Periyadan K. Krishnakumar

Macrobenthic community structure in the northern Saudi waters of the Gulf, 14 years after the 1991 oil spill.

The 1991 Gulf oil spill heavily impacted the coastal areas of the Saudi waters of the Arabian Gulf and recent studies have indicated that even 15 years after the incident, macrobenthos had not completely recovered in the sheltered bays in the affected region such as, Manifa Bay. This study investigates the community conditions of macrobenthos in the open waters in one of the impacted areas, Al-Khafji waters, about 14 years after the spill. Diversity measures and community structure analyses indicate a healthy status of polychaete communities. The BOPA index reveals that oil sensitive amphipods were recolonized in the study area. This confirms that the benthic communities of the oil spill impacted area had taken only <14 years to recover in the open waters of the impacted areas. The study also reveals the existence of three distinct polychaete communities along the depth and sediment gradients.

Arsenic and arsenic species in shellfish and finfish from the western Arabian Gulf and consumer health risk assessment

This study reports the levels of total arsenic and arsenic species in marine biota such as clams (Meretrix meretrix; N=21) and pearl oyster (Pinctada radiata; N=5) collected from nine costal sites in Jan 2014, and cuttlefish (Sepia pharaonis; N=8), shrimp (Penaeus semisulcatus; N=1), and seven commercially important finfish species (N=23) collected during Apr-May 2013 from seven offshore sites in the western Arabian Gulf. Total As and As species such as dimethylarsinic acid (DMA), arsenobetaine (AB), trimethylarsine oxide (TMAO), arsenocholine (AC), tetramethylarsonium ion (Tetra), arsenosugar-glycerol (As-Gly) and inorganic As (iAs) were determined by using ICPMS and HPLC/ICPMS. In bivalves, the total As concentrations ranged from 16 to 118mg/kg dry mass; the toxic iAs fraction contributed on average less than 0.8% of the total As, while the nontoxic AB fraction formed around 58%. Total As concentrations for the remaining seafood (cuttlefish, shrimp and finfish) ranged from 11 to 134mg/kg dry mass and the iAs and AB fractions contributed on average 0.03% and 81% respectively of the total As. There was no significant relationship between the tissue concentrations of total As and iAs in the samples. There was also no significant relationship between As levels in seafood and geographical location or salinity of the waters from which samples were collected. Based on our results, we recommend introducing a maximum permissible level of arsenic in seafood from the Gulf based on iAs content rather than based on total As. Our analyses of cancer risks and non-cancer hazards identified non-negligible risks and the potential for hazards; the greatest risks were identified for expatriate consumers of bivalves and high-end consumers of seafood. Despite this, many uncertainties remain that would be best addressed by further analyses.

Status of macrobenthic community of Manifa–Tanajib Bay System of Saudi Arabia based on a once-off sampling event

Shallow water bays located in the western Arabian Gulf experience harsh environmental conditions. Some of these bays, including Manifa-Tanajib Bay System (MTBS), were also exposed to the 1991 oil pollution event. This study investigates the status of the macrobenthos in MTBS during 2006. This bay system is characterized by very shallow inner bays with elevated salinity and temperature compared to the rest of the bay area. As a result mainly of the hyper salinity, the inner bay communities are distinct from the outer bay communities. Overall, fairly high species richness with several rare species was observed. High Shannon-Wiener diversity values and ABC plots indicated the healthy status of the polychaete communities, while BOPA index indicated slightly polluted status in 20% of the stations. The oil sensitive amphipods were not completely re-colonized in 20% of the stations, even after 15 years of recovery from the 1991 oil spill.

Accumulation of Carbonates Contributes to Coastal Vegetated Ecosystems Keeping Pace With Sea Level Rise in an Arid Region (Arabian Peninsula)

This research was supported by a project funded by Saudi Aramco and baseline funding from King Abdullah University of Science and Technology (KAUST). O. S. was supported by an ARC DECRA (DE170101524). Funding was provided to PM by the Generalitat de Catalunya (grant 2014 SGR‐1356) and an Australian Research Council LIEF Project (LE170100219). AAO was supported by a PhD scholarship from Obra Social “LaCaixa”. This work is contributing to the ICTA ‘Unit of Excellence’ (MinECo, MDM2015‐0552). We thank A. Qasem and P. Priahartato, Saudi Aramco, for support and advice on sampling design; R. Lindo, R. Magalles, P. Bacquiran, S. Ibrahim, and M. Lopez, at the Marine Studies section of the Center for Environment and Water of King Fahd University of Petroleum and Minerals; and Z. Batang and staff from the Coastal and Marine Resources core lab at KAUST for help with sampling. We thank I. Schulz, N. Geraldi, K. Rowe, S. Roth, M. Ennasri, D. Prabowo, and I. Mendia for help with laboratory analyses. We wish to thank the two anonymous reviewers, as well as Editor in chief M. Goni, for their precious comments/suggestions for the improvement of the manuscript. The data sets, including 14C and 210Pb data, CaCO3 concentration values, porosities, and CaCO3 depth profiles for all cores, are available in the open repository Pangaea (Saderne et al., 2018; https://doi.pangaea.de/10.1594/PANGAEA.887043).

Evaluation of toxic elements As, Cd, Cr, Cu, Ni, Pb and Zn in the surficial sediments of the Red Sea (Saudi Arabia)

• Contamination of metals was studied in the surficial sediments of the Red Sea (Saudi Arabia).