Aquarium Therapy

Fish tanks lower blood pressure and heart rate
Higher numbers of fish also helped to hold people’s attention for longer and improve their moods
One in ten Britons now have pet fish

By Sarah Knapton, Science Editor


For years dentists and doctors have installed fish tanks in their waiting rooms in the hope of calming down stressed patients before they go under the drill or stethoscope.

Now a new study has shown for the first time that staring at swimming fish really does lower blood pressure and reduce heart rate.

In the first investigation of its kind, experts from the National Marine Aquarium, Plymouth University and the University of Exeter assessed people’s physical and mental responses to tanks containing varying levels of fish.

Even viewing an empty tank with just rocks and seaweed lowered heart rate by three per cent. But when fish were introduced heart rate fell by seven per cent. Watching fish also reduced blood pressure by four per cent.

Higher numbers of fish also helped to hold people’s attention for longer and improve their moods.

“Fish tanks and displays are often associated with attempts at calming patients in doctors’ surgeries and dental waiting rooms,” said Deborah Cracknell, PhD Student and Lead Researcher at the National Marine Aquarium.

“This study has, for the first time, provided robust evidence that ‘doses’ of exposure to underwater settings could actually have a positive impact on people’s wellbeing.”

The researchers conducted their study when the National Marine Aquarium refurbished one of its main exhibits – in a large 45ft, 550,000 litre tank – and began a phased introduction of different fish species.

They were able to assess the mood, heart rate and blood pressure of 112 participants as fish numbers in the exhibit gradually increased. They claim the results should persuade companies to include fish tanks in officers to help workers manage stress levels.

Dr Sabine Pahl, Associate Professor in Psychology at Plymouth University, said: “While large public aquariums typically focus on their educational mission, our study suggests they could offer a number of previously undiscovered benefits.

“In times of higher work stress and crowded urban living, perhaps aquariums can step in and provide an oasis of calm and relaxation.”

Dr Mathew White, an environmental psychologist at the University of Exeter, added: “Our findings have shown improvements for health and wellbeing in highly managed settings, providing an exciting possibility for people who aren’t able to access outdoor natural environments.

“If we can identify the mechanisms that underpin the benefits we’re seeing, we can effectively bring some of the ‘outside inside’ and improve the wellbeing of people without ready access to nature.”

The research was published in the journal Environment and Behaviour.