Tropical fish may be an attractive addition to the home, but are not as harmless as they might appear.
The average UK household could emit up to 12.4% CO2 and use up to 30% water.
These findings are part a study conducted by the Cardiff University Water Research Institute.
Scientists examined the environmental impacts of factors including the amount and type of energy and water consumed by aquariums.
In the UK, there are four million households that own a fish as a pet. And it is estimated that 70% have a tropical aquarium in freshwater,” said Dr William Perry.
“The carbon footprint for owning pets like dogs and cat has already been calculated. But we have now provided estimates of the carbon dioxide produced by running a tropic aquarium, along with estimated water consumption.”
The study estimates the environmental impact of keeping fish in countries including France, Poland, and the UK.
The aquariums that were examined ranged in size from 50 litres to 400 litres and the way they are maintained.
In the UK, tropical aquariums produce between 85.3kg and 635.2kg CO2 annually – that’s 1.6% to 12.4% the average UK household annual emissions.
Research also found that tropical aquariums used 156-31200 litres water annually, which is 0.2%-30.1% of UK average annual household water usage depending on the size and maintenance.
Most important environmental factors are the size of the aquarium, the amount of water heated, and the level of decarbonisation on the electricity grids of different countries.
“Ornamental Fishkeeping can be an environmentally friendly pet choice, as opposed to owning a dog or cat of average size. They are likely produce more emissions due to their meat consumption,” said Dr Perry.
However, environmental impacts can be significant depending on aquarium sizes, how they are run, and where the country is.
The impact on the environment of a high water usage will not be easy to reduce. It will take ingenuity and creativity at the individual level.
Journal of Fish Biology published the research on the environmental impact of maintaining a tropical tank in Northern Europe.