‘Farmed’ mussels are actually wild Mussels that are gathered when they are young and encouraged to grow on man-made structures. This suspension method typically uses ropes to collect and grow mussels in open oceans or bays—the same waters as their wild counterparts. The main difference between them? Monitored suspension growth keeps mussels off the ocean floor and reduces their mortality rates. Both these benefits are transferred to the consumer: cleaner and less-gritty mussels results from little ocean floor contact and higher survival rates means cheaper costs.
Now the ever-apparent question regarding any form of farmed food—what’s the environmental impact? Good news—mussels IMPROVE the environment. Mussels feed on naturally occurring and abundant phytoplankton, therefore no manmade feed is required and NO CHEMCIALS are added. Mussels are filter feeders, which means they REDUCE the impacts of pollution. Agricultural runoff and pollution increase nitrogen and phosphorus levels, which in turn increases the phytoplankton population. More mussels feeding on plankton means natural plankton levels can be maintained.
Furthermore, harvesting off of suspension systems is easy and leads to no habitat damage or destruction. On the flip side, wild Mussels are dug up and scraped off rocks during harvest, impacting the natural habitat. Another environmental positive—the potential for cross-contamination with wild, native species is nearly non-existent.
We wouldn’t being doing our job if we didn’t mention any potential drawbacks. Over-populated farms can lead to increased waste, but farms are highly regulated by numerous sustainability and environmental councils.
If that doesn’t convince you, about 90% of worldwide shellfish consumption (mussels, oysters and clams) is farmed shellfish.
A little more detail:
The life-cycle of farmed mussels—begins in late spring as wild mussels begin to naturally spawn. Collector lines (such as buoy floated rope) sit in the water and collect mussel larvae. By fall, the mussels are large enough to be collected for socking, a processes by which the mussels are placed inside a long casing, similar to a nylon or sock. Here, the mussels can equally compete for nutrients, eventually moving to the outside of the sock and causing the sock to collapse into a rope in the center of a mussel column. After approximately two years in the water, the mussels are harvested, cleaned and packaged—sometimes resting in salt-water tanks between cleaning and packaging.