Manila Bay Research Articles

Morphological and molecular characterization of two potentially toxigenic species of the genus Pseudo-nitzschia (Bacillariophyceae) in Luzon Island, Philippines

Harmful algal blooms are a major concern for the environment and industries like fisheries, healthcare, and tourism in coastal countries such as the Philippines. Blooms of diatoms (Bacillariophyceae) seldom cause harm, but half of the species in the cosmopolitan genus Pseudo-nitzschia produce the neurotoxin domoic acid. Only two published Pseudo-nitzschia surveys in the Philippines carried out morphology-based species identification. Molecular taxonomy has revealed a high level of cryptic diversity corresponding to minute morphological differences. This study sought to explore the diversity of and characterize the genus Pseudo-nitzschia in mariculture zones around Luzon Island using morphological and molecular information. Ten culture strains of Pseudo-nitzschia isolated from shellfish farms were used for morphological and molecular species identification. The secondary structure of the internal transcribed spacer 2 region revealed five strains from Pagbilao Bay to be most similar to P. brasiliana, the first record of this species in Luzon. Meanwhile, four Bacoor isolates and one from Pagbilao clustered within a monophyletic clade representing P. pungens, previously found in Manila Bay. Three single nucleotide polymorphisms and one hemi-compensatory base change were found among the P. pungens strains. Morphological characters, specifically cell shape, apex shape, and poroid density confirmed both species identities. Based on band striae, all P. pungens strains were of the nominal variety, P. pungens var. pungens. This study is among the first culture-based taxonomic studies of diatoms in the Philippines, in this case confirming the presence of harmful microalgae in the coastal ecosystems of the country.

Combating of Illegal, Unreported, and Unregulated Fishing Activities Along Manila Bay

This study delves into the complexities of enforcing fishing regulations in Manila Bay, Philippines, where licensed fishing is a prevalent activity. The legal framework prohibits any fishing practices detrimental to the marine ecosystem, mandating penalties for infractions. The objective of this qualitative investigation was to uncover the challenges encountered by enforcement agencies and to delineate the strategies they employ. Employing random sampling, twenty-two (22) enforcement personnel from the provinces of Bataan, Pampanga, and Bulacan were selected for participation. A thematic analysis was conducted on the data gathered through in-depth interviews utilizing a semi-structured questionnaire, which facilitated the extraction of seven significant themes: inadequate equipment, an increase in false informants, adverse weather conditions, repeat offenses, joint operations, a reward system, and prosecution processes. The findings indicate a recurring issue of re-offense among violators, attributed to the inadequate monitoring, control, and surveillance capabilities of the law enforcement authorities. The lack of proper equipment further hampers the authorities’ ability to effectively enforce regulations, leading to a rise in illegal fishing activities. The study suggests the imperative need for developing a comprehensive and effective strategy to curb illegal fishing in Manila Bay, emphasizing the importance of collaborative efforts and a coordinated approach among law enforcement bodies. Keywords: Manila Bay, rewards, meeting, violent offenders, patrol boats, inclement weather, active gears

GROUND DEFORMATION MONITORING OF RECLAIMED LANDS ALONG MANILA BAY FREEPORT ZONE USING PS-INSAR TECHNIQUE

Abstract. In response to escalating land demands, land reclamation plays a vital role, but this comes with the challenge of ground deformations that threaten livelihoods and safety. To address the growing concern, Persistent Scatterer Interferometric Synthetic Aperture Radar (PS-InSAR) is utilized. This remote sensing method is known for its cost-effectiveness, efficiency, and high-resolution capabilities, to monitor vertical ground deformations in Manila Bay Freeport Zone's reclaimed areas. Through adaptation and implementation of PS-InSAR via SARPROZ, measurements along the satellite’s line-of-sight (LOS) is integrated both for ascending and descending geometries using the Nearest Neighbor Vector (NNV) approach to decompose and derive precise vertical displacement values. Correlation analysis with annual leveling data from six benchmarks reveals a strong relationship with correlation coefficient > 0.80. The results indicate relative stability with localized subsidence due to differential settlement and nearby construction. The results from the PS-InSAR technique show that ground deformation on reclaimed lands is expected to continue. Hence, monitoring should be implemented to observe sustained settlements after reclamation, identify areas with significant deformations, detect building and structural deformations, and initiate solutions to reduce the risk of environmental hazards.

INVESTIGATION OF THE EFFECT OF SPACE VARYING WIND INPUT ON HYDRODYNAMIC MODELING IN MANILA BAY AND LAGUNA LAKE

Abstract. Surface water currents and waves are largely driven by wind forcing by inducing shear stress to the water surface. The circulations formed carry with it various materials and pollutants all over a large body of water like the Manila Bay and Laguna Lake. Considering the spatial and temporal variability of wind over the Bay and the Lake is essential to model the hydrodynamics of water more accurately. This study simulated bay hydrodynamics using high resolution space- and time-varying wind data from Weather Research Forecasting (WRF) as input and compared the results with using uniform-directed wind. The downscaled winds from WRF demonstrated patterns in agreement with the country’s seasonal monsoon wind dynamics. Its effect on the bay hydrodynamics is more pronounced during the dry season as it changes the flow direction of water at the bay mouth. On the other hand, the hydrodynamic difference in circulation patterns for the lake was accentuated with a more defined clockwise gyre circulation during the wet season where prevailing winds are stronger. Thus, it is imperative to incorporate spatially varying wind input to accurately characterize the bay water movement. Results also showed that global weather inputs can be used in areas with scarce monitoring stations as long as they are validated.

Dolomite Beach as a Tourist Attraction in Manila as Perceived by Local Residents: Basis for Tourism Promotion

Dolomite Beach, also known as Manila’s first man-made beach, is a fake sand beach formed through the process of nourishment on Manila Bay in Manila, Philippines. This is a new addition to Manila’s tourism industry. This study aims to make Dolomite Beach an effective tourist hotspot for Manila by increasing its significance and positioning it as a top attraction. It adopts a quantitative approach using Frequency Distributions, Weighted Means, and Standard Deviations through a descriptive study with 383 participants. Moreover, local residents had a high perception of Dolomite Beach as a tourist destination. The survey results show that, despite some initial controversy surrounding its construction, the majority of respondents favored of turning Dolomite Beach into a tourist attraction. The respondents felt excited when it was featured among the things to do in Manila for tourists. Many respondents expressed support for the establishment of an artificial white sandy beach in the city and looked forward to increased local and international tourism while providing more job opportunities for people who live in Manila. The benefits are many, not only for the residents of Manila but also for the overall community. The proactive involvement of residents, who are important players in the tourism industry, drives tourism growth. Therefore, this study shows that Dolomite Beach can be one of Manila’s leading tourist attractions.

A Case Study of Water Pollution in Manila Bay, Philippines

A Case Study of Water Pollution in Manila Bay, Philippines

Tourism Destination Potential and Environmental Sustainability of Manila Bay Dolomite Beach

Since the country’s tourism have a great impact on the economy, the Philippine government continues to develop and rehabilitate, if necessary, the tourist attractions in the country. One of the country’s rehabilitation projects is at the Manila Bay (Adel, 2022) where the Dolomite Beach, a reclaimed shoreline, is part of the DENR’s Rehabilitation program. Since its opening, it earned the potential to be a tourist destination in the Manila area. However, a number of individuals have raised concerns with regards to sustaining its clean environment given its location as a public destination spot. This prompted the researchers to study the tourism destination potential and environmental sustainability (perception of respondents)) of the Manila Bay Dolomite Beach. Utilizing convenience sampling, 121 respondents (comprising of government officials, residents, and business operators at the beach) were surveyed. Results indicated that Manila Bay Dolomite Beach has a potential to be a tourist attraction, with respondents expressing strong agreement towards its appeal, particularly its shoreline, white sandy beach, and sunsets. Furthermore, respondents demonstrated commitment to environmental protection, as evidenced by their agreement to adhere to rules, dispose of waste responsibly, and act as responsible tourists. Statistical analysis revealed a significant positive correlation (Pearson r = 0.298, p < 0.001) between the potential of the beach as a tourist destination and its environmental sustainability. Thus, the findings emphasized the importance of stakeholders' commitment to environmental conservation for the long-term success of tourism in the area.

Frequent, year-round monitoring reveals significant shorebird abundances in northern Manila Bay, Philippines

Frequent, year-round monitoring reveals significant shorebird abundances in northern Manila Bay, Philippines

Contamination of Bisphenol A, Nonylphenol, Octylphenol, and Estrone in Major Rivers of Mega Manila, Philippines.

Endocrine-disrupting compounds (EDCs) such as natural and synthetic hormones as well as phenolic industrial chemicals are considered contaminants of emerging concern in environmental waters. While EDCs carried through rivers may impact ecosystem health and productivity, these compounds are still not widely studied nor regulated. In the present study, we report the occurrence of EDCs in urban rivers in Mega Manila, namely, the Marikina, Pasig, Angat, and Pampanga Rivers that drain into Manila Bay. Endocrine-disrupting compounds may have reached these rivers through domestic wastewater and industrial effluents. Water samples from the rivers were extracted by solid-phase extraction before instrumental analysis using a liquid chromatograph coupled to a mass spectrometer. The analytical method exhibited good linear response (>99% in the concentration range of 1-50 µg/L) and low instrument detection limits (0.14-1.46 µg/L) for the hormones estrone (E1), estradiol, ethinylestradiol, progesterone, and testosterone, and the industrial chemicals bisphenol A, nonylphenol, and octylphenol. Of the hormones, E1 was detected up to 11 ng/L. Bisphenol A, nonylphenol, and octylphenol were measured up to 54, 1878, and 62 ng/L, respectively. Endocrine-disrupting compounds are not yet monitored in water bodies in the Philippines and there are no local guidelines yet on occurrence, pollution prevention, and mitigation. Environ Toxicol Chem 2024;43:259-266. © 2023 SETAC.

MANILA BAY WATERSHED SCORECARD: A GIS-BASED QUANTITATIVE WATERSHED HEALTH ASSESSMENT

Abstract. Watershed health refers to the maintenance of the normal status of a watershed. With the use of Geographic Information Systems (GIS), a watershed health assessment framework was developed and applied to the Manila Bay Watershed (MBW) based on the sub-indices used by the US EPA and the Minnesota DNR. These three sub-indices were used and modified: geomorphology, connectivity, and hydrology. Geomorphology sub-index accounted for the effects of soil erosion using the Unit Stream Power-based Erosion/Deposition model (USPED). Connectivity sub-index considered the connection between habitats within three environments: terrestrial, aquatic, and riparian zone. Hydrology sub-index accounted for the effects of impervious cover and urbanization on the movement of water using three factors, namely, natural cover, tree cover, and loss of hydrologic storage. Land cover map was the most used dataset in this scorecard, where the maintained natural land covers generally received high scores and built-up areas received the lowest. The overall watershed health score of MBW is 75.713 from the mean of the three sub-indices. Pampanga River Basin, which is the largest river basin within the MBW, got the highest score of 79.462 since it consists of huge portions of maintained natural land cover. Manila River Basin, known to have dense built-up areas, got the lowest average of 60.773. On the provincial level, the province of Nueva Ecija got the highest score, and the National Capital Region (NCR) got the lowest. The developed framework successfully quantified a relative health score which can be used to rank and prioritize subwatersheds, and to measure in totality the improvement or degradation of subwatershed/s over time.

Source tracking of fecal contamination in Asian green mussels (Perna viridis) harvested in Manila Bay, Philippines by molecular detection and genotyping of Cryptosporidium spp.

Manila Bay, a multipurpose body of water located around Metro Manila, Philippines, is progressively deteriorating because of massive pollution. Reports have shown that the bay and its aquatic resources (i.e., seafood) are contaminated with fecal matter and enteric pathogens, posing a threat to public health and industry. This problem raises the need for a microbial source tracking methodology as a part of the rehabilitation efforts in the bay. Bivalve mollusks cultivated in water can serve as sentinel species to detect fecal pollution and can complement water monitoring. With the use of polymerase chain reaction and DNA sequence analysis, this study detected Cryptosporidium spp. in Asian green mussels (Perna viridis) cultivated and harvested in Manila Bay and sold in Bulungan Seafood Market, Parañaque, Philippines, from 2019 to 2021 with an overall occurrence of 8.77% (n = 57). The analysis of the 18S rDNA segment revealed three genotypes from Cryptosporidium-positive samples, namely, Cryptosporidium sp. rat genotype IV (60%), C. galli (20%), and C. meleagridis (20%). These findings suggest fecal pollution in bivalve cultivation sites coming from sewage, nonpoint, and agricultural sources. The presence of C. meleagridis, the third most common cause of human cryptosporidiosis, in mussels poses a threat to human health. Thus, there is a need to establish routine detection and source tracking of Cryptosporidium spp. in Manila Bay and to educate seafood consumers on food safety.

Molecular Identification and Phylogenetic Analysis of Bioluminescent Bacteria Isolated from Selected Marine Crustacean in Manila Bay, Philippines

Bioluminescent bacteria (BLB) are the most widely distributed light-emitting microorganisms, most of which are found as symbionts of free-living marine organisms, including the crustacean species. In this study, 4 out of 7 marine crustaceans in the northeastern section of Manila Bay were found to contain bioluminescent bacteria. Marine crustacean species namely Thenus orientalis (Oriental Slipper Lobster), Oratosquilla oratoria (Mantis Shrimp), Penaeus monodon (Giant Tiger Prawn), Litopenaeus vannamei (Whiteleg shrimp), Scylla serrata (Mud Crab), Portunus pelagicus (Blue Swimming Crab), and Charybdis feriata (Crucifix crab), were swabbed after collection. Bioluminescent bacteria were isolated from the inner surface of the carapace, eyes, abdomen, and abdominal segments of the crustacean samples. All glowing colonies were isolated and upscaled. Only bioluminescent bacteria from T. orientalis, O. oratoria, and P. monodon completed the isolation process and were identified using 16S rRNA gene sequencing for phylogenetic analysis. Furthermore, results from molecular identification through Nucleotide BLAST identified that it was Vibrio alginolyticus and Mucus bacterium. At the same time, the presence of Vibrio rumoiensis was also identified which was proved to be understudied and needs exploration. This study was aimed to identify the present bioluminescent bacteria in selected marine crustaceans in Manila Bay, Philippines through microbiological isolation, molecular identification, and phylogenetic reconstruction.

People in PowerPoint Pixels: Competing justice claims and scalar politics in water development planning

Coastal megacities all over the world face challenges related to climate adaptation, ecosystem protection and inclusive development. In response, governments develop high-level and long-term climate adaptation plans to guide coastal development. In Metro Manila, a consortium of Dutch and Philippine consultants developed the Manila Bay Sustainable Development Master Plan (MBSDMP). The planning team stressed the importance of inclusive and participatory planning, yet, the pre-set premises of the masterplan, such as the high-level and long-term planning scale and corresponding problem formulation, determined which justice claims were foregrounded in the project, disadvantaging small-scale fishing and informal settlement communities. ‘Justice’ is a contested concept. Hence, we deploy a critical theory and politics of expert knowledge lens to investigate how struggles over competing justice claims unfold in water development planning. The scalar politics as manifested in the MBSDMP planning process hides particular conceptions of justice while privileging others in congruence with the larger scale uneven political-economic development dynamics. We provide three examples of scale framing in the planning process that functioned to legitimize the contested displacement of informal settlements by pointing to economic development, disaster risk reduction, or environmental protection. Planning design choices involving scalar out-zooming enabled the uptake of these justice claims, while backgrounding the justice claims of negatively affected groups: namely, the urban poor and small-scale fishing communities. The case analysis provides conceptual-empirical insights relevant for coastal cities' grassroots and policy action platforms anticipating climate change impacts and strategizing their stance in the politics of climate adaptation planning.

Accumulation and exposure classifications of plastics in the different coastal habitats in the western Philippine archipelago

Studies consistently ranked the Philippines as one of the top contributors of plastic wastes leaking into the ocean. However, most of these were based on probabilities and estimates due to lack of comprehensive ground-truth data, resulting also in the limited understanding of the contributing factors and drivers of local pollution. This makes it challenging to develop science-driven and locally-contextualized policies and interventions to mitigate the problem. Here, 56 sites from different coastal habitats in the western Philippine archipelago were surveyed for macroplastics standing stock, representing geographic regions with varying demography and economic activities. Clustering of sites revealed three potential influencing factors to plastic accumulation: population density, wind and oceanic transport, and habitat type. Notably, the amount and types of dominant plastics per geographic region varied significantly. Single-use plastics (food packaging and sachets) were the most abundant in sites adjacent to densely populated and highly urbanized areas (Manila Bay and eastern Palawan), while fishing-related materials dominated in less populated and fishing-dominated communities (western Palawan and Bolinao), suggesting the local industries significantly contributing to the mismanaged plastics in the surveyed sites. Meanwhile, isolated areas such as islands were characterized by the abundance of buoyant materials (drinking bottles and hygiene product containers), emphasizing the role of oceanic transport and strong connectivity in the oceans. Exposure assessment also identified single-use and fishing-related plastics to be of “high exposure (Type 4)” due to their high abundance and high occurrence. These increase their chances of encountering and interacting with organisms and habitats, thus, resulting into more potential harm. This study is the first comprehensive work done in western Philippines, and results will help contextualize local pollution, facilitating more effective management and policymaking.

Bacterial composition and antibiotic resistome profile of water in the Manila Bay South Harbor

Anthropogenic activities in Manila Bay, the oldest and busiest international port in the Philippines, may cause changes in flora and fauna within its harbors. Specifically, the ballasting and deballasting of ships may accidentally introduce new populations of microorganisms, plants, and animals. Ballasting (and deballasting), or the process of carrying in/out of seawater from ship tanks in major ports/harbors, are causing major disturbances, particularly in marine ecosystems. Previous studies have shown that marine microorganisms comprise 98% of the primary production and regulation of the ocean's biogeochemical processes. However, with the continuous community disturbances due to human influence, potential marine bacterial populations with antibiotic resistomes may occur, and impact marine diversity. Since data on the microbial communities in Manila Bay South Harbor are limited, this study determined the bacterial composition and antibiotic resistome profiles of water samples from the area. Next-generation sequencing techniques and culture-based methods were utilized to elucidate the bacterial and functional diversity, as well as the antibiotic resistome of the water samples from the Manila Bay South Harbor. The bacterial diversity of the water sample was made up primarily of members of Bacteroidetes, Firmicutes, and Prevotella. The Clusters of Orthologous Group (COG) Level 1 identified metabolism as the most dominant functional predicted metagenome. The characterization of antibiotic resistance genes (ARGs) from water samples revealed that ARGs encoding resistance to multidrug was the most abundant. On the other hand, the identified antibiotic-resistant bacteria included ampicillin-resistant Escherichia coli, multidrug-resistant Klebsiella pneumoniae, ampicillin- and cefuroxime-resistant Vibrio alginolyticus and ampicillin resistant Vibrio furnissii. The above results provide a baseline marine bacterial community and antibiotic resistome profile of the Manila Bay South Harbor. This information is critical in gaining a better understanding of the potential roles of shifts in marine microbiomes, and in turn, help in developing appropriate solutions for managing the undesirable consequences of ballast water.

Land use/land cover (LULC), change detection, and simulation analysis of Manila Bay’s Dolomite mining site in Cebu, Philippines using Sentinel–2 satellite

Dolomite mining in Barangay Pugalo – Pasol, Alcoy, Cebu, and the Manila Bay beach project along Roxas Boulevard, Metro Manila, Philippines has long been controversial due to the ecological, environmental, and economic implications. From the threat of rising sea levels to questionable management solutions, this sand project cannot be fully measured because of the absence of an environmental impact study. The primary objective of this research is to develop a geospatial study of the Cebu mining site using Sentinel–2 satellite data utilizing remote sensing techniques and Quantum GIS where 2018, 2020, 2030, and 2050 classification and simulation analysis shows an increase in Soil and a decrease in Vegetation and Built-up classes. Dolomite sand sustainability and longevity in Manila Bay's Dolomite Beach, are also assessed using related literature. With the help of this analysis, it’s possible to identify specific changes and predict which land will be impacted by upcoming years when current practices in the area do not change. It can also be utilized as resource management, environmental policy, and regulation support tools in identifying ecological problems while serving as a source of historical information for future land management and support for the long-term use of natural resources and expanding populations.

Assessment of Microplastics in the Surface Water of Sitio Pulo, Navotas, Metro Manila

Microplastics are synthetic polymer particles with a length of 5 mm or less with no well-defined lower boundary. These debris particles are known to affect marine and aquatic organisms which poses a threat to biodiversity and marine resources. In this study, the isolated microplastic from the coastal and lagoon surface waters of Sitio Pulo is described. Sitio Pulo is a barrier island mangrove sanctuary located at Brgy. Tanza I, Navotas City surrounded by Manila Bay. The samples collected last July 4 and 25, 2019, were isolated, profiled, and analyzed. A total of four hundred forty-nine (449) microplastic fragments were isolated from the surface water samples with a median length of 1.096 (IQR 0.809–1.578) mm. The isolated microplastics exhibit roundness, whiteness, and yellowing indicating signs of mechanical, chemical and photodegradation. It is also noted the putative effects of the weather disturbances in accelerating the discharge of nascent microplastics in Manila Bay. The isolated microplastic composition includes the commodity polymers polyethylene (PE) and polypropylene (PP). The presence of microplastics in the surface waters of Sitio Pulo reflects the worsening plastic pollution problem in Metro Manila.

Attachment of potential cultivable primo-colonizing bacteria and its implications on the fate of low-density polyethylene (LDPE) plastics in the marine environment

Plastics released in the environment become suitable matrices for microbial attachment and colonization. Plastics-associated microbial communities interact with each other and are metabolically distinct from the surrounding environment. However, pioneer colonizing species and their interaction with the plastic during initial colonization are less described. Marine sediment bacteria from sites in Manila Bay were isolated via a double selective enrichment method using sterilized low-density polyethylene (LDPE) sheets as the sole carbon source. Ten isolates were identified to belong to the genera Halomonas, Bacillus, Alteromonas, Photobacterium, and Aliishimia based on 16S rRNA gene phylogeny, and majority of the taxa found exhibit a surface-associated lifestyle. Isolates were then tested for their ability to colonize polyethylene (PE) through co-incubation with LDPE sheets for 60 days. Growth of colonies in crevices, formation of cell-shaped pits, and increased roughness of the surface indicate physical deterioration. Fourier-transform infrared (FT-IR) spectroscopy revealed significant changes in the functional groups and bond indices on LDPE sheets separately co-incubated with the isolates, demonstrating that different species potentially target different substrates of the photo-oxidized polymer backbone. Understanding the activity of primo-colonizing bacteria on the plastic surface can provide insights on the possible mechanisms used to make plastic more bioavailable for other species, and their implications on the fate of plastics in the marine environment.

TRANSFORMATION OF THE NORMALIZED DIFFERENCE CHLOROPHYLL INDEX TO RETRIEVE CHLOROPHYLL-A CONCENTRATIONS IN MANILA BAY

Abstract. Manila Bay is one of the most significant harbors in the region, enabling commerce and trade between the Philippines and other countries. Its abundant natural resources have provided for generations of its inhabitants and have driven socio-economic development for centuries. Like other water bodies adjacent to highly urbanized cities, the increased organic and nutrient loading from untreated domestic, industrial, and agricultural wastes resulted to further degradation of its water quality. While frequent water quality monitoring is ideal, data from traditional field sampling methods might not be sufficient to assess the spatial and temporal variations of water quality in Manila Bay. Remote sensing fills the need for a frequent and full overview of the bay’s water quality. Sentinel-3 images were initially processed through the Case 2 Regional CoastColour (C2RCC) model to retrieve the remote sensing reflectance. The Normalized Difference Chlorophyll Index (NDCI) was computed for the images and were modeled against the C2RCC-derived chlorophyll-a estimates. From this, we were able to get a general equation (TNDCI – transformed NDCI) to retrieve chlorophyll-a concentrations from two reflectance bands (Oa8 and Oa11). TNDCI gave an R2 of 0.9 and RMSE = 5.12 µg/L as compared to C2RCC values, and an R2 = 0.85 and RMSE = 2.44 µg/L with field data.

SPATIO-TEMPORAL CHARACTERIZATION OF MANILA BAY USING OPTICAL WATER TYPE AND WATER QUALITY MAPPING USING SENTINEL-3 OLCI IMAGES

Abstract. Optical water type (OWT) classification provides a way to delineate surface waters according to spectral properties caused by optically active constituents. This classification is useful in mapping out spatial variability and describing changes in water quality over time as it uses inherent optical properties to discriminate areas of a water body. We used Sentinel-3 OLCI images from July 2017 to December 2020 to classify OWT in Manila Bay and to generate chlorophyll-a and total suspended matter (TSM) concentration layers using C2RCC algorithm. Nine coastal OWT classes for Manila Bay having consistent presence and spatial distribution seasonally were identified. The most dominant class, OWT 6, (3.50 µg/cm3 chlorophyll-a; 4.93 g/m3 TSM) was concentrated around the central area of the bay, covering as much as 79% of it. Chlorophyll-a and TSM concentrations were higher in the nearshore areas and were decreasing offshore. The class with the second highest concentrations, OWT 7, (9.11 µg/cm3 chlorophyll-a; 26.80 g/m3 TSM) were found near river outlets, where high nutrient and sediment loadings coming from the watershed enter the bay. Lowest concentrations (0.26–0.70 µg/cm3 chlorophyll-a; 0.64–1.10 g/m3 TSM) were found in OWT 1, OWT 2, and OWT 3, all located farthest from the shore, such as the mouth of the bay leading to the open sea. Validation using in situ observations showed that C2RCC produced relatively good estimates for chlorophyll-a concentrations of up to 12 µg/cm3 (RMSE=1.71 µg/cm3). No conclusion was drawn for TSM due to insufficient data.