Friday , April 16 2021

Dolphins avoid “bends” when diving underwater by reducing their heart rate



Dolphins are able to avoid decompression sickness when they are deep in the ocean by consciously lowering their own heart rate before diving, new research reveals

The condition, also known as curvature, occurs when dissolved gases come out of a solution in bubbles and can affect any area of ​​the body and can be fatal.

Researchers at the Fundación Oceanogràfic worked with dolphins to find out how they cope with diving and depth changes without developing a condition.

They found that dolphins actively slowed their heart before diving and could even adjust their heart rate depending on how long they planned to dive.

Their findings, published in the journal Frontiers in Physiology, provide new insights into how marine mammals store oxygen and adapt to pressure as they dive.

Researchers at Fundación Oceanogràfic worked with dolphins to find out how they cope with diving and depth changes without developing a condition

Researchers at Fundación Oceanogràfic worked with dolphins to find out how they cope with diving and depth changes without developing a condition

The research team worked with three male dolphins with bottles specially trained to hold their breath for different times according to instructions.

Dr Andreas Falman, lead author, said: “We have trained dolphins to take longer, shorter breaths and where they can do whatever they want.

“When asked to hold their breath, their heart rate dropped before or just when they started holding their breath.

“We also found that dolphins continued to reduce their heart rate faster as they prepared for longer breaths compared to other restraints.”

The results reveal that dolphins, and possibly other marine mammals, can consciously change their heart rate to suit the length of their planned dive.

Dr Falman said: “Dolphins have the capacity to change the rate of heart rate as much as you and I can reduce the rate at which we breathe.

“This allows them to save oxygen while diving, and it can also be crucial to avoid diving-related problems such as decompression sickness,” he said.

Understanding how marine mammals are able to dive safely for long periods of time is crucial to mitigating the health effects of sound disturbances caused to them.

“Human-made noises, such as explosions underwater during oil exploration, are associated with problems such as curves in these animals,” explained Dr. Falman.

The research team worked with three male dolphins with bottles specially trained to hold their breath for different times according to instructions.

The research team worked with three male dolphins with bottles specially trained to hold their breath for different times according to instructions.

Avoiding sudden loud disturbances and instead slowly increasing noise levels over time will reduce stress levels for diving marine mammals, he said.

“In other words, our research can provide very simple mitigation methods to enable humans and animals to safely share the ocean.”

Falman said the practical challenges of measuring the dolphin’s physiological functions, such as heart rate and respiration, had previously prevented scientists from fully understanding the changes in their physiology during diving.

To solve the problem, the team worked with a small sample of three trained male dolphins housed in a care facility.

Their findings, published in the journal Frontiers in Physiology, provide new insights into how marine mammals store oxygen and adapt to pressure as they dive.  Picture of shares

Their findings, published in the journal Frontiers in Physiology, provide new insights into how marine mammals store oxygen and adapt to pressure as they dive. Picture of shares

“We used specially designed equipment to measure lung function in animals and attached electrocardiogram (ECG) sensors to measure heart rate,” he said.

Andy Asabas is a dolphin care specialist at Siegfried and Roy Secret Garden and a dolphin habitat in Mirage, Las Vegas, home to the dolphins that were studied.

He said: “The close relationship between trainers and animals is extremely important when training dolphins to participate in scientific studies.”

“This bond of trust has allowed us to have a safe environment for dolphins to become acquainted with specialized equipment and learn to breathe in a fun and stimulating training environment.

“The dolphins all participated in the study voluntarily and were able to leave at any time,” Jabas explained.

WHAT IS A HYPERBARIAN CHAMBER AND HOW IS IT USED?

A hyperbaric chamber is a room or tube under high pressure where the patient is given pure oxygen to breathe.

The air pressure in these chambers is three times higher than the normal outside pressure.

The lungs work on gas exchange, which occurs more or less efficiently at different pressures.

At this higher air pressure, the lungs can take in more oxygen than under normal conditions.

All tissues in the body need oxygen to live and stay healthy, so in a hyperbaric chamber the lungs receive more oxygen which is then carried throughout the body to regenerate tissues that may be fighting or infected.

Oxygen also helps reduce inflammation and stimulate the growth of new blood vessels.

WHAT ARE THE HYPERBAR CHAMBER TO USE FOR TREATMENT?

Hyperbaric oxygen therapy is a proven treatment for decompression sickness, a condition that some people develop after diving into SCUBA, where high pressure to be deep under water causes nitrogen to form in their blood vessels.

This usually causes muscle and joint pain and fatigue, but in rare cases can prove fatal. Hyperbaric oxygen therapy reverses the process by allowing dangerous nitrogen bubbles to form.

According to the Mayo Clinic, doctors may also recommend hyperbaric oxygen therapy for:

  • Anemia, severe
  • Brain abscess
  • Air bubbles in blood vessels (arterial gas embolism)
  • Burn
  • Decompression sickness
  • Carbon monoxide poisoning
  • Crushing injury
  • Deafness, suddenly
  • Gangrene
  • Skin or bone infection that causes tissue death
  • Untreated wounds, such as a diabetic foot ulcer
  • Radiation injury
  • Skin grafting or flaking of the skin at risk of tissue death
  • Loss of vision, sudden and painless

Although it has been claimed that therapy helps with a range of other medical problems, there is only scientific evidence to support the above purposes.

There is no significant reason to believe that it treats conditions such as fibromyalgia, depression or chronic fatigue syndrome.


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