Shorebird droppings analysis: Microplastics and heavy metals in a key conservation reserve and adjoining sand beaches in the west coast of India.

Coastlines are susceptible to plastic and heavy metal pollution, which can accumulate from both marine and terrestrial sources. Shorebirds, top-level predators in these fragile ecosystems are considered as indicators of environmental health. Here, we tested the occurrence of microplastics and heavy metals in the droppings of ten regular wintering migrant shorebird species in Kadalundi-Vallikkunnu Community Reserve and adjoining sand beaches during November, December and January, each year, between 2019 and 2021. Heavy metals were analysed by Flame Atomic Absorption Spectrophotometer and the microplastic polymer compositions were identified using ATR-FTIR spectroscopy. We detected high concentrations of heavy metals such as Zinc, Copper, Cobalt, Chromium, Lead and Cadmium in droppings. Polyethylene, Polypropylene, Polystyrene, Poly Vinyl Chloride, Nitrile and Polyethylene terephthalate were the polymers identified. Polystyrene (42.6 %) and chromium (ranges between 7.83 and 88.45 mg/kg) were found to be the most abundant contaminants in most of the species.

Unveiling the ecological status of the Arabian Gulf's marine ecosystem: Insights from benthic community analysis.

This study assessed the ecological health of waters within the Saudi Arabian Exclusive Economic Zone, by utilizing benthic biotic indices with a marine monitoring dataset covering the years 2013 to 2018. This comprehensive evaluation covered a vast expanse, encompassing 67 distinctive sampling locations characterized by a wide range of depth and salinity gradients. The study examined spatial fluctuations in the benthic community and assessed potential correlations with environmental variables, including salinity, depth, sediment texture, total organic carbon, and other relevant factors. The macrobenthic density varied across the study sites, with an average density of 566 ± 120 ind.m-2. The Shannon diversity index ranged from 3.21 and 5.90, with an average of 4.70 ± 0.52. Based on the average AMBI values, all the locations were categorized as either slightly disturbed or undisturbed. Additionally, the M-AMBI analysis indicated that 95.5 % sites were in good or high ecological status.

A baseline quantitative assessment of deep-sea benthic fauna of the Gulf of Aqaba (Northern Saudi Arabia, Red Sea).

The Gulf of Aqaba (hereafter 'the Gulf') is a narrow, semi-enclosed, warm, high saline, and oligotrophic water body. This baseline study provides the first quantitative data on deep-sea (207-1281 m depth) benthos of the Gulf. Fifty-five benthic species (predominantly polychaetes) with a density of 160-670 ind. m-2, species richness of 11-25, and Shannon-Wiener diversity (H') of 3.14-4.17 bits. ind.-1 were recorded from nine stations. The density and H' of benthos of the Gulf are comparable with those of the Red Sea, while both are lower than those reported from the Arabian Sea and the Mediterranean Sea. The good-high ecological status of benthic communities indicates the absence of major stress in the deep-sea habitats of the Gulf. As large-scale urbanization is proposed in the Saudi coastal areas of the Gulf, this study is expected to provide a baseline dataset for future environmental impact assessments.

Baseline patterns of structural and functional diversity of benthic amphipods in the western Arabian Gulf.

This work presents the structural and functional traits of benthic amphipods in the Saudi waters of the Arabian Gulf. Sixty-two species belonging to 37 genera and 17 families were recorded. Sensitive species such as Grandidierella bonnieroides, G. exilis, Gammaropsis atlantica and Caprellidea indet., were mostly dominant. The average values of richness, density and diversity (H' log2) were 11 ± 1, 512 ± 232 ind. m-2 and 3.1 ± 0.1 respectively. The density decreased with increased in depth (nearshore (NS) - 784 ± 445 and offshore (OS) - 222 ± 28, p = 0.023), while evenness (NS - 0.93 and OS -0.94) and diversity (NS - 3.10 and OS - 3.18) were unaffected by depth. Interstitial space dwellers (56.76%) and surface deposit feeders (60.16%) were dominant in the nearshore sand substratum. However, domicolous (72.2%) with suspension and surface deposit feeders (71.7%) were more in offshore silt sediments. The combination of depth, pH and TPH (p = 0.249) influenced the distribution of amphipods.