Seabed Mining Could Significantly Impact Benthic Boundary Ecosystem

A study by oceanographers at the University of Hawaiʻi at Mānoa has provided the first in-depth look at an enormous but poorly understood region of the global ocean, the abyssal benthic boundary layer, which lies a few meters above the seafloor.

This zone has only been sampled a handful of times, and the study revealed a dynamic community that may be more sensitive to seasonal changes than previously understood. The research, published in Limnology and Oceanography, also concluded that deep-sea mining could have significant and unavoidable impacts on biodiversity, regardless of the time of year.

“Given the remoteness of this environment, we have extraordinarily limited knowledge of the animals that inhabit this zone,” said Gabrielle Ellis, lead author of the study and recent oceanography graduate from the UH Mānoa School of Ocean and Earth Science and Technology. “This study represents a significant contribution to our understanding of the benthic boundary layer community, and it starts to unravel temporal dynamics in the abyss.”

This community of organisms, like much of the deep-sea ecosystem, is reliant on organic material that falls from the surface ocean down to great depths.

Using seawater pumps attached to a structure that descends to the seafloor, the