A groundbreaking thesis by NIOZ marine biologist Coral Diaz-Recio Lorenzo, set to be defended at Utrecht University on January 26, reveals a wealth of biodiversity in hydrothermal vents and manganese nodule fields in the deep oceans, surpassing initial expectations.
The research emphasizes a critical message echoed by marine ecologist Sabine Gollner of NIOZ – the need for extreme caution before endorsing commercial deep-sea mining in these mineral-rich habitats.
Diaz-Recio Lorenzo's Ph.D. research delves into copepods collected from hydrothermal vents in the Lau Basin, near Tonga, using advanced underwater robots. These small, shrimp-like creatures dominate the vents, and samples were meticulously gathered from various locations within the basin.
DNA analysis uncovered isolated populations with minimal interaction, even among those from different basins. Surprisingly, specimens that looked alike from more distant basins were genetically distinct, challenging conventional species categorization.
The study's second phase explored manganese nodules from the Clarion Clipperton Zone, depths of 4,000 to 5,000 meters in the Pacific Ocean. Diaz-Recio Lorenzo found that these nodules housed diverse communities, with individual counts ranging from 10 to an astonishing 200-plus individuals of nematodes, copepods, and other species.
Notably, animals specific to nodules were absent in sediment samples collected around them, indicating a unique relationship. Some creatures even utilized nodules as reproductive habitats, as evidenced by discovered eggs.