Nekton

Characteristics of Monsoon Current Patterns in Maluku Waters in the ENSO Period

2026-05-12T07:46:04+00:00

The hydrodynamic conditions of the Maluku waters are highly dynamic and are generally influenced by several oceanographic factors, including current patterns that are also affected by variations in monsoonal winds. At present, global climate change associated with the El Niño–Southern Oscillation (ENSO) phenomenon is suspected to have altered wind and current patterns. This study aims to examine the variations in monsoonal wind patterns and monsoonal current patterns during ENSO events in the Maluku waters, including the Seram Sea, Banda Sea, and Arafura Sea. Monthly averaged wind and current data were obtained from the Copernicus database, while ENSO index data were acquired from the National Oceanic and Atmospheric Administration (NOAA) database. The results indicate that the average maximum wind speed during the West Monsoon reaches 6.1 m/s with a southeastward direction, whereas during the East Monsoon it reaches 9.2 m/s with a northwestward direction. Based on the direction of movement, the prevailing winds are characterized as monsoonal winds. The average maximum current velocity during the West Monsoon reaches 0.8 m/s with an eastward direction, while during the East Monsoon it reaches 1.4 m/s with a dominant westward movement. The dominant direction of current movement generally follows the direction of the monsoonal winds. The influence of ENSO indicates that the average wind speed and spatial distribution of winds increase during El Niño events, whereas the average current velocity and spatial distribution of currents increase during La Niña events.

Coral Reef Fish Community in the Waters of Osi Island West Seram Maluku

2026-05-12T07:46:34+00:00

Coral reef fish are a crucial fishery resource in tropical waters, including Maluku. Information regarding the species of coral reef fish caught in the waters of Osi Island, West Seram District, is still limited. This study aimed to identify the coral reef fish species captured in the waters of Osi Island and its surroundings based on their meristic and morphometric characteristics. The research was conducted in December 2024, utilizing 12 fish specimens caught by local fishermen. Species identification was carried out through the observation of meristic and morphometric characters, which were then matched with identification keys and taxonomic literature. The results revealed seven coral reef fish species belonging to five genera: Lutjanus, Pterocaesio, Myripristis, Sargocentron, and Siganus. The species identified included Lutjanus rufolineatus, Lutjanus fulviflamma, Pterocaesio tesselata, Myripristis berndti, Myripristis murdjan, Sargocentron tiereoides, and Siganus fuscescens. Pterocaesio tesselata and Siganus fuscescens were the most commonly found species, with three specimens of each. The meristic and morphometric characteristics of all specimens fell within the ranges described in previous studies for these species. This study contributes additional baseline information on the diversity of coral reef fish in Maluku waters.

Socio-Economic Study of Traditional Fishermen in Sayolo Village Papua as a Basis for Affirmative Welfare Programs

2026-05-07T01:07:50+00:00

Traditional fishers in coastal areas of Papua face limitations in fishing technology, access to capital, and market access, which contribute to the low welfare levels of fishing households. This study aimed to analyze the socioeconomic conditions of traditional fishers in Sayolo Village, Teminabuan District, South Sorong Regency, and to formulate the need for affirmative programs to improve their welfare. This study employed a descriptive qualitative and quantitative approach through field observations, in-depth interviews, questionnaires administered to 30 fisher household heads, and Focus Group Discussions (FGDs) involving relevant stakeholders. The results showed that 70% of respondents worked as full-time fishers, with educational attainment predominantly at the elementary school level (53%). Average fish catches ranged from 30–45 kg per week during the peak fishing season and declined to 15–20 kg per week during unfavorable seasons. Net income ranged from approximately IDR 200,000 to IDR 650,000 per week, which remained below the Provincial Minimum Wage. Operational cost structures were dominated by fuel expenses, accounting for 45–55% of total costs, thereby increasing income vulnerability among fishers. Existing affirmative programs included fishing gear assistance, fish processing training, and village financial support; however, their implementation remained uneven. The policy implications suggest the need to strengthen fishers’ institutions, improve access to financial capital, provide post-harvest facilities, and promote the empowerment of coastal women based on local resource potential.

Marine Macro-Debris Pollution on the Coast of Negeri Haruku Village

2026-05-11T14:46:00+00:00

Marine debris is an environmental issue of both national and global concern, particularly marine macro-debris. This study was conducted to determine the level of marine macro-debris pollution along the coast of Negeri Haruku village. Data were collected at three sites considered representative of the Negeri Haruku coastline. A 100-m shoreline transect was used for data collection and divided into 20 segments, from which five segments were randomly selected for sampling. The Clean Coast Index (CCI) was calculated to assess beach cleanliness, while the Plastic Abundance Index (PAI) was used to measure the proportion of plastic debris relative to the total amount of beach debris. The results showed that plastic debris dominated other debris types at all observation sites. This was reflected in the PAI values, namely 4.82 at the site near the river mouth, indicating high plastic density; 1.51 at Hii Beach, indicating moderate plastic density; and 6.09 at Totu Beach, indicating high plastic density. Totu Beach had the highest CCI value of 22.2, indicating a very dirty condition, while the site near the river mouth had a CCI value of 12.6, indicating a dirty condition. In contrast, Hii Beach was classified as clean, with a CCI value of 3.82. A paradoxical pattern was also observed in this study: even at a site with no apparent human activity, debris density was higher (5.55 ± 0.77 items/m²) than at the other two sites. This suggests that the debris may have originated from other locations and been transported by ocean currents. Based on the Clean Coast Index, only Hii Beach was classified as clean, whereas the site near the river mouth and Totu Beach were classified as dirty.

The Effect of Total Suspended Solids on Phytoplankton Abundance and Water Quality Dynamics in Intensive Shrimp Ponds in Kraksaan, Probolinggo, Indonesia

2026-05-13T09:55:32+00:00

Intensive cultivation of whiteleg shrimp (Litopenaeus vannamei) has the potential to increase suspended solids concentrations, which can affect water quality and phytoplankton community structure. This study aims to analyze the effect of reducing Total Suspended Solids (TSS) concentrations through the application of a filtration system on phytoplankton abundance and water quality dynamics in intensive ponds. The study was conducted in intensive shrimp ponds in Kraksaan District, Probolinggo Regency, East Java, using an observational-experimental approach comparing pond conditions without filtration, mechanical filtration, and chemical filtration. The parameters observed included TSS, phytoplankton abundance, and several water quality parameters such as temperature, clarity, pH, dissolved oxygen (DO), salinity, nitrate, and orthophosphate. The results showed that mechanical filtration was able to reduce TSS most effectively with a range of 38–47 mg/L compared to chemical filtration (57–63 mg/L) and without filtration (81–91 mg/L). The decrease in TSS was followed by an increase in water clarity and DO concentration. The highest phytoplankton abundance was found in the mechanical filtration treatment (2,870–3,084 ind/L), followed by chemical filtration (2,121–2,291 ind/L), while without filtration showed the lowest abundance (1,062–1,401 ind/L). These results indicate that reducing TSS through the filtration system increases light penetration, thus supporting phytoplankton photosynthetic activity. Overall, the application of filtration systems, especially mechanical filtration, plays an important role in improving water quality and increasing phytoplankton productivity, thus potentially supporting ecosystem stability and the sustainability of intensive vannamei shrimp farming systems.

Seagrass Community in the Coastal Waters of Hitalawa Beach, Negeri Oma, Indonesia

2026-05-13T18:42:59+00:00

The limited data and information on seagrass ecosystems in Negeri Oma provided the basis for this study. The lack of previous studies offers an opportunity to examine the ecological potential of seagrass more comprehensively and to contribute to the conservation and sustainable management of coastal resources. This study aimed to analyze the species composition and description of seagrass, density and relative density, as well as frequency of occurrence and relative frequency of seagrass species in the coastal waters of Hitalawa Beach, Negeri Oma. The study employed a line transect–quadrat method, consisting of six transects with a total of 30 quadrats. Six seagrass species were recorded, namely Cymodocea rotundata, Halodule pinifolia, Syringodium isoetifolium, Enhalus acoroides, Halophila ovalis, and Thalassia hemprichii. The overall seagrass density reached 89.55 shoots/m², placing the seagrass condition at Hitalawa Beach in scale category 3, namely moderately dense, with a density range of 75–125 shoots/m². The highest frequency of occurrence was recorded for T. hemprichii, which was found in most of the observation plots. Water temperature and salinity across the six transects ranged from 31.2–32.5°C and 27.7–31‰, respectively. The findings indicate that the coastal waters of Hitalawa Beach support a relatively diverse seagrass community with moderately dense seagrass conditions. This study provides updated baseline information on the condition of seagrass beds in the area and may support future coastal resource conservation and management efforts.