Author contributions
DJJ led the design of the study along with SLJ, with assistance from MJE, who organized trace metal sampling operations for ACE Leg 1 & IN2018V_02 and all operations for IN2018V_04, BST & DCO, who designed and conducted the shipboard incubations, and ANA, who planned coring operations and conducted sediment and pore water sampling for cruise IN2018V_04. DJJ conducted seawater sampling, processed, and analyzed samples from ACE Leg 1, IN2018V_02, IN2018V_04, and Line P cruise 2012-13. SLJ conducted sampling for ACE Leg 2. DJJ processed and analyzed samples from DY110 and ACE Leg 2. MJE assisted in seawater sampling for ACE Leg 1, IN2018V_02 and IN2018V_04. BT and DO analyzed particulate samples from IN2018V_04 regeneration experiments. PN processed and analyzed samples from M77/4. DJJ and DG processed and analyzed samples from GP13. DJJ led interpretations and writing, and all authors contributed to the manuscript.