Distribution and sources of polycyclic aromatic hydrocarbons in the water column of Kongsfjorden, Arctic.

Kongsfjorden is known for its characteristic multi-layer water mass formed by the convergence of freshwaters from nearby glaciers and rivers and saline water from the Atlantic and Arctic. The distribution of polycyclic aromatic hydrocarbons (PAHs) in the water column of Kongsfjorden was investigated and their potential sources were analyzed. The total concentrations of 16 PAHs in the surface seawater and river water were in the range of 33.4-79.8 ng/L (mean 48.5 ng/L) and 2.3-201.4 ng/L (mean 126.1 ng/L), respectively. Horizontally, PAHs were mainly concentrated around river estuaries and the glacier front in the dissolved phase. Vertically, the PAHs in the particulate phase followed surface-enrichment and depth-depletion patterns in most stations, with the maximum concentration found at 50 m depth in the central area of Kongsfjorden. The compositions of PAHs in seawater and rivers were similar, with two-ring and tricyclic PAHs comprising the majority of the dissolved and particulate phases. PAHs found in Kongsfjorden waters appeared to be derived from multiple sources such as petroleum and coal combustion. PAHs in the bay mouth of Kongsfjorden were mainly introduced by the West Spitsbergen Current and the Arctic waters, while in the inner bay, atmospheric deposition and local sources were the major contributors. The distribution of PAHs was mainly attributed to the suspended particulate distribution.

The ecotoxicological effects of microplastics on aquatic food web, from primary producer to human: A review.

The prevalence of microplastics in global waters raises the concern about their potential effects on aquatic biota. In aquatic environment, microplastics are almost ubiquitously present in all compartments from surface water to benthic sediment, making them accessible to a wide range of aquatic biota occupying different habitats. Exposure to microplastics may induce detrimental implications to the health of aquatic organisms. This review describes the wide occurrence of microplastics ingestion by aquatic fauna and evaluates the ecotoxicological effects of microplastics as well as the associated chemicals on aquatic biota including phytoplankton and fauna from both freshwater and marine environments. Trophic transfer of microplastics and associated contaminants along the aquatic food chain and potential impacts on human health are also discussed. Finally, this review emphasizes the current knowledge gaps and gives recommendations for the future work.