The Conditions of Seagrass at the Small Islands in the Eastern Waters of Bintan Island, Riau Archipelagos, Indonesia

Abstract

Seagrasses can grow and develop well in shallow reef environments, on muddy substrates to coral rubble, and in clear and calm waters. Seagrass beds have important roles and functions from both ecological and economic aspects. The ecological aspect is the main source of organic matter production, habitat for various biota, nurseries, spawning grounds, a food source for rare biota, and supporting the biodiversity of marine biota, as well as the economic value of seagrass ecosystem services. Increased development and community activities in coastal areas are believed to have led to a decline in the condition of seagrass beds. Currently, there are no ongoing studies on the condition of seagrass beds, especially on small islands. This study is a monitoring effort for coral reefs and related ecosystems (mangroves and seagrasses) conducted from 2015-2019. The objective of this study is to obtain information on the condition of seagrass beds on small islands and in the eastern waters of Bintan Island. Data collection on species diversity and density was done using transects perpendicular to the coast. Species identification and percent cover analysis were conducted using the Guidelines for Monitoring Seagrass Meadows in Indonesia and the KMNLH (2004) classification of seagrass conditions. The results of the 2015-2019 surveys revealed a diversity of nine seagrass species, including Thalassia hemprichii (Th), Cymodocea rotundata (Cr), Enhalus acoroides (Ea), Syringodium isoetifolium (Si), Halodule uninervis (Hu), Halophila ovalis (Ho), Halodule pinifolia (Hp), Cymodocea serrulate (Cs), and Thalasodendron ciliatum (Tc). Of the nine dominant species found namely, Thalassia hemprichii dan Enhalus acoroides, while species are rarely found namely Halodule pinifolia (Hp) and Thalasodendron ciliatum (Tc). The density of the Enhalus acoroides species did not show any change during 2015-2019. Overall, from 2015 to 2019 the seagrass condition at each monitoring station declined and was categorized as unhealthy.