Java Sea Research Articles

Possible effects of shipping routes on coral reef degradation and diversity in Karimunjawa Marine National Park, Java Sea

The Karimunjawa Marine National Park, situated in the Java Sea, Indonesia, is renowned for its rich biodiversity and lively coral reefs. However, amidst the backdrop of this natural beauty, concerns have been raised regarding the potential impacts of shipping activities on the health and diversity of these fragile ecosystems. The increase in maritime traffic, including commercial vessels, tourist boats, and fishing vessels, traversing through the Karimunjawa Marine National Park, raises significant environmental concerns. The movement of these vessels, especially along specific shipping routes, has the potential to disturb and damage coral reefs through various mechanisms. Hence, this study aimed to investigate the possible impacts of shipping routes on the coral abundance and diversity and the coral health in the Karimunjawa Islands, Java Sea, Indonesia. This study categorized ship routes into West Route, East Route, and Non-Route and assessed coral health and diversity across 15 islands. Key metrics analyzed included coral disease prevalence, coral cover, diversity index, species richness, relative abundance, and evenness, using 15 × 2 m belt transects at 3 and 8 m depths with three repetitions each. Statistical analysis revealed significant differences in coral abundance and species richness among ship-route groups, but no significant depth-related differences. These results suggest that while shipping routes affect certain aspects of coral health and diversity, other factors may be more influential in shaping coral disease prevalence and overall diversity in Karimunjawa reefs.

The Impact Of Sea Sand Mining On The Environment And Economy In Bawean Island

This study analyzes the impact of sea sand mining on the environment and local economy in Bawean Island. Located in the Java Sea and part of Gresik Regency, East Java Province, Bawean Island is renowned for its biodiversity and natural beauty. Both legal and illegal sea sand mining have caused various problems, including increased coastal abrasion and erosion, degradation of seawater quality, damage to coral reef ecosystems and mangrove forests, and beach pollution. The economic impacts include a decline in fish catches, reduced tourism appeal, and social conflicts between pro-environment communities and mining parties. The research methodology used is qualitative descriptive, employing literature review for data collection. The findings indicate that sea sand mining results in serious ecosystem damage and adversely affects the economic well-being of local communities. To address these issues, recommended measures include reviewing local regulations, reassessing environmental permits, revoking non-compliant mining licenses, developing alternative economies, planting mangroves, promoting the benefits of mangroves, and adopting an interagency approach. This study emphasizes the importance of sustainable natural resource management and marine ecosystem protection to ensure the well-being of Bawean Island's communities.

Techno-Economic Analysis of Utilization Offshore Platform in the Java Sea to Produce Hydrogen with Offshore Wind Turbine-Based Energy Sources

Abstract Indonesia’s geographical condition, which consists of 70 percent ocean territory, holds the potential for utilizing offshore wind turbines to provide cleaner energy. In this study, economic calculations were conducted for offshore wind turbines to generate green electricity and green hydrogen. The chosen ocean area for this endeavor is around the Papa offshore platform in the Java Sea. This area has experienced an economic decline, making it viable for repurposing as a sub-station for a powerhouse and an electrolyzer plant. Based on meteorological data analysis results, the area around the Papa offshore platform exhibits an average at height of 119 m; the wind speed is 5.5 m/s.The prevailing wind direction is East Southeast (ESE), with a frequency of 25.2%. Further analysis of wind farms aimed at generating a capacity of 100.8 MW revealed an optimal potential energy generation of approximately 141,656.9 MWh per year. For scenario 1 (electricity production), the cost is $0.192/kWh. The levelized cost of hydrogen (LCOH) for scenario 2 (offshore electrolyzer) and scenario 3 (onshore electrolyzer) is $9.44/kg and $10.1/kg, respectively. To assess investment feasibility, a Net Present Value (NPV) analysis was conducted. This analysis yielded a selling price of electricity at $0.0271/kWh for the first scenario. For the second scenario, the selling price of hydrogen was calculated at $17.11/kg, and for the third scenario, it was $16.99/kg. Considering its flexibility and potential response to restrictions, the third scenario was deemed the most suitable for offshore utilization to produce clean energy.

Assessment of mangrove structures and biomass on islands along the Java Sea: a case study on Bawean Islands and Karimunjawa Islands

Mangroves on the islands along the Java Sea play a crucial role in supporting biodiversity, protecting coastlines, and sequestering carbon. However, there is a lack of information on mangrove structure and biomass in the area. This study aimed to assess the mangrove structures and biomass on Desa Daun, located on the Bawean Islands, and Kemujan Island, located on the Karimunjawa Islands, respectively. The study utilized a combination of line transect and quadrant plot methods with a size plot of 10x10 m. We established 7 line transects and 28 quadrant plots in the mangrove forest of Desa Daun and similarly set up 7 line transects and 21 quadrant plots on Kemujan Island. Within each quadrant, the mangrove species were identified, and their diameters at breast height (DBH) were recorded. To assess the relative significance of each species, the importance value index (IVI) was calculated, and allometric equations were applied to estimate biomass and carbon storage in the trees. PlanetScope imagery was also used to quantify the carbon stock of mangroves on those islands. In Desa Daun, 13 mangrove species were identified, while 12 species were recorded on Kemujan Island. The species Nypa fruticans and Excoecaria agallocha exhibited the highest IVI in Desa Daun and Kemujan Island, respectively. Notably, Rhizophora apiculata demonstrated the greatest biomass in both locations, with measurements of 43.08 Mg B/ha in Desa Daun and 102.22 Mg B/ha in Kemujan Island. Overall, mangrove stands on Desa Daun stored biomass of 113.60 Mg B/ha and carbon of 50.98 Mg C/ha, whereas mangrove stands on Kemujan Island stored biomass of 295.04 Mg B/ha and carbon of 131.95 Mg C/ha. Mangrove stands of the whole Bawean Islands sequestered 22,941 Mg C, while Karimunjawa Islands hold much higher C stocks, 79,451 Mg C. Despite being smaller in size, the Karimunjawa Islands have more extensive mangrove coverage compared to the Bawean Islands due to their geomorphological characteristics, which in turn influence their mangrove structures and carbon stocks. However, the loss of mangroves in the Karimunjawa Islands due to aquaculture expansions could increase carbon loss in the islands.

The Red Snapper Fishery in the Eastern Java Sea and Its Fishery Management Recommendation

Abstract For decades, the red snapper fishery has been considered a potential demersal fishery in the east part of Java Sea. The fluctuating fishing effort caused the biomass of red snapper has a fluctuate every year. The study’s goal is to analyze the changing conditions of the red snapper fishery in the east part of Java Sea as a basis for developing management recommendations. The production and efforts data were collected from Brondong Nusantara Fishing Port from 2008 to 2021. The data was analyzed using a non-equilibrium surplus production model and depicted using Kobe Plot to know the change direction of red snapper fishery. The result shows that red snapper fishery in the east part of Java Sea has been overfishing with the abundance of biomass has been overfished. This study’s recommendations for fisheries management are to limit fishing efforts and allowable catch in order to improve the red snapper fishery in the east part of Java Sea.

Determining demersal fisheries status in fisheries management arena (FMA) 712 under data limited situation

Abstract Demersal fisheries in FMA 712 have been established since the early 1950’s, industrialization in demersal fisheries was started on 1970’s with the operation of trawl fleets in Java Sea. The exploitation continued until the 1980s when the Trawl Ban regulation was enacted. According to historical statical data from 1980 the number of demersal fishing fleets are still dominating and endangered the sustainability of demersal fish stock in FMA 712. This study presented alternatives approaches to determining demersal fisheries status in FMA 712 using the Bayesian surplus production model (cMSY) and Length-Based Spawning Potential Ratio (LBSPR). The cMSY analysis was conducted using time series production data and known CPUE represent the area in FMA 712 and the LBSPR model was conducted using the life-history parameters and the length frequency data. The results show that current demersal fisheries condition is overexploited, points of estimation of the Biomass condition based on 1980-2022 data: B/BMSY 0,803, F/FMSY 1,75 and MSY 323.000 ton. Additionally, the spawning potential ratio (SPR) of the dominant demersal fish species (Lutjanus malabarius and Portunus pelagicus) was lower than the limit reference point (<0,20), indicating overexploited. This study demonstrates that alternatives approaches could be applied to limited data fisheries and provide useful and robust recommendations.

Unexpected social change: The transformation of the Pati Regency’s coastal community due to the Indonesian government’s trawl restriction policy

Abstract Indonesia’s developmental endeavors, with a focal point on Java Island, presented an overarching concern for the excessive depletion of its coastal and maritime reservoirs. This fundamental notion laid the groundwork for Indonesian governmental actions in 2015 under the stewardship of Minister of Marine Affairs and Fisheries Susi Pujiastuti. During this period, a proactive measure was introduced, entailing the imposition of fishing limitations within the Northern Java Sea vicinity. Embodied within the Ministerial Regulation of Marine Affairs and Fisheries No. 2 of 2015, the restriction of Deploying Trawl and Seine Nets within Indonesian Fishery Management Zones became a tangible manifestation aimed at upholding the preservation of coastal and maritime resources. After an approximate span of eight years since the enforcement of this policy, noteworthy transformations have transpired within the northern Java capture fisheries sector. Comprehensive interviews, meticulous observations, and scrutiny of documents within the Pati Regency (particularly in the Juwana sub-district) within the Central Java province revealed discernible shifts within coastal communities in a relatively brief span. Employing the social-ecological system framework, an analytical lens was cast upon the repercussions of this governmental restriction policy on the circumstances of the Juwana sub-district’s coastal communities, notably the fishermen. The curtailment imposed on fishing apparatus compelled fishermen to modernize and enhance the efficiency of their equipment. The evolving working ethos of the community trended toward collective endeavors and opportunistic pursuit of commercial prospects. Nevertheless, simultaneous challenges surfaced, including societal disparities amidst coastal communities, the marginal involvement of local governance, and the plausible peril of ecosystem detriment beyond the initial boundaries.

Formal Safety Assessment of the Connection of the Sunda Strait and Java Sea Through the Implementation of IMO Routeing Measures

Formal Safety Assessment of the Connection of the Sunda Strait and Java Sea Through the Implementation of IMO Routeing Measures

Characteristics and Distribution of Chemical-Biological Parameters in The Seawaters of Eastern Java Sea

The Java Sea is influenced by the west and east monsoons, which have an impact on hydrodynamic processes and chemical-biological water quality. Chemical-biological parameters play an important role in the food chain cycle that occurs in these waters. The quality of the eastern Java Sea waters is still limited by chemical-biological parameters, so the characteristics and distribution of these waters can be comprehensively known. chemical-biological. This study aimed to analyze the characteristics and distribution of nitrate, phosphate, oxygen, chlorophyll-A, and NPP parameters in the eastern Java Sea waters. This study used secondary data with daily temporal resolution from January to December 2020. Spatial analysis uses the climatological averaging method for 6 months as a statistical representative of the west monsoon and east monsoon. For each parameter, a vertical analysis was conducted to compare parameter values between the coastal waters of Tuban, Java Sea, and Banjarmasin Waters. Correlation analysis between parameters was conducted using the Pearson correlation method. Nitrate, phosphate, oxygen, chlorophyll-A, and NPP concentrations have temporal and spatial variability. Monsoon factors in Indonesia have a strong influence on the variability of nitrate, phosphate, oxygen, chlorophyll- A, and NPP concentrations. During the east monsoon, the concentration of chemical-biological parameters decreases, while in the west monsoon, the concentration increases and reaches its highest value. Generally, high concentrations occur in the northern and southern parts of the study site, around the coastal areas of Java and Kalimantan. Key Word: Chemical-Biological Parameters, Java Sea, Tuban Waters

THE BIRDS OF THE KANGEAN ISLANDS AND AN APPRAISAL OF THEIR CONSERVATION STATUS

The Kangean islands are a biologically poorly known archipelago situated in the Java Sea, Indonesia, approximately 120 km directly north of Bali. These islands host an avifauna comprising at least 13 endemic subspecies, two of which have by some sources recently been considered species. We combine historical published literature with our own surveys of the archipelago in 2007–2008, 2010 and 2023 to produce a complete list of the islands’ birds (n=140 species) and their distribution across the islands. We evaluate in more detail the conservation status of all endemic taxa, as well as several others we consider to be of concern. Despite its listing as Vulnerable on the IUCN Red List, the endemic Kangean Tit-babbler Mixornis prillwitzi is highly tolerant of habitat degradation and is among the islands’ least threatened birds. However, because of trapping, the archipelago’s endemic taxon of Red-breasted Parakeet Psittacula alexandri kangeanensis, and its populations of Green Junglefowl Gallus varius and Common Hill Myna Gracula religiosa are likely at risk of extirpation. The endemic taxon of White-rumped Shama Copsychus malabaricus, sometimes afforded species rank as ‘Kangean Shama’ C. nigricauda, may already be (at least functionally) extinct in the main archipelago. We recommend longer and more detailed surveys of the islands’ birds, and that an effective protected area is established on main Kangean island, which hosts the largest area of remaining forest in the archipelago and most of its endemic taxa.

Pemanfaatan Data Satelit Himawari-8 dalam Analisis Kejadian Hujan Lebat di Jombang

On February 2, 2021, flooding struck Jombang, damaging 38 houses and public facilities due to heavy rainfall from cumulonimbus clouds. The analysis of convective cloud development using Himawari-8 Satellite with RGB Day Convective Storm, 24H-Microphysics, Airmass, and Cloud Convective Overlay methods revealed that the microphysics phase occurred in two different phases on February 1 and 2. The peak temperature of the Cb cloud during the development phase ranged from -20 to -60°C. Convective cloud clusters originated from the Java Sea and the Southern Sea. The peak cloud formation occurred at 12:00 UTC on February 1 and 2. Increased updraft and thickness intensity strengthened convective cloud formation. During the decay phase, downdraft increased with a decrease in cloud distribution, as observed in the Day Convective Storm and 24H-Microphysics images.

PENANGANAN BANJIR DAERAH ALIRAN SUNGAI BABON KOTA SEMARANG

Floods are natural disasters that we often encounter during the rainy season. Apart from there are also tidal floods which are caused by global warming, this problem occurs in the city of Semarang, especially North Semarang, specifically the north coast of the Java Sea. Floods that occurred in 2021 in the city of Semarang include Starting from Genuk, Kaligawe, Satsiun Tawang, Tanjungmas, Karangayu, the flood disaster was caused by high rainfall, while tidal floods caused high tides and inundated roads and houses of residents on the north coast of Semarang city. To handle this problem, the government Currently we have made embankments, namely making embankments including the Sringin River which is equipped with a ponpa, Tenggang River, Babon River, Semarang River, Banger River, and others. These embankments are equipped with pumps so that when the water from upstream to downstream is high, the water is pumped. to the sea, the aim is to find out one of the annual discharges of the river, namely the Babon, and to find out the tamping capacity of the Babon River Longstorage. Apart from that, there is a method for handling tidal floods, namely using the Babon River Longstorage which is equipped with a pump, if there is high tide which inundates roads and houses. residents then the pump is turned on, whereas if the water recedes and does not inundate residential areas then the pump is turned off. Flood control analysis is calculated using the HEC-RAS program simulation using a return period of 50 years. Based on calculations using the HEC-HMS program. The flood discharge is 2,529 m3/sec. The high tide elevation is + 1.67 m, while the normal water level is -0.5 m.

The performance of anchovy purse seine in the North Coastal Java Sea, Indonesia

Small pelagic fishes including anchovies in Indonesia are caught by using different types of fishing gears. However, the anchovy purse seine commonly used polyethylene (PE) as material webbing which is less effective in the North Coastal Java Sea. This study aims to describe the design and construction of the anchovy purse seine and the characteristics of this gear construction. The research was carried out in the North Coastal Java Sea of Indonesia between May and June 2021. The main data from the nine anchovy purse seine units were collected using purposive sampling. The sampling method was performed by identifying and measuring the components of the number of anchovy purse seiners. The ratio of the length of the head rope to the length of the ground rope is between 0.926 and 0.991, so the net is not exactly rectangular, but almost trapezium in shape. The anchovy purse seine was constructed using webbing polyamide (PA) with 8 mm–9 mm in mesh size, which is considered a small mesh size. It is assembled with some ropes, floats, and sinkers. The anchovy purse seine is characterized by the dominant buoyancy value, 48 % larger than the sinking force. The sinking speed is 0.15 m/s, and the sinking time is 164 s. The anchovy purse seine's design and construction are suitable for operating in the waters of North Coast of Java.

OPERATION TECHNIQUE AND OPERATIONAL TIME CALCULATION OF PURSE SEINE IN FISH CAPTURE: A CASE STUDY ON KM. MUTIARA SEJATI

A purse seine is an active fishing gear operated by encircling schools of fish. KM. Mutiara Sejati is one of the fishing vessels based in PPP Bajomulyo, Central Java, employing purse seine for small pelagic fisheries. That research aimed to explore the operational techniques of purse seine fishing gear and determine the time calculation for its operation. The study was conducted over five months, from October 2022 to March 2023, utilizing observation, interviews, and documentation as research methods. The operational area of the vessel was in the WPP 712 (Java Sea) with PPP Bajomulyo serving as the fishing base. Based on the research findings, the operational process of small pelagic purse seine began with a series of steps, including the deployment of fish aggregating devices, activation of vessel lights, deactivation of lights except for those at the stern, lowering of the boom lights, total shutdown of vessel lights, setting of the net, purse line retrieval, retrieval of the boom lights, net hauling process, catch retrieval, and ultimately, the re-arrangement of fishing gear. Calculation results indicated that the average operational time for the fishing gear during the nighttime was 87 minutes, while during the early morning hours, it was 83 minutes.

RANCANG BANGUN JEMURAN KERUPUK OTOMATIS BERBASIS IOT UNTUK PRODUSEN KERUPUK IKAN DI SIDAYU GRESIK

Gresik Regency is one of the regencies in East Java province with a geographical location directly adjacent to the coast of the Java Sea. The amount of milkfish cultivation that can be produced from ponds located on the north coast of Gresik Regency has a high potential value to be utilized as processed fish products. One of the most widely produced processed fish products is milkfish crackers. The availability of easily obtained raw materials does not make it difficult to process fish crackers. Drying crackers by drying in the sun will run smoothly in hot weather or dry season. However, when entering the rainy season, there are often many obstacles, namely the heat of the sun that does not match what is needed, such as cloudy weather and even if it suddenly rains, which sometimes causes mold on the crackers because there is not enough time to take the crackers that are being dried. The drying process must always be supervised directly by humans, besides that there are several types of crackers with different compositions that have different drying times. This tool is enabled to recognize the weather including light intensity, air temperature, and rainfall so that it is considered more efficient to use during the rainy season. The user simply puts the fish crackers on the clothesline and when the tool recognizes rainy or cloudy conditions, the fish cracker clothesline will be pulled by an electric motor to be put into the room. When the user is away, the clothesline can also be monitored and controlled remotely. As a result, the IoT-based Automatic Cracker Clothesline System can recognize whether the weather is sunny, hot, or rainy. The system can also extend the clothesline automatically when the weather is sunny or hot, the system can pull the clothesline when it rains or cloudy automatically. The system can send notifications to the smartphone according to the weather conditions and the position of the clothesline being pulled or extended in realtime, the system can display the indicators of each sensor to the smartphone. Users can also enter the drying time and minimum temperature range into the system. As a result, the system can run well to recognize the weather around the cracker clothesline and can insert crackers when it is raining, cloudy or when the drying time has expired automatically.

Quaternary deposition and erosion in the northeastern Sunda Strait: An interplay between sea level, tectonics, and magmatic activity

The northeastern Sunda Strait is a narrow strait separating Java and Sumatra islands. Currently, it forms a seaway between the Java Sea and the Indian Ocean. The geological setting of the region is extremely dynamic, but how the Plio-Pleistocene interplay between sea level oscillations, magmatism, and tectonics, which lead to the current setting, has not been completely understood. We analysed an important set of legacy shallow seismic data from this area to decipher these intricate relationships. Our results indicate that the tectonic extension partly dismantled the Indonesian arc since the Middle Miocene. However, volcanic products formed a barrier between the Sunda Shelf and the Indian Ocean during the Late Pliocene to the Middle Pleistocene. Marine flooding started during the Middle Pleistocene but bypassed the barrier by flooding the NW edge of Java Island. During the Late Pleistocene, high amplitudes and longer periods of the glacial-interglacial cycles ultimately connected the Java Sea with the Indian Ocean. Still, it was only during the Holocene that important erosion made this seaway efficient in transporting seawater between the two reservoirs.

Primary Productivity Variation in Banten Bay and Java Sea and Its Relationship with Fish Catches

Abstract Ecosystems carry out internal activities, one of which is by carrying out production which is the process of inputting and storing energy from sunlight as a primary energy source called primary productivity. The development of wider coastal areas is a major factor in the importance of assessing the quality of water fertility as a measure of ecosystem change. The aim of this research is to predict the value of primary productivity in Banten Bay and the Java Sea seasonally from 2005-2020 based on MODIS Fluorescence satellite image data and processed using the Vertically Generalized Production Model (VGPM). Net Primary Productivity results obtained in Banten Bay in the West Season 148.23 mgC.m−3.d−1; Transitional Season I 148.06 mgC.m−3.d−1. East Season with 154.05 mgC.m−3.d−1; Transitional Season II 170.10 mgC.m−3.d−1 while in the Java Sea in the West Season 100.05 mgC.m−3.d−1; Transitional Season I 82.20 mgC.m−3.d−1; East Season 110.84 mgC.m−3.d−1; Transitional Season II 95.97 mgC.m−3.d−1 which decreased in value from 2005 to 2020 in both regions. Water fertility in Banten Bay and the Java Sea is higher in the nearshore area than the open sea which is influenced by chlorophyll-a, PAR availability, day length, temperature, maximum carbon fixation, euphotic zone depth, and area. Trophic status in each season in Banten Bay is included in the Oligotrophic class while in the Java Sea it is included in the Oligotrophic and Mesotrophic classes. NPP has a positive correlation with the overall capture of small pelagic fish species of 0.654 (average).

Sea surface temperature budget in Indonesian seas: the role of vertical turbulent flux and its east–west variations

Abstract The vertical turbulent flux, which comprises heat flux and vertical mixing, is one of key processes governing seawater temperature changes in the vertical direction. In this study, the influence of vertical turbulent flux on sea surface temperature (represented by a layer between the free-surface and approximately 20 m depth) in Indonesian seas was diagnosed from an eddy-permitting ocean modeling experiment result. The heat flux, as the sum of the net heat flux at the surface and penetrative shortwave radiation at the base of the surface layer, induced a net cooling tendency in both eastern and western Indonesia (represented by the Java Sea and Banda Sea, respectively). The cooling tendency due to the heat flux was opposed by the warming tendency induced by vertical mixing at the base of the surface layer, preventing excessive heat loss in the surface layer. An exception occurred during the Boreal Autumn in the Banda Sea, when the heat flux and vertical mixing resulted in warming and cooling tendencies, respectively. It was further found that the effect of vertical mixing on the surface layer heat budget was sensitive to the selection of the base layer depth, highlighting the mixing-related dynamic variation within the water column. In summary, this study provides additional insights into the near-surface dynamics that govern sea surface temperature seasonality in Indonesian Seas.

Identification, Mapping and Solutions for Drought Management in Kaliori District, Rembang Regency, Indonesia

Rembang Regency is one of the regencies in Central Java that often experiences drought. Based on the results of the mapping of drought-prone areas for 2020 carried out by the Rembang Regency government, there are 63 villages spread across 14 sub-districts, 18,885 families are recorded as experiencing drought. Kaliori District is one of the sub-districts in Rembang Regency that is experiencing drought, this sub-district consists of 23 villages and is directly adjacent to the north of Java Sea. The purpose of this research is to be able to do a mapping for planning sustainable drought solutions, obtain quantitative data on drought and stages of drought management. The stages of the research carried out were site surveys and interviews related to drought in the Kaliori area. Prior to the Focus Group Discussion (FGD), a questionnaire was prepared. This research was conducted through joint FGD with all village heads in Kaliori District regarding water drought in Rembang. Based on the FGD and the statistical analysis results, it was found that 70% of Kaliori District experienced drought. When there is a drought, generally villages in Kaliori sub-district use water from water tanks and some use wells of poor quality and having a salty taste. The majority of villages in Kaliori Sub-district experienced a drought that lasted for 4-5 months of a year. Several parties involved in dealing with drought in Kaliori Sub-district included PAMSIMAS, Karang Taruna, Banser, Paguyuban, and P3A. Some solutions proposed are river connection, estuary river gate, and reservoir optimation.

Cross-shelf transport of high chlorophyll-a coastal waters by frontal eddies in the south of Java sea

Intense mesoscale eddy activity has been observed off the southern Java coast (SJC), yet its impact on local ecosystems remains largely unknown. To investigate this, we examined remotely sensed altimetry, chlorophyll-a (Chl-a), and sea surface temperature (SST) data, focusing on their response to eddies in the region. Our eddy detection and tracking analysis revealed a unique cyclonic frontal eddy near the SJC coast and a large anticyclonic eddy offshore, active from July to September 2019. The cyclonic frontal eddy induced water transport through eddy filaments, upwelled subsurface cold water, and enhanced Chl-a concentrations by horizontally entraining Chl-a-rich shelf water offshore. The anticyclonic eddy then contributed to further distributing this enriched water southward. The mean cross-shelf transport associated with the frontal eddy was estimated at 1.80–2.33 Sv offshore, exporting approximately 1.87–2.40 × 103 tons of Chl-a to the Indian Ocean during its lifetime. Additionally, the spatial cross-correlation analysis of zonal and meridional wind stress with Chl-a revealed relatively high correlation values (0.6–1) and short lag times (<5 days) in offshore areas, indicating that the role of wind in the Chl-a advection cannot be ignored. We propose a three-stage mechanism to explain the presence of high Chl-a offshore:1) Wind-driven upwelling intensifies coastal nutrients, elevating Chl-a concentrations in coastal waters, 2) Frontal cyclonic eddy facilitates the retention and offshore export of these upwelling-enriched waters. and 3) Anticyclonic eddy advects these nutrient-rich waters further south. The combination of enhanced coastal upwelling and eddies can explain nutrient-rich coastal waters in offshore regions.