Microplastics in fishes of commercial and ecological importance from the Western Arabian Gulf.

Microplastic particles (MPs) in the gastrointestinal tracts of nine fish species of commercial importance from different habitats (coastal, pelagic, and reef-associated) in the Saudi EEZ of the Arabian Gulf were quantified and classified. A total of eight MPs were retrieved from a total of 140 individual fish examined, with an average of 0.057 ± 0.019 microplastic items per fish (excluding possible plastic fibers). On average, 5.71%, of the fish dissected contained MPs, ranging from 5 to 15% of individual fish examined containing MPs among species (Siganus canaliculatus and Rastrelliger kanagurta, respectively). Ingested plastic consisted primarily of fishing threads (1.04 ± 0.06 mm), followed by fragments (1.16 ± 0.11 mm). It is likely that the fibers, originated from the fisheries, recreational boating, laundry, domestic wastewater, and other human activities, which is also widespread and abundant (found in 58.58% of the fish studied). Polyethylene (PE) and polypropylene (PP) were identified as the most abundant polymers ingested by the fishes. There was no significant difference (p < 0.05) between the presence of microplastic in fish depending on their habitat. The prevalence of MPs is relatively low compared to those in other regions, despite the massive industrialization of the Saudi Arabian Gulf.

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.

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.