Editorial on the Research Topic Ocean Acidification in Latin America

Alberto Acosta^1,2*Joan-Albert Sanchez-Cabeza³Betina J. Lomovasky⁴Cecilia Chapa-Balcorta⁵Jose Martin Hernandez-Ayon⁶

• ¹Faculty of Sciences, Pontifical Javeriana University, Bogotá, Colombia
• ²Pontificia Universidad Javeriana, Bogotá, Colombia
• ³Universidad Nacional Autonoma de Mexico, Mexico City, Mexico
• ⁴Universidad Nacional de Mar del Plata, Mar del Plata, Argentina
• ⁵Universidad del Mar, Puerto Ángel, Mexico
• ⁶Centro de Investigacion Cientifica y de Educacion Superior de Ensenada, Ensenada, Mexico

The research compiled in this special issue reveals a mature, multidimensional scientific landscape, where diverse methodological approaches, geographical regions, and biological groups intertwine to offer a more comprehensive understanding of ocean acidification in Latin America. The emerging body of work shows a scientific community successfully transitioning from specific descriptive studies initiated in the early 21st century toward integrative research that captures the complexity of the phenomenon and its underlying physical, chemical, and biological mechanisms. This methodological evolution manifests through three complementary approaches that constitute the backbone of regional research. High-resolution environmental monitoring in the Colombian and Mexican Pacific has captured the variability of the carbonate system at daily and seasonal scales, while observational programs have been established in critical ecosystems such as Caribbean rhodolith beds. In parallel, controlled experimentation has generated fundamental knowledge of physiological stress response mechanisms, ranging from biochemical adaptations in Antarctic mollusks to differential tolerance in infaunal bivalves subjected to combined acidification and food limitation. Complementing these approaches, the advanced statistical modeling developed for the Gulf of Mexico represents a qualitative leap by enabling the spatial reconstruction of acidification parameters using Artificial Intelligence (AI) and machine learning algorithms, overcoming the limitations of traditional sampling.Geographically, the studies trace a comprehensive arc spanning the Eastern Tropical Pacific, the Caribbean, the sub-Antarctic regions and Antarctica. The Pacific emerges as an area of special interest, with seminal contributions in Colombia unraveling CO₂ dynamics during La Niña events, and Costa Rica identifying key factors for coral reef development. The Caribbean region demonstrates notable scientific productivity, with advances in understanding rhodolith beds as potential biogeochemical refuges, and studies from Puerto Rico on the impact of Sargassum influx, and tri-national capacity assessments.The biological dimension of the research effort spans from organismal responses to ecosystem dynamics. Mollusks emerge as a paradigmatic study group, with research ranging from physiological responses in Antarctic snails to tolerance studies in Chilean infaunal bivalves. Benthic ecosystems receive special attention, particularly Caribbean rhodolith beds and Pacific reef systems, while planktonic communities are indirectly addressed through their relationship with CO₂ fluxes in the southwestern Atlantic and the Colombian Pacific.The studies' temporality evidences growing methodological sophistication, articulated across three complementary scales. Short-term, high-resolution investigations capture hourly and daily variability in the carbonate system in specific scenarios, while seasonal-scale studies unravel intra-annual cycles in systems subjected to ENSO events, upwelling, seasonal rainfall, and river discharge. Long-term initiatives, coupled with regional capacity assessments, lay the foundations for sustained monitoring programs and propose roadmaps for scientific development in the coming decades. Exploring innovative financing mechanisms, such as blue carbon credits, could provide a sustainable funding source for these critical long-term efforts. The relevance and significance of these findings are considerably magnified when contextualized within the broader panorama of contemporary Latin American ocean acidification (OA) research. This region possesses an exceptional diversity of marine systems that serve as unique natural laboratories for studying ocean acidification under extreme and variable environmental conditions. From the planet's most productive upwelling systems and estuarine coastal zones to extensive tropical river mouths and complex Mesoamerican reef systems, Latin America -spanning the Gulf of Mexico, the Caribbean, and the Atlantic and Pacific Oceans-offers a complete spectrum of conditions for understanding how ocean chemistry responds to multiple climatic and oceanographic forcings.However, this environmental richness and complexity are accompanied by a significant and persistent scarcity of systematic, long-term data, a fundamental limitation that has begun to be addressed through visionary collaborative initiatives. The creation of research networks like the tri-national network for the Gulf of Mexico (Cuba, Mexico, and the U.S.) to address the socioeconomic and ecological impacts of open and coastal acidification; the strategic formation of the GOA-ON Caribbean Hub, the Latin American Ocean Acidification Network (LAOCA), which reached its 10 th anniversary in November 2025, and the Research Network of Marine-Coastal Stressors in Latin America and the Caribbean (REMARCO) represent crucial and well-oriented efforts to overcome historical barriers of technical capacity, limited infrastructure, inefficient scientific communication, and insufficient funding that have characterized regional marine research for decades.Innovative research on the southwestern Atlantic shelf and the Colombian Pacific underscores the critical need for this collaborative approach, revealing that the spatial and seasonal variability in CO₂ fluxes is too complex for conventional large-scale climate models to capture with sufficient accuracy. Collectively, these studies illustrate a regional scientific community undergoing rapid growth and maturation, one that is beginning to produce robust, context-specific data essential for understanding the unique interplay between global stressors and local drivers that characterize our seas. The studies presented in this special issue not only advance our knowledge but also critically illuminate the specific gaps that Latin America must overcome. These works represent a fundamental step in transitioning from a general diagnosis of ocean acidification to the development of applied solutions and informed policies. One of the most profound challenges is inequality in scientific production. The aforementioned network initiatives are vital strategies to counteract structural disparities. These networks promote equity in knowledge generation, standardize methodologies, and strengthen regional governance. However, persistent challenges include: technical and legal barriers to inclusive participation, the development of open-access databases and knowledge exchange platforms, and the need to incorporate considerations of food security, livelihoods, equity, transparency, and public participation. Growing pollution and massive Sargassum events underscore how organic carbon fluxes exacerbate coastal acidification. Addressing this requires closing the gap between science and action through robust policies. It is fundamental to understand that acidification is a problem directly driven by CO₂, and that technological solutions like Solar Radiation Management (SRM) cannot directly address ocean acidification (Williamson and Guinder, 2022). SRM, which seeks to reflect sunlight to cool the planet, does not reverse the ocean chemistry altered by CO₂ and could even redistribute acidity to greater depths. Therefore, the primary solution is the decarbonization of our economies and a drastic reduction in CO₂ emissions (Hoegh-Guldberg et al., 2023). Promoting a circular economy and implementing Integrated Coastal Zone Management (ICZM) and the restoration of blue carbon ecosystems are essential tools for this transition, transforming scientific evidence into regulatory action. Concurrently, research into marine Carbon Dioxide Removal (mCDR) techniques is accelerating. These include ocean nutrient fertilization (with N, P, Fe); macroalgal cultivation and sinking; direct ocean capture; ocean alkalinity enhancement via electrochemical or other means; ecosystem restoration; and artificial upwelling-downwelling. It is critical to note that all of these potential solutions require extensive validation, risk assessment, and scaling studies before deployment. Furthermore, implementing ethical and regulatory frameworks is essential to mitigate potential ecological risks associated with new research and technologies (mCDR). The scarcity of historical data in the region is a critical barrier. Long-term time series, like those from the ESTOC station in the North Atlantic, are invaluable as they confirm that the surface ocean is actively absorbing anthropogenic carbon and undergoing acidification, with trends accelerating in recent decades (Pérez et al., 2023). Statistical modeling depends on these sustained observations for validation. It is imperative to scale up monitoring effortspotentially funded through diverse sources including private investment (e.g., carbon credits), philanthropy, and government and academic grants-to capture the complex interaction dynamics within Latin American coastal zones, where river inputs, upwelling, and extreme climate events create a mosaic of acidification conditions. Understanding these interactions is essential for refining global predictive models.