Divergent communities of Marine Nematodes in impacted beaches of Bandar Abbas (Iran)

Abstract

Free-living marine nematodes play crucial roles in the benthic ecosystem and serve as valuable bioindicators for monitoring environmental stress. We explore the community structure of free-living marine nematodes in the beach ecosystem near Bandar Abbas port city of Iran. The research focused on assessing the impact of domestic and industrial influences during winter and summer seasons in 2018 and 2019. Three coastal locations, namely KhurGursuzan (KG), Power Plant (PP), and Resalat (RE), were sampled, with KG under domestic wastewater influence, PP characterized by industrial activities, and RE serving as the control site. A total of 41 nematode genera were identified during the study, and dominant genera varied across locations, namely, Daptonema, Sabatieria, Promonhystera, Ptycholaimellus, and Eleutherolaimus at KG; Spirinia, Chromadorina, Terschellingia, Eleutherolaimus, and Promonhystera at PP; and Oncholaimus, Pomponema, Viscosia, Ptycholaimellus, Daptonema, and Eleutherolaimus at RE. These dominant genera accounted for 80% of the total nematode community during the sampling periods. The study revealed significant differences in abundance and genus diversity among the sites, with pollution-affected sites exhibiting the lowest nematode diversity. Sediment granulometry showed a positive correlation with genus diversity across the sites, and the structure of the nematode assemblage was negatively influenced by polychlorinated biphenyls and total organic matter. Surprisingly, the spatial patterns in nematode assemblage structure and diversity remained consistent across both studied years. These findings contribute to our understanding of marine ecosystem health and the role of free-living nematodes as bioindicators in the Persian Gulf.