Banuet-Martínez Marina, Espinosa-de Aquino Wendy, Elorriaga-Verplancken Fernando R, Flores-Morán Adriana, García Olga P, Camacho Mariela, Acevedo-Whitehouse Karina
Unit for Basic and Applied Microbiology, School of Natural Sciences, Autonomous University of Queretaro, Queretaro, Mexico.
Department of Fisheries and Marine Biology, Centro Interdisciplinario de Ciencias Marinas, Instituto Politécnico Nacional (CICIMAR-IPN), La Paz, Mexico.
PLoS One. 2017 Jun 28;12(6):e0179359. doi: 10.1371/journal.pone.0179359. eCollection 2017.
The past decades have been characterized by a growing number of climatic anomalies. As these anomalies tend to occur suddenly and unexpectedly, it is often difficult to procure empirical evidence of their effects on natural populations. We analysed how the recent sea surface temperature (SST) anomaly in the northeastern Pacific Ocean affects body condition, nutritional status, and immune competence of California sea lion pups. We found that pup body condition and blood glucose levels of the pups were lower during high SST events, although other biomarkers of malnutrition remained unchanged, suggesting that pups were experiencing early stages of starvation. Glucose-dependent immune responses were affected by the SST anomaly; specifically, pups born during high SST events had lower serum concentrations of IgG and IgA, and were unable to respond to an immune challenge. This means that not only were pups that were born during the SST anomaly less able to synthesize protective antibodies; they were also limited in their ability to respond rapidly to nonspecific immune challenges. Our study provides empirical evidence that atypical climatic conditions can limit energetic reserves and compromise physiological responses that are essential for the survival of a marine top predator.
在过去几十年里，气候异常现象越来越多。由于这些异常往往突然且出乎意料地发生，通常很难获得它们对自然种群影响的实证证据。我们分析了东北太平洋最近的海表面温度（SST）异常如何影响加利福尼亚海狮幼崽的身体状况、营养状况和免疫能力。我们发现，在SST较高的时期，幼崽的身体状况和血糖水平较低，尽管其他营养不良的生物标志物没有变化，这表明幼崽正处于饥饿的早期阶段。依赖葡萄糖的免疫反应受到SST异常的影响；具体而言，在SST较高时期出生的幼崽血清中IgG和IgA的浓度较低，并且无法对免疫挑战做出反应。这意味着不仅在SST异常期间出生的幼崽合成保护性抗体的能力较弱；它们对非特异性免疫挑战的快速反应能力也受到限制。我们的研究提供了实证证据，表明非典型气候条件会限制能量储备，并损害对海洋顶级捕食者生存至关重要的生理反应。
