Tropical Oceanographic Research Frontiers

Abundance and Characterization of Microplastics in Marketed Edible Salt from a Coastal Region of South Sumatra, Indonesia

Fri, 19 Jun 2026 00:00:00 +0000

Microplastic contamination in food products has become an increasing environmental concern due to its widespread occurrence in marine and coastal ecosystems. Edible salt, a commonly consumed marine-derived product, has been recognized as a potential pathway of human exposure to microplastics. This study investigated the occurrence, abundance, and physical characteristics of microplastics in commercial table salt marketed in Sungsang Village, Banyuasin Regency, South Sumatra, Indonesia. Two locally marketed salt brands were analyzed using density separation, vacuum filtration, and microscopic examination. Microplastic particles were characterized according to their shape and size distribution. Microplastics were detected in all samples, with abundances ranging from 513 to 587 particles/kg. Fragments were the predominant particle type. Most particles were within the 50–300 μm size range, indicating that small-sized microplastics constituted a substantial proportion of the contamination. Based on average salt consumption rates, consumers may have been continuously exposed to microplastics through their daily consumption of salt. The presence of microplastics in all analyzed samples indicated that contamination could have occurred throughout the production and distribution chain of commercial salt. These findings contributed to the growing body of evidence regarding microplastic contamination in edible salt and highlighted the importance of routine monitoring and improved plastic waste management in coastal environments to reduce contamination of food products.

Blue Economy Development in ASEAN: Opportunities, Challenges, and Pathways Toward Ocean Sustainability

Rogelio A. Cruz, Maria Elena P. Santos — Wed, 14 Oct 2026 00:00:00 +0000

The blue economy has emerged as a strategic framework for reconciling ocean-based economic development with marine ecosystem conservation and social well-being, particularly in maritime regions such as Southeast Asia. As one of the world’s most ocean-dependent regions, the Association of Southeast Asian Nations (ASEAN) possesses extensive marine resources that support fisheries, marine tourism, shipping, offshore energy, and emerging marine biotechnology industries. This review critically synthesizes the development, governance, challenges, and future prospects of the blue economy across the ten ASEAN member states. A total of 40 peer-reviewed journal articles published between 2010 and 2024 were systematically reviewed and organized into four thematic areas: (i) the sectoral composition and economic contribution of blue economy activities; (ii) policy, institutional, and governance frameworks; (iii) environmental and socioeconomic constraints; and (iv) emerging pathways toward sustainable and inclusive ocean-based development. The synthesis indicates that ASEAN’s ocean-based sectors collectively generate an estimated USD 360–380 billion annually, demonstrating their substantial contribution to regional economies. However, their long-term sustainability remains constrained by fragmented governance, marine ecosystem degradation, unsustainable resource exploitation, uneven institutional capacity, and inequitable distribution of economic benefits. Significant differences among member states further highlight the need for context-specific national strategies supported by stronger regional coordination. Future blue economy development should prioritize integrated ocean governance, sustainable blue finance, technological innovation and transfer, ecosystem-based management, and meaningful participation of coastal communities. Strengthening these mechanisms would enable ASEAN to move beyond sector-driven ocean exploitation toward a more resilient, inclusive, and environmentally sustainable blue economy while accelerating progress toward Sustainable Development Goal 14 (SDG 14: Life Below Water) and the broader 2030 Agenda.

Plankton Ecology in the Philippines: Diversity, Dynamics, and Ecological Significance Across Tropical Marine and Freshwater Ecosystems

Maria Kristina L. Reyes, Eduardo B. Metillo — Wed, 14 Oct 2026 00:00:00 +0000

Plankton communities in the Philippines occupy a critical ecological position in one of the world's most biologically diverse marine regions. Situated within the Coral Triangle and traversed by the Western Pacific Warm Pool, Philippine waters support extraordinary phytoplankton and zooplankton assemblages that regulate primary production, mediate carbon fluxes, and sustain the productivity of pelagic and coastal fisheries. Yet these communities are shaped by complex interactions among the Southwest and Northeast Monsoons, seasonal upwelling, El Niño–Southern Oscillation (ENSO) events, eutrophication, and the proliferation of harmful algal blooms (HABs), particularly Pyrodinium bahamense var. compressum causing paralytic shellfish poisoning across coastal provinces. This review synthesizes published knowledge on phytoplankton diversity, zooplankton assemblage structure, HAB ecology, nutrient–plankton interactions, and the roles of plankton in biogeochemical cycles within Philippine marine and freshwater ecosystems. We further evaluate the impacts of eutrophication in enclosed bays such as Manila Bay and Laguna de Bay, coastal upwelling dynamics in the Visayas and Mindanao Seas, meroplankton contributions to larval connectivity, and emerging threats from climate change and land-based pollution. Knowledge gaps, monitoring priorities, and research directions including molecular approaches, autonomous sensing, and citizen science are identified. Integrative and long-term ecological research on Philippine plankton is urgently needed to support evidence-based marine spatial planning, fisheries management, and coastal conservation policy.