in this study but usually fulfill the weather goal (± 10 % standard uncertainty). The inconsistencies observed among approaches compromise the consistency of data sets among regions and through time, highlighting the need for a validated standard operating procedure for spectrophotometric carbonate ion measurements as already available for the other measurable CO2 variables.
Structure and biodiversity of coralligenous assemblages dominated by the precious red coral Coral... more Structure and biodiversity of coralligenous assemblages dominated by the precious red coral Corallium rubrum over broad spatial scales. Sci. Rep. 6, 36535.
Virtually all sub-regions of the Mediterranean Basin, on land and in the sea, are impacted by rec... more Virtually all sub-regions of the Mediterranean Basin, on land and in the sea, are impacted by recent anthropogenic changes in the environment. The main drivers of change include climate (temperature, precipitation, atmospheric circulation, extreme events, sea-level rise, sea water temperature, salinity and acidification), population increase, pollution, unsustainable land and sea use practices and non-indigenous species. In most areas, both natural ecosystems and human livelihoods are affected. Due to global and regional trends in the drivers, impacts will be exacerbated in the coming decades, especially if global warming exceeds 1.5 to 2°C above the pre-industrial level. Significantly enhanced efforts are needed in order to adapt to inevitable changes, mitigate change drivers and increase resilience. Due to anthropogenic emissions of greenhouse gases, climate is changing in the Mediterranean Basin, historically and projected by climate models, faster than global trends. Annual mean...
Toxins, 2022
Pufferfishes are among the best-known marine organisms that accumulate marine biotoxins such as T... more Pufferfishes are among the best-known marine organisms that accumulate marine biotoxins such as Tetrodotoxin (TTX). In the Mediterranean Sea, the silver-cheeked toadfish Lagocephalus sceleratus is the most reported TTX-bearer, causing many fatal and non-fatal cases. In Lebanon, no previous studies have measured TTX levels although the possibility of TTX-poisoning is high since L. sceleratus is caught in different sizes and can be mistaken with other small fishes. Hence, this study reports TTX and its analogue 4,9-anhydro TTX in L. sceleratus collected from Lebanese waters in the Eastern Mediterranean Sea. The results show that TTX concentrations in fish tissues varied between 0.10 and 252.97 µg/g, while those of 4,9-anhydro TTX oscillated between 0.01 and 43.01 µg/g. Internal organs of L. sceleratus were the most toxic parts of its body, with the highest TTX levels found in gonads (mainly ovaries) and liver, followed by the muscles and skin with concentrations always exceeding the s...
Concentration of ion carbonate has become the fifth measurable variable of the seawater CO2 syste... more Concentration of ion carbonate has become the fifth measurable variable of the seawater CO2 system since the publication of the work by Byrne and Yao (2008) introducing a spectrophotometric method similar to the standard pH procedure. However, opposite to pH, the ion carbonate method has been refined and updated in a series of works(Easley et al., 2013; Patsavas et al., 2015; Sharp et al., 2017 and Sharp and Byrne, 2019) that introduced modifications in the equations relating the UV absorbance measurements and the final ion carbonate concentration, the reagent used and other details. Except for the USA seminal research group, and the two Spanish teams at the IEO A Coruña and IIM-CSIC, no other oceanographic group has published research data using the ion carbonate spectrophotometric methods. The work by Fajar et al. (2015) used a collection of Spanish cruises from 2009 to 2014 to compare the initial spectrophotometric ion carbonate methods by Byrne and Yao (2008) and Easley et al. (...
MARIA S. MERIAN-Berichte; M145; ISSN 2195-8483, 2019
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Papers by Abed El Rahman Hassoun
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