From: Christopher Gribbon [c.gribbon@dundee.ac.uk] Sent: Wednesday, June 27, 2001 11:30 AM To: blue_planet@lists.ient.com Subject: Re: [BLUE PLANET] - Cetacean diving >Does anybody on this list know the answers to the following questions: > >1. How long can dolphins and orcas hold their breathes? > >2. How deep can they dive? I recall offhand that the answer to 1 is "Half an hour" in the BP book. I *think* that the answer to 2 would be "as far as you can swim in 15 mins", but I wouldn't bet my life on it. *************************************************************************** To unsubscribe from this list send mail to majordomo@lists.ient.com with the line 'unsubscribe blue_planet' as the body of the message. From: Cjbeiting@aol.com Sent: Wednesday, June 27, 2001 10:16 AM To: blue_planet@lists.ient.com Subject: [BLUE PLANET] - Cetacean diving Does anybody on this list know the answers to the following questions: 1. How long can dolphins and orcas hold their breathes? 2. How deep can they dive? Any info would be appreciated. CJ Beiting CJBeiting@aol.com *************************************************************************** To unsubscribe from this list send mail to majordomo@lists.ient.com with the line 'unsubscribe blue_planet' as the body of the message. From: R. Alexander Andersen [blood_dragon@hotmail.com] Sent: Wednesday, June 27, 2001 12:17 PM To: blue_planet@lists.ient.com Subject: Re: [BLUE PLANET] - Cetacean diving > > >Does anybody on this list know the answers to the following questions: > > > >1. How long can dolphins and orcas hold their breathes? > > > >2. How deep can they dive? > >I recall offhand that the answer to 1 is "Half an hour" in the BP book. >I *think* that the answer to 2 would be "as far as you can swim in 15 >mins", but I wouldn't >bet my life on it. Hi, this is my first posting to this list.. As a cetacean "fanatic" and student in marinebiology specializing in cetaceans it varies indvidually. The largest record was held by a orca for depth, as it was found in a underwater telephonecable at the bottom of the sea. As far as I know these guidelines could be helpful for anyone who would like to play a cetacean or with them.. One bottlenose dolphin repeatedly dived almost 300 metres and stayed down for 5 minutes. Pilot whales have reached 600 metres on 16-minute dives. The record dolphin dive belongs to an orca off Alaska that became entangled in telegraph cable at a depth of 1,030 metres. Thats the depth extremes.. Dolphins can be considered to have a free dive limit and its a continuous process: moving to surface for every breath, swimming 24 hrs/day whole life. Average 5 knots:Max velocity about 30 knots. with regards Tidedancer Aka Nacha Aka Alexander _________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com. *************************************************************************** To unsubscribe from this list send mail to majordomo@lists.ient.com with the line 'unsubscribe blue_planet' as the body of the message. From: Sir Charles [chalz@earthlink.net] Sent: Wednesday, June 27, 2001 12:34 PM To: blue_planet@lists.ient.com Subject: Re: [BLUE PLANET] - Cetacean diving > 1. How long can dolphins and orcas hold their breathes? > > 2. How deep can they dive? Tagging my memory from the 'Dolphins' IMAX show, it's 8min for dolphins, and I believe 50 meters deep. But, this isn't the 'uplifted' sort ;) You also have to mind that dolphins are *incredibly* powerful swimmers. Ever notice how high they can jump out of the water from a very shallow depth? *************************************************************************** To unsubscribe from this list send mail to majordomo@lists.ient.com with the line 'unsubscribe blue_planet' as the body of the message. From: Heivilin, Jim [banzai@missouri.edu] Sent: Wednesday, June 27, 2001 1:19 PM To: 'blue_planet@lists.ient.com' Subject: RE: [BLUE PLANET] - Cetacean diving > -----Original Message----- > From: R. Alexander Andersen [mailto:blood_dragon@hotmail.com] > Subject: Re: [BLUE PLANET] - Cetacean diving > Thats the depth extremes.. > I beg to differ but I can't recall the source of my information off the top of my head, however, sperm whales can hold their breaths in excess of four hours and can dive to depths of 10,000 feet. Of course that doesn't answer the original question, since in the Blue Planet timeline all other cetaceans are extinct. > Dolphins can be considered to have a free dive limit and its a > continuous process: moving to surface for every breath, > swimming 24 hrs/day whole life. Average 5 knots:Max velocity > about 30 knots. > Dolphins are considered to "sleep" about four hours (IIRC) in every sixteen or twenty-four. However half their brain is awake and monitoring their environment during this "sleep". Jim *************************************************************************** To unsubscribe from this list send mail to majordomo@lists.ient.com with the line 'unsubscribe blue_planet' as the body of the message. From: David R. Crowell [gpfarm-dave@northnet.org] Sent: Wednesday, June 27, 2001 2:40 PM To: blue_planet@lists.ient.com Subject: Re: [BLUE PLANET] - Cetacean diving In doing some research today in an attempt to answer my own question about the sleep cycles of dolphins I came a across some rather interesting information. It appears that Dolphins spend up to 33% of their lives in a state of "resting" with only one hemisphere of their brain active. According to most scientists dolphins do not (can not?) enter REM sleep, this verified by observation and EEG. Another source listed an observed 6 minutes of REM sleep in a pilot whale. Other whales appear to enter true sleep for varying periods of time. The reason for dolphins sleeping this way is that they must be conscious in order to breathe, unlike humans who breathe automatically. Dolphins are also very active during a portion of the night, this is thought to correspond to the time when prey fish are close to the surface. Given these oddities of dolphin sleep, perhaps they are not affected as much as humans by Posieden's longer local "day". the lack of REM sleep and dreaming suggests interesting possibilities for mis-communication between humans and cetaceans. Perhaps part of the uplift process gave dolphins the ability to dream? Certainly dolphins live in a much more three dimentional world than humans do. And a world shaped more by sonar than by sight. This doubtless has profound effects on their mental structure, perception influencing reality as much as reality influences perception. Something also for the linguists to add to the debate on how language shapes mental constructs of the world. Just a few thoughts. --dave ----- Original Message ----- From: Heivilin, Jim 30 knots. > > > Dolphins are considered to "sleep" about four hours (IIRC) in every sixteen > or twenty-four. However half their brain is awake and monitoring their > environment during this "sleep". > > Jim > *************************************************************************** *************************************************************************** To unsubscribe from this list send mail to majordomo@lists.ient.com with the line 'unsubscribe blue_planet' as the body of the message. From: Cjbeiting@aol.com Sent: Wednesday, June 27, 2001 3:23 PM To: blue_planet@lists.ient.com Subject: [BLUE PLANET] - Re: Cetacean Diving Thanks for the information, Alexander. Please let me ask another question: if dolphins can get down to 300 meters (and the Orca record is over 1000), how do they avoid "the bends" that we get? CJ Beiting CJBeiting@aol.com *************************************************************************** To unsubscribe from this list send mail to majordomo@lists.ient.com with the line 'unsubscribe blue_planet' as the body of the message. From: David R. Crowell [gpfarm-dave@northnet.org] Sent: Wednesday, June 27, 2001 3:52 PM To: blue_planet@lists.ient.com Subject: Re: [BLUE PLANET] - Re: Cetacean Diving Iirc it has to do in part with the fact that they are not breathing pressurized gas at depth. There is something else metabolically different about them too I think. Presumably Divers have the same metabolic differece although Squid do not. That at least would be my interpretation of the depth limit differences for Divers and Squid in the rulebook. ----- Original Message ----- From: To: Sent: Wednesday, June 27, 2001 4:22 PM Subject: [BLUE PLANET] - Re: Cetacean Diving > Thanks for the information, Alexander. > > Please let me ask another question: if dolphins can get down to 300 meters (and the Orca record is over 1000), how do they avoid "the bends" that we get? > > CJ Beiting > CJBeiting@aol.com > *************************************************************************** > To unsubscribe from this list send mail to majordomo@lists.ient.com > with the line 'unsubscribe blue_planet' as the body of the message. > > *************************************************************************** To unsubscribe from this list send mail to majordomo@lists.ient.com with the line 'unsubscribe blue_planet' as the body of the message.