Trawling the Plank! What is plankton ? Plankton are organisms that - - PowerPoint PPT Presentation

Trawling the Plank!

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 – 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 larva Slipper lobster adult

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

• n plankton
• Phytoplankton are the

beginning of the food chain

• Zooplankton eat

phytoplankton, which provide food for larger creatures

Example of a food chain

Carnivores Tertiary consumers Humans Omnivores, carnivores or herbivores Secondary consumers Fish Herbivores Primary consumers Zoo Plankton Producers PhytoPlankton D E C O M P O S E R S Sun’s energy O R D E R O F C O N S U M P T I O N

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 ?