Phytoplankton
1. Pelagic environment is the
largest marine ecosystem.
More food, oxygen and biota
(life) are here than anywhere
else.
2. The dominant organism in
the neritic zone and oceanic
zone is plankton
3. Plankton are organisms that
can not make a forward
motion against a current.
4. There are two types of
plankton: phytoplankton &
zooplankton.
5. Phytoplankton are photosynthetic
autotrophs, who begin all marine
food webs.
6. Produce 50-90% of all atmospheric
oxygen, and are critical biomass.
7. They are adapted to a floating
lifestyle because of their:
– Small size - diffusion is quick,
frictional drag from large surface
area to low volume ratio helps
slow sinking.
– Structure - disks shaped or chains
aid in floating.
– Low density - light ions and lipid
by-products of photosynthesis
reduce density and aid floating.
8. They are grouped by
color. Different
pigments allow them to
take advantage of
different light
penetration at various
depths.
9. Phytoplankton are found
in 3 kingdoms and 5
phyla.
10. Commercially, algae are
used as emulsifiers to give
a smooth texture to
puddings, toothpaste, ice
cream, and shoe polish.
11. A “bloom” is an increase in
population density of
phytoplankton associated
with high nutrient levels.
It can be the result of
upwelling or excessive
nutrients.
12. Upwelling is caused by winds and other atmospheric
conditions that move surface water away from the
shore, pulling nutrient rich bottom water to the
surface.
13. Diatoms are dominants
in cool water.
14. Blooms are good for
the food chain, fishing,
and trigger whale
migrations.
15. Blooms of some
plankton, especially in
warm water, may be
harmful.
a. When storms follow hot,
dry weather, dominant
cysts of toxic
phytoplankton may be
released.
b. As these toxic blooms
enter the food chain,
they give off chemical
neurotoxins that
paralyze the predator’s
nerves controlling
breathing and heart
rate.
c. Human consumption of
these organisms result
in paralytic shellfish
poisoning due to
biomagnification.
d. The dominant
phytoplankton in warm
water are
dinoflagellates. They
cause a condition called
red tide.
e. Red tides is a result of a
wind pattern, Peruvian
fishermen named “El
Nino”. The name refers
to the Christ Child,
because the condition
was first observed
during the warm,
Christmas months of the
Southern Hemisphere.
f. A change in winds
direction blows surface
water toward the land
and prevents upwelling.
Water is depleted of
nutrients and fishing is
poor.
http://app.discoveryeducati
on.com/player/view/assetG
uid/E586AE5C-CF4D-4FD6809B-EEE342C33ACA
Zooplankton
1. Zooplankton are the
primary consumers,
heterotrophic herbivores,
in food webs.
2. They are the smallest and
most numerous marine
animals.
3. Their population density
depends on the
availability of
phytoplankton upon
which they graze.
4. There are two groups of
zooplankton:
a. Meroplankton
- planktonic larvae who will
become adult fish, worms,
Mollusks, and Crustaceans
- The advantage of
meroplankton lifestyle is
reduced competition from
adults for the same basic
needs.
- Predation is extremely
high because of their size
and lack of adaptability.
b. Holoplankton
• will remain plankton
throughout life
• Remain visible, but tiny
5. Copepods (phylum:
Arthropoda) are 95% of all
zooplankton. Others are krill,
foraminifera and members of
the Kingdom Protista, Phylum
Protozoa
6. Zooplankton are grouped
by the way they move.
• By pseudopods
(amoeba)
• By flagella (euglena)
• By cilia (paramecium)
Vertical Migration
• Vertical migration is a
daily pattern of
phytoplankton and
zooplankton changing
positions like a day and
night shift.
During the day • phytoplankton produce
lipids by photosynthesis.
• Because oils are less
dense than water, the
products of
photosynthesis increase
their buoyancy.
As the sun goes down • The phytoplankton
use lipids for energy
which causes them to
sink in the water
column.
• In response to the
“rain” of
phytoplankton
descending, the
zooplankton move up
in the water column
to graze on them.
As the sun comes up • Photosynthesis again
causes more production
than the organisms need
at that time, the
phytoplankton become
lighter and begin to float
upward.
• The zooplankton begin
their downward response
to graze again and to take
advantage of reduced
visibility and less heat than
at the surface.
• These two periods of
grazing:
– protect both populations
– reduces predation
– distributes stress in the
ecosystem
http://youtu.be/FBEDd7o
bCAc
Taxonomy
Taxonomy is a system of
grouping organisms
based on
- Phylogeny (evolutionary
relationships)
- Biochemistry
- Morphology (structure)
There are 7 taxa:
1. Kingdom: the 5
kingdoms are:
-
Monera
Fungi
Protista
Plantae
Animalia
2. Phylum: major marine
phyla from kingdom
Animalia:
-
Porifera
Cnidaria
Annelida
Mollusca
Arthtropoda
Echinodermata
Chordata
3. Class: major marine classes
From Phylum Mollusca:
- Gastropoda
- Pelecypoda
- Cephalopoda
From Phylum Arthropoda:
- Crustacea
From Phylum Chordata:
-
Chondrichtyes
Osteichthyes
Amphibia
Reptilia
Aves
Mammalia
4. Order:
- Subgroups of a class
- for birds and fish the suffix is
“formes”
5. Family:
- subgroups of an order;
- suffix is “ae”
Ex: Hominidae
6. Genus:
- subgroups of families
- first part of scientific name
- always capitalized
Ex: Homo
7. Species:
- “specific” organisms that can
produce an offspring
- second part of the scientific name
- always in lower case
Ex: sapiens
• Carrolus Linneaus developed a
system of naming organisms
based on visible
characteristics.
• The use of terms (genus &
species) is called binomial
nomenclature or the scientific
name.
• A dichotomous key is used to
identify the names of
unfamiliar organisms. The key
is based on two choices for
each pair or related
characteristics.
• Scientists use a revised
system based on
biochemistry to name all
the discovered organisms.
• Only about 1 million of
nearly 10 million
organisms have been
identified and named so
far.
Order Cetacea - Whales, Dolphins,
Porpoises
Phylum Chordata;
Class Mammalia
Cetaceans are grouped on the
basis of their mouths:
a. Mysticeti
-
whales with baleens
(strainers) for plankton
Both nostrils have a blow
hole
b. Ordontoceti
- whales, dolphins, and
porpoises with teeth
- Carnivores
- 2 nostrils but only 1 blow
hole
- Smaller in size
Marine Mammal
Characteristics:
1. Hair (@birth)
2. Nurse young
3. Breathe air
4. Warm blooded
5. Placenta (live births)
6. Horizontal tail (ALL
marine cetaceans)
Blue whale
- is the largest animal
- 100 ft. long
- 150 tons.
Narwhal
- has a tusk that is 8 ft.
- left tooth found only in
males.
Beluga whales
- pure white as adults
- “sea canaries”
Dolphins
- are the most social 7
intelligent whale.
- Body temperature of
97.7o F
- 7 minutes between
breaths
- 25 mph swimming speed
- River dolphins of S.
America cannot swim in a
straight line
Marine Mammals
Protection Act of 1972
• Whales and all marine
mammals are protected
• Passed in response to
purse-seine killing of
dolphins in huge 4,000 ft
long nets.
• Many are still being
hunted to extinction
under the guise of
scientific research or are
by-catch of the tuna
fishery.
• 1 million deaths/year
• Tuna caught on lines is “certified” as dolphin safe by
company employees
• International Whaling Commission (I.W.C.) is a whaler’s
organization that sets quotes based on catch size. They
are not a regulatory agency and compliance is voluntary.
Cetacean Adaptations:
Swimming:
- powerful tail flukes
- Fluke markings are like
fingerprints for ID
- Sei whales are fastest
(40mph)
Digestion
- Multi-compartmentalized
stomachs “chew” food
- Teeth are conical and
unspecialized
- Baleen whales
- feed by swimming through
pockets of plankton
- using “bubble” nets to
corale their food.
- Stomachs hold 2 tons of
krill
- Toothed whales hunt in packs
and seek out individual fish,
penguins, seals, sharks or
other whales.
Circulation
- high blood volume holds
maximum oxygen and glucose
levels
- Large whales have large veins
- Blood can be shunted to
brain, heart, lungs, and
muscles and away from
stomach and kidneys to
protect vital organs.
• A 4-chambered heart can transfer
arteriole heat to the veins as
blood flows toward the tail
(counter-current heat exchange)
• Blubber insulates against the cold.
• Overheating is solved by sending
blood to surface tissues (flukes
and fins) and by-passing the
countercurrent vessels.
• Whales in captivity exercise less
and often lose the ability to cool
off by straightening the fins.
Senses
- Vision is poor
- Vocalizations & echo-location
compensate
- Whales have no vocal cords
but make songs, clicks and
shines by vibrations in the
blow hole.
- Communicate to:
- Indicate territories
- Attract mates
- Homing device for young
- Families of whales have their
own dialect
- Sounds are emitted and amplified in the head through an
oil filled cavity called a melon.
- Incoming vibrations are focused through the jaw and
melon to the inner ear and the brain.
- The sounds are extremely
accurate and VERY LOUD
- Can be used to stun prey
- Blue whale can make a
sound of 188 decibels.
(can rupture a human
eardrum)
- When whales enter the
thermocline, sounds can
be heard 1/4 of the
distance around the
earth.
Diving:
- lungs are completely
filled and emptied
quickly through the
blow hole on the top
of the head.
- A trachea under the
blow hole connects
directly to lungs.
- Cannot breathe
through their
mouth.
- The nasal passage closes
when relaxed to prevent
water from entering the
lungs & allows them to
sleep for short periods
without drowning.
- Whales can accumulate
sleep.
- Some whales go to depths
of 13,000 ft and breathe
every 90 minutes
- Oxygen is stored in the
muscles
- Ribs are collapsible to
reduce internal air pockets.
Excretory:
- Specialized kidneys allow
whales to drink salt water.
- The urine is very saline
Reproduction
- mating usually occurs in
early summer
- Implantation of the egg
may be delayed several
months, so that
gestation finishes up in
the warm summer
months.
- Many whales only have
one calf every 2-3 years.
- Babies weigh 200 lbs to
1 ton.