UK researchers conduct DNA tests to detect early presence of invasive species in water

With the help of a technique developed by scientists from the University of Southampton, Bangor University and the National Oceanography Centre, the artificially introduced species could help in detecting non-native species within the coastal waters of Southern England.

During the study, a worm named Cephalothrix simula, was found to be especially fatal for the human body, as it contains neurotoxins. The particular species was found in the North West Pacific Ocean.

For the experiment, researchers gathered samples of water and sediment from four marinas around the UK. The samples were then analysed and the DNA of every sample was examined to determine the presence of species in the ecosystem.

According to the results, organisms leave traces of their DNA through various means. For instance, a fish may lose its scales, while many others can release eggs and sperms during the spawning season. By means of the new technique, the team was able to extract the genetic material. Also known as the environmental DNA (eDNA), the samples were then compared to the global DNA databases in order to identify the existence of these species.

“We are enormously excited about the potential for eDNA in the detection of invasive species. This initial work gives us confidence that the technique could be invaluable both for catching invasions early on and also for monitoring the success of eradication efforts,” according to Luke Holman.

The research draws attention to the fact that there are many species which arrive on the shores, which are not native to the UK. These can be carried on ship hulls and in ballast water tanks and further from one international harbor to another.

Based on the results, 18 non-indigenous species were identified across four sampled marinas, which includes Anglesey, the Bristol Channel, the River Blackwater and Southhampton Water. Furthermore, it was observed that the Cephalothrix simula worm was not previously detected during the study carried out in the UK in May 2017, although it was found in Cornwall, the next year. The experts noted that if the invasive species were not caught early on, it would have devastating effects on the country’s native wildlife habitats.

“We know that the muddy flats of Southampton water and the Solent area provide a great deal of food for foraging birds so we should be worried about any species with an ability to change the sediment,” Holman added.

The eDNA metabarcording surveys are becoming increasingly popular in the process of biodiversity monitoring, but the detection of invasive species has stayed limited, until the introduction of the recently discovered technology. As a result, the team further hopes to extend the monitoring of non-invasive indigenous species and their presence in natural resource agencies both in the UK and also elsewhere.