Transcript Plankton PPT

•All about Plankton
Phytoplankton
• Microscopic plants that drift in the upper
waters of the oceans
• Use sunlight to produce their own food
through the process of photosynthesis:
CO2 + H2O  C6H12O6 + O2
Carbon dioxide + water  sugar + oxygen
Phytoplankton, cont’d
• Are critical to all life on earth because they
are the basis of food webs and generate
most of the atmospheric O2
• When conditions are right (i.e., sufficient
nutrients) they are capable of blooms – very
rapid growth in numbers
• Are collected in funnel-shaped plankton
nets towed behind research vessels
Plankton
Nets
Just how tiny can they be?
• Femtoplankton- little known group, viroplankton fall here
Piccoplankton 0 - 0.002 mm
Ultraplankton 0.002 - 0.0055 mm
Nannoplankton 0.005 - 0.06 mm
Microplankton 0.06 - 0.5 mm
Mesoplankton 0.5 - 1.0 mm
Macroplankton 1.0 mm - 1.0 cm
Megaloplankton greater than 1.0 cm
The last 4 groups are called net plankton as they can be
caught with plankton nets. The first 3 groups are obtained
through centrifugation, filtering, or settling of samples.
Types of Phytoplankton
There are 3 main types:
1. Diatoms
2. Dinoflagellates
3. Coccolithophores
Diatoms
• Are the most dominant and
productive phytoplankton
• Have beautifully ornate shells made
of silica; unique to each species of
diatom
• Used in silver polish, toothpaste, and
for filtering beers, wines, and juices
Although thousands of species exist, diatoms are usually divided in two
groups: the pennates (pen-shaped) or the centric (rounded)
© Canadian Museum of Nature
Centric
Pennate
Cyclotella
Nitzschia
Diatoms
A Diatom by Any Other Name…
• There may be up to 100,000 different species of diatoms
(15,000 have been identified so far).
• Each species requires certain ecological conditions in
order to survive
Chemical
•Nutrients
•pH
•Salinity
Physical
•Temperature
•Light
Who Touched the Thermostat?
• Because of their ecological eccentricities,
and the fact that their glass shells remain
long after they die, diatoms can provide
scientists with a stunning insight into the
environments and climates of the past!
• By dating a soil sample and studying its
diatom fossil content (number and type), we
can estimate the climate of a given period.
Where and How to Core?
Iqaluit
Boothia Peninsula
Lake JR01
Coring a Core…
© Canadian Museum of Nature
Dinoflagellates
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Most have 2 flagella (whips)
Some are capable of bioluminescence
(producing light)
Some cause “red tide” – they bloom so
extensively that the water looks red
Some release a neurotoxin that is stored in
certain shellfish and causes Paralytic
Shellfish Poisoning (PSP) in humans
when shellfish are eaten
Dinoflagellates
Red tide
Bioluminescence
Bioluminescence
Coccolithophores
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Are covered with discs made of calcium
carbonate (CaCO3)
White Cliffs of Dover are fossilized
coccolith deposits – allowed the British to
make many strategic tunnels during WWII
Can thrive in nutrient-poor waters where
other phytoplankton cannot survive
Photos of Coccolithophores
Remember
More diverse and abundant =
Warmer
Less diverse and scarcer =
Colder
Zooplankton
• Microscopic (not all) animals that feed on
diatoms, dinoflagellates, and other
phytoplankton or on other zooplankton
• Some members remain as zooplankton their
whole life (copepods, krill, etc.) while
others are just in their juvenile stage (crabs,
sea stars, barnacles, lobsters, etc.)
Temporary Zooplankton
Crab larva
Squid larva
Zooplankton, cont’d
• Copepods make up more than 70% of the
zooplankton
• Krill are shrimp-like creatures about the
size of your thumb yet have the largest
biomass of any species on earth!
• Krill are eaten in tremendous numbers by
some of the largest marine animals (whale
sharks and baleen whales)
Photos of Copepods
Photos of Krill
Humpack
Whales Feeding
on Krill
Adaptations of Plankton
• Plankton cannot swim against an ocean
current, yet it is important for each type of
plankton to remain in the upper part of the
water column
• Their small size (microscopic) allow them
to float and resist sinking
Adaptations of Plankton, cont’d
• Phytoplankton must remain in the upper
part of the water so that they have access to
sunlight so that they can photosynthesize
• Zooplankton must remain in the upper
water column because that’s where their
food is - the phytoplankton