Seals can frequently be seen in California waters, off the coast of New England, and on icebergs in the Arctic. These creatures are highly adapted to both aquatic and terrestrial environments.
However, are they able to breathe while submerged in water?
Being mammal, seals cannot breathe underwater. They can, however, stay underwater for up to thirty minutes at a time. Their substantial muscle mass that carries oxygen and blood is the reason for this. Their muscles also contain a large quantity of a protein that stores oxygen.
Safes Oxygen In The Blood And Muscle:
Mammals of the sea are called Marine. They require oxygen from the air even though they live in the water for the most of their life.
Since they lack gills, they are unable to breathe underwater. Seals can dive for extended periods of time, though.
Their blood and muscles have undergone a unique adaptation that allows them to achieve this. Oxygen is carried by red blood cells and the protein myoglobin, which is present in muscle tissue.
Compared to land mammals of comparable size, seals have more muscle mass and blood.
It also means that their bodies have a greater capacity to hold oxygen than normal, which they use to breathe while submerged. Their muscles also contain 10 times more myoglobin than those of humans.
Seals require less on their lungs because of their large capacity for oxygen storage in their bodies. Indeed, unlike humans, they do not even hold their breath when submerged.
Their bodies contain sufficient oxygen reserves to enable them to dive without having to take a deep breath.
Their Heart Rate Slows Before They Dive:
Seals have another unique adaption related to their hearts, in addition to having more blood and muscle.
A seal’s heart beats between 75 and 120 beats per minute (bpm) on average. They may lower their heart rate to four to six beats per minute before plunging.
Along with lowering body temperature, they also slow down their metabolism. This suggests that their body requires less oxygen to function overall.
At last, real seals, or those in the Phocidae family, release their breath before plunging.
Given that most animals, including humans, inhale deeply before submerging themselves, this may seem contradictory. However, doctors think that breathing out can help avoid “the bends,” also known as decompression sickness.
Rapid drops in outside pressure are referred to as decompression sickness. The difficulty lies in rising to the surface, where there is less pressure, not in diving itself.
A rapid rise in temperature can cause nitrogen bubbles to develop in the blood and joints. This can result in lung and spinal cord injury in mild cases, along with some physical pain.
Because of their blood and muscle tissue, seals can release their breath to avoid the bends. Compared to the air in their lungs, they depend far more on the oxygen in those areas.
How Long Can A Seal Stay Underwater?
Therefore, seals do not hold their breath or breathe underwater. How long can they survive underwater only on the oxygen stored in their tissue and blood?
Seals have a minimum 30-minute underwater duration, although the duration varies according on the species.
Elephant seals have a two-hour maximum diving time. However, because their prey is frequently nearer the surface, most species’ dives last between three and seven minutes.
A seal’s only food source is the water. They eat a variety of fish, squids, and sometimes even sharks.
If necessary, seals can even sleep underwater. Their brains stay just enough active to notify them when they are low on oxygen.
Additionally, it aids in their awareness of any nearby risks so they can flee.
Seals are aquatic mammals that spend approximately 50% of their lives in the water. Their bodily structure is designed for movement in water, not on land.
Harbor seals may reach a top speed of 12 mph when swimming, using their flippers as rudders and their tails as propellers. They are far more awkward when on land.
Unlike sea lion flippers, theirs do not rotate. Seals rely on their bellies and tails to help them flop and bounce their spherical bodies along.
Seals Need To Spend Time On Land:
Seals have unique adaptations for the water, yet they are not entirely aquatic creatures. Although they can sleep underwater, it is easier for them to relax on land because swimming requires energy.
Seals give birth on land, but they are also capable of feeding their babies in the ocean.
For their own safety, seals must also come ashore. Great white sharks and occasionally killer whales hunt seals. Seals can avoid these predators and remain vigilant by going back to shore.
Seals must also be on land in order to molt. The process by which a seal sheds its outermost covering of skin and fur is called molting. During this period, harbor seals will also molt their whiskers. To stay warm while submerged in the water, they must channel the flow toward their internal organs.
Despite the moniker, “catastrophic molting” is a normal process for elephant seals. It takes four to five weeks, but all of their old skin and fur fall off at once.
They also move quickly because they remain on land the entire time.
Conclusion:
Even though they live in the water for a large portion of their lives, marine mammals are still mammals. This implies that they take in oxygen from their surroundings through their lungs.
Seals are similar to fish without gills in that they are unable to breathe underwater. In contrast, seals must use the oxygen that is stored in their blood and muscles to survive deep dives.
Compared to animals of the same size, they have more tissue and more proteins in their muscles that store oxygen.
In order to help battle the bends, seals actually exhale before diving rather than holding their breath underwater.