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Contact Name
Surya Darma
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admin.jlk@untan.ac.id
Phone
+6285750630630
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Editorial Address
Jl. Prof. Dr. Hadari Nawawi, FMIPA Universitas Tanjungpura
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Kota pontianak,
Kalimantan barat
INDONESIA
Jurnal Laut Khatulistiwa
ISSN : 26146142     EISSN : 26148005     DOI : http://dx.doi.org/10.26418/lkuntan
Jurnal Laut Khatulistiwa is the media for dissemination of information about the ideas from researchers and practitioners whose interested with marine issues. This journal published three times a year by Department of Marine Science, Faculty of Mathematic and Natural Sciences, Tanjungpura University, i.e at February, June and October. The scope of the articles on this journal is focus on study of marine science, including utilization of computing technology and marine instruments, development of measurement methods, and other related study. This journal is expected to be helpfull for practitioners, policy makers, lecturers, students and other parties to better understanding the situation and condition about marine and can provide inspiration on development of ideas to contribute improvement solutions for marine issues globally.
Articles 10 Documents
Search results for , issue "Vol 9, No 1 (2026): February" : 10 Documents clear
Analisis Variabilitas Gelombang Swell di Perairan Menui, Kecamatan Menui Kepulauan, Kabupaten Morowali, Provinsi Sulawesi Tengah Borjus, Borjus; Irawati, Irawati; Pratikino, Asrin Ginong
Jurnal Laut Khatulistiwa Vol 9, No 1 (2026): February
Publisher : Dept. Marine Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26418/lkuntan.v9i1.104091

Abstract

This study analyzes the characteristics and variability of swell waves in the Menui Waters, Morowali Regency, during the 2015–2024 period using ECMWF data. The analysis was conducted through statistical methods, spatial mapping, and Python-based data visualization. The results indicate that swell dynamics in the study area are primarily controlled by the southeast monsoon (June–August), while the contribution of tropical cyclones is relatively minor. Period distribution shows dominance of short-period wind waves (71.1%) and moderate-period swell (28.8%), with the latter exhibiting an average wave height of 0.74 m, approximately 2.6 times higher than wind waves, whereas long-period swell rarely develops due to the semi-enclosed basin characteristics. An increasing trend in wave height observed in several years, particularly in 2015, 2019, and 2024, suggests the influence of climate variability and change.
Analisis Komparatif Metode FFT Dan Least Squares Dalam Penentuan Komponen Pasang Surut Di Perairan Indonesia Al-Ghifari, Najwan; Budiarsa, Anugrah Aditya; Ritonga, Irwan Ramadhan; Riza, Muhammad; Sihotang, Zetsaona; Mandang, Idris
Jurnal Laut Khatulistiwa Vol 9, No 1 (2026): February
Publisher : Dept. Marine Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26418/lkuntan.v9i1.103907

Abstract

This study evaluates the performance of Fast Fourier Transform (FFT) and Least Squares (LS) methods in tidal analysis across four strategic locations representing Indonesia's diverse tidal regimes: Belitung, Bontang, Melonguane, and Natuna. Eight principal tidal components (O1, K1, M2, S2, N2, K2, P1, Q1) were analyzed. The results demonstrate that the Least Squares method is significantly superior, achieving an RMSE reduction of 79.2% to 94.0% compared to FFT. While tidal classifications based on Formzahl numbers remained consistent across both methods—identifying diurnal types in Belitung and mixed-prevailing semidiurnal types elsewhere—the LS method provided more precise harmonic constants. These findings recommend the LS method for high-accuracy operational tidal modeling and sea-level prediction in Indonesian waters.
Kepadatan dan Pola Distribusi Kima (Tridacnidae) di Perairan Pulau Lemukutan Kalimantan Barat Ikhsan, Arman Nur; Panggabean, Grin Tommy; Alkadrie, Syarif Iwan Taruna; Saputra, Andrian; Hidayat, Enjang Hernandi; Firdaus, Moh Rezha Sabda; Djuniadi, Sj.; Saniswan, Yuda; Putra, Eko Rahmanza
Jurnal Laut Khatulistiwa Vol 9, No 1 (2026): February
Publisher : Dept. Marine Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26418/lkuntan.v9i1.99890

Abstract

Lemukutan Island is a marine conservation area in Bengkayang Regency, West Kalimantan, with high marine resource potential. Besides supporting tourism activities such as diving and snorkeling, its waters host ecologically important giant clams (Tridacnidae), which function as natural biofilters in reef ecosystems. However, information regarding the biodiversity and population status of giant clams in this area remains limited. This study aimed to assess the density and distribution patterns of giant clams in the waters of Lemukutan Island. Field data were collected in July 2025 at four observation stations representing the eastern and western parts of the island using the belt transect method (50m x 5 m). Data analysis included calculations of density, relative abundance, and distribution patterns using the Morisita Index. A total of 329 individuals belonging to three species were recorded: Tridacna crocea, T. maxima, and T. squamosa. T. crocea was the most dominant species at all stations, with the highest average density (0.231 ind/m²) and relative abundance (14.732%). In contrast, T. squamosa showed the lowest average density (0.067 ind/m²). Station 2 exhibited the highest overall density (0.254 ind/m²) and relative abundance (16.241%) compared to other stations. The distribution pattern of giant clams was predominantly clumped. However, a more uniform distribution of T. crocea and T. maxima was observed at Stations 3 and 4. Variations in density and distribution were closely associated with coral reef availability and water quality conditions. These findings provide baseline data to support sustainable conservation and management of giant clams in Lemukutan Island waters.
Variasi Konsentrasi Nutrien dan Dampaknya terhadap Kelimpahan Fitoplankton di Perairan Teluk Semarang Jati, Oktavianto Eko; Afiati, Norma; Purnomo, Pujiono Wahyu; Ayuningrum, Diah; Dewi, Desca Estiyani
Jurnal Laut Khatulistiwa Vol 9, No 1 (2026): February
Publisher : Dept. Marine Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26418/lkuntan.v9i1.104265

Abstract

Phytoplankton are important microorganisms in water ecosystems. They help in the nutrient cycle. Nutrients in water affect how many and what types of phytoplankton are present. This also impacts the fertility of coastal waters like Semarang Bay, which are influenced by human activities. This study looks at the link between water nutrients, phytoplankton, and water fertility. The study used a descriptive, quantitative method on November 10, 2024, at 6 chosen locations. Measurements taken on-site included DO, temperature, salinity, pH, and transparency. Lab tests looked at phytoplankton types, chlorophyll-a, silica, nitrate, nitrite, orthophosphate, and TSS using SNI and APHA methods. The main phytoplankton types were Diatoms, Dinoflagellates, and Cyanobacteria (26 types), with Chaetoceros being the most common (1,598 cells/L). Bacteriastrum and Chaetoceros were seen most often. Environmental data showed temperatures from 29.2–33.3°C, pH 8.6–8.8, DO 5.3–7.3 mg/L, salinity 32–33‰, and water clarity 0.55–5.97 m; chlorophyll-a 1.55–8.85 µg/L. TSS levels were 18.58–38.94 mg/L, nitrate 1.3–1.9 mg/L, nitrite 0.01–0.02 mg/L, and phosphate 0.8 mg/L, with the highest silica at Station 4. PCA analysis showed a productivity pattern (PC1) that was positively associated with chlorophyll-a, phytoplankton numbers, silica, and dominance, but negatively associated with TSS, nitrate–nitrite, and transparency. This means silica helps diatom growth, while high TSS can reduce productivity by blocking light, even though it might bring nutrients.
Pengaruh Perubahan Suhu Permukaan Laut (SPL) di Selat Makassar terhadap Curah Hujan di Kota Samarinda dan Makassar pada Fase ENSO Asyikin, Nurul; Yusuf, Mustaid; Sihotang, Zetsaona; Wiyani, Riski Indah
Jurnal Laut Khatulistiwa Vol 9, No 1 (2026): February
Publisher : Dept. Marine Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26418/lkuntan.v9i1.103504

Abstract

Sea Surface Temperature (SST) is a key oceanographic parameter that influences atmospheric processes, particularly weather and climate variability, including rainfall, and its variability is closely linked to large-scale climate phenomena such as ENSO. This study examines the relationship between SST variability in the Makassar Strait and rainfall in Samarinda City and Makassar City under three climate conditions representing ENSO phases: El Niño (2015), normal conditions (2017), and La Niña (2022). Daily SST and rainfall data were converted into monthly mean values and analyzed using Pearson correlation to assess the strength and direction of their relationship. The results show that SST–rainfall correlations in Samarinda City were −0.423 during El Niño conditions, −0.219 during normal conditions, and −0.39 during La Niña conditions, indicating a moderate influence during El Niño and weaker relationships in other phases. In Makassar City, correlation values were −0.331 in 2015, −0.10 in 2017, and +0.69 in 2022, suggesting weak relationships during El Niño and normal conditions but a strong positive relationship during La Niña conditions. Overall, these findings demonstrate that the influence of SST variability in the Makassar Strait on rainfall differs by region and ENSO phase, providing useful insight for developing region-specific rainfall prediction models based on oceanic and climatic variability.
Pengaruh ENSO terhadap Curah Hujan Tahunan di Wilayah Urban Balikpapan Berdasarkan Oceanic Niño Indeks Periode 1995–2024 Valennur, Muhammad Audric; Hidayat, Rafli Akbar; Anargya, Daniswara Alief Aydin; Budiarsa, Anugrah Aditya; Al-ghifari, Najwan
Jurnal Laut Khatulistiwa Vol 9, No 1 (2026): February
Publisher : Dept. Marine Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26418/lkuntan.v9i1.104008

Abstract

Global climate variability, particularly the El Niño–Southern Oscillation (ENSO), influences rainfall patterns in tropical regions, including Indonesia. Balikpapan City, as a coastal urban area, is highly vulnerable to changes in rainfall, while studies linking the ENSO index to local-scale rainfall remain limited. This study aims to analyze the relationship between ENSO variability and annual rainfall in the urban area of Balikpapan. The data used included annual rainfall from the Sultan Aji Muhammad Sulaiman Sepinggan Class I BMKG Station and the Oceanic Niño Index (ONI) issued by the National Oceanic and Atmospheric Administration (NOAA) during the period 1995–2024. ENSO variability is represented by annual extreme ONI values and analyzed using descriptive statistics and Pearson's correlation. The results show that annual rainfall in Balikpapan City tends to decrease during the El Niño phase and increase during the La Niña phase, although this pattern is not always consistent from year to year. Pearson correlation analysis shows a weak relationship between ENSO and annual rainfall, with a coefficient of determination (R²) value of 0.0365. These findings indicate that ENSO plays a role as one of the factors controlling rainfall variability in Balikpapan City, but it is not the sole dominant factor, so the influence of regional and local climate processes also needs to be considered.
Sebaran Frekuensi dan Pola Distribusi Lola (Trochus niloticus Linnaeus, 1767) di Perairan Pulau Lemukutan dan Pulau Penata Besar Kalimantan Barat Panggabean, Grin Tommy
Jurnal Laut Khatulistiwa Vol 9, No 1 (2026): February
Publisher : Dept. Marine Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26418/lkuntan.v9i1.100164

Abstract

Lemukutan and Penata Besar Islands located in Bengkayang Regency, are characterized by coral reef formations and relatively clear waters that meet the ecological requirements for the natural habitat of the lola snail, Trochus niloticus. This study aimed to analyze the size–frequency distribution and spatial distribution pattern of T. niloticus in the waters of Lemukutan and Penata Besar Islands. Sampling was conducted using the belt transect method (50 m × 4 m) at four stations: Tanjung Jati, Penata Besar, Tanjung Batu Bedaon, and Melanau Timur (Batu Kapal). A total of 67 individuals were recorded during the study, consisting of 12 individuals (17.91%) at Tanjung Jati, 15 individuals (22.39%) at Penata Besar, 27 individuals (40.30%) at Tanjung Batu Bedaon, and 13 individuals (19.40%) at Melanau Timur (Batu Kapal). The population was dominated by individuals in the size classes of 8.5–9.1 cm and 9.1–9.7 cm, representing 34% of the total observations, indicating a predominance of medium-sized individuals. Spatial distribution analysis using the Morisita Index revealed a clumped distribution pattern (Id > 1) at Penata Besar, Tanjung Batu Bedaon, and Melanau Timur (Batu Kapal). In contrast, the population at Tanjung Jati exhibited a random distribution pattern (Id = 0.86). These findings provide baseline ecological information to support sustainable management and conservation strategies for T. niloticus in the study area.
Tren Sea Surface Temperature Pada Monsun Timur di Perairan Indonesia Berdasarkan Data Reanalisis Copernicus Marine Kusumaningsih, Alvianita Rika Putri; Pitriani, Pitriani; Sukma, Nimaz Tegar
Jurnal Laut Khatulistiwa Vol 9, No 1 (2026): February
Publisher : Dept. Marine Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26418/lkuntan.v9i1.104191

Abstract

Sea Surface Temperature (SST) is an important oceanographic parameter that is sensitive to seasonal variability and climate change. Indonesian waters experience strong SST dynamics, particularly during the east monsoon (June–August), which are influenced by monsoonal winds and oceanographic processes such as upwelling. This study aims to examine the variability, anomalies, and long-term trends of SST during the east monsoon in Indonesian waters. The study uses SST reanalysis data from the Copernicus Marine Service for the period 2005–2025 with a spatial resolution of 1/12°. The analysis includes the calculation of annual mean east monsoon (JJA) SST, SST anomalies relative to climatological values, and long-term trends using linear regression and the Mann–Kendall test. The results show that east monsoon SST exhibits interannual variability, with values ranging from approximately 28.1 to 29.3 °C. SST anomalies indicate noticeable year-to-year variations. Trend analysis reveals a statistically significant increase in SST during the east monsoon, with a warming rate of about 0.03–0.04 °C per year. These results indicate that ocean warming continues to occur even during the east monsoon period, which is typically associated with surface cooling. The findings provide important insight into changes in sea surface temperature in Indonesian waters and may support further studies on climate change impacts on marine ecosystems and the management of marine resources.
Analisis Pemantauan Sebaran TSS Menggunakan Aplikasi Google Earth Engine Sebagai Dasar Pengelolaan Pesisir Terpadu Di Wilayah Sekitar Pantai Pasir Padi Farhaby, Arthur Muhammad; Guskarnali, Guskarnali; Setiawan, Fahri; Winarto, Mito; Arianto, Firdaus Dwi
Jurnal Laut Khatulistiwa Vol 9, No 1 (2026): February
Publisher : Dept. Marine Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26418/lkuntan.v9i1.101296

Abstract

Abstract The coastal waters surrounding Pasir Padi Beach, located on the eastern side of Pangkalpinang, constitute a transitional zone between terrestrial and marine environments that is highly susceptible to sedimentation pressure, particularly from tin mining activities. This study aims to map and analyze the distribution and concentration of Total Suspended Solids (TSS) in the coastal waters of Pasir Padi Beach and its surrounding areas. The monitoring was carried out using a Google Earth Engine–based platform over a four year period (2022–2025) utilizing Sentinel 2A satellite imagery. The analysis employed a modified version of the Parwati method to estimate TSS. The findings revealed TSS concentrations ranging from 60–80 mg/L and >80 mg/L, represented by red and orange colors, which were predominantly distributed along the coastline. Meanwhile, the green areas, indicating TSS concentrations of 20–30 mg/L, functioned as a transitional or coastal belt before reaching the offshore waters characterized by low TSS values of 0–20 mg/L, depicted in blue. These results demonstrate that regions located near river mouths and tin mining zones are more prone to high sedimentation intensity, with the highest accumulation occurring toward offshore areas. Consequently, periodic monitoring is essential to mitigate potential environmental impacts such as river mouth siltation and disruptions to coastal dynamics and coastal activities.
Kajian Keramahan Lingkungan Pukat Cincin pada KM. Berkah Sandrego 2 di Kepulauan Bangka Belitung Misuari, Muhammad Nur; Dwikusuma, Agung; Suharyanto, Suharyanto; Mardiah, Ratu Sari; Irawan, Andi; Priyadi, Hermawan Gatot
Jurnal Laut Khatulistiwa Vol 9, No 1 (2026): February
Publisher : Dept. Marine Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26418/lkuntan.v9i1.100501

Abstract

Maintaining the potential sustainability of fish resources in the sea, the government began “Code of Conduct for Responsible Fisheries (CCRF)” concept since it was adopted at the FAO Conference on October 31, 1995 to overcome irregularities in capture fisheries activities. The criteria for environmentally friendly fishing gear must have high selectivity, the gear does not damage the habitat, does not endanger the lives of fishermen, produces quality fish, the product does not endanger consumers, low by-catch, fishing gear provides minimal impact efforts on the diversity of biological resources, does not catch protected biota species that are threatened with extinction and is socially accepted by the community. The purpose of this study is to determine the environmental level friendliness of purse seines by means of observation, documentation, and interviews. The purse seine catches results in the study at KM. Berkah Sandrego 2 consists of Sardinella gibbosa by 25%, Amblygaster sirm by 27%, Selarodies leptolepis by 19%, Selar crumenophthalmus by 8%, Atule mate by 4%, Rastrelliger kanugarta by 6%, Euthynnus affinis by 9%, and other catches by 2%. The 88.32% catch total is the main catch (HTU), while 11.68% is bycatch (HTS) with total catch of fish that can be utilized at 100% and unutilized total catch at 0%. The assessment shows that this fishing gear is in the environmentally friendly category. The evaluation resulted in a score of 28 and a total score of 848, which proves that the purse seine is in the 28-36 category (very environmentally friendly).

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