Dr Giovanni Turchini, with colleague Professor Sena De Silva, has found that an estimated 2.48 million tonnes of forage fish—an increasingly limited biological resource - is used by the global cat food industry each year.
"That such a large amount of fish is used for the pet food industry is real eye opener," Dr Turchini said.
"What is also interesting is that, in Australia, pet cats are eating an estimated 13.7 kilograms of fish a year which far exceeds the Australian average per capita fish and seafood consumption of around 11 kilograms. Our pets seem to be eating better than their owners."
The potential over fishing of marine resources continues to be debated as the fishing industry and conservation scientists try to determine the best way to sustain wild fish stocks.
"The central issue is not an advocacy of pets versus aquaculture or other agricultural/animal husbandry activities"
Dr Giovanni Turchini
Wild forage fish, such as sardines, herring, anchovy and capelin, are an important link in the marine food chain, forming the diet for larger fish like tuna, swordfish and cod and marine birds and mammals. Forage fish are also caught for commercial purposes and turned into fishmeal and fish oil for use, primarily, by the fish farming industry.
With wild fish stocks reaching a phase of stagnation, thought to be a result of over- exploitation and weather change phenomena, there is a growing view that forage fish supplies could be better utilised.
"While much of the criticism has been on the grounds that forage fish could be better used for human consumption directly, particularly amongst the poorer nations of the world, rather than in the production of food for farmed fish, little attention has been paid to the amount of forage fish used by the pet food industry," Dr Turchini said.
"Pet ownership is increasing globally. The pet food industry is moving towards a constant increase of production and manufacturing and marketing premium and super-premium products. These gourmet pet foods contain a significant amount of fish that may be suitable for direct human consumption, while different raw material unsuitable for human consumption, such as by-products of the fish filleting industry, could be used."
Dr Turchini believes the estimated forage fish consumption in the pet food industry brings to the forefront a much needed debate in an area that warrants further and urgent investigation. Other sectors that make use of wild catch for non-human food production such as fur animal rearing, feed for ornamental fish, bait and attractants for recreational fishing, and bait for commercial crayfish industry also need to be monitored.
"I am not advocating the need to reduce, significantly, the fishmeal and fish oil use in aquaculture if it were to sustain in the long term. In this regard, it is important to note that all sectors associated with the aquaculture industry are making a concerted effort to reduce the use of forage fish," Dr Turchini said.
"The central issue is not an advocacy of pets versus aquaculture or other agricultural/animal husbandry activities, but the need for a more objective and pragmatic approach to the use of a limited and decreasing biological resource, for human benefit."