Environmental baseline study adopting omics approach in deep-sea mining scenario

Abstract

The underwater minerals were first discovered in the 1870s but interests towards them raise recently due to the shortage in terrestrial metal resources. Capturing of these underwater minerals, which consist of an economically attractive amount of iron, copper, platinum, and rare earth, etc, are regarded as deep-sea mining activities. However, these minerals resources often associated with a unique deep-sea habitat. For instance, the polymetallic nodules are most abundant in the abyssal plain, cobalt curst only precipitate in low current velocity affecting seamounts and seafloor massive sulphide correlated with the hydrothermal vent activities. These deep-sea habitats were the common heritage of human society and precious resources in both paramedical, environmental, sociological, and economic aspect as they hold an extraordinary of biological community of their own. The removal of the underwater minerals would greatly impact these associating communities and hence affecting the ecosystem of the deep sea. Based on sustainable development, the impact of mining should be minimized to the deep-sea ecosystem. To achieve that, the United Nations had established the International Seabed Authority (ISA) to license all contracts for exploitation and exploration of seabed mining activities beyond national waters, where most of the minerals resource deposits. The ISA requires a comprehensive Environmental Impact Assessment (EIA), which includes processes of screening, scoping, baseline study, risk assessment, and mitigation, before any proposed commercial deep-sea mining activities. However, the baseline study of deep-sea mining remains incomplete. The deficiency in baseline condition hinders the predictions of the resilience and recovery of the deep-sea organisms, leading to no underwater minerals’ exploration projects authorized by ISA to avoid irreversible damage to the deep-sea ecosystem. Therefore, to collect the missing information in the deep-sea habitat, this thesis work proposed an omics approach for baseline studies. A comparative proteomics study of in situ copper exposure and a genetic study applying metabarcoding techniques. The results from the proteomics work suggested a deep-sea bioindicator candidate, Abyssorchomene distinctus, and potential corresponding biomarker proteins such as Na⁺/K⁺ ATPase, cuticle, chitinase towards copper exposure. Meanwhile, the genetic study performs on vent crab, Austinograea rodriguezensis, shown the potential of using environmental DNA as a source of metabarcoding in deep-sea biodiversity assessment. In short, this thesis work provides insights into the omics approach to conduct baseline studies in deep-sea mining EIA context.

Date of Award	2020
Original language	English
Awarding Institution	The Hong Kong University of Science and Technology