Thanks for your question.
>How many different type of whales are there in the world? Have any >been
>totally wiped out? If so which ones?
There are currently 11 recognised species of baleen whales (which includes
things like humpback whales and blue whales) and 67 recognised species of
toothed whales (which includes sperm whales and dolphins, and also the
little known beaked whales).
However, we are still in the process of discovering new species some of
which we just haven't seen before because they live very far out in the
ocean, such as Bahamonde's beaked whale off Chile (discovered in 1995), and
now perhaps yet another new species of beaked whale in the North Pacific off
California (Dalebout et al in prep), as well as at least 1 more species of
beaked whale known from sightings alone (Mesoplodon species "A") in the
Eastern Tropical Pacific. There also appears to be more than one species of
Bryde's whales, one of the medium sized baleen whales. A common form, a
Japanese coastal form and a Solomon Islands pygmy form, but scientists are
stilltrying to work exactly how these forms are related to each other.
We have not totally wiped out any species completely, although we did
exterminate all of the North Atlantic stock of gray whales by the end of the
18th century. The eastern North Pacific stock (California-Chukotka) was also
almost wiped out twice, once in the late 1800's and again, after a brief
respite in whaling had allowed numbers to recover a bit, in the early
1900's. Protected since 1946, this population has now increased to
apparently equal or even exceeding pre-exploitation numbers.
Northern right whales were also heavily exploited, and the population today
numbers only about 300 animals. Worryingly, this population does not seem to
be recovering either, even after years of protection.
The Chinese river dolphin, the baiji, is threatened by hunting and habitat
degradation. It now numbers only about 50 individuals, and it appears the
only hope for this species is to transfer all the animals to a specially
built captive facility near the river.
The vaquita, in the Gulf of Mexico, is another extremely endangered species.
Numbering only about 200 individuals, the vaquita's main threat is bycatch
in local fisheries.
Hope this information helps
PS Apologies if this is a double posting. I tried to send this message about
an hour ago but am not sure it went through
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