Guide to translocating coral fragments for deep-sea restoration

Corals in rocky deep-sea environments are foundation species postulated to enhance local diversity by increasing biogenic habitat heterogeneity and enriching local carbon cycling. However, deep-sea corals are highly vulnerable to disturbances (e.g., trawling, mining, and pollution) and are threatened by expansive changes in ocean conditions linked to climate change (e.g., acidification, warming, and deoxygenation). Once damaged by trawling or other disturbances, recolonization and regrowth of deep-sea corals may require centuries or longer, highlighting the need for their stewardship. To this end, the sustainability of deep-sea corals may be enhanced not only by protecting existing communities, but also by repopulating disturbed areas using active restoration methods. We recently reported one of the first studies to explore applied methods to restore deep-sea coral populations by translocating coral fragments of multiple coral species using translocation modules (Boch et al. 2019). Branches of deep-sea corals were collected by remotely operated vehicle (ROV) from 800–1300 m depth off central California and propagated into multiple fragments at the surface. These fragments were then attached to translocation modules (“coral pots”) using two different attachment methods and placed in the same habitat to assess their survivorship (n=113 total fragments, n=7 taxa, n=7 deployment groups). Survivorship per year ranged from 0 – 100% depending on coral taxon and type of attachment method. Given relatively high survivorship among 5 out of 7 taxa studied, this report provides a more detailed step-by-step guide for fabricating coral translocation modules and for processing coral fragments from multiple taxa for deep-sea coral translocation. New survivorship data are provided as well, from new observations of translocated corals since the original publication, along with new insights from additional efforts focused on Sibogagorgia cauliflora husbandry. 2020 NOS (National Ocean Service) ONMS (Office of National Marine Sanctuaries) CoRIS (Coral Reef Information System) Submitted Public Domain 1936