Subscribe to our newsletter
Get the latest news, events and developments from iAtlantic, straight to your inbox.
The Robotic Cartridge Sampling Instrument (RoCSI) environmental DNA (eDNA) sampler autonomously filters seawater in situ, and preserves the DNA material from sloughed cells, scales, faeces or other material left behind in hard-to-sample marine environments down to 4,500 m deep
In 2021, RoCSI was installed on the AUV Autosub6000 and successfully deployed for the first time during the iAtlantic flagship expedition iMirabilis2 around Cabo Verde, demonstrating the ability of RoCSI to work autonomously at depth in an AUV (see Figure below). Despite some technical difficulties experienced with the AUV, there were 3 partially successful missions in total, each with very different depth profiles, successfully demonstrating the advancement of RoCSI from Technology Readiness Level (TRL) 5 to 7; 40 samples were collected from depths up to 3,400m. In 2022, an additional deep-sea deployment of the RoCSI was made in Whittard Canyon (RRS James Cook cruise 237) using a new AUV, the Autosub5. During the JC237 expedition, RoCSI was incorporated into the Autosub5 during its first ever science mission accomplishing simultaneous molecular and image surveys in the submarine canyon. In total, 60 samples were collected over different habitats in parallel with bathymetry (50 m altitude), high-resolution sidescan sonar (15 m altitude) and photography (4-5 m altitude).
To understand the natural state of marine ecosystems, there is a need to characterise biological baselines in remote environments that are often challenging to sample. Currently, environmental impact assessments of the deep-sea benthos employ imaging and acoustic technologies. However, the use of emerging technologies to facilitate genetic observations has great potential to improve baseline data, especially in environments like the deep-sea. Hence, the analysis of eDNA samples collected autonomously using the RoCSI eDNA sampler can characterise biological communities with high sensitivity and species-level accuracy without disturbing organisms in the environment, by sequencing DNA signatures from sloughed cells, scales, faeces or other material left behind. The approach can be used, for example, to monitor changes in assemblage composition, or traces of invasive species, which might be at low densities on photographic surveys.
Susan Evans, National Oceanography Centre UK (susan.evans[at]noc.ac.uk)
Main contributors: Susan Evans, Robin Brown, James Wyatt, John Walk, Daisy Tong, Christopher Cardwell, Kevin Saw, Nathan Hubot, Julie Robidart, based at the National Oceanography Centre (UK) and the Ocean Omics/Minderoo Foundation (Australia)
iMirabilis2 and JC237 expedition leads: Covadonga Orejas (IEO-CSIC, Spain) and Veerle Huvenne (National Oceanography Centre, UK)