Data from: Breaking out of the comfort zone: El Niño-Southern Oscillation as a driver of trophic flows in a benthic consumer of the Humboldt Current ecosystem

The trophic flow of a species is considered a characteristic trait reflecting its trophic position and function in the ecosystem and its interaction with the environment. However, climate patterns are changing and we ignore how patterns of trophic flow are being affected. In the Humboldt Current ecosystem, arguably one of the most productive marine systems, El Niño-Southern Oscillation is the main source of interannual and longer-term variability. To assess the effect of this variability on trophic flow we built a 16-year series of mass-specific somatic production rate (P/B) of the Peruvian scallop (Argopecten purpuratus), a species belonging to a former tropical fauna that thrived in this cold ecosystem. A strong increase of the P/B ratio of this species was observed during nutrient-poor, warmer water conditions typical of El Niño, owing to the massive recruitment of fast-growing juvenile scallops. Trophic ecology theory predicts that when primary production is nutrient limited, the trophic flow of organisms occupying low trophic levels should be constrained (bottom-up control). For former tropical fauna thriving in cold, productive upwelling coastal zones, a short time of low food conditions but warm waters during El Niño could be sufficient to waken their ancestral biological features and display massive proliferations.

物种的营养流（trophic flow）是反映其在生态系统中营养级位置与功能、以及与环境相互作用的特征性状。然而当前气候格局正发生改变，我们对营养流格局正如何受到影响仍缺乏认知。洪堡洋流生态系统（Humboldt Current ecosystem）堪称全球生产力最为旺盛的海洋生态系统之一，厄尔尼诺-南方涛动（El Niño-Southern Oscillation）是该系统年际及更长时间尺度变率的主要驱动源。为评估该变率对营养流的影响，我们构建了针对秘鲁扇贝（Argopecten purpuratus）的长达16年的单位体重体细胞生产速率（P/B）序列；该物种属于起源于热带的动物类群，却在这一寒冷生态系统中得以繁衍。在厄尔尼诺典型的营养盐匮乏、水温偏高的环境条件下，该物种的P/B比显著升高，这源于快速生长的幼贝大量补充入种群。营养生态学理论预测，当初级生产受营养盐限制时，占据低营养级的生物的营养流应受到上行控制（bottom-up control）。对于在寒冷且生产力旺盛的沿岸上升流区繁衍的起源于热带的类群而言，厄尔尼诺期间短暂的食物匮乏但水温偏高的环境，足以唤醒其祖先的生物学特征，进而表现出大规模种群增殖。