Diversity pattern and juvenile fish assemblage in the nearshore habitats of the Sumbawa Island, Indonesia

Abstract

The coastal ecosystem plays a vital role as essential habitat for juvenile and small marine fishes. This study aimed to analyze juvenile and small-sized fish assemblage in the nearshore habitats of Sumbawa Island. Sampling was carried out in the morning at low tide when new and full moon from November 2020 to January 2021. Five sampling sites were selected based on habitats their adjacency to the river mouth. During the study period, 6349 individuals belonging to 74 species and 37 families were recorded. The number of Ambassis vachellii was the most significant, followed by Hypoatherina temminckii, and Eubleekeria splendens. The highest fish biomass was occupied by E. splendens, followed by Plotosus lineatus, and Planiliza macrolepis. Physico-chemical parameters were not varied between sampling sites, except salinity. Estuaries with vegetated areas have a higher species richness, diversity, and evenness index than the unvegetated area. Juvenile and small-sized fishes varied between sites but not varied between moon phases. Research findings confirm that the nearshore habitat of Sumbawa Island has a significant capacity to support the early life stage of many marine fish species.