Work

Exploring the potential of well-upwelling for coral bleaching mitigation via integrated machine learning and particle swarm optimization algorithms

Year: 2025

Type: article

Abstract: Coral reefs, critical marine ecosystems threatened by escalating sea surface temperatures, demand innovative solutions to mitigate thermal stress. This study introduces a novel Well-Upwelling (WU) system that strategically injects chilled seawater to form a three-dimensional cooling umbrella over coral habitats, leveraging computational fluid dynamics (CFD), machine learning (ML), and a hybrid Particle Swarm Optimization (PSO-DPSO) framework to optimize submerged nozzle layouts and parameters. Categorical Boosting (CatBoost) were validated as superior for predicting jet dynamics, enabling efficient optimization of nozzle diameter (d0), exit velocity (u0), and discrete layouts. A Case study near Nanshan Harbor, China—where severe heat stress occurred in 2024 (DHW > 8)—revealed that tidal current velocity primarily influenced cooling efficiency, reducing the effective cooling volume (Ve) by up to 73.9% under high flows. Ambient temperature had a secondary effect, with a 0.3°C increase enhancing Ve by 7.1%. The integrated PSO-DPSO algorithm improved cooling efficiency by 17.8–46.1% compared to random layouts, identifying optimal parameters (u0 = 0.20 m/s, d0= 0.21 m) that balanced efficiency and thermal retention. Notably, the optimized system reduced the Degree Heating Week (DHW) value during the study period from 1.83 to 0.45 in the Well-Upwelling region, corresponding to a 1.38°C decrease in average temperature—below the threshold (DHW < 1) that induces visible coral stress. This work establishes a scalable, data-driven framework for hydrodynamic optimization, demonstrating the WU system’s potential to mitigate coral bleaching by effectively reducing thermal stress in dynamic marine environments.

Source: Applied Ocean Research

DOI: 10.1016/j.apor.2025.104756

Authors: Zhiyu Zou, Yonggang Zhao, Lulu Yue, Yifan Qi, Shicheng Hu, Wei Fan

Institution: Zhejiang University

Language: English

Topic: Coral and Marine Ecosystems Studies

Subfield: Ecology

Field: Environmental Science

Domain: Physical Sciences

SDGs: Life below water, Affordable and clean energy, Climate action

Open Access status: gold

Estimated APC paid: $2,950