Plastic pollution in Ghana. Credit: Muntaka Chasant/Wikimedia Commons

The BBC documentary "Blue Planet II" raised environmental awareness, but may not have discouraged people from choosing plastic, says new research.

Blue Planet II, broadcast in 2017, included messages about the on the oceans, including the growing problem of pollution. This was credited with creating a "Blue Planet effect," which included people choosing to consume less plastic, for example by opting for reusable items like water bottles instead of single-use versions.

Now, an experiment by Imperial College London and the University of Oxford shows that while watching the documentary increased in a group of volunteers, this did not translate into choosing to use fewer . The results are published in Conservation Science and Practice.

First author Matilda Dunn, from the Centre for Environmental Policy at Imperial, said: "The findings from our experiment are counter to the popular idea that 'Blue Planet II' reduced viewers' preference for plastic, instead demonstrating that human behaviors are complex and determined by more than just knowledge.

"However, 'Blue Planet II' may have had a wider impact by increasing conversations around ocean plastic pollution, allowing the topic to become more politically palatable."

Choice experiment

To find out whether "Blue Planet II" changed people's plastic-choice behavior, the team conducted an experiment with 150 people split into two groups. Both groups completed a questionnaire that measured their understanding of and attitudes towards marine conservation issues.

One group was then shown the original The Blue Planet documentary, which aired in 2001 and contained no plastic or ocean conservation messages. The other group was shown "Blue Planet II." After the viewings, both groups filled in the same questionnaire.

Before and after both showings, participants were also offered a choice of drinks and snacks, either in paper or plastic packaging, and noted which participants chose. The team controlled for any other differences between the options, such as flavors or sizes of the snacks, for example by offering the same soft drinks in both plastic and paper cups.

Increased understanding, same choice

While watching "Blue Planet II" greatly increased understanding of marine conservations issues as revealed by the questionnaires, there was no significant difference in the choices people made between plastic and paper-packaged snacks.

Co-author Dr. Morena Mills, from the Centre for Environmental Policy at Imperial, said: "Many previous studies of people's preference for plastic rely on individuals reporting their own preference, which can be unreliable. We are the first to use this type of experimental design along with measuring observed behaviors to test the hypothesis."

The researchers are planning to use this evaluation method to test the effectiveness of other conservation-related mass media interventions on changing individual behaviors.

"Evaluating the impact of the documentary series Blue Planet II on viewers' plastic consumption behaviors," by Matilda Eve Dunn, Morena Mills and Diogo Veríssimo, is published in Conservation Science and Practice.

More information: Matilda Eve Dunn et al. Evaluating the impact of the documentary series Blue Planet II on viewers' plastic consumption behaviors, Conservation Science and Practice (2020). DOI: 10.1111/csp2.280