CAR 2022 – Dissertation by Lauren Geiser

The deep-sea is the largest continuous ecosystem on Earth, yet it remains one of the least understood by scientists. Exploitation of the deep-sea takes several forms including commercial fishing and, in the near future, mining. Bottom trawling is a destructive, nonselective fishing method that is well established globally. Consequently, its environmental impacts have been well studied. Deep-sea mining (DSM), on the other hand, has not yet begun commercially, but is expected to commence in both national and international waters within the next few decades. Since no large-scale seabed mining has yet taken place, its environmental impacts remain uncertain. This thesis explores the similarities of deep-sea bottom trawling (DSBT) and DSM to determine if the well-known environmental impacts of DSBT can be used to predict those of DSM. Methodologies are compared, as well as the biotic and faunal aspects of their respective ecosystems. It is likely that the environmental effects of DSBT can and should be used in assessing the impacts of DSM. Because full-scale in situ testing remains challenging and expensive for submarine mining, this insight may prove helpful in establishing preliminary regulations and environmental protections for DSM.