Orpheus: The First Steps Towards Exploring Ocean Worlds

Bikini Atoll: Into The Atomic Abyss

<div><span>This expedition focused on obtaining valuable field samples for studying climate change and coral reef ecosystems in an important but understudied part of the world&rsquo;s oceans. Identifying long-term patterns of climate variability is critical for determining the causes of current shifts, and thus predicting potential climate change in the future. Documenting century-scale climate oscillations in the Western Pacific Warm Pool (WPWP) is particularly important for understanding natural climate variability around the globe. Tropical corals, with rapid growth rates and annual banding in their carbonate skeletons, provide ideal archives for well-dated paleoclimate records that extend back several centuries. During this expedition, we recovered the first long coral records from Micronesia that will allow us to identify century-scale climate variability in the important WPWP region.</span></div>

Approach & Findings

Mission Overview

<p><span>This expedition also provided the opportunity to investigate coral reef ecology and coral health in relatively remote and pristine regions across Micronesia. This research is essential, given that corals around the world are declining due to local environmental degradation and large-scale climate change. The team collected coral reef survey data, together with coral tissues and water samples, from across a broad area with gradients of island size and human population. Diversity and abundance of coral communities appear to reflect population density on the islands, possibly due to local fishing pressure on herbivorous fish. Analysis of the microbial and molecular lipid composition of coral tissues provides insight into the functioning of the coral symbiont system in both healthy and stressed (diseased or bleached) samples. During the expedition, coral reef ecological surveys revealed the first instance of cyanobacterial infection of crustose coralline algae, and documented the new expansion of the range of White Plague Disease into the western equatorial Pacific.</span></p>

Coral Core Drilling