The blooms of Alexandrium catenella, the main producer of paralytic shellfish toxins worldwide, have become the main threat to coastal activities in Southern Chile, such as artisanal fisheries, aquaculture and public health. Here, we explore retrospective data from an intense Paralytic Shellfish Poisoning outbreak in Southern Chile in Summer–Autumn 2016, identifying environmental drivers, spatiotemporal dynamics, and detoxification rates of the main filter-feeder shellfish resources during an intense A. catenella bloom, which led to the greatest socio-economic impacts in that area. Exponential detoxification models evidenced large differences in detoxification dynamics between the three filter-feeder species surf clam (Ensis macha), giant barnacle (Austromegabalanus psittacus), and red sea squirt (Pyura chilensis). Surf clam showed an initial toxicity (9054 µg STX-eq·100 g⁻¹) around 10-fold higher than the other two species. It exhibited a relatively fast detoxification rate and approached the human safety limit of 80 µg STX-eq·100 g⁻¹ towards the end of the 150 days. Ecological implications and future trends are also discussed. Based on the cell density evolution, data previously gathered on the area, and the biology of this species, we propose that the bloom originated in the coastal area, spreading offshore thanks to the resting cysts formed and transported in the water column.

Harmful algal blooms of toxin-producing microalgae are recurrent in southern Chile. Paralytic shellfish poisoning (PSP) outbreaks pose the main threat to public health and the fishing industry in the Patagonian fjords. This study aims to increase understanding of the individual and spatial variability of PSP toxicity in the foot of Concholepas concholepas, Chile’s most valuable commercial benthic invertebrate species, extracted from the Guaitecas Archipelago in Chilean Patagonia. The objective is to determine the effect of pigment removal and freezing during the detoxification process. A total of 150 specimens (≥90 mm length) were collected from this area. The live specimens were transferred to a processing plant, where they were measured and gutted, the foot was divided into two equal parts, and pigment was manually removed from one of these parts. The PSP toxicity of each foot (edible tissue) was determined by mouse bioassay (MBA) and high-performance liquid chromatography with fluorescence detection and postcolumn oxidation (HPLC-FLD PCOX). The individual toxicity per loco, as the species is known locally, varied from 95%), neoSTX and GTX2. The removal of pigment produced a reduction in PSP toxicity of up to 90% and could represent a good detoxification tool moving forward. The freezing process in the muscle with pigment did not produce a clear pattern. There is a significant reduction (p < 0.05) of PSP toxicity via PCOX but not MBA. Furthermore, the study discusses possible management and commercialization implications of the findings regarding small-scale fisheries.

The study investigates the implementation and functioning of the Productive Development Committee (CDPR) pilot plan in Biobío Region. The objective is to identify facilitators and obstacles during the launching of an institutional design towards decentralization. Methods consist of in-depth interviews to key informants. Results suggest the early functioning of CDPR faced a problem of legitimacy among those in charge of applying the reforms. The research highlights the need to reinforce multilevel coordination, as a key factor of decentralization public policy design. At the subnational level, a high evaluation of bottom-up approaches was observed, which is not necessarily grounded in the assessment of associated benefits and risks. Findings shed light on important aspects that should be observed during the implementation of institutional reforms towards territorial decentralization in Chile and elsewhere.

Harmful algal blooms (HABs) represent a critical environmental challenge for coastal social-ecological systems, generating risks to human health, livelihoods, food security, and ecosystem services. The unprecedented 2016 HAB crisis in southern Chile, triggered by the northward expansion of the paralytic toxin-producing dinoflagellate Alexandrium catenella , caused extended fishing closures and severe socio-economic disruptions across artisanal fishing communities in the Los Lagos and Los Ríos regions. Despite effective monitoring and management systems that largely prevented human poisoning, previous research has highlighted persistent challenges related to trust, participation, communication, and the integration of local knowledge in HAB governance. To examine these social and relational dimensions, this study analyzes community narratives of the 2016 HAB crisis through a social capital lens, drawing on 64 participants engaged in five participatory workshops conducted in the rural coastal villages of Mississippi, Huiro, Bahía Mansa, Pasaje Amortajado, and Carelmapu. Using a participatory elicited letter-writing approach, we collected and analyzed narratives associated with bonding, bridging, and linking social relationships to: (1) document how participants represented the impacts and consequences of the HAB crisis; (2) examine how social relationships were described and attributed meaning in participants’ accounts; and (3) explore the implications of these narratives for understanding adaptive capacity, community resilience, and future HAB governance. The results portray HABs as protracted socio-environmental crises marked by economic disruption, emotional distress, dietary changes, and interpretations of environmental change. Bonding narratives emphasized family support, intergenerational knowledge, and cultural continuity. Bridging narratives highlighted the circulation of experiential warnings, environmental observations, and calls for collective organization among fishing communities. Linking narratives expressed concerns regarding institutional transparency, communication, and participation in environmental governance. Across all three dimensions, the letters transformed memories of the 2016 crisis into future-oriented reflections, communicating lessons, concerns, warnings, and recommendations directed toward future generations and future HAB events. The findings demonstrate the value of interpreting community narratives through a social capital lens for understanding how coastal communities experience, remember, and interpret environmental crises. By revealing the social resources, collective memories, and future-oriented reflections embedded in local narratives, this study contributes to discussions of adaptive capacity and community resilience while highlighting the potential of participatory narrative approaches to inform more legitimate, participatory, and adaptive HAB governance.