Chemosynthetic Ecosystems: Understanding What's at Risk and Tools for Effective Management.
Résumé
Discovery of chemosynthetic ecosystems in the 1970s changed the way we think about dynamic processes of the Earth and Ocean and about the extremes at which life can exist on this planet and elsewhere in the universe. Chemosynthetic ecosystems support organisms that rely on microbial primary production based on energy from chemical reactions, i.e., organisms with exquisite biochemical, physiological, morphological, and behavioural adaptations to their environment. Since their discovery, chemosynthetic ecosystems have served as living libraries for science stakeholders, and scientific literature on these ecosystems is abundant, of high impact, and expanding exponentially. In addition to their biodiversity and ecosystem services, a major conservation stake of chemosynthetic ecosystems is thus a type of service seldom reported in conservation studies: their knowledge value. The potential for environmental impacts resulting from scientific research at hydrothermal vents motivated the InterRidge Statement of Commitment to Responsible Research Practices at Hydrothermal Vents. While this Statement reminds scientists of their responsibilities as stewards of the environment they study, management areas that include conservation and scientific research objectives are likely more effective stewardship tools. A greater level of threat to chemosynthetic ecosystems is posed by industries that seek to mine mineral deposits at vents or engage in oil and gas extraction near seeps, and by the extensive collateral impacts of bottom fishing. Oil extraction and bottom trawling already affect large areas of potential seep habitat, and licensing activity for mining exploration around hydrothermal vent systems is underway. These activities impose urgency to establishment of guidelines for networks of managed chemosynthetic areas in regions within and beyond national jurisdiction. We present a set of design principles formulated to safeguard biodiversity, ecosystem function, and the knowledge value of chemosynthetic ecosystems within the framework of exploitation of seabed resources. The patchy distribution of chemosynthetic ecosystems in space and time requires coarse- to fine filter spatial management strategies, depending on where habitat patch distributions fall along a gradient from semi-continuous to highly dispersed across a bioregion. Because the distribution and biogeography of chemosynthetic habitats in the deep sea are still very poorly known, management plans to maintain ecological, scientific, and commercial values must be adaptive to incorporate increasing ecosystem knowledge and demand trust and collaboration among all stakeholders.