Report by ocean scientists Angelika Brandt, Julia Swigart, and Elva Escobar
The original Challenger voyages in the 19th Century unfortunately did not reach the higher latitudes of the Pacific. However, Challenger’s legacy continues to inspire explorers to all places where the deep-sea fauna is poorly known. This July, we embarked on a mission to the north Pacific in Dutch harbor (Unalaska, Aleutian Islands, Alaska, USA) on the German research vessel RV Sonne for the AleutBio (Aleutian Trench Biodiversity Studies) expedition. Our mission is to study the biodiversity associated with the soft sediment floor and deep-water column both within the Aleutian Trench and along the canyon’s north and south ridges.
AleutBio contributes to the UN Decade for Ocean Exploration in close collaboration with the Challenger 150 project and coordinates with DOSI (The Deep Ocean Stewardship Initiative). In addition to conducting our scientific program, we update a daily blog for public outreach and occasionally post on Instagram @aleutbio (when the ship’s internet allows).
Mission to the Deep
Our sampling during this six-week expedition is designed to shed light on the distribution of marine organisms and contribute to our understanding of changes in biodiversity and its distribution in the North Pacific, the gateway to the Arctic. AleutBio (SO293) is analysing seafloor organisms of all sizes (protists, meio-, macro- and megafauna) in addition to conducting biogeochemical studies, in the eastern Bering Sea as well as in the abyssal and hadal areas of the eastern Aleutian Trench. We plan to describe biodiversity, highlight biogeographic relationships, and examine species connectivity with the Arctic Ocean and Kuril-Kamchatka Trench in times of rapid climate change. Bathymetric mapping will be used to explore the bottom topography to define the most appropriate location for instrument deployment.
We plan to compare our new biological samples from the eastern Aleutian Trench with the biological samples from the sampling areas of previous expeditions, KuramBio I and II, and from previous Russian expeditions. That work will include integrative taxonomic work on key species that may be critical to understanding and clarifying relationships. In addition, we will use standard molecular techniques as the basis for phylogeographic surveys and connectivity studies, as well as state-of-the-art genomic techniques to integrate the data into in-depth phylogenetic analyses.
We have already completed the first two weeks of research, uncovering some satisfying results and unexpected surprises from the deep seafloor. Here are a few highlights!