Sensitivity of fish stock trajectories to climate forcing and human exploitation at a global scale

Abstract

Global fisheries are under increasing pressure from overfishing and climate change, threatening marine biodiversity and food security. Disentangling the impacts of these two drivers is essential for sustainable management, yet it remains a major challenge due to the complex nature of marine ecosystems. Here, we utilize a data-driven empirical dynamic modelling framework to assess causal relationships between harvest rate, sea surface temperature (SST), and the productivity of 155 fish stocks worldwide. Our analysis identifies fishing pressure as the most prevalent driver of stock productivity, with a causal link detected in 71 stocks (45.8%). SST was also identified as a significant driver of productivity in 39 stocks (25.2%). While the impact of harvest rate was stock-specific, being either positive or negative, the influence of SST was predominantly negative and, in many cases, intensified over time. These results provide empirical evidence that direct exploitation and climate warming are systematically impacting fish stock productivity, with direct exploitation emerging as the predominant driver across stocks. This predominance suggests that improved harvest management could help buffer or mitigate some of the negative impacts of climate warming on fisheries productivity.