Journal of Marine and Coastal Science

Estimation of Phosphorus Storage in Seagrass in the Coastal Waters of Eastern and Northen Bintan Island

Luthvi Nurwulandari — 2025-09-29

The eastern and northern coastal waters of Bintan Island are seagrass conservation areas with high biodiversity and coverage. Seagrass is known to play an essential role in the carbon cycle and has the potential to store phosphorus, but limited information is available regarding its phosphorus reserves. This study aims to estimate phosphorus (P) storage in seagrass and analyze the relationship between seagrass ecological parameters and phosphorus content. A field survey and hierarchical sampling technique were conducted at six locations, with samples of seagrass, substrate, and water analyzed in laboratory. Results showed the highest seagrass density in Pengudang (816 shoots/m²) and the lowest in Berakit 2 (107 shoots/m²); the highest coverage in Teluk Bakau 1 (83.5%) and the lowest in Teluk Bakau 2 (43.1%); and the highest biomass in Pengudang (138.55 gr/m²) and the lowest in Berakit 2 (19.39 gr/m²). The highest phosphorus storage was recorded in Berakit 2 (0.321%) and the lowest in Teluk Bakau 2 (0.258%). A positive correlation was observed between coverage and phosphorus content, indicating that increased seagrass coverage potentially enhances phosphorus storage capacity. These findings offer new insights into the role of seagrass in the phosphorus cycle and its implications for sustainable coastal ecosystem management.

Genetic Diversity of Unhatched Sea Turtle Eggs in Buleleng, Bali Indonesia Hatchery Based on The Mitochondrial Control region Locus

Immanuel Pratama — 2025-09-29

Sea turtles are protected animals that are threatened with extinction due to natural and anthropogenic factors such as coastal erosion and illegal trade. This study aims to analyze the genetic diversity of sea turtles in Buleleng using mitochondrial DNA from unhatched egg samples. Samples were collected from two nests at several breeding sites to determine genetic variation within a single conservation area. Molecular analysis was conducted on the control region locus with a sequence length of 869 bp. The results of the identification showed that the samples originated from three species: green sea turtles (Chelonia mydas), olive ridley sea turtles (Lepidochelys olivacea), and hawksbill sea turtles (Eretmochelys imbricata), with sequence similarities of 99.44%–99.77%. The phylogenetic tree formed four clades with bootstrap values of 79–100%, supporting the classification and kinship relationships between species. Low intraspecific genetic distance (0–0.2%) and interspecific genetic distance (16.4–21.4%) indicate high similarity within a species and significant differences between species. The results of this study can be used to strengthen effective genetics-based sea turtle conservation programs in the Buleleng region of North Bali.

Analysis of Water Quality in Pangeranan Estuari, Bangkalan, Madura Using the Pollution Index and Storet Methods

Annisa Arrayanul Jannah — 2025-09-29

The extensive use of estuaries makes them vulnerable to being used as dumping sites for waste from human activities. Continuous accumulation of rubbish in estuaries can cause water pollution and decrease water quality. Pangeranan Waters is one of the estuari waters in Bangkalan Regency, East Java which is widely used by the community. Therefore, the aim of this research is to determine the water quality of the Pangeran Bangkalan Madura River estuari using two different methods. This research was conducted in November 2024 by collecting in-situ and ex-situ data at low and high tide. The results of water quality measurements are then analyzed to determine its status using two methods, namely Pollution Index and Storet. From this analysis, the water quality status was Pollution Index obtained as follows: at low tide, it shows a moderate level of pollution, while at high tide and highest tide, the status shows heavy pollution. The results of analysis using the Storet method show that the average physical parameter skorat stations 1 to 5 is -9, which is in the lightly polluted category. Meanwhile, for chemical parameters, the average skorobtained was -60, which is classified as heavily polluted.

Estimation of Sources and Marine Debris Dynamics Movement along the Coast of Sukajaya Lempasing Village, Lampung Province

Muhamad Gilang Arindra Putra — 2025-09-29

The coastal zone is a transitional area characterized by complex dynamics influenced by the interaction between land and sea. One of the consequences of this interaction is the accumulation of solid pollutants in the form of waste, which has the potential to disrupt the surrounding ecosystem's balance. This study aims to estimate the origin and movement pathways of marine debris along the coast of Sukajaya Lempasing Village by analyzing surface current patterns. The methods applied include purposive sampling and both quantitative and qualitative descriptive analysis. Waste data collection followed the guidelines issued by the Ministry of Marine Affairs and Fisheries in 2024, while surface current simulations were conducted using MIKE 21 with the Flow Model Flexible Mesh module. Monitoring results indicated that plastic waste dominated at all stations, with the highest number recorded at Station 1 (671 items), which also had the greatest total waste weight, amounting to 38.5 kg. The average waste density in the study area was 4.82 pcs/m². Surface current speeds ranged from 0.004 to 0.008 m/s on March 28, 2024, and from 0.005 to 0.015 m/s on April 2, 2024. Based on modeling results and interviews with local residents, the primary source of the waste was river discharge, which was then transported by longshore currents and subsequently accumulated along the coast of Sukajaya Lempasing Village.

Analysis of the Influence of Wind, Rainfall, and Sea Surface Temperature on Handline Catch Yields at Bungus Ocean Fishing Port

dewi joni lestari lestari — 2025-09-29

West Sumatra is one of Indonesia's Fisheries Management Areas with significant tuna potential, particularly yellowfin tuna (Thunnus albacares) and bigeye tuna (Thunnus obesus). This study aims to examine the influence of wind speed, rainfall, and sea surface temperature (SST) on handline catch yields at Bungus Ocean Fishing Port, West Sumatra, during the 2019–2023 observation period. The methodology employed a survey approach using secondary data obtained from https://data.marine.copernicus.eu/ the Meteorological Station of the Meteorology, Climatology, and Geophysics Agency (BMKG), and catch data from Bungus Ocean Fishing Port logbooks.The results indicate that the highest wind speed variability occurred during the 2019 East Monsoon Season, ranging from 8.80–11.10 m/s (25%) with a northwest direction, while the lowest wind speed was recorded during the 2021 Transitional Season 0.50–2.10 m/s, northerly (4%). The highest rainfall (552 mm/hari) occurred during the 2022 Transitional Season 2, while the lowest (30 mm/hari) was observed in 2019 during Transitional Season 2. The highest SST (30.31°C) was recorded during Transitional Season 1, and the lowest (27.19°C) during Transitional Season 2. The peak catch (451,201 tons) occurred during the 2019 west monsoon, whereas the lowest yield (20,359 tons) was recorded in 2023 during Transitional Season 2. Multiple linear regression analysis revealed that wind speed, rainfall, and SST collectively explained 25.2% of the variation in tuna catches, though their influence was not statistically significant. Correlation analysis further demonstrated no strong interdependence among wind speed, rainfall, and SST variables, factors outside the investigated variables accounted for 74.8% of the variance.