Study gives first insights into the stress response of a jellyfish to global warming

The world’s underwater communities, despite their vast expanse, remain largely unexplored and inadequately studied. However, a recent publication in Nature Communications provides initial insights into the stress response of deep pelagic jellyfish to global warming and the sediment mounds induced by deep-sea mining. The study was conducted by the GEOMAR Helmholtz Centre for Ocean Research Kiel.

According to the study, the primary environmental stressor for deep-sea organisms is the disruption associated with commercial mining for resources on the seafloor. Mining operations disturb the seafloor by extracting fine sediment, creating suspended sediment ‘clouds’ along the seafloor, which extend for tens to hundreds of kilometers throughout the water column.

Dr. Helena Hauss, co-first author of the study and Research Director of Marine Ecology at the Norwegian Research Centre (NORCE), highlighted the significance of the midwater, emphasizing its role in the global ocean’s capacity to store carbon and its importance as a food source for various marine species.

Due to the complex nature of determining stress in jellyfish, the study adopted a multi-faceted approach, investigating their response through physiology, gene expression, and the microbial symbionts on the jellyfish’s exterior, as explained by Vanessa Stenvers, co-first author of the study and a doctoral candidate at GEOMAR and the Smithsonian Institution.

During the study, jellyfish exhibited gene expression related to respiration, innate immunity, and wound repair in response to higher sediment treatments, indicating increased stress. With climate projections estimating a one-degree rise in sea temperatures over the next 84 years, the authors express concern about the potential starvation of jellyfish due to increased energy expenditure resulting from human activities such as deep-sea mining. This increased stress, as observed in the helmet jellyfish, could lead to heightened energy needs that may not be met due to the generally scarce food availability in the deep sea, ultimately resulting in starvation.