The deep benthos is simultaneously the largest and least explored ecosystem on the planet. Covering nearly 60% of the Earth’s surface, it supports an almost unimaginable reservoir of biodiversity, rivaling all terrestrial habitats combined. Its microbial and metabolic diversity have revolutionized our view of how life is sustained, not once, but twice (first with the discovery of chemoautotrophic organisms at hydrothermal vents, and again with the discovery of cognate communities at methane cold-seeps). In spite of these major discoveries, the deep benthos is essentially invisible. Only a select few will ever witness it first hand, while for the rest, it will remain a dark and unfathomable abyss.
This places the deep benthos in a precarious position. Human activities that influence the deep sea go unnoticed. Without a thorough understanding of its ecology, it is impossible to assess the damage caused by anthropogenic impacts. Although recent and ongoing studies have shed light on many species and communities, the deep benthos remains largely unexplored. Two studies, both released this week, reveal simultaneously how little we know about the deep benthos and how human impacts, even unintentional ones, could shape this ecosystem.