Finding the ‘Nemo effect’: no evidence that animal movies drive demand for pets, say researchers

Following the release of ‘Finding Nemo’, numerous global news providers, including the BBC and CNN, reported that the movie’s popularity was driving an increase in demand for clownfish as pets and threatening wild populations. This effect, dubbed the ‘Nemo effect’ by media outlets, was so widely reported that it became conventional wisdom amongst amateur animal lovers and experienced conservation scientists alike despite there being little evidence that the effect even existed.

When the much-awaited sequel ‘Finding Dory’ was released, there was yet another flurry of reports suggesting that the film might have a similar effect on wild populations of the blue tang, the species of the movie’s protagonist. Conservation organisations, such as the Saving Nemo Conservation Fund, launched campaigns urging consumers not to buy the blue tang to keep as pets. Similar warnings were raised by numerous high-profile voices, such as Ellen DeGeneres, who voiced the movie’s protagonist, Dory.

Now, a team of scientists has found that concerns that blockbuster animal movies might inspire consumer demand for wildlife were largely unfounded. Published in the journal Ambio on 14 August, their results suggest that the release of ‘Finding Dory’ did not lead to an increased demand for blue tang fish. Instead, there was an increase in online information-seeking behaviour about the species.

Lead by Dr. Diogo Veríssimo at the University of Oxford’s Department of Zoology, the team analysed fish purchase data from a major US importer ornamental fish, visitation data from 20 aquariums across the US, and online search data from Google Trends. Using a synthetic counterfactual method, the team compared observed data patterns with patterns that would have been expected if the movie had not been released.

Contrary to media reports about the ‘Nemo effect’, the scientists failed to find a link between the release of ‘Finding Dory’ and the number of blue tang fish imported into the US. Similarly, the team did not find an effect of the movie’s release on visits to aquariums in the US. 

However, what the researchers did find was a link between the movie’s release and online searches. In particular, there was a sharp rise in frequency of Google searches for the scientific name of the blue tang, Paracanthurus hepatus, in the week following the movie’s release. 

Taken together, these results suggest that instead of causing environmental harm, animal movies might instead bring attention to lesser-known species such as the blue tang. Given that more familiar species are often judged by the general public as more worthy of conservation, blockbuster animal movies might actually be beneficial for conservation efforts, contrary to the fears initially expressed in media reports. 

About why the ‘Nemo effect’ became so widely accepted despite the lack of evidence supporting its existence, Dr. Veríssimo said: ‘We think these narratives are so compelling because they are based on a clear causal link that is plausible, relating to events that are high profile – Finding Dory was one of the highest grossing animated movies in history.’

Pointing to the fact that narratives surrounding the ‘Nemo effect’ were echoed even by conservation scientists, Dr. Veríssimo and his co-authors argue that it is important for scientists to remain sceptical when commenting on potential threats to the environment to ensure that public trust in scientists does not erode. 

Moreover, the scientists suggest that focusing on unsubstantiated threats to biodiversity can also be harmful to conservation efforts by diverting the public’s attention from actual threats to biodiversity. Stronger communication between the press and the scientific community is needed to ensure that stories based solely on anecdotal evidence do not gain unwarranted momentum.

Denis Lan