Dolphins are amazing marine mammals that seem to effortlessly glide through the ocean. But like all air-breathing animals, dolphins need to come to the surface regularly to take a breath. If you’ve ever wondered how often dolphins need to breathe, you’ve come to the right place.
If you’re short on time, here’s the quick answer: dolphins generally come up for air every 3-8 minutes, but can hold their breath for up to 15 minutes if needed.
Dolphin Physiology Allows Them to Hold Their Breath
Lung Capacity and Blood Oxygen Storage
Dolphins have lungs that can hold more air by volume compared to land mammals of similar size. Their lungs are also more flexible and efficient at diffusing oxygen into the bloodstream. According to researchers, dolphins can hold about 2.5 times more oxygen-rich air in their lungs than humans can.
In addition to larger lung capacity, dolphins store more oxygen in their blood and muscles. Their blood has 25% more red blood cells than human blood, allowing it to carry more oxygen. Dolphins also have a larger blood volume overall proportional to their body size.
Plus, their muscles contain a protein called myoglobin which stores high volumes of oxygen when diving underwater.
Slowing Heart Rate to Conserve Oxygen
A dolphin’s heart rate can drop from 100 beats per minute to just 4 to 8 beats per minute when diving. This drastic change conserves oxygen for brain and organ function. Their flexible ribcage can also collapse under high water pressure, reducing oxygen demands.
According to The American Chemical Society, some dolphin species can slow their heart rate to one-tenth their normal rate while diving deep for food. This ability to alter metabolism helps dolphins hold their breath up to 12 minutes in exceptional cases.
Tolerance for Carbon Dioxide Buildup
While holding their breath, CO2 starts accumulating in a dolphin’s blood and tissues in lieu of normal oxygen. This buildup triggers the urge to breathe in land mammals. However, dolphins have adaptations allowing them to tolerate higher CO2 concentrations before needing to take the next breath.
For comparison, humans start feeling discomfort from CO2 buildup after just one minute of holding breath. But dolphins can withstand over 10 times more CO2 in their blood before reaching their limit, allowing impressive breath-holding duration.
Their adaptable physiology permits survival in marine environments.
Breathing Frequency Depends on the Dolphin’s Activity
Resting or Milling Near the Surface
When dolphins are resting or slowly milling near the water’s surface, they generally come up to breathe every 30-60 seconds. Since they are not exerting much energy during these relaxed behaviors, dolphins can hold their breath for longer between breaths.
Some research shows that dolphins may hold their breath for over 20 minutes while resting near the surface. However, typically they will breathe more frequently, every 30-90 seconds, during rest.
Traveling Steadily
When swimming steadily at a moderate pace, say 3-6 mph, dolphins often surface to breathe every 30-90 seconds. The faster the pace, the quicker they need air. Bottlenose dolphins have been observed breezing along smoothly at 10 mph while regularly surfacing to breathe every 30-45 seconds.
The rhythmic timing of their breathing gives them the stamina to keep up brisk swimming for extended periods.
Diving and Foraging
During deep dives in search of food, dolphins maximize their breath-holding ability. When diving to the seafloor to hunt for fish, squid, and crustaceans, the length of time dolphins can stay submerged largely depends on the depth.
Bottlenose dolphins can hold their breath for 5-8 minutes when diving to depths of around 300 feet. The record for the longest bottlenose dolphin dive registered an amazing 15 minutes to a depth of more than 1,000 feet!
The depth, duration, and frequency of dolphin dives vary greatly based on their target prey and how far they have to plunge to reach it. When targeting a large school of fish, dolphins may charge to the depth where the fish are swarming and snap up many prey in just one or two dives before returning to the surface.
In contrast, when searching for bottom-dwelling crabs scattered on the seafloor, dolphins may dive dozens of times in quick repetition with only brief pauses at the surface between dives.
Mother-Calf Pairs Must Stay in Close Contact
Newborn Calves Can’t Hold Their Breath Long
When a baby dolphin is first born, their lungs and respiratory system are still developing. As a result, newborn calves are only able to hold their breath underwater for around 2-3 minutes at a time before needing to come back up to the surface for air.
This is much less than the 15-20 minutes that mature adult dolphins can remain submerged.
The mother dolphin must therefore stay close by her newborn calf, surfacing regularly every few minutes so the baby can take a breath. She assists the calf to the surface, making sure it has adequate air.
Without this maternal support and contact, the vulnerable baby would be unable to get enough oxygen and would perish.
Mothers Support Calves Until They Mature
Mother dolphins continue this intensive care of their offspring until they have developed enough to dive and hunt capably on their own. It takes at least 2-3 years before a dolphin calf has matured to where it has full control over its breathing and can remain underwater for longer spans without assistance.
Until it reaches this milestone, it relies heavily on its mother to help it pace its surfacing and teach it proper underwater behavior.
The close mother-calf bond is a hallmark of dolphin society. The mothers care deeply for their babies and the survival of the pod depends on this relationship. By staying in tight formation, the mothers can make sure the calves continue to breathe and grow into healthy juvenile dolphins that will strengthen the pod for years to come.
Training and Physical Conditioning Extends Breath Holding
U.S. Navy Marine Mammals
The U.S. Navy has long made use of bottlenose dolphins and California sea lions to perform important tasks like underwater mine detection. These highly trained marine mammals go through rigorous physical conditioning to increase their breath holding capacity (often over 10 minutes) so they can stay underwater longer while carrying out their duties.
Their training focuses on cardio conditioning as well as breath control techniques. Swimming laps while holding their breath, timed breath holds, and low oxygen tolerance training are all part of the regimen.
The animals are carefully monitored by veterinarians and animal care specialists to ensure their health and safety at all times.
Performance Animals in Oceanic Parks
Dolphins and whales featured in shows at popular oceanic parks like SeaWorld also undergo special breath hold training. These captive animals learn behaviors through positive reinforcement from trainers that involve staying below the surface for extended periods.
Killer whales at marine parks have achieved breath holds of over 15 minutes during training. However, some animal rights groups argue this type of conditioning is stressful and raises ethical concerns over using performance animals purely for entertainment purposes.
On the other side, marine park supporters contend the breath hold training is done voluntarily by the animals and enhances the medical care and enrichment they receive. The debate over captive marine mammals continues as public attitudes shift on what constitutes acceptable animal welfare standards.
Conclusion
Dolphins are undoubtedly impressive in their ability to efficiently store oxygen and tolerate carbon dioxide buildup while diving underwater for food. On average, they resurface every 3-8 minutes to breathe, but can push it to 15 minutes when necessary.
Still, mothers must keep a close eye on their calves who cannot hold their breath nearly as long. With training and improved physical conditioning, a dolphin’s breath-holding abilities can improve dramatically over time as well.