Weird stuff

'High' fish swim farther

Salmon exposed to cocaine are swimming significantly farther than their drug-free counterparts, scientists have revealed.

In a new study, researchers found the illicit drug - increasingly detected in rivers and lakes - can dramatically alter how fish behave in the wild.

The experiment tracked 105 juvenile Atlantic salmon over eight weeks in Sweden's Lake Vattern.

Some fish were exposed to cocaine, others to benzoylecgonine - the chemical cocaine breaks down into - while a control group remained drug-free.

Fish exposed to benzoylecgonine swam up to 1.9 times farther per week and travelled distances of up to 7.6 miles more than unaffected salmon.

Scientists say the changes became more pronounced over time, suggesting the drug is altering how fish interact with their environment.

Study co-author Dr Marcus Michelangeli of Griffith University's Australian Rivers Institute, said: "Where fish go determines what they eat, what eats them, and how populations are structured.

"If pollution is changing these patterns, it has the potential to affect ecosystems in ways we are only beginning to understand."

The study is the first to examine the effects of cocaine contamination on fish in natural conditions rather than in a laboratory.

Surprisingly, the byproduct benzoylecgonine had an even stronger impact on movement than cocaine itself.

Researchers say traces of the drug are entering waterways through human waste after consumption.

Dr Michelangeli added: "The idea of cocaine affecting fish might seem surprising, but the reality is wildlife is already being exposed to a wide range of human-derived drugs every day."

Despite the unusual findings, experts stressed there is no risk to people eating fish.

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Frequent naps could signal serious illness

Some types of naps could increase a person's death risk.

Researchers have identified three types of daytime snoozing linked to a higher risk of early death - long naps, frequent naps, and morning naps.

The study, by Mass General Brigham, tracked 1,338 older adults for up to 19 years using wearable sleep monitors.

It found those who napped earlier in the day - between 9 a.m. and 1 p.m. - faced a 30 per cent higher risk of death compared to afternoon nappers.

Meanwhile, each additional hour of daytime sleep increased mortality risk by 13 per cent, while every extra nap raised the risk by seven per cent.

Lead author Chenlu Gao said: "Excessive napping later in life has been linked to neurodegeneration, cardiovascular diseases and even greater morbidity.

"Many of those findings rely on self-reported napping habits and leave out metrics like when and how regular those naps are.

"Our study is one of the first to show an association between objectively measured nap patterns and mortality, and suggests there is immense clinical value in tracking napping patterns to catch health conditions early."

Experts stress that the naps themselves are unlikely to be the direct cause.

Instead, they may signal underlying health issues.

Researchers wrote: "Our findings suggest that excessive napping may be an early marker of underlying health conditions, which ultimately lead to increased mortality if not managed."

Conditions such as heart disease, diabetes, chronic pain and dementia could all be behind increased daytime sleepiness.

Sleep disorders may also play a role.

The team added: "Excessive daytime sleepiness may be caused by underlying sleep disorders such as obstructive sleep apnoea."

The condition disrupts breathing during sleep and has been linked to high blood pressure, stroke and heart disease.

Inflammation in the body may also connect frequent napping to poorer health outcomes.

However, scientists are keen to stress the findings show a link - not cause and effect.

Dr Gao said: "It is important to note that this is correlation not causation."

She added tracking nap patterns could help doctors spot health problems earlier.

So while the occasional nap can be refreshing, experts say persistent daytime dozing may be worth a closer look.