Sound science: How research can inform sustainability in sports

Adoption of sustainable actions in sport

The climate crisis impacts all sports, from the mountains to the seas. Record high temperatures, rainy conditions and lack of snowfall are curtailing the length of ski seasons; football pitches are at risk of becoming both too hot and waterlogged; and athletes, tennis players, and cricketers performing in soaring temperatures are suffering from heat stress.

Faced by these threats, the sports industry is increasingly taking action to reduce the impact of sport on the environment, from large-scale sustainability policies to smaller behavioural changes. Importantly, more and more organisations are finding ways to balance scientifically informed decisions with their own sporting priorities. The development of LED technologies for lighting sports grounds, for example, has been embraced due to the marked reduction in energy costs and the reduced effect of light pollution on the surrounding environment.

However, the effectiveness of many sustainability policies and practices has been called into question. LED lighting is an effective alternative, but it does not fully address the impact of man-made light pollution on the environment. Meanwhile, it has become commonplace for sports clothing to be made from recycled polyester, but damning new research is showing that this material can be just as damaging to the environment. Bigger events have also made unsubstantiated claims about their sustainability status. Organisers of the 2020 Tokyo Olympics, for example, claimed that they had used sustainably-sourced timber to build new stadia, but NGO investigations revealed that the wood was actually sourced from protected rainforests.

So how do we make sure that sustainability solutions are effective in a space where greenwashing is rife? Sound scientific understanding and an engagement with scientific research is an important step and a great place to start.

Case study: how the science of sound can inform marine sports sustainability

Taking a closer look at the marine sports industry in Miami shows how understanding and engaging with scientific research can help sports bodies make important decisions that will protect their local environments.

Situated adjacent to the Biscayne Bay, the city of Miami is a hotspot for boating. As of March 2023, it hosts 59,556 registered vessels. Miami also hosts several marine sports events, including the Luminsea Offshore Powerboat Races, the Bacardi Cup Invitational Regatta, and a ‘Jet Ski Invasion’ hosted by the Florida Ski riders, in which 400 jet ski riders ride through the Bay. Large-scale sailing events involve vast numbers of participants, media teams, medical and spectator boats, and have a significant impact on the local marine environment.

Vessels can introduce risks of boat strike, carbon emissions and chemical pollution, but their impact goes deeper. The marine region in the Biscayne Bay boasts high biodiversity, including many threatened and endangered species such as the Florida Manatee, Manta Ray, and the Smalltooth Sawfish. It also acts as a nursery habitat for the critically endangered Great Hammerhead. The noise generated by these marine sports events has the potential to impact this marine life.

Marine life uses sound for important behaviours, including finding food, navigation, and avoiding predators. Fish grunt and chirp to communicate with each other, while marine mammals rely on sound travelling further and faster underwater to find mates across huge distances. It’s no surprise, then, that additional noise from vessels can introduce difficulties. Research has shown motorboat noise can reduce parental care in Ambon Damselfish, interrupt feeding in Humpback Whales, and prevent embryonic development and increase mortality in Sea Hares.

Scientists from the University of Exeter and University of Bristol, supported in part by funding from Global Sustainable Sport, are interested in what sounds fish are hearing in Miami, and how the effects of noise pollution can be mitigated. Working with local researchers, they have used underwater microphones placed among shark nursery sites, coastal fish assemblages, mangroves, seagrasses, and sand flats, and recorded the sounds of the area across several weeks.

As well as uncovering swooping whistles of Gulf toadfish and defensive chirps of damselfish, man-made noise was an unsurprisingly common feature. Biological sound in Miami is punctuated by as many as 74 boat passes in an hour. Jet ski engines drown out fish vocalisations, and fireworks, cruise liners, and the blasting boomboxes of beachgoers all register within fish hearing capacity. It’s inevitable that humans and biodiversity will continue to coexist in areas like Miami, and so this type of scientific research is vital in ensuring that marine life is protected from human impacts, particularly during large-scale sporting events.

Scientific research into underwater soundscapes and the effects of man-made noise on marine life can be influential in policy making. In 2014, following a rising number of studies demonstrating a negative effect of shipping noise on marine mammals, the International Maritime Organisation produced guidelines for ships to reduce the amount of underwater noise they produce. Since then, they have continued to use science to inform practice by identifying routes that are scientifically advised to avoid Particularly Sensitive Sea Areas and through the development of a $2m UN funded partnership to address the issue of shipping noise on marine life. This demonstrates how industries can partner with scientists to address noise pollution if they make it a priority.

Considering the clear links between sports and anthropogenic noise, this is an approach that sport should look to emulate. Powerboats could be sound-proofed, which would reduce the impact of events such as the Luminsea Offshore Powerboat Races. Given that the size, type of fuel, and number of engines all contribute to the power and type of sound, limits on engine types in races could help mitigate the impact of noise. Meanwhile, sports stakeholders and scientists can work together to help each other: sailing boats can be used to help generate acoustic data that can be used by scientists.

Perhaps a city like Miami, which sits at the cross-section of recreation and the marine environment, could be at the forefront of a movement to bring science and sports together to protect the marine environment.

What does this tell us about the role of science in sport sustainability?

Scientific understanding already has a track record of leading to change in sports. The increasing awareness of plastic pollution, for example, has led to the London marathon opting for compostable cups, the phasing out of reusable plastic cutlery at Premier League stadiums, and the invention of an entirely new sustainable sport – plogging. When it comes to the marine environment, The Ocean Race has laid out ambitious sustainability goals and regularly tracks progress in meeting them. Considering that 80% of environmental pollution from sports events is pre-determined in the design phase, having available information on environmental impacts early in the process could vastly decrease the impact of sport and encourage positive, effective action.

However, while the scientific understanding on issues such as plastic pollution has helped shift perspectives and create positive change, it doesn’t always translate into sustained behavioural change. To take the Premier League as an example: while the phasing out of plastic cutlery is good PR, a recent BBC Sport investigation showed that clubs took a combined 81 domestic flights to travel to 100 games in two months. Engaging with scientific insights is crucial, but sports stakeholders must be consistent and act accordingly. One of these clubs, Liverpool, recently received an ISO 20121 certification, bringing into question how comprehensive the ISO certification process is.

Science can also play a key role in ensuring the impact of global climate policy. Signatories to the landmark 2023 UN High Seas Treaty, signed earlier this month, can engage with scientific research to ensure that the historic agreement meets its ambitions, and scientific understanding will be a key part of ensuring that the treaty is ratified and carried out effectively. Engaging with research will ensure that areas that are affected by humans, rather than unused, unfished, or untouched areas, are selected as areas of protection. Scientific understanding of where fishing is concentrated, where marine life is moving, and which habitats are most vulnerable will also be key in ensuring that the treaty is effective in practice.

Even where scientific understanding is available, clearly it is still often difficult for sports stakeholders to know which measures are appropriate, and many organisations are guilty of not modifying their most damaging behaviours. The example of Miami and the impact of noise pollution on marine life shows how the impact of sports events can often be hidden or go unnoticed. Scientists can shine a light on these critical issues, and sports stakeholders can utilise this science to make sure that their decisions are genuinely sustainable.

Ultimately, it is only through collaboration and shared understanding that scientists, policymakers, and sports stakeholders can truly create a sustainable future for the sports industry and the planet.