A Heriot-Watt scientist has worked with colleagues at the University of Edinburgh's Roslin Institute to develop a method to detect a deadly oyster parasite without harming the shellfish.
The European flat oyster (Ostrea edulis) has seen its numbers plummet over the past two centuries due to overfishing, habitat loss and disease. They are now rare and protected in the wild.
Among the most persistent threats is Bonamia ostreae, a microscopic parasite that causes a condition known as bonamiosis, which can devastate oyster populations but is harmless to humans.
Until now, detecting the presence of the parasite has involved dissecting a sample of oysters, an approach that is not only destructive but also impractical for monitoring rare or restoration-targeted populations.
The Heriot-Watt and Roslin Institute team has pioneered a new method that uses oyster poo to screen for the parasite's DNA.
By analyzing the waste material left after holding oysters overnight in aerated seawater, scientists can determine whether any oysters are infected, without harming a single animal.
Test sites in Essex and Argyll
Lead author Dr. Tim Bean from the University of Edinburgh's Roslin Institute says the technique is a step forward for oyster conservation and aquaculture biosecurity.
Dr. Bean said, "Oysters poo contains traces of Bonamia DNA if they're infected. By sampling this material, we can screen large numbers of oysters at once without the need to sacrifice them."
The team tested the method at several sites across the UK, including Bonamia-positive waters in Essex and West Loch Tarbert in Scotland.
They found the non-invasive method was at least as sensitive as traditional tissue sampling and histology, and often more effective than water-based environmental DNA techniques.
Source - https://phys.org
