Adriana Santos-Martínez

Storm surge is one of the most destructive coastal hazards associated with tropical cyclones, yet detailed assessments remain scarce for small Caribbean islands. This study assesses hurricane storm surge flood risk in the Archipelago of San Andrés, Providencia, and Santa Catalina, Colombia, under near-past climate conditions (1980-2010) for 100- and 500-year return periods. Storm surge was simulated from a synthetic tropical cyclone dataset of 1,078 tracks; a composite risk index was then constructed by combining the hazard with a vulnerability index based on elevation, proximity to drainage and coastline, land-use, and population density. Exposed elements were identified and classified as residential, economic, functional, or ecological. Under the 500-year return period, risk affects 3.7% of San Andrés (247 elements; 178.9 ha) and 3.3% of Providencia and Santa Catalina (185 elements; 36.9 ha), with risk concentrated along the eastern and northeastern coast of San Andrés and the northern coast and inter-island isthmus of Providencia and Santa Catalina. Economic and residential elements dominate exposed assets by count (49.8% and 38.1% in San Andrés), while ecological elements, predominantly mangroves, dominate by area (89.1% in San Andrés; 80.1% in Providencia and Santa Catalina) and account for 95% of the high-risk area in Providencia and Santa Catalina. Block-level outputs (50 and 57 affected city blocks, respectively) can support coastal and the land-use planning in defining setback zones and prioritizing mangrove restoration. This study highlights the need for integrated coastal management that link community, technical modeling, spatial planning, and ecosystem preservation.

Storm surge is one of the most destructive coastal hazards associated with tropical cyclones, yet detailed assessments remain scarce for small Caribbean islands. This study assesses hurricane storm surge flood risk in the Archipelago of San Andrés, Providencia, and Santa Catalina, Colombia, under near-past climate conditions (1980-2010) for 100- and 500-year return periods. Storm surge was simulated from a synthetic tropical cyclone dataset of 1,078 tracks; a composite risk index was then constructed by combining the hazard with a vulnerability index based on elevation, proximity to drainage and coastline, land-use, and population density. Exposed elements were identified and classified as residential, economic, functional, or ecological. Under the 500-year return period, risk affects 3.7% of San Andrés (247 elements; 178.9 ha) and 3.3% of Providencia and Santa Catalina (185 elements; 36.9 ha), with risk concentrated along the eastern and northeastern coast of San Andrés and the northern coast and inter-island isthmus of Providencia and Santa Catalina. Economic and residential elements dominate exposed assets by count (49.8% and 38.1% in San Andrés), while ecological elements, predominantly mangroves, dominate by area (89.1% in San Andrés; 80.1% in Providencia and Santa Catalina) and account for 95% of the high-risk area in Providencia and Santa Catalina. Block-level outputs (50 and 57 affected city blocks, respectively) can support coastal and the land-use planning in defining setback zones and prioritizing mangrove restoration. This study highlights the need for integrated coastal management that link community, technical modeling, spatial planning, and ecosystem preservation.

Extreme weather events are increasingly disrupting mangrove forests, undermining their structure, function, and the ecosystem services they provide. Although ecosystem-based disaster risk reduction (Eco-DRR) is gaining attention, operational frameworks linking ecological processes with hurricane response remain limited, particularly in tropical island systems. This study develops a decision-oriented Eco-DRR framework that integrates ecological thresholds with hurricane response while incorporating community perspectives. It is applied to the Archipelago of San Andrés, Providencia, and Santa Catalina (Seaflower Biosphere Reserve, Colombian Caribbean), which was severely impacted by Hurricane Iota (Category 4) in 2020. The framework is built on three pillars: ecological restoration principles, adaptation to island conditions, and participatory integration of scientific and local knowledge. It comprises three components: (1) a protocol covering preparedness, response, and restoration phases; (2) a threshold-based decision pathway using indicators such as hydrological connectivity and natural regeneration capacity to determine when passive recovery or active restoration is required; and (3) a cost–benefit layer linking restoration investments to ecosystem service values. Results show that mangrove restoration must be site-specific and process-based, with active interventions justified only when ecological thresholds are exceeded. Community participation is essential for identifying priority areas and aligning actions with locally valued services. Restoration costs range from $3,000 to $1,250,000 per hectare, while ecosystem service values average about $194,000 per hectare annually, indicating strong returns. At the archipelago scale (~210 ha), long-term benefits far outweigh restoration costs. Overall, the framework advances Eco-DRR into a practical, scalable decision-support tool to strengthen resilience in mangrove-dependent socio-ecological systems under increasing climate risk.

Long-term monitoring is essential for understanding how recurring disturbances, such as hurricanes and coral bleaching, affect reef fish communities and ecosystem processes. This study evaluates temporal trends (2013–2025) in fish assemblage composition, functional diversity, and nutrient excretion proxies (C, N, and P) across three reef sites on San Andrés Island in the Colombian Caribbean. Our results reveal significant shifts in community structure following major disturbances in 2020 (Hurricanes Eta, Iota) and 2023 (mass bleaching event). Taxonomic and functional richness (TRich, FRich) fluctuated throughout the study period, whereas functional divergence (FDiv) declined earlier (2016), highlighting site-specific differences. A trait-based nutrient-excretion proxy (NPC composite score) identified key species that maintain nutrient cycling. Despite recent coral bleaching, certain sites exhibited functional resilience, sustained by the persistence of high-performing nutrient providing species. However, the overall disconnect between taxonomic recovery and functional stability suggests that ecosystem-level processes remain vulnerable, even when species richness appears to recover. This highlights the importance of integrating functional traits and nutrient recycling proxies into monitoring programs to better predict long-term variability in San Andrés Island reefs under a changing climate. Our findings provide a framework for prioritizing management efforts in the Seaflower Biosphere Reserve with emphasis on maintaining ecosystem services.

Microplastic (MP) pollution poses a significant and emerging threat to global marine ecosystems; however, regional data for the Caribbean remain limited. This study presents a spatial and temporal characterization of MPs in surface and mid-waters of the Colombian Caribbean (Atlántico and Magdalena departments), which were analyzed as independent compartments due to methodological differences in sampling strategies. Sixteen sampling stations were established across two anthropogenic influence zones: Zone 1 (nearshore/bather zone) and Zone 2 (offshore). MPs were quantified and characterized according to shape, color, size, and polymer composition using attenuated total reflectance Fourier transform infrared microspectroscopy (µATR-FTIR) and multivariate techniques. MPs were detected in 100% of samples. Surface water MP abundance was higher in Magdalena (4.5 MPs m⁻³) than in Atlántico (1.7 MPs m⁻³). Mid-water MP concentrations reached maximum values during the high rainfall season in Atlántico, reflecting localized hydrological and anthropogenic influences rather than vertical gradients. Higher concentrations were generally observed in the nearshore Zone 1 compared to offshore Zone 2, although these differences were not consistently statistically significant. Fibers and fragments were the predominant shapes, and synthetic–natural polymer blends, polyethylene terephthalate (PET), polypropylene (PP), and polyacrylic acid (PAA) were the most prevalent. Generalized Additive Models (GAM) indicated that strong fluvial inputs and proximity to urban and riverine sources were factors driving MP distribution. Additionally, the detection of polymers reported in the literature as rare and high-risk, such as acrylonitrile butadiene styrene (ABS), acrylonitrile styrene acrylate (ASA), styrene–ethylene–butylene–styrene (SEBS), and polyvinyl stearate (PVS), highlights the complexity of MP sources in the region. Overall, these results provide the first spatial and temporal characterization of MPs in the surface and mid-water of the Colombian Caribbean and identify critical contamination hotspots that warrant targeted mitigation strategies.

Climate Change (CC) is a global phenomenon with differentiated impacts. Its effects are felt in marine and terrestrial ecosystems and organisms, and in the most vulnerable economies and societies. CC is altering the ocean’s chemistry, initiating cascading socioenvironmental impacts. The fisheries sector is the most affected. In the Western Caribbean’s Archipelago of San Andrés, Providencia, and Santa Catalina, identified as having the highest climatic risk, these impacts are pronounced. This study comprehensively reviews existing knowledge on climate change effects on fishery resources and incorporates fishers’ perceptions through two rounds of surveys in 2019 and 2022. The findings reveal significant consequences for fishery resources, including alterations in biological properties and species distribution, loss of critical coastal fish breeding habitats, reduced fisheries productivity, and increased local and cross-border conflicts over fish resources. Especially, after the destructive impact of Hurricane Iota (2020), fishers shifted their hazard perception, elevating hurricanes as a significant threat alongside drought. These evolving perceptions emphasize the need for comprehensive policy strategies to address multiple hazards and their interactions, aligning with fishers’ priorities and enhancing the resilience of the fishing sector. This research underscores the urgency of ecosystem-based and co-management policies, alternatives for artisanal fishers, and heightened climate risk perception.

Insular and coastal territories like those in the Seaflower Biosphere Reserve are exposed to strong winds, waves, storms, and hurricanes. In November 2020, Hurricanes Eta and Iota provided a costly reminder of the risks facing Seaflower’s people and ecosystems. Coral reefs and mangroves are natural shields, reducing wind and wave strength during normal and extreme conditions. These coastal protection ecosystem services (ES) are vital for human safety and well-being, and become more important given the heightened vulnerability of low-lying insular islands to climate change impacts. These ecosystems also provide biodiversity refuge ES for fishes and shellfish, key for food security and resilience to global challenges like hurricanes, sea level rise, and global warming. Despite their importance, these valuable ecosystems are threatened by anthropogenic pressures, jeopardizing the survival and well-being of islanders; their restoration and recovery require improved management and decision-making, and heightened societal awareness of our dependence on marine ecosystems and their potential as climate change adaptation solutions. We identify ES provided by coral reefs and mangroves, interdisciplinary management tools, and recommendations to motivate society and decision-makers to expand efforts for the protection, restoration, and use of these ecosystems as Nature-based Solutions for climate change adaptation and mitigation in Seaflower.