(They reproduce more slowly than other
fish do.): sharks are not able to repopulate or reproduce themselves quickly
and sharks are slow breeders.
(They are more likely to become extinct
than other fish.): This makes them much more vulnerable and in danger of dying
out than many other fish species.
A further example of endangered species is
the shark. Around 40 million sharks are killed each year. That's quite a lot.
Consequently the number of sharks is decreasing. So let's take a closer look at
the causes of this.
Firstly, in recent decades sharks have
become important. This is largely due to the growing popularity in some parts
of the world for the consumption of shark - it has become a very valuable food
source.
OK, so maybe you're thinking 'Well, lots of
other fish like cod, salmon or tuna are caught for human consumption and they
aren't disappearing at the same rate as sharks. ' Well, that's true. But the
difference here is sharks are not able to repopulate or reproduce themselves
quickly like the other types of fish that are commonly fished as a food source.
Why? Because sharks are slow breeders. Sharks mature slowly and it takes them
years to reach the age for egg production and then they produce only a few eggs
so that means just a few new sharks. Humans have a nine month pregnancy or
gestation period whereas some shark species are thought to have extremely long
gestation periods, as long as three years. This makes them much more vulnerable
and in danger of dying out than many other fish species.
