Gastropods of Tanjung Pasir Mangroves: Silent Indicators of Coastal Balance

Mangrove ecosystems are often praised as natural coastal defenses, yet their resilience is quietly supported by small but crucial organisms. Among the tangled roots of the Tanjung Pasir mangroves in Teluknaga, gastropods—shelled mollusks—play a fundamental ecological role. Beyond their place in the food web, gastropods act as sensitive indicators of environmental change. A study by Lutviah Rahmawati and Agung Setyo Sasongko offers valuable insight into how gastropod communities reflect the ecological condition of this mangrove system.

Conducted in December 2023, the study sought to understand the structure of gastropod communities and their relationship with physico-chemical water parameters. Gastropods were chosen due to their limited mobility and continuous response to environmental changes, making them reliable bioindicators. In essence, analyzing gastropod communities allows researchers to “read” the ecological health of mangrove waters.

Using purposive sampling across three observation stations—representing different levels of human activity and coastal influence—the researchers identified five gastropod species belonging to four genera. Species such as Telescopium telescopium and Cerithidae cingulata showed notably high densities in certain stations. Interestingly, areas with high abundance did not always correspond to high diversity, suggesting that some species were able to dominate space and resources more effectively than others.

Spatial distribution patterns further revealed ecological dynamics within the mangrove ecosystem. Most gastropod species exhibited uniform distribution, while a few showed clustered patterns, indicating habitat preference, substrate suitability, and adaptive strategies. These patterns are not random; they emerge from interactions between organisms, sediment characteristics, tidal influence, and organic matter availability.

Ecological index analysis strengthens this narrative. The moderate diversity index (H’ = 1.03), relatively balanced evenness (E = 0.64), and a high dominance index (C = 0.95) at specific stations illustrate a community that is structured but not degraded. When combined with favorable water quality parameters—temperature, salinity, pH, and dissolved oxygen—the findings indicate that the gastropod community in Tanjung Pasir mangroves is generally stable and well-balanced.

This study highlights an important message: even small, often overlooked organisms like gastropods provide critical insights into ecosystem health. While this article presents a narrative overview, the full journal paper offers detailed analyses of species composition, station-level variation, and environmental interactions. For readers interested in mangrove ecology and molluscan indicators, the original publication is well worth exploring in full.

Reference

Rahmawati, L., & Sasongko, A. S. (2025). Community Structure of Gastropods in Mangrove Ecosystem in Tanjung Pasir Village, Teluknaga, Tangerang District. Jurnal Moluska Indonesia, 9(2), 40–49.

https://doi.org/10.54115/jmi.v9i2.136