Among the species identified is a worm originating from the North West Pacific Ocean which includes neurotoxins that are potentially fatal if they enter the human body.


The researchers, led by Luke Holman, a PhD student at the University of Southampton collected water and sediment from four marinas around the UK and analysed the DNA of each sample to conclude which species had been present in each ecosystem.

Organisms leave traces of their DNA in water systems through a variety of mean. The team extracted this genetic material, known as environmental DNA (eDNA), and compared it to global DNA databases to identify the presence of species.

Luke Holman explained:

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

There are many ways in which species that are not native to the UK arrive on its shores. They can be carried in ballast water tanks or on ship hulls from one international harbour to another, something especially common in places like Southampton. They can also hitch a lift on live fish stocks and oysters imported for British fish farms.

Overall, the team identified 18 non-indigenous species across the four sampled marinas (Southampton Water, Anglesey, The Bristol Channel and River Blackwater). The worm had not been previously detected in the UK when this study was conducted in May 2017 although it was found in Cornwall the following year.

The researchers also found other introduced species, such as an Asian date mussel, and another type of worm known as Paranais frici. If not caught early, invasive species can damage native wildlife habitats.

According to UK's National Oceanography Centre, eDNA metabarcoding surveys are more and more common in biodiversity monitoring, but their use for the detection of invasive species is still limited. This study, published in the journal Scientific Reports, is the first of its kind in the UK.

The team now aspires to provide guidance for routine monitoring of non-indigenous species to natural resource agencies both in the UK and elsewhere.

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