Humans aren't the only ones placing pressure on dwindling fish stocks, cats - or rather cat food manufacturers - are doing the same.
According to Dr Giovanni Turchini and Professor Sena De Silva from Deakin University in Australia, the global cat food industry is using an estimated 2.48 million tonnes of "forage fish" every year.
"That such a large amount of fish is used for the pet food industry is a real eye opener. Our pets seem to be eating better than their owners." Turchini said.
In Australia, pet cats eat an estimate 13.7 kg of fish every year - several kilograms more than their owners.
The fish targeted, which include sardines, capelin, anchovy and herring, are collectively known as forage fish and an important part of the food chain, as they form the diet of larger fish, mammals and sea birds.
Gourmet pet foodsTurchini said that there is a view that wild stocks are being over-exploited already and supplies of forage fish 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 among 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.
"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."
Turchini said that the gourmet pet foods contained significant amounts of fish that may be suitable for human consumption, when cats could instead be fed on raw materials, such as byproducts from the fish filleting industry, that humans couldn't eat.
Turchini also said that the amount of fish used in ornamental fish foods, fishing baits and non-human food production (such as fur-rearing) also required attention.