Plankton trawl
What is plankton ?
Plankton are organisms
that drift in the ocean
because they either do
not swim or are too
small to resist ocean
currents.
There are two types of plankton
Plant plankton =
Phytoplankton
– Need sunlight +
nutrients
– Make sugar + O2
– First order producers
Animal plankton =
Zooplankton
– First order consumers
Where does plankton live?
• Plant plankton move with the currents,
remaining in the top few metres of
water
• Animal plankton are free swimming,
hiding in the day and feeding at night
Think about it!
• Why do you think
plankton are
almost
transparent?
Who are plankton?
Some big animals
start life as plankton…
• Many larger
animals are
plankton when
they are young
• The plankton may
be baby starfish,
jellyfish or
shrimps
http://www.livingclassrooms.org/lbo/plankton/index.html
They’re called -Meroplankton
• Meroplankton spend only the larval or early
stages of their life as part of the plankton and
spend their adult lives on the reef.
• Many well-known animals found on the Great
Barrier Reef spend time as free-swimming
meroplankton, bearing little or no resemblance
to the adult they will become.
• Meroplankton includes sea urchins, starfish, sea
squirts, most of the sea snails and slugs, crabs,
lobsters, octopus, marine worms and most reef
fishes.
Examples of Meroplankton
1. Tube Anemone
Larvae
Adult
2. Sea cucumber
Larvae
Adult
3. Sea star (starfish)
Larvae
Adult
Crustaceans display some of the most spectacular
metamorphoses from free-swimming meroplankton to
reef-dwelling adult.
Slipper Lobster larva
Slipper lobster adult
Slipper Lobster
larva
Holoplankton
• Holoplankton
• Holoplankton spend
their entire lives as
plankton.
• This group includes
krill, copepods,
various pelagic
(free swimming)
sea snails and
slugs, jellyfish and
a small number of
the marine worms.
Holoplankton Example
1.Diatoms
The food chain
• All creatures, including
people, are dependent
on plankton
• Phytoplankton are the
beginning of the food
chain
• Zooplankton eat
phytoplankton, which
provide food for larger
creatures
Example of a food chain
Plankton Trawling
• Shorts
• NO shoes
• Workbook +
pencil can go to
the dry lab
• Listen carefully !
Setting the net
• Find a spot
where you can
see
• Listen carefully
• Watch the
process
Trawling
• Move carefully around
the boat.
• Try spotlighting marine
life in the water.
• Enjoy the lights of
Yeppoon.
• Watch for turtles,
stingrays, squid and
fish
Retrieve net
• The teacher will
retrieve the net
• Inspect for
jellyfish
• Bring the net
aboard
Bio-luminescent
• Light made by life
• Lights out !
• Rub the net
• What do you see?
• Why?
• How?
Pour it in
• Pour the catch into
your specimen
container
• Look after your
sample
• Don’t shake or drop
• Live animals !!
• What can you see?
Getting off
• Wait for instructions
• Hold the sample jar
carefully
• Watch your step
• Wait at the light for
your teacher
Back to the Dry lab
• To see your catch
you will need to
listen carefully
• Tip off excess water
• Place sample into
Petri dish
See your catch
• Take turns
• Share your
discoveries
• What can you
identify ?