Is eating farmed mussels more sustainable than veganism?

19 November, 2019 by
John Susman

When talk of seafood sustainability gets heated, some punters open up faster than new-season mussels, only the rhetoric is not soft and sweet, it’s often a wave of emotions that gets in the way of the science.

Seafood sustainability is a complex discussion. As landdwellers who barely dip our toes in the deep blue, we have little else to rely on but our emotions, perceptions, and at times, blurred lines of debate.

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Of course, there is one seafood that naturally comes to the surface as one of the most sustainable options on the planet — farmed mussels.

In fact, a study by the Ecological Society of America declared eating farmed mussels may even be a greener option than veganism.

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A member of the invertebrate mollusc family, including clams and oysters, they differ to more developed molluscs such as the octopus, which is not only more mobile, but evolved significantly, too.

Mussels, like clams and oysters, are sessile (immobile) and replicate plants as they filter nutrients from water.

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Here in Australia, we are blessed with the small, sweet and soft luxury of the blue mussel (Mytilus galloprovincialis), the likes of which are farmed in Spring Bay, Tasmania, and in the cold, nutrient-rich waters of the Great Southern Ocean that flows into Boston Bay, Port Lincoln, South Australia.

Farmed mussels are actually environmentally benign. In fact, their cultivation has a net benefit for the marine environment in which they are produced. Farmed mussels do not require feed. As filter feeders, their role is to filter some 20 litres a day of plankton, algae and whatever else comes their way.

There’s no land erosion, fertilisers or freshwater used; they produce an omega-3 rich meat and they’re cleaning up the oceans. They’re like the mate that gets up early after an all-night house party and cleans your house before you’ve risen from your slumber. They’re the magic genies of the deep blue!

In Boston Bay, mussel brood stock the size of a human head sit deep on the ocean floor and release their spawn each June.The spat floats through the water column until it can find a substrate to attach itself to.

The tiny hairs known as the byssus thread (which we have come to refer to as ‘beards’) have miniscule suckers on the end of them, which help the spat attach to rope, and it is on these ropes in Boston Bay where mussels get to work.

They’re grown on longlines, about 6m into the water column, but above the seafloor to prevent bottom-dwellers such as crabs prizing them open for a snack.

It’s here in the water column of Boston Bay where the South Australian blue mussels filter the water, day in, day out until harvest time the following year.

Once harvested, they’re cleaned, de-byssused and vacuum-packed alive in oxygensaturated seawater as ‘pot ready’ for market.

They’re cheap, versatile, soft and sweet — and greener than the grass around a fire hydrant.

But don’t take my word for it. They’re accredited as a Friend of the Sea and the National Association for Sustainable Agriculture Australia, too.

If you want to make a sustainable choice, choose farmed South Australian mussels. You know it makes sense!

Image: Nick Karvounis