Even in the harshest environments, the abyssal zones of our oceans harbor a surprising array of life. A recent study by an international team of scientists highlights that a variety of species with astonishing adaptative abilities flourishes at the bottom of the ocean, despite very unfavorable conditions. This discovery prompts a call to protect these areas, which are increasingly coveted by the mining industry.
Unexpected Findings
During an expedition off the Azores, at a depth of 1,700 meters in a site where the water is particularly acidic and loaded with heavy metals, scientists were amazed to find an “abundant fauna.” This observation suggests a significant environmental plasticity of marine species, according to the study published in the journal Scientific Reports.
Research Focus: Hydrothermal Vents
The research focused on hydrothermal vents, common in abyssal environments, located along ocean ridges. Here, in complete darkness, geysers of mineral-rich water heated to nearly 400°C erupt from the depths, gradually forming towering underwater chimneys. These environments are colonized by specific species. However, the conditions at the Capelinhos site appeared particularly toxic.
“Scientists expected to find lower diversity and different species” compared to other typically studied hydrothermal fields, states a release from the French Research Institute for Exploitation of the Sea.
Contrary to expectations, species such as mussels, shrimp, bivalves, and marine worms thrive just as well as in less extreme conditions.
Key Species: The Bathymodiolus Azoricus Mussel
Scientists especially highlight the “important role of the Bathymodiolus azoricus mussel,” which can grow up to 15 centimeters long. This “engineer species” creates small turbulences that mix the seawater, reducing the concentration of metal-rich fluids from the geysers. This process fosters a complex habitat that supports a diverse associated fauna, despite significant environmental constraints.
It’s yet another proof that the ocean depths are far from a lifeless desert, and its inhabitants even possess superpowers.
Adaptation and Energy Sources
Joan Alfaro Lucas, the study’s lead author, now at the University of Victoria in Canada, points out the surprising fact that these organisms can thrive in Capelinhos, particularly since they utilize completely different resources from the fauna of neighboring hydrothermal fields. The species at Capelinhos seem to derive their energy mainly from methane, which is abundant there, in contrast to the usual chemical components like hydrogen sulfide.
Protecting These Habitats from Mining Exploitation
Given the major environmental changes – even leading to extreme conditions – there will always be life forms capable of adapting and thriving. This resilience is crucial, especially if hydrothermal fields are to be protected from destructive human activities. The mining industry’s interest in exploiting the seabed for precious metals poses a significant threat. “The potential exploitation of these deposits could have impacts still unknown on this fauna with extraordinary adaptive capacities,” comments Jozée Sarrazin, a researcher in ecology at Ifremer.
Without a deep understanding of these ecosystems, exploitation is not justifiable. The metal extraction methods at the bottom of the oceans would be particularly devastating, akin to open-pit mining on land but conducted at thousands of meters depth.
Currently, intense discussions are underway to pave the way for these practices in international waters. The scientific community is calling for a moratorium, allowing for more research on the species inhabiting the ocean floor.
