Innovation and aquaculture
by Ioannis Zabetakis, Alexandros Tsoupras and Ronan Lordan, University of Limerick, Ireland
"Last November, the Round Table on Responsible Soy Association (RTRS) held a workshop, outlining how feed producers can produce Aquaculture Stewardship Council (ASC)-certified feed. The event, organised with Salmofood, brought together 50 leaders, interested in incorporating the RTRS principles and criteria into their value chains to promote sustainable soy.
From an environmental perspective, the ASC has recognised the RTRS certification standard for soy as the most comprehensive standard available, especially with regard to the environment."
This piece of news highlights that there is an increasing need in the aquaculture sector for affordable and sustainable fish feeds. The dimension of sustainability is a crucial one. If we think that up to 50 percent of aquafeeds consist of fish oil and that fish oil, being originated from wild fish (sardines) isn"t a sustainable component, there is an ever increasing demand for plant/vegetable oils to replace, at least, partially, fish oil in fish feeds.
Since 2004, at the University of Limerick, we have been working on how to increase the sustainability of aquaculture and the nutritional value of sea bream, sea bass and salmon. We focus on how to produce sustainable fish feed for the production of sea bass and sea bream (Sparidae and Moronidae) and we have developed a novel (European-patented) fish feed for the families of Sparidae and Moronidae, enriched with polar lipids originated from the by-product of the olive oil industry, called olive pomace. Olive pomace is a rather cheap, but excellent, source of polar lipids with strong anti-thrombotic activities.
This innovative fish feed containing olive pomace (in a range from 3.1% to 7.7% of the weight of the fish feed) is rich in polar lipids with strong anti-Platelet Activating Factor bioactivities. Platelet Activating Factor (PAF) is a potent inflammation mediator in our bodies; if we consume, in our diets, foods rich in anti-PAF bioactivities, inflammation and the onset of atherosclerosis in our body is reduced.
The novel fish feeds that we have patented includes between three-to-seven percent of olive pomace per 100 grams of fish feed, depending on the fish species. This novel fish feed has been studied in the aquaculture production of sea bass and sea bream and it was found that the polar lipids with strong anti-PAF actions have been incorporated in the flesh of the final fish produced (sea bass and sea bream)!
In the patent, all the feeding information is given on how the fish flesh has been enriched with the beneficial polar lipids of olive pomace. The combination of the lipid biological activity of fish and olive by-products resulted in a functional food that can provide the appropriate nutrients (bioactive polar lipids) that can reduce the risk for cardiovascular diseases (CVDs) and other inflammation-related chronic disorders, in the context of a balanced diet.
In addition, such valorisation of olive by-products in fish feed can also provide beneficial environmental and economic impact and increase the sustainability of aquaculture by decreasing our dependence on fish oils.
Organic farmed salmon is also another sustainable source of high nutritional value against atherosclerosis and CVDs. Organic farmed salmon is produced, using a diet containing only organically-approved natural ingredients from sustainable sources. All ingredients are GMO free.
Fish are reared in large pens, which allow them to follow their natural shoaling behaviour, pens contain less than 10kg/m3 cubic metre – less than half of that of conventional farms. The organic production sites of such farming are continuously flushed with clean water, preventing any build-up of parasites or pollutants. This natural, healthy environment and low population density allows the fish to develop good muscle tone and body shape.
Recently, we have shown that Irish organically-farmed salmon is an excellent, rich source of highly bioactive polar lipids, with strong antithrombotic activities and, thus, cardio-protective properties. Incorporation of such a sustainable and functional fish, to a healthy dietary pattern, can reduce the risk of chronic disorders.
In addition, Atlantic organically-farmed oily fish species, such as salmon, seem to be sustainable sources of functional bioactive compounds (i.e. anti-thrombotic polar lipids) and we study them into developing novel food supplements, nutraceuticals and drugs, aiming to reduce the risk of inflammation-related disorders, such as atherosclerosis and CVDs, cancer, renal disorders and neurodegenerative disorders.