Shark Tags: Taking a Bite out of this Deep-Sea Mystery In Hawaiian mythology, sharks were considered gods called Aumakua and were guardians of the sea. Today, the image of a shark's dorsal fin slicing through water strikes fear into many who believe that sharks are bloodthirsty killers. These misconceptions have continued throughout the years because little is known about sharks. However, with increasing technology comes increasing knowledge about these misunderstood animals.

Surprisingly, Greek philosopher Aristotle was one of the first to study sharks. Aristotle was intrigued by marine biology. He recorded the first scientific study of sharks and their relatives, and was the first to group them together as one family since they have cartilage instead of bones. Aristotle wrote about sharks in his book On the History of Animals in 350 BC. His studies are the basis for much of today's knowledge of sharks.

What would Aristotle learn if he were able to use today's technology? In his time fishermen cut small notches in tails of fish in order to study population and to see where they traveled by capturing and releasing them again.

Not much has changed in the way sharks are studied today, but advances in technology have helped scientists to learn information that is more exact. One of the most up-to-date tagging systems uses satellite technology to study sharks. Scientists use "tags" equipped with satellite transmitters so they can learn swimming and migration patterns, diving depths, and feeding locations. It can also help measure age and growth by allowing scientists to locate the shark again for more study.

The satellite tag used by the National Oceanic and Atmospheric Administration (NOAA) is composed of an ARGOS satellite transmitter, long-life batteries, and aerial and saltwater switches. All of these components are encased in a waterproof resin pod that is attached to the base of the shark's dorsal fin. It is streamlined in design and lightweight so it will not interfere with the shark as it swims.

The transmitter sends a unique shark identifying code with radio waves to orbiting satellites that have the ARGOS receivers. The signal from the tag is then sent to a lab where a biologist can plot the shark's track and study the data.

Because radio waves do not travel well underwater, especially at the varying depths the shark can live in, the tag records and saves all the information and then sends it in spurts whenever the shark's fin is out of the water. The saltwater switch on the tag ensures that it does not transmit when underwater so it can save battery power.

Of course, before scientists can tag a shark, they have to catch it first! This also hasn't changed much from the past. There are various methods depending on the type and size of the shark. They usually involve nets or tools that hold a shark's tale. In all cases scientists and fishermen who participate in tagging programs are trained how to capture, tag, and release the sharks safely. In order to study them, the sharks need to live a full, healthy life.

Once the shark is tagged and measured it is released. Scientists push the shark through the water until it starts swimming under its own power to ensure its well-being.

By studying things like migration patterns scientists can help sharks and humans coexist safely. They would know where to avoid areas where there is a chance of being attacked such as breeding grounds and feeding grounds. Through tag studies scientists have learned these to be very specific. Fisherman could also lessen the amount of sharks accidentally caught in their nets by avoiding areas of high traffic.

Learning the nature of sharks can stop misunderstandings and make it possible for sharks and humans to live together peacefully. As you can see, it takes teams of creative minds, technology, and time, to learn about these mysterious animals.