Do Dolphins Sleep?

Have you ever asked yourself do dolphins sleep, or how? To be perfectly honest, I have not. In fact, this question was brought up by a 6-year-old kid to me last month.

We all know that dolphins (and whales) are mammals just like us. They are warm blooded and give birth to live young. In addition, they have similar bone structures.

The biggest difference is their respiratory system that allows them to spend 30 minutes or more without needing to surface for air! Many of us must be thinking they have HUGE lungs! In fact, no, the size of lungs does not determine the amount of oxygen that can be stored. Dolphin lungs contain more air cells and have two layers of capillaries compare to human lungs which has only one layer. This increases the surface area of the lungs and therefore increases the efficiency of gas exchange.

Now, back to the initial question. For mammals on land, breathing is an unconscious effort. Our body takes in air automatically. However for dolphins, it has to be a conscious effort because of their undersea environment. In other words, they have to actively decide when to breathe. It is not feasible to be totally unconscious because they need to wake up in time to breathe. Thus this is a problem because brains of a mammal need to enter into an unconscious state from time to time so that our brains can function correctly.

Scientists have studied and discovered that the solution for dolphins to sleep is to let half of the brain sleep at a time. Therefore, one half of the brain goes to sleep at one time and the other is fully aware of its surroundings. Scientists have also discovered that dolphins are in this state approximately 8 hours a day! This is the exact amount of sleep that we are advised to have as well!

Hence, the dolphins are not completely unconscious but still get the right amount of rest it needs.

How amazingly unique God has created all creatures so that they can adapt and survive in different climates and surroundings. I do think that dolphins are one of the most beautiful animals on Earth. Until today, their 'smile' still melts my heart like butter =)

Reena

On dolphins at RWS

17 February 2010
Will there be dolphins at Resorts World Sentosa? Part 2
Eighteen wild dolphins in the Philippines have yet to be sent to Resorts Worlds Sentosa, reports Today.
Dolphins still depicted on the Resorts World Sentosa website.

The delay is because "the facilities to house them in Singapore are not finished". The Resorts World Sentosa spokesman Robin Goh said "construction of the Marine Life Park is on schedule and is slated for an opening after 2010".

These dolphins from the Solomon Islands were sent to Subic Bay Marine Exploratorium in the Philippines for training in late 2008. The dolphins were supposed to be sent to Singapore by end 2009, but are now still at Subic Bay.

The Singapore Society for the Prevention of Cruelty to Animals (SPCA) has posted the Philippine newspaper report on its Facebook page. Deirdre Moss of the SPCA said the society "objects to the keeping of dolphins in captivity, as they are usually caught/kept for the purpose of training to entertain/amuse the public" and in doing so, they are "also forced to adapt to an alternative lifestyle in a man-made structure".

Mr Goh said animals acquired for its Marine Life Park are in accordance with the Cites agreement. "In the meantime, the dolphins are in good hands and being looked after according to international standards," he added.

In Jun 09, there was a Solomon Star report that "The Philippines-owned CITES science team has just sent a letter to the government of Philippines that the import of the dolphins from Solomons earlier this year is NOT legal under Philippine law."

Many Singaporeans were shocked by the film "The Cove" on dolphin hunting in Japan for meat and the captive dolphin trade. As Salina Ibrahim, a newspaper reader, writes "Singapore is indirectly guilty of contributing to the entertainment market that demands the capture of dolphins in the first place".

Mr Ric O'Barry, in an interview about "The Cove", shares how Singaporeans can make a difference: avoid live dolphin shows. He notes that Singapore has them and that more are in the pipeline. 'Consumers have all the power. Don't buy a ticket,' he says.

Mr Ric O'Barry is a former dolphin trainer who caught and trained the creatures that appeared in the iconic 1960s TV show Flipper. Now an animal-rights activist, he had a change of heart after he realised how miserable the intelligent, emotional animals were in captivity. Today, he works to undo the craze for live dolphin shows he helped spawn decades ago.

taken from from http://wildshores.blogspot.com/2010/02/will-there-be-dolphins-at-resorts-world.html