Sometimes you hear on the news that a shark attacked a human. Each year, around 70 people around the world are bitten by a shark. There are a lot of negative prejudices about sharks. Almost every movie depicts the sharks as dangerous creatures for humans.
I can understand that these movies and stories make you feel scared for sharks. There are also many people that like metal detecting that are very afraid of these prehistorical beasts. They are very scared, because they know that sharks can observe electromagnetic fields.
When you want to go metal detecting in the sea, you might want to know if your metal detector attracts sharks.
The answer is no. According to research by Oregon Wave Energy, sharks will only detect a weak electromagnetic field with frequencies between 1/8 and 8 Hz. The average waterproof metal detector sends out electromagnetic fields with frequencies between 5 and 20 kHz.
This is 1000 times more than the frequencies that sharks will recognize. This means that you don’t have to worry about attracting sharks with your metal detector.
In this article I will tell you everything that you need to know when you want to go metal detecting in the sea. I will mention the most important things that attract sharks. I will also give you an advice about reducing the chance that you get bitten by a shark during metal detecting in the water.
General information about sharks
Sharks are a group of cartilaginous fish. This means that the skeleton of a shark is fully made of cartilage. The oldest fossils of a shark are already 400 million years old. The average shark has a life expectancy of 20 to 30 years.
Sharks are never toothless. This means when a shark loses its first teeth row, it will be replaced by new teeth from the second row and so on. A shark uses more than 1000 teeth during a lifetime!
There are 375 shark species, divided into eight groups. The size of a shark can vary between 20 centimeters and 12 meters. A shark breathes with its gills. On both sizes of the head of the shark are five gill slits located.
When a shark closes its mouth, the water can get into the gills. The gills take out the oxygen from the water. A shark can see, taste, hear and smell very good. Sharks can smell a single drop of blood from 0.62 miles (1 kilometer)!
But there is one thing that scares the most of the people who like to metal detect: sharks can observe electric currents and magnetic fields…
How does a shark observe an electromagnetic field?
A shark can observe an electromagnetic field because a shark has a special extra sense. This sense is called the ‘’Ampullae of Lorenzini’’ (electroreceptors). These electroreceptors are located on the head of the shark. A shark is able to observe a little electromagnetic field with these electroreceptors.
What is the most important purpose of these electromagnetic organs?
These electroreceptors have three main functions for the shark:
1. Navigation through turbid ocean water
Sharks can use their electroreceptors to detect electromagnetic fields to navigate through the ocean. They can especially use this skill in turbid ocean waters where their other senses may be limited. The shark uses the Earth’s magnetic field to orient itself and navigate through the ocean.
2. Hunting for hidden prey
All living animals in the ocean produce little electromagnetic fields. The shark uses their electroreceptors in the end stage of prey capture. The shark can find fish under the sandy bottom by using his electroreceptors.
3. Finding food-rich volcanic islands
A shark can find food-rich volcanic islands by using his ability to detect electromagnetic fields. A shark can find food-rich volcanic island because the rocks are magnetic in these areas.
Does my metal detector attract sharks because sharks have electroreceptors?
Allright, a shark can observe an electromagnetic field with his head…. and a metal detector also produces an electromagnetic field….. Does this mean that I attract sharks when I am metal detecting in the sea?
The answer is no. Sharks will only detect weak electromagnetic fields. These weak electromagnetic fields have frequencies between 1/8 and 8 Hz while the average waterproof metal detector produces frequencies that are 1000 times higher than this. You don’t have to worry about getting bitten by a shark while metal detecting.
But… there are some other things that attract sharks. You should definitely be aware of these factors. The main factors that attract sharks are:
1. Blood
Sharks have a really good sense of smell. Sharks can easily smell only one single blood drop from a mile away. Blood is therefore really attractive for sharks.
2. Sound
According to scientists, sound is the main reason why sharks move into an specific area. Sharks can be attracted by special sounds like a prey in trouble. Sharks can hear the sounds from 250 meters. The sharks are especially attracted to irregular sounds below 50 Hertz.
3. Food
Food can also be an important factor for attracting a shark. When a shark is hungry, he wants to eat. The most sharks are hunting for prey at dusk and dawn.
4. Color
There are some scientific experiments that indicate that sharks react to some specific colors. The colors: silver, yellow and white might attract sharks.
5. Shiny jewelry
Silver shiny jewelry that reflects the sunlight could look like little fish in need. It is definitely not a good idea to wear silver jewelry while swimming in a sea where sharks live.
What are the most dangerous sharks for human?
1. The great white shark
This is one of the largest sharks in the ocean. The great white shark is known as the shark that has the most attacks on a human on his name. The great white shark often eats big prey.
2. The bull shark
The bull shark is a shark that is unpredictable and aggressive. The shark often shows up in warm, shallow coastal waters. This is why he is really dangerous for humans.
3. The tiger shark
This shark is also one of the largest sharks in the ocean. The tiger shark is a carnivore. You may know this shark, because he has a skin that looks like a tiger skin. A tiger shark can become really aggressive when he feels threatened.
How can I reduce the chance of getting bitten by a shark during metal detecting?
- Avoid wearing silver jewelry. This could look like a little fish in panic. The ideal prey for a shark. Make sure that you don’t wear silver jewelry during metal detecting in the sea.
- Avoid little wounds. A shark can smell your blood from a mile away. Make sure that your wear good protective clothing while metal detecting in the sea. This will reduce the chance of getting a little wound that produces blood.
- Try to avoid to search in cloudy water. When you are searching in cloudy waters, a shark may see you as a seal. This is a prey of the shark. Make sure that you only search in clear water. This will reduce the chance that a shark sees you as a prey. You can also better see the shark if you search in clear water.
- Try to avoid to be in the water when a school of fish passes you. Sharks like to eat little fish, so try to avoid to get too close to a school of fish when you are metal detecting in the sea. You can recognize a school of fish by the seabirds that are flying above them.
- Don’t make noises that look like a fish in need. Sharks are attracted by sounds that look like a prey in need. Do not produce these sounds when you are metal detecting.
- Do not detect during twilight. The most of the time the sharks will hunt for prey during the night. At these times a prey can’t see the shark. Try to avoid metal detecting at night, because there is always a chance that a shark sees you as a prey.
- Don’t go too deep into the sea. The deeper you go into the sea, the higher the chance of encountering a shark. Try to stay close to the coastline when you are metal detecting in the sea.
- Stay close to a friend. Try to stay close to a friend. The chance that a shark attacks you when you are with a friend is much smaller than when you are alone. The chance of spotting a shark is also higher when you are with your friend. This will make you better prepared.
Final Conclusion
You don’t have to worry about getting bitten by a shark during metal detecting in the sea because sharks are not attracted by the electromagnetic field of your metal detector.
Sharks won’t attack you if they don’t have a reason for it. You can decrease the chance of getting bitten by a shark by avoiding little wounds that produce blood, searching by night, wearing silver jewelry, and making sounds that resemble prey in distress.
Frequently Asked Questions
Where do the most of the sharks live?
Sharks almost live in every ocean around the world except from the cold waters around the north and south poles.
Always try to stay calm. Probably the shark won’t attack you if you don’t make him feel threatened. When you have the feeling that he is going to attack you. Try to scream for help and stay in front of the shark because the most of the sharks will attack you from behind.
The most dangerous sharks are the great white shark, the tiger shark and the bull shark. These sharks are very big and they can be really aggressive when they feel threatened.