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Many scientists have always been confused about how animals can go through long journeys and not get lost on the way, especially in the ocean. Most have discovered that migrating animals can use magnetism to tell where they are, but they are still not sure how this works. Kenneth Lohmann of the University of North Carolina at Chapel Hill, along with a few researchers and graduate students, made an important discovery by tracking the movement of young sea turtles in a large tank. They attached a computer onto each turtle to control the magnetic field surrounding them. Then, they created magnetic fields that are similar to those found during a turtle's journey across the Atlantic Ocean.
When the turtles were surrounded by a magnetic field found on the west part of the Atlantic (near Puerto Rico), they swam in a northeastern direction. When they were surrounded by a magnetic field found on the east side of the Atlantic (near the Cape Verde islands), they generally swam towards the southwest. This shows that sea turtles can figure out what type of magnetic field they are in and use that to swim in the right direction.
The researchers found that sea turtles use the strength of the magnetic field and the inclination (angle in which the field intersects Earth) to determine which way to swim. Lohmann and Putman explained that near the Equator, magnetic field lines are almost parallel to Earth. (see the picture) The farther away you are from the Equator and the nearer you are to the North/South poles, the steeper these lines become. Also, magnetic fields are usually stronger near the poles and weaker near the Equator.
This discovery can help scientists track the movement of sea turtles more effectively. It also helps our understanding of navigation, and may be useful for ships traveling across the ocean. From reading this article, I wonder if other animals can also find their location this way. If so many other animals can find out about the magnetic field around them and where they are, why can't humans? Did we lose a gene or trait that finds magnetism? I hope scientists will do similar experiments on other migrating sea animals and figure out how they detect magnetism from the Earth.
- "Migrating Sea Turtles Have Magnetic Sense for Longitude." Science Daily 28 Feb.
4 comments:
Excellent details given, lots of facts and information in your post.
Really insightful questions too; you bring up interesting points. I think that in the discussion paragraph, though, more content is needed. Expand on your reflections after reading the article rather than the questions.
Great job!
Hey Cindy, great article choice!
Your title instantly drew me in, and it was interesting to read your blog post about sea turtles. Your summary was effective, but at first was a little confusing.
Reading your blog, I had some of the same questions. I think some birds do the same thing, but I'm not sure.
Great job!
You did a good job on explaining how the experiment was conducted and the results. However, you can include more on your discussion.
For your question about other species using the same method as sea turtles, birds are another type of animal which also use magnetic poles to navigate, especially during migration.
Hi Cindy,
I have read other articles about the topic of animals using magnetism to keep on track during migration. You mentioned that during the experiment, the turtles would swim in a certain direction depending on the magnetic field. Does that mean that if the magnetic field of the Earth changes, which many scientists predict is happening or will happen soon, the migration for all the turtles will be off? Magnetic pole changes have occurred in the past, so how would the animals adapt? Additionally, I have watched a documentary, in which they found a small amount of magnetic material in the human brain, and you mentioned that we might have lost the gene for it. Perhaps, it is because we no longer have the need to migrate.
Good work!~
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