Clipperton Atoll, Eastern Tropical Pacific
January-February 2022
Expedition Goals and Summary
In collaboration with the S/Y Acadia, Nic Duprey and I led an expedition to Clipperton Atoll, an extremely remote island at the southwestern edge of the oxygen minimum zone, in order to collect coral cores, coral tissue samples, and seawater samples.. The principal goal of this work is to understand the past evolution of the oxygen deficient zones of the Northern Tropical Eastern Pacific, and to use this information to extrapolate how these zones may change as the ocean continues to warm. We collected more than 10 coral cores, 100 coral tissue samples, and 25 seawater samples. This work represents a key aspect of a larger project that we are leading: reconstructing the history of the oxygen deficient zones of the entire Northern Tropical Eastern Pacific. Eventually this work will allow for the reconstruction of the history of the area going back across the 20th century, and will provide key data for modelling future changes in oxygen concentrations in the area.
A surprising finding from this expedition was that we observed massive bleaching (>70%) of the deep reefs at Clipperton across the entire southern edge of the island. This bleaching was likely a result of cold temperature stress on the reef as a result of wind-driven shallowing of the thermocline. In our travels we have been to other coastal reefs that experience upwelling of cold waters, but we have never observed such widespread bleaching.