What is the Native Oyster?
The European Flat Oyster (Ostrea edulis) is the indigenous oyster of Europe and is often called the Native oyster.
It has an oval or pear-shaped shell with a rough, scaly surface. The two halves (valves) of the shell are different shapes. The left valve is concave and fixed to the substratum, the right being flat and sitting inside the left. The shell is off-white, yellowish or cream in colour with light brown or bluish concentric bands on the right valve. The inner surfaces are pearly, white or bluish-grey, often with darker blue areas.
Why the Native Oyster?
Oysters are fantastic marine creatures, an individual animal can filter up to five litres of water per hour.
They use their gills to both breathe and feed. They inhale water and sort the particles from the water column. Small hairs on their gills called cilia then migrate those particles down towards their mouths. Inedible particles are bound into mucus known as pseudo-faeces, which is rejected.
As a result of this activity, oysters draw all sorts of elements from the water column and deposit them on the sediments, which as a result improves water clarity. Oysters are therefore our seas’ most effective water filters.
But there is more to the story than just that. In addition, Oyster also provide habitat for other marine life. They create nursery habitat for fish and crabs and provide small animals shelter from larger predators.
In essence, oysters can be considered to be ‘Ecosystem Engineers’, and play a vital role in the protection of fragile marine ecosystems.
Why do we need Native Oyster Restoration?
There is a challenge to be faced because despite the fact that oysters are amazing ‘Ecosystem Engineers’ they themselves are under threat.
Over time the growth of the human population has resulted in overfishing, physical damage to benthic habitats, pollution and eutrophication.
Worse was to come in 1979 when the disease Bonamia ostreae was detected in Native oyster populations in France, Spain and Denmark. This parasite can cause over 90% mortality among oysters, when initially introduced into a naïve population. Bonamia has continued to spread throughout Europe and further damage the populations of Ostrea edulis.
As a result, in order for all us to share in the benefits these wee creatures can deliver we need to help them by restoring their reefs.
What is Native Oyster Restoration?
These are projects designed to help restore functioning Native oyster reefs to sites that have long since gone extinct, or that have been severely damaged.
There is a pan European body NORA (The Native Oyster Restoration Alliance) that has been set up to help foster a coordinated European effort to help this species. This organisation is hugely important as it allows everybody involved in the effort to share experiences and learnings in what is a major undertaking.
What is our role?
At some point, and it is difficult to say exactly when it happened, our business has become entangled in all these efforts to save this precious creature.
Yes, we are still a food production business, but something has changed and now everything we do is done in relation to the Native oyster.
From a practical point of view, we are the key supply chain producer for the Glenmorangie DEEP project, which aims is to restore a Native oyster reef to the Dornoch Firth in front of the distillery. We are currently on growing tens of thousands of juvenile oysters for this effort.
We are also involved in other small scale restoration efforts, and in a much more major project to create a Native Oyster ‘ARK’. The goal of this effort is save the remaining wild Scottish populations and their distinct genetic profiles.
It is deeply satisfying to be more than just another oyster farming business, and we hope that our small contribution together with all the efforts of many others can create a real and lasting positive change for the Native oyster.