Dr. León-Muñoz, Jorge

2025, Molinet, Carlos, Soto, Doris, Dr. León-Muñoz, Jorge, Díaz, Manuel, Espinoza, Katherine, Henríquez, Jorge, Matamala, Thamara

Chile is the world’s leading exporter of farmed mussels, with an annual harvest of about 400,000 tonnes; this production is based on the capture of wild seeds, the availability of which may be threatened by climate change and overfishing. Climate change has led to a decrease in annual precipitation, which increases the salinity of the water column and may affect the vertical distribution of mussel populations in fjords. In Reloncaví Fjord, Chile, observed changes in precipitation are reducing freshwater inputs, leading to potential shifts in the habitat and distribution of the economically important Chilean mussel (Mytilus chilensis) and a competing species, Aulacomya atra. This study analyses the vertical dynamics of mussel beds in relation to changing environmental conditions, including freshwater inputs, salinity and hydrological regimes in a fjord exploited for mussel seed collection. The results suggest that decreasing trends in precipitation could lead to increased surface salinity, reducing M. chilensis beds while favouring A. atra, with negative consequences for wild seed collection, thus threatening the Chilean mussel farming industry and predicting socio-economic consequences for small-scale aquaculture. This study also describes the increasing fishing pressure on wild mussel larvae, suggesting joint effects that cannot be disentangled with the information currently available and that represent a key challenge for the design of adaptation measures to climate change. Therefore, this study highlights the need for better monitoring of mussel beds together with seed production and oceanographic conditions, as well as improving aquaculture practices that reduce unnecessary pressure on mussel beds through seed collection in the face of changing environmental conditions.

2019, Aguayo, Rodrigo, Dr. León-Muñoz, Jorge, Vargas-Baecheler, José, Montecinos, Aldo, Garreaud, Rene, Urbina, Mauricio, Soto, Doris, Luis Iriarte, Jose

Oceanographic conditions in coastal Chilean northern Patagonia (41–46°S) are strongly influenced by freshwater inputs. Precipitation and streamflow records have shown a marked decrease in this area during the last decades. Given this hydro-climatic scenario, we evaluated the hydrological sensitivity driven by climate change in the Puelo River (average annual streamflow = 640 m3 s−1), one of the most important sources of freshwater in the fjords and inland seas of Chile’s Northern Patagonia. A lumped hydrological model was developed to evaluate the potential impacts of climate change under the Representative Concentration Pathways (RCP) 2.6, 4.5, and 8.5 scenarios in the near future (2030–2060) using the delta change method based on 25 General Circulation Models. The model was fed by local hydro-meteorological data and remote sensors, simulating well the magnitude and seasonality of Puelo River streamflow. Considering the Refined Index of Agreement (RIA), the model achieved a high performance in the calibration (RIA = 0.79) and validation stages (RIA = 0.78). Under the RCP 8.5 scenario (multi-model mean), the projections suggest that the annual input of freshwater from the Puelo River to the Reloncaví Fjord would decrease by − 10% (1.6 km3 less freshwater); these decreases would mainly take place in summer (~ − 20%) and autumn (~ − 15%). The recurrence of extreme hydroclimatic events is also projected to increase in the future, with the probability of occurrence of droughts, such as the recent 2016 event with the lowest freshwater input in the last 70 years, doubling with respect to the historical records.