# Environmental Assessment in Panguil and Iligan Bay, Philippines: Review and Future Perspectives

Joemar S Macalisang, Jeffrey Ken B Balangao, Ferlyn V Logronio

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## To cite this version:

Joemar S Macalisang, Jeffrey Ken B Balangao, Ferlyn V Logronio. Environmental Assessment in Panguil and Iligan Bay, Philippines: Review and Future Perspectives. Journal of Environmental Nanotechnology, 2024, 13 (3), pp.188-196. hal-04728082

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# Environmental Assessment in Panguil and Iligan Bay, Philippines: Review and Future Perspectives

Joemar S. Macalisang<fnref n="1" />,<fnref n="2" />*, Jeffrey Ken B. Balangao<fnref n="3" /> and Ferlyn V. Logronio<fnref n="4" />

## ABSTRACT

Northern Mindanao, in the southern Philippines, is known for its rich biodiversity and vital coastal ecosystems. Rapid economic growth in the region, marked by industrialization and urban expansion, raises concerns about pollution and its impact on water quality and marine life. This review deals with environmental assessments conducted in Panguil and Iligan Bay, focusing on pollutant levels and their effects on marine life. By analyzing data from sediments, phytoplankton, benthic foraminifera, seagrasses and macroinvertebrates, key contaminants affecting the region's environmental health and biodiversity were identified. Findings across various studies were integrated to provide a comprehensive understanding of contamination trends and biodiversity responses. This work emphasizes the interconnected environmental challenges in Iligan and Panguil Bay, along with the surrounding areas, urging a multifaceted approach that promotes sustainability, fills research gaps, and informs effective conservation and management strategies.

**Keywords:** Environmental assessments; Pollutants; Marine life; Panguil bay; Iligan bay.

## 1. INTRODUCTION

Northern Mindanao, located in the southern part of the Philippines, is a region renowned for its rich biodiversity and vital coastal and marine ecosystems (Jimenez et al. 2009; Orbita and Gumban, 2013; Boco et al. 2014; Metillo et al. 2015; Keith et al. 2018; Jimenez et al. 2020; Lagud et al. 2020; Sienes et al. 2022). The region, shown in Fig. 1, is currently experiencing a phase of significant economic transformation, driven by major infrastructure projects and increased industrial activity. Among these developments is the construction of a new bridge across Panguil Bay, which aims to enhance connectivity, promote economic growth, and facilitate transportation and trade across the municipalities and cities in the area. While these advancements promise substantial economic benefits, they also raise concerns about potential environmental impacts, particularly on the region's coastal and marine ecosystems.

Panguil Bay, a critical component of Northern Mindanao's coastal environment, is especially susceptible to the effects of intensified human activity and industrialization. Historically, the bay and even neighboring areas have been challenged by pollution, notably from heavy metals and other contaminants resulting from industrial discharges, and urban waste (Enguito et al. 2018; Jimenez et al. 2018; Cabili and Orbita, 2024; Enguito and Matunog, 2017; Roa, 1998). The anticipated increase in regional development and

industrial activities due to the new bridge and other economic initiatives could aggravate these environmental issues, making it imperative to assess and monitor the status of the bay's ecosystem.

<figure><img src="image_3.png" /><figcaption>Fig. 1: Northern Mindanao region or Region 10 boundary map (source: PhilAtlas)</figcaption></figure>

In addition to Panguil Bay, Iligan Bay is also of significant concern due to its proximity to various industrial operations. This bay has been identified as potentially vulnerable to pollution associated with industrialization. Previous studies have documented issues related to water quality and heavy metal contamination in Iligan Bay, raising alarms about the

<footnote n="1">¹College of Engineering and Technology, Northwestern Mindanao State College of Science and Technology, Tangub City, Philippines</footnote>

<footnote n="2">²School of Graduate Studies, J.H. Cerilles State College Pagadian-Annex, Pagadian City, Philippines</footnote>

<footnote n="3">³Department of Manufacturing Engineering Technology, College of Technology, University of Science and Technology of Southern Philippines, Cagayan de Oro City, Philippines</footnote>

<footnote n="4">⁴College of Agriculture and Environmental Studies, Northwestern Mindanao State College of Science and Technology, Tangub City, Philippines</footnote>

<footnote>Received: 13.07.2024</footnote>

<footnote>Accepted: 28.09.2024</footnote>

<footnote>Published: 30.09.2024</footnote>

<footnote>*joemar.macalisang@nmsc.edu.ph</footnote>
potential impact of continued industrial activities on the bay's ecological health (Teves, 1994; Demotica et al. 2012; Balala and Oclarit, 2007; Lacuna and Alviro, 2014; Unsing and Lacuna, 2014).

<figure><img src="image_4.png" /><figcaption>Fig. 2: Misamis Occidental boundary map (source: PhilAtlas)</figcaption></figure>

<figure><img src="image_5.png" /><figcaption>Fig. 3: Lanao Del Norte boundary map (source: PhilAtlas)</figcaption></figure>

Figs. 2 and 3 provide boundary maps of Misamis Occidental and Lanao del Norte provinces, respectively, illustrating the interconnected bays of Panguil Bay and Iligan Bay. These maps highlight the geographic focus of the study, showing the spatial relationship between these two critical water bodies and emphasizing their importance within the broader context of Northern Mindanao's coastal and marine ecosystems.

The rapid economic progress in Northern Mindanao, characterized by increased industrialization, urban expansion, and enhanced trade and tourism activities, necessitates a comprehensive evaluation of the region's coastal and marine environments. As industrial activities and infrastructure projects expand, the risk of further pollution and its impact on water quality and marine biodiversity increases. The construction of the new bridge over Panguil Bay, in particular, is expected to heighten local and regional economic activities, potentially leading to further environmental pressures.

This review aims to address these concerns by consolidating research on pollution and ecological assessments in Northern Mindanao's coastal areas, with a specific focus on Panguil Bay and Iligan Bay. This review will provide a comprehensive understanding of the current environmental status, identify emerging trends, and highlight areas that need further investigation. It is significant because it addresses the dual challenges of balancing economic development with environmental preservation. As Northern Mindanao continues to grow, it is essential to assess the potential impacts of infrastructural and industrial activities on coastal ecosystems and implement effective measures to mitigate adverse effects. It also provides valuable insights into the condition of Northern Mindanao's coastal and marine environments, aiding policymakers and stakeholders in making informed decisions that promote sustainable development while safeguarding natural resources and marine biodiversity. The integration of economic progress with environmental management is essential for the sustainable development of Northern Mindanao.

## 2. METHODOLOGY

Research papers published between 2002 and 2024 were collected for this review. The studies were chosen based on their relevance to environmental pollution, marine biodiversity, and ecological indicators in Panguil and Iligan Bay, Northern Mindanao, Philippines. Key inclusion criteria included studies on seawater quality, heavy metal and microplastics accumulation, biodiversity assessments, and pollution impacts. Data were extracted from peer-reviewed journal papers. Published review articles were also considered (Wang et al. 2013; Tian et al. 2020; Karaouzas et al. 2021; Poikane et al. 2020; Adyasari et al. 2021; Yan et al. 2021; Pinna et al. 2023). This review focused on collecting various findings related to heavy metal concentrations, microplastics, species diversity, and the health of marine ecosystems.

## 3. DISCUSSION

Previous studies conducted in Panguil and Iligan Bays consistently reported alarming presence of heavy metals in various environmental samples. These findings are supported by the presence of metals like lead, cadmium, and mercury in sediments, water, and biota. Moreover, several studies are also conducted and confirmed the presence of microplastics. The various studies linked the pollutants from diverse sources, including industrial discharges, agricultural runoff, and domestic wastewater, contributing to the degradation of these coastal ecosystems.

The ecological implications of heavy metal contamination in these bays are significant, since they can bioaccumulate in organisms, leading to adverse health effects and disruption to the food webs. These
pollutants can also impair water quality, reducing the availability of oxygen and affecting aquatic biodiversity. Furthermore, the presence of heavy metals in these coastal areas poses risks to human health, particularly for communities relying on marine resources for livelihood.

## 3.1 Panguil Bay

Recent studies conducted in the Panguil Bay and nearby areas have highlighted significant environmental concern related to pollutants and ecological health as shown in Table 1.

<table><caption>Table 1. Summary of key findings and indicators from studies in Panguil Bay and nearby areas</caption><thead><tr><td>Reference</td><td>Key Findings</td><td>Pollutants</td><td>Ecological Indicators</td><td>Location</td></tr></thead><tbody><tr><td>Enguito et al. (2018)</td><td>High heavy metal levels in seawater</td><td>Various metals</td><td>Impact on water quality</td><td>Port of Ozamiz</td></tr><tr><td>Jimenez et al. (2018)</td><td>Lead contamination in waters</td><td>Lead</td><td>Health risks</td><td>Port of Mukas</td></tr><tr><td>Cabili and Orbita, (2024)</td><td>Heavy metal accumulation in mangroves</td><td>Various metals</td><td>Mangrove health</td><td>Kauswagan, Lanao del Norte</td></tr><tr><td>Nabua et al. (2023)</td><td>Status of mangroves</td><td>Not specified</td><td>Mangrove condition</td><td>Panguil Bay</td></tr><tr><td>Lacuna et al. (2012)</td><td>Phytoplankton diversity and abundance</td><td>Not specified</td><td>Changes in diversity and abundance</td><td>Panguil Bay</td></tr><tr><td>Osing et al. (2019)</td><td>Mangrove species composition</td><td>Not specified</td><td>Mangrove species diversity</td><td>Panguil Bay</td></tr><tr><td>Fabiosa et al. (2021)</td><td>Invasive mussel Mytella strigata</td><td>Not specified</td><td>Invasive species impact</td><td>Panguil Bay</td></tr><tr><td>Villanueva et al. (2021)</td><td>Diversity of mangrove species</td><td>Not specified</td><td>Mangrove species diversity</td><td>Panguil Bay</td></tr><tr><td>Jumawan et al. (2021)</td><td>Assessment of mud crab fishery</td><td>Not specified</td><td>Mud crab fishery status</td><td>Panguil Bay</td></tr><tr><td>Dejarme et al. (2015)</td><td>Bacterial contamination in bivalves and farmed seaweed</td><td>Not specified</td><td>Fecal coliform contamination, health risks</td><td>Panguil Bay</td></tr><tr><td>Gamolo and Besagas, (2018)</td><td>Microbiological profile of cultured seaweeds Kappaphycus alvarezii</td><td>Not specified</td><td>Safe microbiological profile for consumption</td><td>Kolambugan, Lanao del Norte</td></tr><tr><td>Bonifacio et al. (2022)</td><td>Presence of Microplastics in sediments and in marine biota</td><td>Microplastics</td><td>Impact on water quality Impact on the sediments Health impacts</td><td>4 areas within Panguil Bay</td></tr></tbody></table>

Enguito et al. (2018) and Jimenez et al. (2018) found alarming levels of heavy metals, including lead, cadmium, and mercury, in seawater from the Port of Ozamiz and Port of Mukas, respectively, attributing this pollution primarily to industrial discharges and stressing the need for urgent pollution control. Cabili and Orbita, (2024) documented heavy metal accumulation in mangrove sediments. Moreover, Bonifacio et al. (2022) detected in their study conducted in 2022 microplastics in sediment samples and in the clam tissues sampled along different sites in Panguil Bay coming from fishing nets, rope materials, and food and drink wrappers/packages. Nabua et al. (2023) noted a decline in mangrove health and biodiversity due to pollution and land conversion. Lacuna et al. (2012) linked phytoplankton community changes to water quality variations, suggesting their use as indicators of environmental shifts. Osing et al. (2019) highlighted that while reforested mangroves had lower biodiversity, they were essential for ecosystem restoration. Villanueva et al. (2021) and Jumawan et al. (2021) emphasized the importance of mangrove conservation and sustainable fisheries management. Additionally, Dejarme et al.

(2015) and Gamolo and Besagas, (2019) raised concerns about bacterial contamination in bivalves and seaweeds, pointing to the need for improved food safety and aquaculture management.

## 3.2. Iligan Bay

Research studies in Iligan Bay have highlighted several critical issues related to different pollutants like heavy metals and macro and microplastics and to ecological health. This is shown in Table 2. Ganaway and Lacuna (2014) observed that pollution in Iligan city's coasts led to reduced diversity and altered community structures of benthic foraminifera, illustrating broader ecological impacts. Vicente et al. (2002) linked harmful algal blooms (HABs) in the bay to nutrient pollution from agricultural and industrial sources, emphasizing the need for effective nutrient management. Tampus et al. (2014) identified areas with severe pollution in seawater and recommended enhanced monitoring and control measures. In a related study, Tampus et al. (2013) found significant degradation of riparian vegetation due to pollution, underscoring the need for restoration efforts.
Castañeto and Lacuna (2015) noted that coastal zooplankton diversity and abundance were negatively impacted by water quality, highlighting the importance of maintaining good water conditions. Superada and Tampus (2015) confirmed that macroinvertebrates are reliable indicators of pollution levels. Balala and Oclarit (2007) found potential for bioremediation using marine bacteria from industrial effluents. Unsing and Lacuna (2014) reported significant negative effects of industrial pollution on foraminifera. Siblos and Tabugo (2024) used bacterial communities as bioindicators for mangrove health, while Recamara et al. (2015) showed that Marine Protected Areas (MPAs) improved reef fish diversity. Lacuna and Alviro (2014) documented that pollution significantly impacted the diversity and abundance of

benthic foraminifera in Iligan city's nearshore sediments, indicating their potential as bioindicators of marine environmental health. Lacuna et al. (2013) found that foraminiferal assemblages along the southeast coast of Iligan Bay reflected water quality and pollution levels, supporting their use as bioindicators for marine environmental monitoring. Overall, the studies emphasize the detrimental effects of pollution and the importance of both monitoring and conservation strategies. Several studies also detected and confirmed the presence of plastic waste specifically mesoplastics and microplastics in several biota and on the different areas within the Iligan Bay (Laput et al. 2024; Bacosa et al. 2024; Celmar et al. 2024) which causes further environmental and health concern.

<table><caption>Table 2. Summary of key findings and indicators from studies in Iligan Bay</caption><thead><tr><td>Reference</td><td>Key Findings</td><td>Pollutants</td><td>Ecological Indicators</td><td>Location</td></tr></thead><tbody><tr><td>Ganaway and Lacuna, (2014)</td><td>Benthic foraminifera diversity in polluted coasts</td><td>Not specified</td><td>Reduced foraminifera diversity</td><td>Iligan City</td></tr><tr><td>Vicente et al. (2002)</td><td>Harmful algal bloom</td><td>Not specified</td><td>Algal blooms</td><td>Iligan Bay</td></tr><tr><td>Tampus et al. (2014)</td><td>Seawater quality in stressed zones</td><td>Not specified</td><td>Quality status</td><td>Iligan Bay</td></tr><tr><td>Tampus et al. (2013)</td><td>Riparian vegetation assessment</td><td>Not specified</td><td>Vegetation quality</td><td>Iligan City</td></tr><tr><td>Castañeto and Lacuna, (2015)</td><td>Coastal zooplankton composition</td><td>Not specified</td><td>Zooplankton diversity</td><td>Iligan City</td></tr><tr><td>Superada and Tampus, (2015)</td><td>Macroinvertebrates as indicators of water quality</td><td>Not specified</td><td>Water quality</td><td>Iligan City</td></tr><tr><td>Balala and Oclarit, (2007)</td><td>Heavy metal biosorption by marine bacteria</td><td>Various metals</td><td>Biosorption effectiveness</td><td>Iligan Bay</td></tr><tr><td>Unsing and Lacuna, (2014)</td><td>Benthic foraminifera assemblages and environmental parameters</td><td>Not specified</td><td>Assemblage variation</td><td>Iligan City</td></tr><tr><td>Siblos and Tabugo, (2024)</td><td>Bacterial communities in mangrove species</td><td>Not specified</td><td>Microbial diversity</td><td>Bayug Island, Iligan City</td></tr><tr><td>Recamara and De Guzman, (2015)</td><td>Reef fish communities in Marine Protected Areas</td><td>Not specified</td><td>Fish community patterns</td><td>Iligan Bay</td></tr><tr><td>Lacuna and Alviro, (2014)</td><td>Tropical foraminiferans community structure and environmental health</td><td>Not specified</td><td>Indicators of environmental health</td><td>Iligan City</td></tr><tr><td>Lacuna et al. (2013)</td><td>Foraminiferal assemblages and sediment structure in the southeast coast</td><td>Not specified</td><td>Foraminifera as indicators of environmental health</td><td>Southeast coast of Iligan Bay</td></tr><tr><td>Laput et al. (2024)</td><td>Presence of Microplastics in edible bivalve mollusc</td><td>Microplastics</td><td>Stress to the marine life</td><td>Buruun, Iligan City</td></tr><tr><td>Bacosa et al. (2024)</td><td>Mesoplastic evidence in sandy beaches of Iligan City</td><td>Mesoplastic</td><td>Detrimental effects to the marine organism and to the environment</td><td>Beaches in Iligan City</td></tr><tr><td>Celmar et al. (2024)</td><td>Microplastics in seagrass</td><td>Microplastics</td><td>Health impacts</td><td>Iligan Bay</td></tr></tbody></table>

### 3.3. Environmental Status and Emerging Challenges

Significant levels of heavy metals reported in seawater samples (Enguito et al. 2018; Jimenez et al. 2018) from the Port of Ozamiz and the Port of Mukas due to industrial discharges, which are primary source of contamination, pose potential health risks to local communities dependent on these bays for their

livelihood. Similarly, Cabili and Orbita (2024) found heavy metal accumulation in mangrove sediments in Kauswagan, Lanao del Norte, emphasizing the critical role of mangroves in sequestering contaminants and mitigating pollution. Heavy metals are widely regarded as harmful due to their potential to accumulate in soil, water, and living organisms, leading to toxic effects on ecosystems and human health. Their persistence in the environment makes them particularly dangerous, as even
low concentrations could cause long-term contamination and disrupt biological processes (Sardar et al. 2013; Yadav et al. 2020; Jiang et al. 2021; Balangao et al. 2023; Tanjung et al. 2019; Sany et al. 2013; Witkowska et al. 2021; Mitra et al. 2022).

Nabua et al. (2023) revealed a decline in mangrove health and diversity in Panguil Bay due to pollution and land conversion, calling for conservation efforts. Osing et al. (2019) compared species composition and diversity of natural and reforested mangrove forests in Panguil Bay, finding that reforested areas had lower biodiversity but were crucial for ecosystem restoration. These studies collectively highlight the importance of conservation efforts to restore and protect mangrove ecosystems, which play a vital role in coastal resilience.

Ecological indicators such as benthic foraminifera and macroinvertebrates were used by Lacuna and Alviro (2014), Ganaway and Lacuna (2014), and Superada and Tampus (2015) to assess the health of coastal environments. Their findings demonstrated that pollution led to reduced species diversity and altered community structures, with benthic foraminifera and macroinvertebrates proving to be reliable indicators of water quality.

Microbial health and phytoplankton communities were significantly impacted by pollution (Gamolo and Besagas, 2018; Dejarme et al. 2015; and Lacuna et al. 2012). This had a cascading effect on the health of commercially important species and overall ecosystem productivity. The presence of bacterial contaminants in cultured seaweeds and commercially important bivalve species in Panguil Bay raised concerns about food safety and the need for improved management practices.

Harmful algal blooms (HABs) were another area of concern, as reported by Vicente et al. (2002), who linked the occurrence of HABs in Iligan Bay to nutrient pollution from agricultural runoff and industrial effluents. Tampus et al. (2014) and Unsing and Lacuna (2014) provided further evidence of the significant impact of industrial activities on coastal water quality and marine biodiversity, with industrial pollution leading to critical pollution levels in certain areas. Balala and Oclarit (2007) explored the potential for bioremediation using marine bacteria isolated from industrial effluents, offering a possible solution to mitigate the effects of heavy metal contamination.

Reef fish communities in Marine Protected Areas (MPAs) in Iligan Bay showed positive outcomes, as reported by Recamara and De Guzman (2015). Their study indicated that protection efforts improved fish diversity and abundance over time, demonstrating the effectiveness of conservation measures. However, the

introduction of invasive species like the mussel Mytella strigata, as documented by Fabiosa et al. (2021), poses additional challenges to local biodiversity and ecosystem stability.

Jumawan et al. (2021) emphasized the need for sustainable fisheries practices to protect valuable sea animals such as mud crabs from overfishing and habitat destruction. The findings underscore the urgent need for stringent environmental regulations, enhanced pollution monitoring, and community involvement in conservation efforts. This comprehensive assessment highlights the critical importance of balancing economic development with environmental sustainability to protect the coastal and marine ecosystems of Northern Mindanao amidst rapid industrialization and infrastructure development.

The methodologies employed by literature studies vary, with some focusing on direct measurement of heavy metal concentrations in water and sediments (Enguito et al. 2018; Cabili and Orbita, (2024), while others used ecological indicators like benthic foraminifera and macroinvertebrates (Lacuna and Alviro, 2014; Superada and Tampus, 2015). The results generally align in indicating significant pollution levels and their adverse effects on marine biodiversity, though the specific sources and impacts of pollutants differ. For instance, Vicente et al. (2002) focused on nutrient pollution and HABs, while Gamolo and Besagas (2018) examined microbial contamination in aquaculture.

A consistent trend across these studies is the significant impact of industrial and agricultural activities on coastal pollution and marine biodiversity. There is a clear need for improved pollution control and conservation measures. However, gaps remain in long-term monitoring data and the understanding of complex interactions between pollutants and marine ecosystems. Some studies, like those by Recamara and De Guzman (2015) and Fabiosa et al. (2021) highlight the effectiveness of MPAs and the threats posed by invasive species, suggesting areas for future research and action.

Plastic pollution in Northern Mindanao's coastal areas has become a growing concern, with research revealing significant contamination from both microplastics and mesoplastics. Bonifacio et al. (2022) found high levels of microplastics in sediments and marine species, such as edible bivalves in Panguil Bay, while Laput et al. (2022) observed microplastic accumulation in gastropods from intertidal zones, highlighting the widespread nature of plastic debris. Celmar et al. (2023) further demonstrated how microplastics enter the marine food web through seagrass ecosystems, threatening species dependent on these habitats. Additionally, Bacosa et al. (2023) provided the first comprehensive evidence of mesoplastics—plastic particles between 5 mm and 25 mm—in the sandy beaches of Iligan City, with higher concentrations found
near the city center and polyethylene mesoplastics being the most common. The long-term effects of these pollutants on marine ecosystems and human health remain unclear, underscoring the need for enhanced waste management, stronger regulations, and public awareness to address the escalating issue of plastic pollution.

The practical implications of these findings include the urgent need for stringent environmental regulations, enhanced pollution monitoring, and active conservation efforts to protect critical ecosystems like mangroves and coral reefs. Theoretically, these studies contribute to our understanding of the use of ecological indicators in monitoring marine health and the potential for bioremediation strategies. Effective management and sustainable practices are essential to mitigate the adverse effects of pollution and ensure the long-term health and productivity of Northern Mindanao's coastal and marine environments.

## 4. CONCLUSION

This review provided a comprehensive understanding of the current environmental status in both Panguil and Iligan Bay. It highlighted the critical need for effective environmental management strategies to address the intricate relationship between industrial activities, pollution, and ecosystem health, emphasizing the urgency to protect human health and biodiversity.

Long-term monitoring programs are essential to track changes in heavy metal contamination and other pollutants in the coastal waters of Northern Mindanao, helping to understand temporal trends and the effectiveness of pollution control measures. Further studies on the effectiveness of mangrove restoration projects, focusing on biodiversity and ecological functions of reforested areas compared to natural mangroves, are also crucial. Expanding research on the use of bioindicators such as benthic foraminifera and bacterial communities will refine their application in environmental monitoring. Investigating the socio-economic impacts of environmental degradation on local communities, particularly those dependent on fisheries and aquaculture, will aid in developing targeted and sustainable livelihood interventions.

Detailed source allotment studies to identify specific industrial and agricultural activities contributing to pollution will enable more precise regulatory actions. Exploring the interactions between local environmental stressors and broader climate change impacts, particularly how rising sea levels and changing weather patterns may exacerbate existing issues, is another critical area. In-depth studies on the impacts of invasive species on local ecosystems and developing management strategies to control their spread are necessary. Investigating innovative bioremediation techniques, such

as the use of marine bacteria for heavy metal biosorption, can lead to practical solutions for cleaning up contaminated marine environments. By addressing these areas, future research can lead to more effective and sustainable management of coastal and marine ecosystems in Northern Mindanao and beyond.

Future studies could also focus on tracking the sources and pathways of microplastics and mesoplastics in Panguil and Iligan Bays, particularly from fishing gear and packaging, to understand their distribution. Research could also assess the physiological and ecological impacts of microplastic ingestion on marine species and investigate the toxic chemicals associated with plastic debris and their effects on marine life and human health. Additionally, studies on the degradation rates of plastics in both sediment and water environments, along with long-term monitoring of plastic pollution levels, are essential for evaluating environmental persistence and the effectiveness of mitigation efforts.

Lastly, this work underlines the complex and interrelated nature of environmental challenges in the coastal regions of Northern Mindanao. Addressing these challenges requires a multifaceted approach that promotes environmental sustainability, fills existing research gaps, and considers both global and local contexts. Policymakers and stakeholders must leverage these insights to develop effective conservation and management strategies that safeguard the region's rich biodiversity and support the well-being of its communities. The forthcoming operation of the new Panguil Bay bridge and the ongoing economic progress further highlight the urgency of these efforts, ensuring that development proceeds in harmony with environmental management.

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