Meiofaunal Dynamics in Oceanic Islands: Insights From Spatial Distribution, Substrate Influence and Connectivity

There is an apparent contradiction between the sedentary lifestyle and direct development of meiofaunal organisms and their widely observed distribution. This study is situated within the theoretical framework of ecological connectivity, metacommunities, and the impact of substrate type, particularly in the unique context of oceanic islands, offering a crucial perspective to unravel the complexities of meiofaunal dispersal and connectivity. We here studied the spatial distribution of meiofauna on natural and artificial beaches of an oceanic island, that is, Gran Canaria (Canary Is., NE Atlantic Ocean). The results revealed higher abundance and richness of meiofauna on artificial substrates compared to natural ones, with nematodes, copepods, and annelids being the dominant groups. The meiofaunal community composition differed significantly between natural and artificial beaches, suggesting colonisation of artificial beaches by natural beach communities. Notably, certain species were exclusively found on artificial beaches. The study highlighted the importance of substrate type in influencing meiofaunal composition, with artificial beaches providing new ecological niches and resources for meiofauna. The dissimilarity between beaches was attributed to morphospecies exclusive to either artificial or natural substrates, emphasising the role of dispersal mechanisms. These findings contribute to understanding the metacommunity dynamics of meiofauna in oceanic islands and call for further research on dispersal potential and biogeography.