Indonesia is exposed to earthquakes, volcanic activities, and associated tsunamis. This is particularly the case for Lombok and Sumbawa Islands in West Nusa Tenggara, where evidence of tsunamis is frequently observed in its coastal sedimentary record. If the 1815 CE Tambora eruption on Sumbawa Island generated a tsunami with well-identified traces on the surrounding islands, little is known about the consequences of the 1257 CE tremendous eruption of Samalas on the neighboring islands, and especially about the possible tsunamis generated in reason of a paucity of research on coastal sedimentary records in this area. However, on Lombok Island, the eruption of the Samalas volcano produced significant volumes of pyroclastic flows that entered the sea in the North and East of the island. These phenomena must have produced a tsunami that left their traces, especially on Sumbawa Island, whose western coastline is only 14 km away from Lombok’s eastern shore. Therefore, the main goal of this study is to investigate, find evidence, and determine the age of marine-origin sediments along the shore of the Alas Strait, Indonesia. We collected and analyzed samples of coral and seashells from marine deposits identified along the west coast of Sumbawa, i.e., in Belang Island and abandoned fishponds in Kiantar Village, in order to identify the sources and the occurrence period of these deposits events. Based on the radiocarbon dating of coral and seashell samples, we concluded that none of the identified marine deposits along the western coast of Sumbawa could be related chronologically to the 1257 CE eruption of Samalas. However, possible tsunami deposits located in Belang Island and abandoned fishponds in Kiantar Village yielded 4th century CE, 9th century CE, and 17th century CE. We also conclude that past large earthquakes triggered these tsunamis since no known volcanic eruption occurred near the Alas Strait at that time that may have triggered a tsunami.

Climbing perch (Anabas testudineus) is one of the economically important freshwater fish in Aceh, Indonesia, but is threatened by habitat fragmentation, overfishing, and the introduction of alien fish species. Therefore, this study aims to analyze the genetic structure of A. testudineus populations in the inland waters of Aceh using the Cytochrome c Oxidase subunit I (COI) marker. A total of 173 samples representing 12 populations, namely Banda Aceh, Aceh Besar, Pidie, Pidie Jaya, Lhokseumawe, West Aceh, Southwest Aceh, East Aceh, Simeulue, South Aceh, Gayo Lues, and Southeast Aceh, were successfully sequenced with a homology level of 98.12-100%. The analysis produced 44 unique haplotypes, with haplotype diversity ranging from 0.476 to 0.857 (average 0.729). The fixation index (Fst) value of 0.770 (p<0.001) showed significant genetic fragmentation, with 77% of genetic variation attributable to population differentiation. The phylogenetic tree reconstruction formed 2 main clades, where clade I comprised the populations of Pidie, Banda Aceh, Aceh Besar, South Aceh, Lhokseumawe, and East Aceh. Meanwhile, clade II comprised the populations of Southwest Aceh, West Aceh, Simeulue, Pidie Jaya, Southeast Aceh, and Gayo Lues. These results confirmed limited gene flow between populations due to geographic isolation and anthropogenic pressures, showing the need for specific conservation approaches for each on unit.

Adidarma 15 Senior High School in Banda Aceh is situated in an area vulnerable to seismic and tsunami disasters, as indicated by the BPBA’s Disaster Map. Established in 1983, the school suffered significant damage during the Aceh Earthquake and Tsunami in 2004. Additionally, the school’s physical environment contributes to its vulnerability to disasters; it lies approximately 20 meters above sea level, 3–4 kilometers from the coastline, and 1–2 kilometers from the river banks. Being located in an urban area surrounded by buildings, restricts the space for emergency responses during disasters.As a public facility, it has vulnerable objects to disasters. There are at least 152 students and a number of school staff who need to be protected from the disasters (earthquakes and tsunamis). They have activity in 5 buildings which have 2-storey buildings which have no supporting facilities for disaster mitigation in the school environment.At Adidarma 15 Senior High School, disaster mitigation efforts represent a commitment to fostering resilience and preparedness within the school community. Through engaging awareness campaigns in student forums and the creation of informative disaster posters, the team empowers students to take charge of their safety. By developing clear evacuation route plans and installing guiding directional signs, they are enhancing the school’s readiness for any challenge. The completion of disaster surveys further solidifies this proactive approach. As a result, students have experienced a remarkable growth in their understanding of disaster mitigation, equipping them with the knowledge to face the future with confidence