eDNA in the Cornish blue

Project Overview

Environmental DNA (eDNA) is genetic material that is shed from macro-organisms. Recent years have seen the piloting of eDNA barcoding in British marine waters. This project looks to collect pilot data from Cornish coastal marine environments to describe the spatial behaviour of blue, thresher & porbeagle sharks and their main teleost prey

Additionally, to make the most impactful use of the efforts of researchers and citizen scientists alike, we will be investigating the wider marine biodiveristy, expanding our target species beyond the elasmobranchs of regional interest, using qPCR to look for eDNA from other marine species. 

Fisheries and tour independent data is rare in this region, resulting in an unknown true abundance and diversity for marine vertebrates, and invertebrates. This study looks to be one of the first to fill this gap, using novel non-invasive approaches. 

This project is based at the Centre of Ecology and Conservation, at University of Exeter Penryn campus, and works with the Genner Lab at the University of Bristol. The project is partly funded by a grant from Exeter Marine. 

Study Area

The area of interest is the pelagic sub-tidal waters off of Cornwall and the Isles of Scilly (UK), shown in this image as the blue shaded area. 

Between April and October 2023, we worked with local tour operators, citizen science sailors, and government entities, to collect samples at points across the southwest - you can see the locations in the map. 


Samples of sea water will be collected either in sterilised litre water bottles (slide image 1), before being filtered and processed using qPCR techniques; or in protoypic sampling technology called 'Metaprobes' (slide image 2). 

To compare both methods of collection, we use species-specific qPCR approaches to quantify the amount of DNA from focal species in each sample. We will use this data to (1) address the efficacy of the protoypic samplers against the industry-standard method of water bottle collection and Sterivex filtration; and (2) answer questions regarding the spatiotemporal dyanmics of species distributions in the southwest UK. 

Prof. Martin Genner & Andrew Saxon at the University of Bristol have been instrumental in helping define the project protocol and facilitating the processing of samples. 

Research Questions

Further work will look to explore punctuated increases in detected abundances of these sharks and fish. 

And concurrent work in this project is deploying and testing a novel method of eDNA sampling - the Metaprobe 2.0, not our creation but a collaborators (check it out here). We will be looking to cross-validate the Metaprobe 2.0 with BRUVs in the Isles of Scilly; and with water bottle sampling off of Cornwall. 

Our 2023 in review!

I'll let the graphic speak for itself, but we had a productive year of sampling and outreach, and look forward to continuing the trend in 2024.

Project funding provided by Exeter Marine (2023/24).

Novel tech with vast implications: Metaprobe 2.0

The Metaprobe 2.0 is a piece of equipment developed at Liverpool John Moore University by Stefano Mariani and Guilia Maiello (GitHub Repo). The Metaprobes are 3D-printed spheres which are deployed with gauze-wrapped cotton, to collect eDNA from water which can passively flow through the holes in the sphere. 

This method of sampling is an order of magnitude cheaper than the traditonal water bottle sampling. Based on collaborators work testing the Metaprobes against a trawl survey, there is good evidence that the Metaprobes will perform as well, if not better, than traditional waterbottle methods. 

In this project, we will test the Metaprobes against traditional water bottle sampling and baited remote underwater surveys in Cornwall and the Isles of Scilly. If we can establish the veracity of eDNA detection via Metaprobe sampling, this work will be very impactful as this method of eDNA sampling and extraction is comparatively more accessible, and could therefore be adopted globally as the new industry standard for eDNA research in the marine environment. 

Outreach and Citizen Science

This project is allowing me to engage with the local and visiting Cornish community. For 2023, the project is working with over 6 different local operators, and a growing number of citizen science sailors. 

If you are planning a journey to/from the Isles of Scilly, or around the offshore waters of Cornwall between April and November, please do get in contact using the Form below. 

Citizen Scientists & Metaprobes

Most of our citizen scientists have and will be sent out with Metaprobes, as they are a far more accessible method of collecting eDNA samples from the marine environment than traditonal water bottle sampling, do not require filtration in the field, and require only a small bags amount of kit. 

Here are some materials we have made for those interested and partaking in our research using Metaprobes. 

Protocols & Social Media

You can find project updates and 'Behind the Science' videos and posts on TikTok and Instagram @marinemollyk.

Many of our protocols and materials are available on the project's GitHub.

PLease follow the links on the embeds to find these resources! 

Thank you to our participatng wildlife tour operators, citizen scientist sailors, and funders.