Medy Ompi, Farnis Binea Boneka, Sandra Tilaar, Stella Tinny Kaunang
Box mussels exhibit patchy distribution patterns across intertidal and subtidal zones, where environmental contrasts strongly influence their physiology and ecology. Intertidal box mussels experience frequent air exposures, variable salinity, acidity, and turbidity during low tide, whereas subtidal mussels generally experience more stable conditions. However, with rising sea temperatures related to global climate change, these stressors may intensify, disrupting the mussel’s activities. Consequently, their roles in marine ecosystems may change, yet knowledge of box mussel responses to environmental change remains limited. This study investigated the effects of site, time (monthly intervals), and position (intertidal vs. subtidal) on mussel growth and survival. Box mussels were transplanted to intertidal and subtidal seabeds at three sites in North Sulawesi: Tiwoho, Tongkaina, and Blongko, from August to November 2023. Shell length and survival rates were analyzed using a three-way ANOVA, with site, time, and position as main factors. The results showed that mean shell length was significantly influenced by all three factors. The box mussels grew rapidly from August to September, followed by slower growth from October to November. The final mean size was higher at Tongkaina compared to Blongko, while Tiwoho did not differ significantly from Tongkaina. Survival declined steadily, averaging 22–40% by November, and was influenced by time and position but not by site. Ascidians were observed attaching to the cages in November. Seawater temperature, ascidian presence, and food availability may influence mussel size and survival. Finally, although the tropical mussel, S. bilocularis, exhibits higher thermal tolerance, it remains vulnerable to ocean warming. © 2026, Faculty of Fisheries, Kasetsart University. All rights reserved.
Laboratory of Aquatic Biology and Ecology, Faculty of Fisheries and Marine Sciences, University of Sam Ratulangi, Manado, Indonesia; De La Salle Catholic University of Manado, Manado, Indonesia
