Early colonization of newly planted mangroves by marine crabs in the northwestern Arabian Gulf

Two newly established Avicennia marina restoration sites along the northwestern Arabian Gulf, including Al-Faw City and Khor Al-Zubair in southern Iraq, were investigated to assess early faunal colonization of restored mangrove habitats.Crabs were sampled from one-year-old mangrove seedlings (mean height ≈ 30 cm).A total of 351 individuals belonging to three species, Opusia indicum, Manningis arabicum, and Nasima dotilliformis, were recorded across ten experimental sites.Crab assemblages differed significantly among sites.At Al-Faw City, O. indicum and M. arabicum dominated, whereas M. arabicum and N. dotilliformis were most abundant at Khor Al-Zubair.Non-parametric analyses revealed significant differences in species abundance among sites (p < 0.05).Diversity indices indicated higher community diversity at Al-Faw City (Shannon-Wiener H' = 0.637; Pielou's J' = 0.918) compared with Khor Al-Zubair (H' = 0.538; J' = 0.776).Community structure analyses using non-metric multidimensional scaling (non-metric multidimensional scaling [NMDS] stress = 0.12) and permutational multivariate analysis of variance (PERMANOVA) confirmed significant differences between sites (pseudo-F = 62.27, p = 0.007).Opportunistic observations of barnacle aggregations and mudskippers further suggest rapid habitat utilization.Overall, the results demonstrate that newly restored mangrove stands can support rapid, site-specific colonization by benthic fauna, highlighting the capacity of mangrove restoration projects to re-establish functional benthic communities within a short time frame in the northwestern Arabian Gulf.