Transcript Honors Marine Biology

Honors Marine Biology
Marine Mammals
December 16, 2-14
Class Challenge
Bird Trivia Quiz
1. True/False: All birds have feathers and
all animals that have feathers are birds.
2. True/False: Most birds have waterproof
feathers, they have a special gland at the
base of their tail that produces oil that
they use to cover their feathers.
Bird Trivia Quiz
3. True / False: Like sea turtles, sea birds
have salt glands that remove extra salts
from their bodies.
4. True / False: There are two natural
forces that a bird must overcome so that
it can fly: Gravity and Drag.
Bird Trivia Quiz
5. True/False: A person who studies birds
is called an Ornithologist.
Ocean Mammals
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Mammals are a group of vertebrates (animals
that have a backbone).
Certain characteristics separate them from all
other animals:
mammals breathe air through lungs,
give birth to live young,
produce milk for their young,
are warm-blooded,
have hair or fur.
They also have relatively large brains
They have a variety of tooth sizes and shapes.
• More than 100 mammals depend on the
ocean for most or all of their life needs.
• Marine mammals have all the
characteristics of mammals, but they have
different appearances and survival
strategies.
• Marine mammals are divided into three
orders: Carnivora, Sirenia and Cetacea.
• Within the order Carnivora are the
pinnipeds (fin-footed mammals such as
seals, sea lions, walruses), the sea otter,
and the polar bear.
• Polar bears are closely related to bears
like the grizzly, but are considered marine
mammals since they have adopted a
marine lifestyle.
Order Carnivora
Within the order Carnivora are:
1. The pinnipeds (fin-footed mammals
such as seals, sea lions, walruses),
2. the sea otter, and
3. the polar bear.
The Harbor Seal
A walrus is easily recognized by its long
tusks and great bulk.
Polar Bears
• Polar bears are closely related to bears
like the grizzly, but are considered marine
mammals since they have adopted a
marine lifestyle
Order Sirenia
• The Order Sirenia is composed of
manatees and dugongs (or sea cows)
Order Cetacea
• The order Cetacea includes whales,
dolphins, and porpoises.
• Cetaceans are relatively large, generally
characterized by streamlined bodies that
glide easily through the marine
environment.
• Whales, dolphins, and porpoises all
belong to the same taxonomic order called
cetaceans. The word cetacean is derived
from the Latin "cetus" (a large sea animal)
and the Greek "ketos" (sea monster).
• There are 86 species of whales, dolphins
and porpoises, collectively known as
cetaceans.
• Most live in oceans and seas worldwide,
both in open and inshore waters.
• Some dolphin and porpoise species can
live in saltwater, brackish water, and
freshwater, and a few species and
populations only live in freshwater rivers
and lakes.
There are two categories of
cetaceans: (Fig. 7.9)
1. Baleen whales (mysticetes) are named for their
feeding apparatus: a series of comb-like baleen plates
that descend from the roof of the mouth.
Made of stiff, flexible material similar to human
fingernails, baleen acts like a sieve, allowing the
whales to strain food such as small fish, krill, and
plankton out of the water.
There are 13 species of baleen whales ranging in size
from the 6m pygmy right whale to the 33m, 120 ton
blue whale, the largest animal on Earth.
While some species “sing”, baleen whales do not have
echolocation abilities.
2. Toothed whales, dolphins, and porpoises
(odontocetes) are a diverse group of over 70 species
which range in size from the 1.4m Hector’s dolphin to
the 18m sperm whale.
They have well-developed echolocation which they
use to locate each other and to hunt fish, squid, and
marine mammals.
Twenty-three cetacean species or populations are
classified as Critically Endangered, Endangered, or
Vulnerable, while many other local and regional
populations are seriously depleted.
The population status and/or distribution of over a third of
all cetacean species are unknown.
• Dolphins can use echolocation to help
them find food or find their way from place
to place. They make special clicking
sounds.
• Scientists think the sounds can be aimed
by the bulge at the front of the head which
is called the melon.
• The clicks bounce back off any object in
their path. Dolphins can tell the size,
shape and direction fish are travelling in.
• This is very important in dark, murky seas
when dolphins cannot see their prey. It
means they can catch fish in total
darkness.
Figure 7.13
• Dolphins: Deep Thinkers?:
Echolocation test
• http://www.youtube.com/watch?v=51G83ja
eNC4&feature
Dolphins in the Military
• Everyone is familiar with security patrol dogs.
You may even know that because of their
exceptionally keen sense of smell, dogs like
beagles are also used to detect drugs and
bombs, or land mines. But a dog would not be
effective in finding a sea mine.
• Sea mines are sophisticated, expensive
weapons that are designed to work in the ocean
where they can sink ships, destroy landing craft,
and kill or injure personnel. Sea mines are made
so that they cannot be set off easily by wave
action or marine animals growing on or bumping
into them. If undetected, sea mines can be
deadly, destructive weapons.
• But just as the dog's keen sense of smell makes it ideal
for detecting land mines, the U.S. Navy has found that
the biological sonar of dolphins, called echolocation,
makes them uniquely effective at locating sea mines so
they can be avoided or removed. Other marine
mammals like the California sea lion also have
demonstrated the ability to mark and retrieve objects for
the Navy in the ocean.
• In fact, marine mammals are so important to the Navy
that there is an entire program dedicated to studying,
training, and deploying them. ($27 Million Dollars) It is
appropriately called the Navy Marine Mammal Program
(NMMP).
• Dolphin Lifesavers: Training for a
Mission
• http://youtu.be/8JNrtFG4RU4
• In the Line of Duty - Military Mammals CBN.com
• http://youtu.be/tv6PFcanyTE
• US Navy Dolphin & Sea Lion Program CNN 8/6/2011
• http://youtu.be/IBOpFMcdzZc
• Navy's Dolphin Work Outsourced to
Robots
• http://youtu.be/akV--UHyk3g
The Bends
• When people dive, they have to be very
careful not to contract a potentially deadly
condition known as the bends.
The bends, Decompression
Sickness or Caisson Disease
Occurs when nitrogen bubbles in the blood
lodge in certain parts of the body.
A bubble caught in a vital organ can be fatal.
Before much was known about
decompression sickness, divers got
bubbles lodged in their joints forcing them
to “bend” over in pain.
Nitrogen in the Blood
• A diver breathes air from the scuba tank that
contains approximately 79 % nitrogen and 21 %
oxygen.
• The pressure of being underwater forces the
nitrogen into the body’s fatty tissues.
• The longer and deeper the dive, the more
nitrogen is forced into the tissues.
• For example, at 10 metres the partial pressure of
each gas is doubled, so twice as much nitrogen
is absorbed into the tissues as on the surface.
• At 30 metres, four times as much nitrogen is
absorbed.
• When the diver comes to the surface; that
is, moves from a greater pressure to
lesser pressure, the nitrogen comes out of
the tissues back into the blood stream.
• This is like a soda bottle being opened.
The gas is kept in solution by the pressure
under the cap; when this is removed the
gas bubbles out.
Getting this nitrogen out of the tissues
at the correct rate is the challenge for
divers.
• To prevent being “bent”, a diver must slow
the rate of nitrogen coming out of the
tissues.
• This is achieved by reducing the change in
pressure by slowing the ascent, even
stopping part of the way.
• With the soda bottle; if the cap is opened a
fraction and the pressure equalizes slowly,
there is little bubbling.
• It is this slow equalizing of the pressure, or
decompression, the diver must go through
during ascent to the surface.
• Most decompression stops are done three
meters below the surface, but if a diver
had been very deep or underwater for a
long time, then the stops might be ten
meters, six meters, and then three meters.
• The longest decompression stop is at
three meters because the greatest
pressure change occurs in the top three
meters of water.
• The time spent at each stop depends on
the length and depth of the dive.
• A dive to thirty meters for thirty minutes
would require a stop of three minutes at
three meters, but a dive to forty meters for
the same length of time would require a
stop of fourteen minutes at three meters.
• This time spent decompressing can be
unnerving for divers, a the surface is so
close but the diver is not allowed to go up:
the natural environment could kill!
How do marine mammals manage
to not get the bends?
• While it is still possible to get some gas anomalies
without compressed air, it is exceptionally rare and
usually involves other issues being present. For diving
marine mammals, they are diving with a set amount of
air in their lungs, a volume that no matter how fast or
slow they ascend will never expand beyond its original
size at the surface, which means that since they have no
way of "loading" their bodies with excess amounts of
gases at depth, the partial pressures of the gases in the
bloodstream will be negligibly similar along depth
gradients
Experiment 7.C: Marine Mammal
Rescue Procedure
Dolphin Diagram of Anatomy
Rescue Procedure:
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Homework
• Complete Module 7 Test
• Reading Module 8 (Marine Ecology) pages 187
– 206
• OYO ALL Questions
• Study Guide: Complete ALL Questions
• Complete Lab
• Quiz: Dolphin Anatomy
• Class Challenge: