NOAA Teacher at Sea
Melinda Storey
Onboard NOAA Ship Pisces
June 14 – July 2, 2010
NOAA Teacher at Sea: Melinda Storey
NOAA Ship Pisces
Mission: SEAMAP Reef Fish Survey
Geographical Area of Cruise: Gulf of Mexico
Date: June 21, 2010
Weather Data from the Bridge
Time: 0800 hours (8 am)
Position: Latitude: 28º 09.6 minutes N Longitude: 094º 18.2 min. W
Visibility: 10 nautical miles
Wind Direction: variable
Water Temperature: 30.6 degrees Celsius
Air Temperature: 27.5 degrees Celsius
Ship’s Speed: 5 knots
Science Technology Log
Atlantic Spotted dolphins are the graceful ballerinas of the sea. They are just incredible! The Gulf of Mexico is one of the habitats of the dolphin because they live in warm tropical waters. The body of a spotted dolphin is covered with spots and as they get older their spots become greater in number.
Here you can see the spots on an older Atlantic Spotted Dolphin. To read more about dolphins go to
http://www.dolphindreamteam.com/dolphins/dolphins.html
Because Dolphins are mammals they breathe air through a single blowhole much like whales. Dolphins live together in pods and can grow to be 8 feet long and weigh 200-255 pounds. Like whales, dolphins swim by moving their tails (flukes) up and down. The dolphin’s beak is long and slim and its lips and the tip of its beak are white. They eat a variety of fish and squid found at the surface of the water. Since dolphins like to swim with yellow fin tuna, some dolphins die by getting tangled in the nets of tuna fishermen.
Newborn calves are grey with white bellies. They do not have spots. Calves mature around the age of 6-8 years or when the dolphin reaches a length of 6.5 feet. Calving takes place every two years. Gestation (or pregnancy) lasts for 11 1/2 months and babies are nursed for 11 months.
While watching the dolphins ride the bow wave, Nicolle and I wondered, “How do dolphins sleep and not drown?” Actually, we found that there are two basic methods of sleeping: they float and rest vertically or horizontally at the surface of the water. The other method is sleeping while swimming slowly next to another dolphin. Dolphins shut down half of their brains and close the opposite eye. That lets the other half of the brain stay “awake.” This way they can rest and also watch for predators. After two hours they reverse this process. This pattern of sleep is called “cat-napping.”
Dolphins maintain a deeper sleep at night and usually only sleep for two hours at a time. This method is called “logging” because in this state dolphins look like a log floating in the ocean.
The 1972 Marine Mammal Protection Act (MMPA) prohibits the hunting, capturing, killing or collecting of marine mammals without a proper permit. Permits are granted for the Spotted Dolphins to be taken if it is for scientific research, public display, conservation, or in the case of a dolphin stranding. The maximum fine for violating the MMPA is $20,000 and one year in jail.
Personal Log
Watching the dolphins playfully swim below us at the bow is like watching water nymphs. I can almost see them smiling. They spring out of the water just ahead of the ship and then peel off at a ninety degree angle. FAST doesn’t even begin to describe their movement. I especially enjoy watching some of them swim upside down, their white bellies gleaming. The CO is really good at spotting them far away. The dolphins swim straight toward the ship lickity-split as if someone just let kids out for recess and they run straight for the playground. We’ve seen some babies with their mothers as well as some older spotted dolphins. It is totally amazing to look straight down into their blowholes! You can even hear them “snort” when they come up for air. Never in my life did I think I would ever have an up-close and personal relationship with a dolphin!
The sunsets here are so spectacular. Check out the middle of the cloud on the left. If you look carefully you can see that the cloud has a heart-shaped opening. Last night’s sunset was purple and orange and just looked like a painting by one of the Masters. Our scientists have told us to watch for the “green flash.” If conditions are right and there aren’t many clouds, you can see a flash of neon green just as the sun plops below the horizon. We keep watching but so far no green flash.
The night is also spectacular. I’ve never seen so many stars in my life. One night I went out to the bow about 12:00am and it was pitch black. Then when I looked up, it was if God had thrown diamonds into the night sky. The half moon glistened against the ocean and the lapping of the water against the bow made it just so peaceful. You don’t see that many stars at home because of all the city lights. This is almost indescribable.
One evening the ship’s crew was fishing with fishing poles off the stern (back) of the ship when one guy said his hook had gotten stuck on something. I find that amazing since they were fishing 60 feet deep. He yanked and pulled and yanked again and finally pulled up what you see here.
The orange mass that you see here is a lot of animals called crinoids. They’ve wrapped themselves around a wire coral, which you can see here at the left side and the top right hand corner. The wire coral is green. The cool thing is all of this was alive and moving. Holding it felt surreal. It was somewhat like holding a big batch of worms.
New Term/Vocabulary
Pod – a group of dolphins
Slipstream – the wake created by the dolphins as they swim
Echelon – the dragging of the babies in the slipstream
Logging – a type of dolphin sleep where they are floating and they look like a log
Cat-napping – a light stage of sleeping
Fluke – the tail of the dolphins
“Something to Think About”
Dolphins are “social animals,” which means they travel together. What would be the benefits for traveling in pods?
“Did You Know?”
Did you know that a mama dolphin doesn’t stop swimming for the first several weeks after the birth of its young? This is because a baby needs to sleep and rest and can only do that by sleeping beside its mother. The baby sleeps while its mother swims, towing the baby along in her slipstream, the drag behind the mom. This is called echelon swimming. If the mother stops swimming, the sleeping baby will sink below the surface and drown.
