Connections to the deep sea: an interdisciplinary approach to ocean change past, present, and future

• Main Author: Fish, Carina R.
• Other Authors: Hill, Tessa M
• Format: Thesis
• Language: English
• Published: eScholarship, University of California 2022
• Subjects: Biogeochemistry; Environmental justice; Chemical oceanography; Ocean acidification
• Online Access: https://escholarship.org/uc/item/3wh4g5mr; https://escholarship.org/content/qt3wh4g5mr/qt3wh4g5mr.pdf

The deep sea is often thought of as removed from terrestrial and nearshore processes. Despite imaginaries of discontinuity, connecting seemingly separate systems informs us on how best to relate to far, or not easily accessible, regions. Such expansive views of interconnections aid in the holistic understanding of whether and how to manage areas both far and near. Toward this, I first illuminate the surface-deep connections through the biogeochemical history of deep sea coral organic skeletons off of North-Central California that reflect overlying surface water processes over the past century. I then investigate the chemical oceanographic changes of the overlying surface waters within the past decade, and attend to the accelerating geopolitical tensions of the deep sea due to demands on land. I document a shift in coral isotopic signatures over the 20th century and modified surface and subsurface waters over the past decade. I present evidence for changes in upwelling with implications for both deep water communities and surface ocean acidification during marine heatwaves. Lastly, I will show the utility of incorporating multiple perspectives to inform 1) the contextualization of deep sea mining, 2) ongoing deep sea mining discussions, and 3) the selection of the overarching goal i.e. centering climate justice rather than green futures.