Water and sediment characteristics in the Avicennia marina environment of the Arabian Gulf: A review

Abstract

Mangroves are halophytic woody plants inhabiting the sea-land confluence of tropical and subtropical regions, influenced by marine and terrestrial factors. Among various others, Avicennia marina is the only mangrove species that thrives the extreme climatic conditions of the Arbian Gulf (the Gulf). Highly varying temperatures, hyper salinity, freshwater scarcity and anthropogenic pressures have resulted in a unique mangrove ecosystem in the Gulf. However, the water and sediment characteristics of the Gulf mangroves evolved due to natural and anthropogenic factors are not well documented yet. This review evaluates the existing literature on the water and sediment characteristics of the Gulf mangroves, and compares them with the international thresholds and regional standards reported in literature. The study reveals that the hydrological factors, such as precipitation, river runoff and groundwater, along with varying temperature and elevated salinity, significantly impacted the growth and distribution of mangroves in the Gulf. Trace elements show elevated concentrations at a few mangrove regions of the Gulf influenced by coastal developments. Furthermore, industrial expansion has resulted in the accumulation of petroleum hydrocarbons and toxic elements, raising concerns about their potential for bioaccumulation and ecological risk. On the other hand, the restoration of mangrove ecosystems in the Gulf poses significant challenges, including identification of potential sites and the reestablishment of suitable environmental conditions that disrupted by natural and anthropogenic pressures. Therefore, this review emphasizes the need for long-term monitoring and comprehensive data on hydrological and chemical parameters impacting Gulf mangrove ecosystems for the implementation of effective conservation strategies.

Keywords: Arabian Gulf; Avicennia marina; Heavy metals; Hydrography; Sediment characteristics; Water quality.