RT journal article T1 Chlorophyll-α forecasting using LSTM, bidirectional LSTM and GRU networks in El Mar Menor (Spain) A1 González Enrique, Francisco Javier A1 Rodríguez García, María Inmaculada A1 Ruiz Águilar, Juan Jesús A1 Carrasco García, María Gema A1 Enguix, Ivan Felis A1 Turias Domínguez, Ignacio José A2 Ingeniería Industrial e Ingeniería Civil A2 Ingeniería Informática K1 chlorophyll K1 machine learning K1 deep learning K1 LSTM K1 Mar Menor K1 eutrophication K1 GRU AB The objective of this research is to develop accurate forecasting models for chlorophyll-α concentrations at various depths in El Mar Menor, Spain. Chlorophyll-α plays a crucial role in assessing eutrophication in this vulnerable ecosystem. To achieve this objective, various deep learning forecasting techniques, including long short-term memory, bidirectional long short-term memory and gated recurrent uni networks, were utilized. The models were designed to forecast the chlorophyll-α levels with a 2-week prediction horizon. To enhance the models’ accuracy, a sliding window method combined with a blocked cross-validation procedure for time series was also applied to these techniques. Two input strategies were also tested in this approach: using only chlorophyll-α time series and incorporating exogenous variables. The proposed approach significantly improved the accuracy of the predictive models, no matter the forecasting technique employed. Results were remarkable, with values reaching approximately 0.90 for the 0.5-m depth level and 0.80 for deeper levels. The proposed forecasting models and methodologies have great potential for predicting eutrophication episodes and acting as decision-making tools for environmental agencies. Accurate prediction of eutrophication episodes through these models could allow for proactive measures to be implemented, resulting in improved environmental management and the preservation of the ecosystem. PB Oxford University Press SN 1367-0751 YR 2024 FD 2024 LK http://hdl.handle.net/10498/39367 UL http://hdl.handle.net/10498/39367 LA eng DS Repositorio Institucional de la Universidad de Cádiz RD 21-sep-2026