Transcript 1. small size - diffusion is quick, frictional drag

6:20A
PHYTOPLANKTON
Spirogyra
The pelagic environment is the largest marine ecosystem. More
food, oxygen and biota (life) are here than anywhere else.
The dominant organism in the neritic zone and oceanic zone is
plankton.
Plankton are organisms that can not make a forward motion against
a current.
Phytoplankton & Zooplankton.
Phytoplankton are photosynthetic
autotrophs, who begin all marine food
webs.
Volvox
They produce 50-90% of all atmospheric oxygen, and
are critical biomass.
They are adapted to a floating lifestyle because of their:
1. small size - diffusion is quick,
frictional drag from large surface
area to low volume ratio helps slow
sinking
2. structure - disks shaped or chains aid in
floating
3. low density - light ions and lipid byproducts of photosynthesis reduce density
and aid floating
They are grouped by color. Different
pigments allow them to take advantage of
different light penetration at various
depths.
6:20B
Phytoplankton are found in 3 Kingdoms and 5 _
Phyla.
Commercially, algae are used as emulsifiers to give
a smooth texture to puddings, toothpaste,
ice cream, and shoe polish.
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.
Upwelling is caused by winds and other
atmospheric conditions that move surface
water away from shore, pulling nutrient rich
bottom water to the surface.
wind
ocean
Happy fish
Normal upwelling
nutrients
Diatoms are dominants in cool water.
Blooms are good for the food chain,
fishing and trigger whale migrations.
6:20C
However, blooms of some plankton,
especially in warm . water, may be
harmful. When storms follow hot, dry
weather, dormant cysts of toxic
phytoplankton may be released.
As these toxic blooms enter the food chain, they
give off chemical neurotoxins that paralyze
the predator's nerves controlling
breathing and heart rate.
Human
consumption of
these organisms
result in paralytic
shellfish poisoning
due to
biomagnification.
The dominant phytoplankton in warm water are
Dinoflagellates. They cause a condition called red
tide.
flagella is a tail-like
structure
Red tides is a result of a wind pattern, Peruvian
fishermen named EI Nino. The name refers to the
Christ Child, because the condition was first
observed during the warm, Christmas months of
the southern hemisphere.
A change in winds direction blows surface water
toward the land and prevents upwelling. Water is
depleted of nutrients and fishing is poor.
wind
ocean
land
No upwelling
El Nino
6:21A
ZOOPLANKTON
Zooplankton are the primary consumers,called
heterotrophic herbivores, in food webs.
They are the smallest and most numerous marine
animals. Their population density depends on the
availability of phytoplankton upon which they
graze.
There are two groups of zooplankton:
Crab zoe
1. Meroplankton - planktonic larvae who will
become adult forms of fish, worms, Mollusks, and
Crustaceans
The advantage of meroplanktonic lifestyle is
reduced competition from adults for the same basic
needs.
However, predation is extremely high because of
their size and lack of adaptability.
2. Holoplankton - will remain plankton throughout
life. They remain visible, but tiny.
Adult
Daphnia
6:21B VERTICAL MIGRATION
__Copepods (Phylum: Arthropoda) are 95 % of
all zooplankton. Others are krill, foraminifera
and members of Kingdom Protista, Phylum Protozoa.
copepod
krill
foraminifera
Zooplankton are grouped by the way they move either by pseudopods like the amoeba (1),
flagella like euglena (2)
or by cilia as in paramecium (3). .
Amoeba
Euglena
Paramecium
Noctiluca
Nostoc
Stentor
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.
6:21 C
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
The zooplankton begin their downward
response to graze _ again and to
take advantage of reduced visibility and
heat at the surface.
These two periods of grazing
1. protect both populations,
2. reduces predation
3. distributes stress in the ecosystem.
Phytoplankton
move
down
Grazing
time
Zooplankton
Move up
6:22A TAXONOMY
Taxonomy is a system of grouping organisms based
on phylogeny (evolutionary relationships),
biochemistry and morphology (structure).
There are seven taxa:
1. Kingdom: The 5 Kingdoms are (1) Monera, (2)
Fungi,
(3) Protista, (4) Plantae, (5) Animalia
2. Phylum: major marine phyla from Kingdom
Animalia: (1) Porifera, (2) Cnidaria, (3) Annelida,
(4) Mollusca, (5) Arthropoda, (6) Echinodermata,
(7) Chordata
. Class: major marine classes from Phylum
Mollusca: (1) Gastropoda,
(2) Pelecypoda,
(3) Cephalopoda
from Phylum Arthropoda: (1) Crustacea
from Phylum Chordata:
(1) Chondrichthyes,
(2) Osteichthyes,
(3) Amphibia,
(4) Reptilia,
(5) Aves
(6) 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
6:22B
6. Genus: subgroups of families; first part of
scientific name and always capitalized ex: Homo
7. Species: "specific" organisms that can produce
an offspring; second part of the scientific name and
always lower case ex: sapiens
Carrolus Linneaus developed a system of naming
organisms based on visible characteristics.
The use of terms - genus and species - is called
binomial nomenclature or the scientific name.
A dichotomous key is used to identify the names of
unfamilial organisms. The key is based on two
choices for each pair of related characteristics.
Only about 1 million of nearly 10 million organisms
have been identified and named
so far.
Scientists use a revised system based on
biochemistry to name all the discovered organisms.
_.
6:23A 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
Humpback whale
b. Odontoceti - whales, dolphins and porpoises with
teeth; carnivores; 2 nostrils but only
_ 1 blow hole; smaller in size
Killer whale
1.
2.
3.
4.
5.
6.
Marine Mammal Characteristics:
1. hair (at birth)
2. nurse young
3. breathe air
4. warm blooded
5. placenta
6. horizontal tail (ALL marine cetaceans)
The Blue whale is the
largest animal - 100 ft.
long,
150 tons. The Narwhal has a tusk that is an 8 ft. left
tooth, found only in males.
_Beluga whales are pure white, Arctic whales called
"sea canaries" because they vocalize so much.
6:23B
_Dolphins are the most' social and intelligent
whale.
-body temperature of 97.7 0 F
-7 minutes between breaths
-25 miles per hour swimming
speed –
- River dolphins of South
America cannot swim in a
straight line
Whales (and all marine mammals) are protected by
the Marine Mammals Protection Act of 1972.
It was passed in response to purse-seine killing of
dolphins in _ huge 4,000 ft. long nets.
However, many are still being hunted to extinction
under the guise of scientific research or are
by-catch of the tuna fishery.
There are over 1 million reported deaths per 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.
6:23C
Cetacean adaptations to marine life:
Swimming: result of powerful tail flukes. Fluke
markings are used like fingerprints for
identification. Sei whales are fastest at 40 m.p.h.
Digestion: multi-compartmentalized stomachs
"chew" food, (even toothed whales don't chew).
Teeth are conical and unspecialized.
Baleen whales feed by jumping through pockets of
plankton (called breaching).
their stomachs can hold 2 tons of krill at one
time.
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.
Their veins are large enough for a
trout to swim through them.
Blood can be shunted to brain, heart,
lungs and muscles and away from
stomach and kidneys to protect vital
organs.
4-chambered heart can transfer arteriole heat to
the veins as blood flows toward the tail - called
counter-current heat exchange.
6:23D
Blubber insulates against cold. Overheating is
solved by sending blood to surface tissues (flukes
and fins) and bypassing the countercurrent vessels.
Whales in captivity exercise less and often lose the
ability to cool off by straightening the fins.
Senses: Vision is poor in most species. Vocalizations
and echo-location compensate.
Whales have no vocal chords but make songs,
clicks and whines by vibrations in the blow hole.
They may communicate to
1. indicate territories,
2. attract mates
3. or act as homing devices for the 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.
melon
The sounds are extremely accurate and
VERY loud - can be used to stun prey.
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 top of the head.
6:23E
trachea
A trachea under the blow hole connects directly to
lung They can not breathe through their mouth and
can
drown unless the top of the head is exposed to air.
The nasal passage closes when relaxed to
prevent water from entering the lungs, and
allows them to sleep for short periods without
drowning. Whales can accumulate sleep.
_
Some whales go to depths of 13,000 ft. and
only breathe every 90 minutes - smaller species
have less range.
0xygen 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.
Mating usually occurs in early summer.
Implantation of the egg is delayed 4 months.
Gestation lasts 7 months, so babies are born in
warm summer months.
Many whales only have one calf every 2-3 years.
Babies weigh from 200 pounds to 1 ton.
Mama and Baby say tootles.
But stay tuned for some very
important pictures of their
friends
Right whale
Sperm whale
Pilot whale
Blue whale