Australian researchers ponder potential of mussel meal as fishmeal substitute in prawn diets

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© GettyImages/LazingBee (Getty Images/iStockphoto)

Green Blue Health Pty Ltd is running a study evaluating the use of mussel meal, at different inclusion levels, as a replacement for fishmeal in black tiger prawn diets.

The research is being conducted at the Bribie Island research facilities in Queensland, Australia, and is supported by a kickstart fisheries scheme run by the Australian government research agency, the Commonwealth Scientific and Industrial Research Organization (CSIRO).

Preliminary observational trials in Thailand have indicated a preference by prawns and barramundi for mussels over wild catch fishmeal, said the founders of Green Blue Health, Anthony Jacobs, who has taken on the role of MD of the company, and Karlie Wilson, its technical director. 

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Tanks used in the prawn feeding trial © Green Blue Health Pty Ltd

The company was established to supply Australian and Asian agribusiness with sustainable proteins from mussels and seaweed.

“The trial will run for six weeks and includes 10 diets to assess partial and full replacement of fishmeal. There are two control diets, the first is a commercial fishmeal diet to assess partial replacement with mussel meal and the second is a zero fishmeal diet to assess full replacement of fishmeal with mussel meal.

“We are using 40 x 100L tanks for the 10 diets which are replicated four times to provide reliable data,” Jacobs told FeedNavigator. 

The company expects to see the results early next year. “Depending on the findings and industry support, we will extend the trial to also include various seaweed options as well as locally available cereal protein options,” continued Jacobs.

Sourcing

The meal in the trial is derived from farmed mussels grown in the Marlborough Sounds, New Zealand.

Several countries are starting to build their mussel aquaculture output. “Other potential sources could include blue mussels from Australia, Denmark, Ecuador and Chile,” said Jacobs.

Is there year-long availability? “Yes, however, the mussel meal, in its dried form, is stable and can be stored for short periods.”

Processing

In terms of the challenges around processing mussel meal, getting rid of the shells can be a hurdle, but Jacobs said the meat, in this trial, is separated from the shells through the use of a high-pressure chucking machine to avoid heat and, thus, nutrient loss.

The process also involves freeze drying and non-polar lipid CO2 extraction steps.

Production value of fisheries and aquaculture in Australia was valued at $3.15bn in 2019-2020. Moreover, Australian aquaculture production increased by 11% in 2019-2020 and now makes up 38% of the total Australian seafood volume, according to a report.

Premium positioning

The secret with mussel meal lies in the nutrient density, which includes a comprehensive range of essential amino acids, vitamins, minerals, and lipids, explained Jacobs.

“We are aiming for a price per kg of our mussel meal akin to that of krill meal, which is also a premium ingredient. The price, dietary benefits of mussel meal and its low volume availability means that it should be selectively prioritized for specific vulnerable life cycle phases.”

Industry nutritionists, he said, see the inclusion of mussel meal as being particularly beneficial for the earlier growth phases.

“We see this study as opening the door for inclusion of mussel meal for a number of other aquaculture species including mud crabs, lobster and barramundi,” added Wilson.