Several projects funded by the EU are prioritizing the development of sustainable aquatic feeds.
WISEFEED, which started this year, will examine the metabolism of farmed fish and develop an aquafeed that combines plant and marine ingredients in order to get the most efficient growth while lowering aquaculture’s dependency on wild fish.
\"Wild fish stocks used to be the basis of the raw material (of aquafeeds) and have gradually been replaced by plant ingredients. This effort needs to be continued so wild stocks are managed in a sustainable way and they are not exploited as aquaculture continues to increase,\" said Ivar Rønnestad, Professor in Environmental Physiology at the University of Bergen, Norway and coordinator of WISEFEED.
However, \"Fish need protein to grow and the challenge with plant protein and other alternative ingredients is that some of them have anti-nutrients while the nutrient composition and quality is not fully sufficient for growth,\" he added.
To find the most sustainable feed for a variety of species, WISEFEED is carrying out dietary experiments in Portugal, Spain and Vietnam. Meanwhile, another project is also looking into increasing the sustainability of feeds.
\"A lot of fish need food that is alive and moves, that is the trigger to feed and it’s the same for freshly hatched fish and crustaceans,\" said Matthias Nölting, coordinator of NEMAQUA, an EU-funded project developing a sustainable solution to supplement or replace artemia, the most important current feed for hatcheries.
\"According to statistics, the world sits at roughly 4 000-4 500 tonnes of quality product each year,\" said Nölting. \"As fish farming grows at large rates, this is in danger of becoming a bottleneck.\" Finding an alternative to artemia would therefore allow aquaculture to address another unsustainable link in its food chain.
\"It is observed in the wild that some fish are also feeding on nematodes,\" said Nölting. NEMAQUA has proven the economical, biological and technical viability of a selected strain of nematodes in feeding juvenile shrimp. They hope to start commercialisation in 2017 while trials for fish will begin in the next two years.
In a similar effort to increase the sustainability of aquaculture, another project is looking into the benefits of reusing excess nutrients in aquaculture systems through aquaponics.
‘Aquaponic systems have two complementary crops, fish and plants, therefore generating an extra income that helps maximise the economical profitability of the facility,’ said Professor Adrian Turek Rahoveanu from the University of Agricultural Sciences and Veterinary Sciences of Bucharest, in Romania.
Prof. Turek Rahoveanu is the coordinator of ECOFISH, an EU-funded project looking to convert conventional aquaculture farms into aquaponic ones. The project tested an aquaponics fish farm system at the University of Galati, also in Romania. This included using farmed sturgeons and rainbow trout to grow lettuce and spinach.
However, they found a big technical and financial challenge in transforming fish farms into aquaponic systems, due to the complexity of the systems. But, according to a survey carried out by ECOFISH, aquaponics systems could still appeal to fish farm owners and supermarkets.
Original article from Horizon EU Research and Innovation Magazine
