Oysters are considered to be a culinary delicacy, but a new piece of research has found that 85% of all oyster reefs have been lost globally.
We're all familiar with the fact that overfishing is a problem, but this research has pointed out another marine ecosystem that's in trouble. Michael Beck and his colleagues estimated the condition of 144 bays and 44 ecoregions across the globe, based on current oyster productivity compared to historical records of catch, and aerial size estimates of the oyster reefs. In many places, historical records suggest that oysters had been abundant in the past - I mean, now oysters are considered to be a rather posh and fancy thing to eat, but they used to be so abundant that they were considered poor man's food.
They found that the condition of 70% of the bays and 63% of the ecoregions they studied was 'poor', which meant they had lost between 90 and 99% of their original abundance. They also found that, especially in Europe and North America, 37% of the oyster reefs were functionally extinct - suffering losses of over 99%. And it;s not just the oyster populations themselves that are suffering - they are important for the rest of the ecosystem too, filtering the water, providing food and the reefs themselves provide a structure and habitat for other species to live on. So when the oysters are lost, the whole ecosystem is in trouble.
The paper also goes on to suggest some conservation techniques that could be employed to help preserve reefs - some of the least affected reefs they studied were in ecoregions where there were marine management systems in place. So they suggest schemes like protected areas, managing the fisheries more closely, and even attempting to restore reefs as well.
So even though it's a worrying picture, there are some possible ways to improve the situation.