Hello Again Loggerhead Fans!
After last weeks's update, we bet you are wondering if transmitter #11462 is still attached to its loggerhead or if it is broken off and drifting on its own like all the others. Today's news is "So far, so good"--it looks like transmitter #11462 is still attached to its turtle! Hurray!!!! "Hang in there #11462!"
Dr. Standora has sent us new data from that transmitter which we have put at the base of this update. As usual, be sure to chart the movements of turtle #11462 and compare them to its movements from last week. Do you notice any interesting changes?
In last week's update, we challenged you to think about why Dr.Standora designed a transmitter that would break away. Here's what Dr. Standora had to say:
"It's very important to use breakaway links when attaching transmitters to air breathing aquatic animals. Animals that feed on benthic (bottom living) organisms might have the transmitter tether get caught on rocks or on coral. This would prevent the turtle from reaching the surface and it would drown. Even pelagic (open water) animals could become entangled in floating debris. Locations where currents meet often collect floating objects. This might provide an abundance of food items, but toxic materials may also be more concentrated at these areas of convergence."
"A serious open ocean problem now are "ghost nets". These are floating nets that may be many miles long and have been lost by their owners. These nets continue to capture fish and other animals until they become so heavy they sink. We design our tethers so they will separate with a hard pull, or will corrode away with time. We don't want the turtle to have the transmitter attached to its shell for the rest of its life."
"These transmitters can with time have fouling organisms attach to their surfaces. The transmitter would then be too heavy to float and would be a constant drag on the turtle. To prevent this we coat the transmitter surface with a special paint which inhibits the growth of organisms."
"Thinking of turtles getting trapped in floating nets reminds me of a time in Costa Rica when Steve Morreale and I had to dive in the water and free an adult leatherback that had become entangled in a mooring line. The turtle had been swimming between boats and its front flipper caught on a rope which had a heavy weight on one end and a float on the other. Every time the turtle took a stroke it looped more rope around its flipper. We put on our masks and snorkels and after wrestling with the several hundred pound turtle managed to cut it free. Without our efforts the turtle surely would have drowned."
Announcing The Journey North Turtle Transmitter Contest (Part 2)
While you may only have intended to learn just about turtles, you now know more about the Gulf Stream than most people on earth! Last week, in Part 1 of the contest we challenged you to estimate the location where transmitter #09037 would be on March 24, 1996, when its batteries ran out of power. Are you ready for Part 2?
Using all the data you've received this spring for transmitter #09037 since it broke loose (see below), can you answer these questions:
Challenge Question # 77
"How fast does the Gulf Stream appear to travel?" and "Where and when do you think the transmitter will reach shore?
(Please provide an exact date and location. Follow the instructions at the base of this update on how to respond to the challenge question.)
Although the batteries in this transmitter are no longer functioning, we can still track it. Try to predict its future movement based on where it has drifted so far. In the next weeks, we will contact an oceanographer who studies the Gulf Stream and ask for his opinion on this Challenge Question.
New Data for Turtle # 11462
Mar. 22: 38.085N, 45.497W
Mar. 23: 38.085N, 44.739W
Mar. 23: 38.017N, 44.638W
Data Points for Transmitter #09037
(After it broke away on Feb 6)
Feb. 06: 35.780N, 73.546W
Feb. 10: 37.427N, 68.767W
Feb. 11: 37.254N, 68.460W
Feb. 12: 37.071N, 68.343W
Feb. 13: 36.819N, 68.107W
Feb. 13: 36.768N, 67.998W
Feb. 17: 37.021N, 67.627W
Feb. 18: 36.962N, 67.483W
Feb. 19: 36.956N, 67.530W
Feb. 20: 36.968N, 67.665W
Feb. 23: 37.271N, 68.813W
Feb. 24: 37.277N, 68.241W
Feb. 25: 36.991N, 67.737W
Mar. 01: 36.575N, 68.281W
Mar. 02: 36.735N, 68.508W
Mar. 03: 37.087N, 68.777W
Mar. 04: 37.111N, 68.624W
Mar. 08: 37.522N, 67.425W
Mar. 09: 37.533N, 66.829W
Mar. 10: 37.607N, 66.220W
Mar. 11: 37.811N, 65.528W
Mar. 15: 37.617N, 63.932W
Mar. 16: 37.757N, 63.705W
Mar. 17: 37.459N, 63.530W
Mar. 18: 37.141N, 63.325W
Mar. 22: 36.845N, 61.122W
Mar. 24: 37.118N, 60.608W
How to Respond To Challenge Question # 77:
1. Address an e-mail message to: jn-challenge@learner.org
2. In the Subject Line of the message write: Challenge Question # 77.
3. In the body of the message, give your school's name and location and answer this question:
"How fast does the Gulf Stream appear to travel?" and "Where and when do you think the transmitter will reach shore?"
The Next Loggerhead Sea Turtle Migration Update Will be Posted on April 17, 1996
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