Noise And Light Pollution: Harming The Biosphere

Light and noise pollution are two of the many ways human activity is affecting the biosphere. Light pollution, caused by artificial light, interferes with the natural cycle of day and night, which plants and animals rely on for survival. This can disrupt photosynthesis and the activities of insects, birds, and other animals. Noise pollution, caused by unwanted or excessive sound, can also have a detrimental impact on both humans and wildlife. It can lead to hearing loss, increased stress and anxiety, and sleep disturbances. In wildlife, noise pollution can interfere with an animal's ability to attract a mate, communicate, navigate, and find food, posing an existential threat to certain species.

Light pollution disrupts photosynthesis and the activities of insects, birds and other animals

Light pollution has a detrimental effect on the activities of insects, birds, and other animals. Nocturnal animals are especially vulnerable to artificial light, which disrupts their natural night and day cycles.

Insects

Insects are drawn to artificial light, which can be deadly for them. Insects such as moths and bees are important pollinators, but artificial light disrupts their nocturnal pollination activities. Moths, for example, are drawn towards the light, away from the flowers they would usually pollinate. This has a ripple effect on the plants that depend on them. Insects are also important food sources for other animals, so a decline in their numbers can have a detrimental effect on the wider food chain.

Birds

Birds that migrate or hunt at night navigate by moonlight and starlight. Artificial light can cause them to veer off course and towards cities, where they may collide with buildings. Migratory birds depend on cues from properly timed seasonal schedules, and artificial light can cause them to migrate too early or too late, missing ideal nesting and foraging conditions.

Other Animals

Artificial light can also affect other animals, such as sea turtles. Baby sea turtles, for example, find their way to the sea by detecting the bright horizon over the ocean. Artificial lights can disorientate them, drawing them away from the ocean and towards danger.

Plants

Plants depend on light and dark to grow and reproduce. Artificial light disrupts their seasonal rhythms and their ability to sense and react to natural light.

Artificial light at night is a cause of insect decline

Insects are attracted to artificial light at night, and this phenomenon has been observed for centuries. However, the exact cause of this behaviour is not well understood. Several theories have been proposed, including:

• Insects are drawn to light through an escape mechanism, directing their flight towards it as they might aim for a gap in the foliage.
• Insects use the moon as a celestial compass cue to navigate, and mistakenly use artificial light sources instead.
• Insects' sensitive night-adapted eyes are blinded by artificial lights, causing them to fly erratically or crash.
• Insects' dorsal-light-response (DLR), a behaviour that keeps their dorsal (top) side to the brightest visual region, is disrupted by artificial light.

Noise pollution can mask and inhibit animal sounds and audition

Noise pollution can have a detrimental impact on the audition and vocalisations of animals, with anthropogenic noise potentially masking or inhibiting animal sounds. Many species of animals, including insects, frogs, birds, and bats, rely on sound for a variety of reasons, such as attracting a mate, communicating, navigating, finding food, or avoiding predators.

Noise pollution can interfere with these vital behaviours, threatening the survival of vulnerable organisms. For example, noise pollution can drown out the mating calls of male frogs, making it difficult for females to locate them. It can also disrupt the nocturnal activities of nocturnal animals, such as hunting and foraging, by turning night into day.

Additionally, noise pollution can have a particularly detrimental effect on marine animals, especially those that rely on echolocation, such as certain whales and dolphins. Naval sonar devices, for instance, produce extremely loud sounds that can travel hundreds of miles through the water and have been linked to mass strandings of whales and dolphins.

The problem of noise pollution is further exacerbated for animals in urban areas, where multiple sources of noise, such as traffic, construction, and industrial activities, can combine to create a chaotic and disorienting soundscape. This can lead to increased stress, anxiety, and even physical damage to the eardrums and inner ears of both humans and animals.

To mitigate the impact of noise pollution on animals, it is essential to reduce noise levels, especially in protected habitats and areas with high biodiversity. This can be achieved through the use of noise barriers, sound-absorbing materials, and stricter regulations on noise emissions. Additionally, raising awareness about the impacts of noise pollution on wildlife can help foster a more considerate approach to noise generation in both urban and natural environments.

Anthropogenic noise can affect communication, use of space, and reproduction

Anthropogenic noise can mask and inhibit animal sounds and animal audition, and it has been shown to affect communication, use of space, and reproduction.

Anthropogenic noise can affect communication by reducing the distance at which a signal can be detected, limiting the ability of the signal to reach its intended receiver, and decreasing the amount of information that can be extracted from a signal.

Anthropogenic noise can affect the use of space by causing animals to move away from the source of the noise, either temporarily or permanently, or by increasing their anti-predator behavior.

Anthropogenic noise can affect reproduction by reducing breeding rates, decreasing hatching success, and impairing juvenile growth and development. It can also lead to poorer body condition and reduced reproductive success.

Noise pollution can cause stress, anxiety, and mental fatigue in humans

• Increased stress and anxiety: The brain is always monitoring sounds for signs of danger, and frequent or loud noise can trigger anxiety or stress. Continued exposure to noise pollution can increase a person's sensitivity to stress, leading to feelings of irritability, frustration, or anger.
• Sleep disturbances: Environmental noise is a common cause of sleep problems, including difficulty falling and staying asleep. It can also reduce sleep quality by altering the amount of rapid eye movement sleep, impacting mood and concentration.
• Cognitive impairment: Noise pollution can affect cognitive functioning, including memory and attention. It can also impair learning and cognitive performance in children, leading to delayed language skills and reduced resilience.
• Cardiovascular issues: Noise pollution has been linked to heart disease, high blood pressure, and stroke. It can also contribute to elevated stress hormones and chronic stress, which are risk factors for cardiovascular disease.
• Other health issues: Noise pollution may also be associated with type 2 diabetes, low birth weight, and childhood learning delays. Research is also investigating potential links to dementia.

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