This dataset contains the locations of a leatherback turtle, a northern elephant seal, and two white sharks for each day over the course of several months. The data used was taken from topp.org (TOPP stands for Tagging of Pelagic Predators), a site that tracks marine animals in an attempt to learn more about them. TOPP's goal is to protect marine wildlife from overfishing, climate change, and various other threats. The purpose of this dataset is to serve as an example of a hand-made animal tracking dataset. For a more extensive dataset using data from TOPP, go here.
The light green track represents a leatherback sea turtle's movements from January 25, 2004, to January 22, 2005. It was caught and tagged near the coast of Costa Rica before heading back out to sea. Leatherback turtles, also known as lute turtles, are born in tropical jungles near shore, but they can swim hundreds of miles north in search of their favorite foods: jellies. They are the largest species of sea turtle, sometimes reaching lengths of over six feet, and also hold the record for deepest divers - they can dive to over 1000 meters below the surface. Leatherback sea turtle populations are declining rapidly all over the world. To save them, we need a better knowledge of where they nest, where they migrate, and where their preferred habitats are.
The gold-brown track represents a northern elephant seal, from the time it was tagged off the coast of California on June 10, 2005, to March 7, 2006. Elephant seals have their name because the males (the bulls) have a long, floppy nose called a proboscis, similar to an elephant's trunk. Northern elephant seals (the species shown in this dataset) are slightly smaller than southern elephant seals, but travel much further - they are the only mammal known to make two long distance migrations per year. An elephant seal typically travels from a breeding colony in Mexico or California up to Alaska to hunt during their first migration, then returns to the breeding colony to molt its fur. Then it will return to Alaska to feed again, before coming back to the breeding colony a second time to mate. Elephant seals hunt for their food - sharks, large fish, crab, squid, and even octopus - by diving.
Both the white and the light blue tracks represent great white sharks, tracked over the same time period as the leatherback turtle. The largest white shark ever recorded was 6.4 meters long, although most white sharks are between 3.5 and 4.6 meters. White sharks have an extra sense that humans don't: electroreception, the ability to sense electricity. They use it to sense the position of their prey while they hunt. White sharks will also put their head above water, or occasionally, "breach" (jump) as high as two meters out of it to inspect their prey! White sharks can live almost as long as humans, with maximum lifespans of over 70 years. The species was once thought to live only near shorelines, but recent data from tagged sharks, such as the sharks shown here, has revealed that they are just as likely to spend their time far out in the Pacific.
This dataset was created using Quantum GIS (or QGIS, or Quantum Geographic Information System), which is a "free, open source geographic information system." A tutorial is available that will walk you through the basics of using QGIS to create SOS-formatted maps, including this one. In addition to this dataset, the tutorial also walks through the creation of the Earthquakes and Nuclear Power Plants dataset and the Global Statistics dataset.