WhaleNet
A Day on a Whale Watch
INFO LINKS
Assumed teacher materials:
nautical chart, Gulf of Maine or other & enlarged simplified
version to track trip
(Instructor can highlight entire course of the trip beforehand to use as
reference)
Globe or world map
Stellwagen Bank poster
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Blue, fin, humpback, minke and sei whales all belong to a group of baleen
whales that whalers named rorquals. This name comes from the Norwegian ror, tube, and hval, whale. These whales have a number of folds, or tube-like
grooves on the throat and chest. We sometimes call them "gulpers"
because when they feed they usually gulp a single huge mouthful of water
and fish. As the water enters the mouth these grooves stretch, the floor
of the mouth ballooning out to form an enormous pouch that increases by
as much as 5 times the amount of fish and water they can take in. When
they close their mouths those grooves contract forcing the salt water out
through the baleen. The food is trapped inside.
22
Even though baleen whales don't live in families, they do sometimes
travel together for a while. If two or more whales are traveling within
50 - 70 feet of each other, and performing the same behaviors, it is called
an "association." These associations may be quite brief, lasting
only a few minutes, maybe several hours, days, or even weeks.
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The Basking shark, which can grow to a length of 45 feet, is second
only in size to the giant Whale shark. Despite their size these sharks
are almost completely harmless. They have 4 to 7 rows of very tiny teeth
which are not used for feeding. 5 large gill openings circle the neck.
Each opening has a gill arch covered with bristle like gill rakers. The
gill rakers look like a whale's baleen. In fact the scientific name for
the basking shark, Cetorhinus maximus, means "big whale- nosed"
shark.
Basking Shark Slide Show
ceto = whale, rhinus = nose, maximus = big
Like baleen, the gill rakers are used to strain very small food from the
water.
24
Fan was first seen in 1988. In 1993 she was seen with her first
known calf, named Slant. The scars on her fluke reminded researchers of
a spreading fan. These scars are from the teeth of orca (killer) whales.
Many orcas feed only on fish like salmon. But some prefer to hunt marine
mammals like seals, dolphins, and even the great whales. About 15% of the
humpbacks that have been identified have orca teeth scars on their bodies,
fins, or flukes.
Crystal was born in 1980, when he was first seen with his mother,
Salt. How old is he now? His mother was the first humpback whale to be
given a "name." She has white scarring on her dorsal fin that
looks like dry caked salt. Her first know calf was named Crystal, because
he is a little piece of her, a "crystal of salt."
Crystal now has many brothers and sisters: Halos, born in 1983, Thalassa
born in 1985, Brine born in 1987, Bittern born in 1989 and Salsa born in
1991. In 1992 Crystal's sister, Thalassa gave birth to a calf named Skeeter,
so he is now an uncle!
Fan, Crystal, Salt, and Brine were seen on Stellwagen Bank during the
summer of 1996.
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After a long winter in the southern breeding grounds where there is
so little food for the humpbacks, eating is their main activity all summer
long. Their stomachs may hold up to a ton of food and these whales may
eat as much as 3,000 pounds of fish (well over a million calories!) each
day. They build up a thick layer of blubber, or fat, which will
help them live through the next winter without food.
BLUBBER GLOVE ACTIVITY
Make your own blubber glove and discover how blubber works.
Supplies:
2 sturdy 1 quart size zip-lock bags
1 can of vegetable shortening such as Crisco
Duct tape
1 bucket of ice water
Towels
Partially fill one bag with shortening. Turn the second bag inside out and put it in the first bag. Zip the edges of the two bags together so that the shortening is enclosed between the two bags. Seal with duct tape to ensure that shortening satys in the bags/glove. You are now ready to use your blubber glove to find out how blubber works.
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This the "fluke print." The old whalers used to think that
it was an oil slick left behind by the whale. It is a brief flattening
of the surface water caused by the upward motion of the whale's tail when
it dives. In fact, if a whale were traveling just beneath the surface we
could follow its path by watching the trail of fluke prints, just like
footprints.
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When a whale "spyhops" one must wonder who is watching who.
It appears that they are scoping out all activity above the surface. The
visibility is poor in the water of the northern feeding grounds because
of all the plankton. Whales cannot see very far beneath the surface. Their
eyes are located at the side of the head, so then can look down, and out,
but not very well in front . In fact their eyes are so far back on the
side of the head that both eyes can never focus on the same thing at the
same time. They are taking in two different images, and in only two dimensions.
28
All humpback whales have bumps the size of a large orange on top of
the head in front of the blowhole. It is said that some whalers used to
call these bumps "stovebolts" because they thought the bumps
held the whale's head together, just like the bolts on an old cast iron
stove. Each bump, or knob, is a large hair follicle that has one or two
bristle-like hairs growing out of it. Whales probably use these hairs very
much like a cat uses its whiskers. They can feel the water movement, and
maybe even sense fish nearby.
29
The most outstanding physical feature of a humpback whale is its enormous
flippers which can reach up to 1/3 the total body length. Each flipper,
or pectoral fin, is 12 - 15 feet long and can weigh up to a ton (2000 pounds).
The genus name for humpback refers to these flippers - Megaptera novaeangliae.
mega, big & pteron, fin or wing, nova, new &
aeangliae, England. Although the humpback whale is found in all
the major oceans, the first one described scientifically was seen along
the Maine coast in 1846, so its genus name translates into "Big winged
New Englander."
These huge flippers, the largest of any whale, are used for steering
and balance, herding fish, guiding young calves, pounding the surface to
show power or stun fish. Inside the flipper is a bone structure similar
to a human hand. They even have finger bones! This is one of many
traces whales still have of their ancient land ancestors.
(sketch of bone structure)
30
"Lobtailing," yet another spectacular behavior of the humpback
whale, may occur for similar reasons as flipper slapping. There are several
thoughts as to why whales "breach," flipper slap and lobtail.These
active behaviors would certainly would help knock off some of the barnacles
that collect on their bodies.They might also help in digesting their food.
Maybe they are territorial statements to the arrival of a new whale, and
are sometimes seen when two whales together separate. They could be a form
of communication, because the sound of a breach splash travels a tremendous
distance, and when a whale jumps out of the water, occasionally other huge
splashes are seen in the distance, as if responding to that sound. These
behaviors at times may also be play. All mammals have play activities,
and young whales have been seen active when they are only a few weeks old.
Whatever the reason for these bursts of energy, a humpback breach is said
to be the single most spectacular behavior of any animal on earth!
31
Millions of tiny plants and animals, most too small to see without a
microscope, live in the ocean. Most of this ocean life is called plankton,
from the Greek word, "planktos," meaning wanderer. Plankton usually
drifts, being carried by waves and current. Some of the animals in the
plankton swim quite well but, because of their extremely small size, they
usually swim vertically in the water.
Plankton is made up of plants (phytoplankton) and animals (zooplankton).
The greatest amount of planktonic life are plants and they are called "primary
producers" because they use the sun's energy to make their own food
through the process of photosynthesis.
The biggest amounts of plankton are found in shallow, coastal waters,
and places in the ocean where there are banks and ledges. It is here that
there is the greatest amount of upwelling, currents of water bringing rich
nutrients from the bottom up to the surface and sunlight.
The least amount of plankton is found in warm tropical seas. In these
areas, where there is little or no plankton, the seas are clear and blue.
Seawater that is rich in plankton is green.
The gills of fishes strain the tiny organisms of plankton. The largest
fish, the 40-foot whale shark, feeds entirely on plankton. Even some of
the world's largest mammals, the baleen whales such as the blue whale and
right whale, feed by sifting tons of planktonic animals called krill. Krill
can grow to be 2 inches long, but most plankton are so small that you would
need a magnifying glass to see them.
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The energetic White-Sided Dolphins range in size from about 6.5 - 9
feet, and can be seen from Cape Cod all the way to Greenland. They are
very social and always found in groups, some as large as several hundred
individuals.
Dolphins and porpoises are all whales belonging to the family of Cetacea,
just like the huge baleen whales. Dolphins are mainly fish eaters, enjoying
sand lance, herring, hake, smelt, and short-finned squid. Like all toothed
whales, dolphins have the ability to "echolocate." They are constantly
sending out rapid clicking sounds that bounce off objects and, like an
echo, return to the dolphin. The returning echo helps them locate each
other, know how deep the water is, find fish to eat, and "see"
our boat.
Dolphin Communication
How do dolphins echolocate?
Dolphin Sounds and information
Information Page 1
Information page 2
Copepod