Lots of whale questions

From: Phil Clapham (phillip.clapham@noaa.gov)
Date: Wed Sep 13 2000 - 08:43:36 EDT


Hello! And thanks for the questions. Here are some answers...

 
> from Mitchell and Jenna M.: When humpback whales bubble net feed, how do the fish get caught in the bubbles? What kind of whales are there other than baleen?
Good question! Well, the fish don't exactly get caught IN the bubbles.
There are two ways that humpbacks use bubbles to trap fish. The first
is a bubble net. This is where the whale blows a number of columns of
bubbles to make a big circle or a spiral around the fish. The fish
can't get through the bubbles, so it's like a big "net" around them.
Then the whale comes up in the middle of the net with its mouth open and
catches the fish. The second method is a bubble cloud. this is where a
whale blows one huge burst of bubbles (probably from the mouth) to make
a giant cloud that's sometimes 60 feet across. The bubbles confuse the
fish, make it very difficult for them to swim, and maybe even make them
bunch up together more tightly (this is what they do in response to an
attack by other fish; it's a very good reaction mostly, because big fish
are usually trying to get one little fish at a time. it's a lousy
reaction to a whale because the whale wants to eat the whole school!)

The other kind of whale other than a baleen whale is a toothed whale.
Most cetaceans (the name we give to all whales, dolphins and porpoises;
it's pronounced se-TAY-shun) are toothed whales - dolphins, porpoises,
beaked whales and the sperm whale. The sperm whale is the only really
large whale with teeth - all the others have baleen.

 
> from Annabel and Nicholas: How many whales have you seen in your life?
Wow! I don't know. Tens of thousands. I've seen more humpbacks and
fin whales than anything else, but also minke whales, right whales,
bowheads, grays, blue whales and sei whales.

> from Jean-Paul and Sophia: What is the shortest whale recorded? What is the greatest depth a whale can dive? What is your favorite whale? How high can an Orca jump out of the water?
It depends on what you mean by "whale". If you mean the great whales,
then the smallest is the pygmy right whale (which some people don't
consider a great whale), which is at most 15-20 feet long. Minke whales
reach 25-30 feet. If "whale" means "cetacean", then that includes all
the porpoises, and the smallest is the vaquita, which is only about 4
feet long.

The greatest depth a whale can dive to is more than 7,000 feet for a
sperm whale (these are the greatest divers of all). There is some
evidence that sperm whales can dive to 10,000 feet, but the 7,000+ ft
record came from a tagged whale, so we know it's correct.

My favorite whale is the humpback.

An orca can clear the water in a breach (jump), so probably it can get
its head at least 20 feet above the water.

> from Nicky A. and Dannie: Have you gone scuba-diving with whales and how did you start being interested in whales?
I've never scuba-dived with whales, but I have spent a fair amount of
time snorkelling with them (humpbacks). It's very cool to see them
underwater! I first became interested in whales twenty years ago, when
I saw a humpback whale off Cape Cod. I started volunteering for a small
research organization, and went on from there.

> from Grace and Chris: Has anyone ever brushed whales' teeth before maybe while in captivity? Appropoximately how many whales are there in the world?
Wow, I've never had THAT question before! I really don't know the
answer. I would guess that aquaria staff do some dental checks on
captive dolphins and whales, but whether this includes brushing I'm not
sure!

There is no way to tell how many whales are in the world. The oceans
are too big and whales are too elusive. There are some estimates for
some large whales (for example, maybe 30-50,000 humpbacks worldwide),
but they're really just guesses. But the answer is certainly in the
hundreds of thousands, if not more.

> from Rebecca and Nick: How many different whale species are there?
There are about 80 species of cetaceans, of which around a dozen are
large whales. There are some species that are rarely seen (one, the
Longman's beaked whale, has never been seen alive and we know about it
only because of a couple of carcasses washed up on a beach!). there are
also lots of scientific arguments about what a species is. For example,
we have recently decided that the right whales of the North Atlantic,
North Pacific and southern hemisphere are three separate species.

Thanks for asking!

Phil Clapham

-- 

Phillip J. Clapham, Ph.D. Large Whale Biology Program Northeast Fisheries Science Center 166 Water Street Woods Hole, MA 02543

tel (508) 495-2316 fax (508) 495-2258 Internet: phillip.clapham@noaa.gov



This archive was generated by hypermail 2b30 : Sat Aug 04 2001 - 10:40:13 EDT