In 2016, scientists in Greenland discovered a 400-year old shark, evidence that some sharks can live for well over 100 years. It’s believed that Dogfish and Whale sharks species live for more than 100 years. But of course, each shark species has a different life expectancy.
Determining the age of sharks
It’s challenging to monitor sharks in the water, particularly because of their migration and feeding patterns. Research around the life expectancy of sharks in captivity has found that they live shorter lives than sharks living in their natural habitat. It’s understandable why it would be impractical to generate deductions from sharks living in captivity.
However, scientists still have a way of determining the age of sharks. They count the number of growth rings that develop on sharks’ vertebrae, with each ring standing for one year. Even so, the average life expectancy varies for each shark species. Here’s the average life expectancy of common shark species:
- Blue Shark: 15 to 16 years
- Sandbar and Brown sharks: 20 to 30 years
- Silky sharks: average 25 years
- Hammerhead sharks: 20 to 30 years
- Great White Shark: an average of 30 years. New research suggests that Great White sharks can reach up to 40 years of age.
Sadly, the lifespan of some shark species is shortening and scientists have reason to believe it’s a result of sharks living in captivity. They found that sharks held in small tanks have a life expectancy of only nine years.
With the above mentioned in mind, it’s clear that sharks should be living in their natural habitat if we want to protect their species.
Where do sharks live?
Different shark species adapt to different water temperatures. There are three main ocean regions where sharks can be found: tropical, polar and in between.
Tropical: tropical ocean regions are near the equator. Shark species such as the Hammerhead Shark and Nurse Shark are prone to live in tropical temperatures.
Polar: ocean regions close to the polar caps. Shark species such as Dogfish, Greenland and Sleeper shark can adapt to icy waters.
In between tropical and polar: these sharks live in between the tropical and polar ocean regions. However, the larger sharks such as the Great White Shark and Basking Shark can alternate.
Why sharks shouldn’t be kept in captivity
Why shouldn’t sharks live in tanks? Well, there are many reasons why sharks shouldn’t be kept in captivity. One reason is that sharks have sensitive senses. Most shark species have between 10 to 13 senses. A captive environment, therefore, causes for sharks to become frustrated, seeing that noisy crowds are a norm at aquariums. Imagine what it must be like inside a tank that’s a minute fraction of their natural habitat with sharp senses.
Learn more about why sharks can’t be kept in captivity.