Data from: Climate and fishing steer ecosystem regeneration to uncertain economic futures

Overfishing of large predatory fish populations has resulted in lasting restructurings of entire marine food webs worldwide, with serious socio-economic consequences. Fortunately, some degraded ecosystems show signs of recovery. A key challenge for ecosystem management is to anticipate the degree to which recovery is possible. By applying a statistical food-web model, using the Baltic Sea as a case study, we show that under current temperature and salinity conditions, complete recovery of this heavily altered ecosystem will be impossible. Instead, the ecosystem regenerates towards a new ecological baseline. This new baseline is characterized by lower and more variable biomass of cod, the commercially most important fish stock in the Baltic Sea, even under very low exploitation pressure. Furthermore, a socio-economic assessment shows that this signal is amplified at the level of societal costs, owing to increased uncertainty in biomass and reduced consumer surplus. Specifically, the combined economic losses amount to approximately 120 million € per year, which equals half of today's maximum economic yield for the Baltic cod fishery. Our analyses suggest that shifts in ecological and economic baselines can lead to higher economic uncertainty and costs for exploited ecosystems, in particular, under climate change.

全球范围内对大型掠食性鱼类种群的过度捕捞，已致使整片海洋食物网发生持久性重构，并引发了严重的社会经济后果。所幸的是，部分退化的海洋生态系统已显现出恢复迹象。生态系统管理面临的一项核心挑战，便是预判生态系统恢复的可行程度。本研究以波罗的海为案例，通过构建统计食物网模型开展分析，结果表明：在当前的温度与盐度条件下，这片已遭受严重破坏的生态系统已无法实现完全恢复，反而将朝着新的生态基准态演替。即便在极低捕捞压力下，这一新的生态基准态仍呈现出如下特征：作为波罗的海商业价值最高的渔业种群，鳕鱼的生物量更低且波动幅度更大。此外，社会经济评估结果显示，由于生物量不确定性上升以及消费者剩余减少，上述生态变化带来的社会成本还会进一步放大。具体而言，年度综合经济损失约达1.2亿欧元，这一数值相当于当前波罗的海鳕鱼渔业最大经济产量的一半。本研究的分析结果表明，生态与经济基准态的转变，会让被开发利用的生态系统面临更高的经济不确定性与成本，在气候变化背景下这一现象尤为突出。