Over the next few weeks, we will be learning all about the Coral Reef
Ecosystems that surround much of the Australian coastline.
You will need to complete the tasks set out below and hand them in at the
conclusion of this section of work for marking.
You will find information attached that will assist you in completing these tasks
titled “Some of the Organisms that Live On Coral Reefs”.
SUBTOPIC
ASSESSMENT TASK TO BE COMPLETED
LOCATIONS OF
AUSTRALIAN CORAL
REEFS
Refer to an atlas for this activity and also collect a map of Australia from
your teacher to complete this activity.
BIOTIC AND ABIOTIC
FACTORS
Refer to your notes on “Biotic and Abiotic Environments”
POPULATIONS AND
COMMUNITY
RELATIONSHIPS
SPECIFIC
RELATIONSHIPS
1. Locate each of the locations of Australian Coral Reefs in the atlas and
prepare a neat, well labelled map:
• Great Barrier Reef
• Flinders Group and Lizard Island
• North West Australia – Rowley Shoals, Scott Reef, Seringapatam
Reef
• Ningaloo Reef
• Abrolhos Islands
• Shark Bay
• The Coral Sea
• Torres Strait
1. What are the biotic and abiotic factors of the Coral Reef Environment?
Give at least 8 examples of each. Represent these as a diagram showing
a scene from a Coral Reef Environment.
Refer to your notes on “Populations and Communities”.
1. What is a limiting factor? What are the limiting factors that affect a coral
reef?
2. Choose one organism that lives on or around the coral reef. If there were
unlimited growth of this organism, what would this do to the biotic and
abiotic factors in this environment? You may represent this information in
any way you wish (i.e. a diagram, list, paragraph etc..)
Refer to your notes on “Special Relationships in an Ecosystem”.
1. Identify five niches of organisms within the coral reef ecosystem. Explain
these in detail.
2. What are the roles that organisms play in a coral reef ecosystem? Give at
least 10 examples. Remember to use the terms commensalism,
mutualism, predation and parasitism.
FEEDING
RELATIONSHIPS
Refer to your notes on “Food Chains and Food Webs”.
1. Construct three coral reef food chains.
2. Construct a coral reef food web with at least fifteen organisms in it.
Make sure the arrows go the right way!
ADAPTATIONS
Refer to your notes on “Plant and Animal Adaptations”.
1. How have the organisms (plants and animals) adapted to survive in a
coral reef environment? Describe at least 10 organisms and their
adaptations. Remember to identify plants and animals and also recall the
three main types of adaptations – structural, behavioural and functional.
CONSERVATION OF
CORAL REEFS
Refer to attached sheets “Natural Threats to Coral Reefs” and
“Anthropogenic Threats to Corals”.
1. In what ways can the delicate balance in a coral reef ecosystem be upset?
Are there any ways that we can prevent this?
These Assessment Items should be assembled in one of the following
ways:
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Made into a booklet
Inserted into a display folder
Packaged into a protective sleeve
Other things to try to remember:
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All pages should have a clear title
Presentation should be neat and tidy
Pages should be numbered and a table of contents must be included
References other than those provided in this booklet must be included in the
correct format
Refer to the Coral Reef Ecosystem Assessment Rubric for details as
to how you will be marked for each task, remembering that:
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You should aim for the highest level you are capable of achieving
Your work ethic and presentation of your assessment tasks will also be assessed
Some of the Organisms that Live On
Coral Reefs
PRODUCERS: (Organisms that photosynthesise to produce their own food – i.e. plants)
• PHYTOPLANKTON (PLANT PLANKTON):
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Halimeda: chains of flat green bead like plates containing calcium carbonate – eaten
by fish and other herbivores – when it dies it form limey chips that form sand on reefs and
may later even form reef structures.
Sea Lettuce: crinkly soft green leafy – eaten by shrimps, shells – provides shelter for many
small organisms (shrimp, fish etc…).
Sea Grapes: green bead-like branching weed – eaten by fish, slugs, shells – provides
shelter for small shrimp, crabs, fish.
Coralline-red Algae: forms a hard (calcium carbonate) red paint-like crust over coral
and coral debris on the reef top – protects the reef from wave damage.
BLUE-GREEN BACTERIA (BLUE-GREEN ALGAE):
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Microscopic single-celled plants living on the surface of the ocean over the reef.
SEAWEEDS (ALGAE):
Form dark blackish slime over rocks and coral debris, eaten by shells, slugs and other small
organisms.
SEAGRASS:
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Green grass-like flowering plants that live on flat sandy areas – eaten by turtles, fish – slows
the movement of water, stops sand from swirling
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MANGROVES:
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CORAL:
- Medium sized trees that grow in the water on the edge of the coral cays (islands) or other
islands on the calm side – have pneumatophores (breathing roots) – are important as many
species of fish and shrimp lay eggs among their roots – leaf litter form rich feeding ground for the
young and other scavengers and decomposers – these and other trees provide shelter and
nesting sites for birds.
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Coral is an animal, but it is sometimes considered a producer because of the
microscopic, single-celled plants (called Zooxanthellae) that live in its skins, which carry
out photosynthesis and provide the coral with food. The coral is then eaten by other
organisms.
CONSUMERS and SCAVENGERS: (Organisms that eat other food I,e, other animals)
** Other terms to know:
1. HERBIVORES: eat plants only – phytoplankton,
blue green algae, seaweed, sea grass.
2. CARNIVORES: eat other animals only – including
zooplankton.
3. OMNIVORES: eat both animals and plants.
4. DETRIVORES: eat detritus (debris), which is small
bits of dead plants and animals floating in the
water currents or settled on the bottom of the
ocean floor.
5. DECOMPOSERS: break down organisms that
have died – bacteria and fungi which live in the
water, on other organisms and in the sediments
at the bottom of the ocean floor.
CONSUMERS and SCAVENGERS: continued…..
• ZOOPLANKTON (ANIMAL PLANKTON):
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SPONGES:
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Consist of flatworms, ribbon worms, and bristle worms – some destroy the coral by
burrowing into it or destroy its skeleton – others burrow into the sand or build tubes on
coral, crabs, sponges and shells.
Polycads: frilly flatworms – many are toxic – eaten by fish, corals, cone shells
Tube worms: e.g. Christmas tree worm and feather duster worm – build tube over coral
killing it – feed on plankton and debris in the water currents – eaten by sea stars, urchins
Ribbon worms: feed on small invertebrates, shrimp etc……, live in crevices, under coral –
eaten by cone shells
CRUSTACEANS:
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Small anemone-like animals living alone or in colonies with a hard calcium carbonate
skeleton which forms the base of coral reefs when the coral animal dies, and when
broken up forms coral sand – some are soft corals which have no hard skeleton – provide
shelter for fish, crabs, shrimp and a support for sponges, anemones, seaweeds – get 98%
of their food from the zooxanthellae (see previous page under coral section) living in their
tissue – feed on phytoplankton, zooplankton, debris, worms, small fish caught with their
stinging cells – are eaten by butterfly fish, crown-of-thorns starfish, turtles, sea slugs, drupa
shells – require very special environmental conditions to live and grow – the balance can
very easily be upset causing the coral to die.
WORMS:
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Attached to dead coral and some crabs – feed by paralysing prey with stinging cells
(nematocysts) on tentacles then bringing it into the mouth – feed on plant plankton,
animal plankton, small fish (butterfly fish), shrimp, crabs and also debris – eaten by sea
slugs – some provide shelter for clown fish or other anemone fish.
CORALS:
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Attached to dead coral, seaweed, crabs – draw water in
through holes and filter debris, bacteria, small animals and plants
from it – eaten by sea slugs, sea stars, sea urchins, fish – provide an
anchor for seaweeds and shelter and a feeding place for crabs,
shrimp, worms, sea cucumbers, gobi fish.
SEA ANEMONE:
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Microscopic and very small animals floating on the surface of the
ocean over the reef and consisting of larvae of many shrimp,
crabs, anemones, urchins, stars, shells and small members of
those groups – eat phytoplankton and are eaten by filterfeeders such as sponges, anemones, clams and whale sharks.
Animals with a hard exoskeleton, jointed legs and antennae and usually 5 pairs of legs
Shrimp: live under coral or in crevices, some burrow in sand, may live on sponges, sea
cucumbers – larvae are a part of the zooplankton – eaten by fish, corals, anemones,
octopus – feed on seaweed, debris, some cleaner shrimps take parasites from fish,
sponges etc…..
Crabs: as for shrimp
Large crabs: e.g. mud crab – scavenge for debris – burrow in the sand – eaten by fish,
sharks, sea stars
Parasitic barnacles: live on other crabs and coral – bore into it, eventually killing it
Mantis shrimp: predators on other crustaceans, small fish, molluscs and worms
MOLLUSCS:
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Gastropods: (snail-like shells) – eaten by triggerfish, wrasses (fish), cone shells, olive shells –
eat other shells, seaweed, blue green bacteria, red coralline algae – the mantle secretes
a hard calcium carbonate shell – examples include:
Limpets – cling to rocks and coral – eat algae
Cowries – live on the reef – eat algae, sponges and debritus
Helmet shells – eat starfish and sea urchins
Olive shells – eat other molluscs and debritus
Cones – can be deadly poisonous – shoot a poisonous harpoon to kill prey
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ECHINODERMS:
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FISH:
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Sea stars: live on the reef and sand bottom between patches of reef – some eat detritus
– others eat sponges, bivalves – the crown-of-thorn starfish eats huge amounts of living
coral – some live cooperatively with worms, snails, crabs, shrimp, and small fish by
providing shelter or transport and in return they get the leftovers – eaten by sharks, fish
and helmet shells
Brittle stars: live under the coral – eat plankton and detritus – eaten by fish
Sea urchins: live amongst the coral – eat algae, sponges, gastropods – eaten by helmet
shells, triggerfish, puffer fish
Sea cucumbers (holothurians): live on the sandy bottom between the patches of the
reef – take in the sand and feed on the algae attached to the grains – also may trap
zooplankton in feeding tentacles found near the mouth or eat detritus – some live on
sponges – eaten by humans, crabs
Damselfish: eat plankton and algae
Wrasse: medium sized fish – eat small invertebrates (shrimp, molluscs etc…) on the
bottom of the sea floor
Butterfly fish: eat live coral
Angelfish: eat sponges and small animals
Eels: eat small fish and debris
Parrotfish: eat algae and destroy coral rock
Surgeonfish: eat algae
Groupers: eat small fish
Cardinal fish: eat shrimp, crabs
Sharks: eat other fish and animals living on the bottom, turtles and seabirds
TURTLES (REPTILES):
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Trumpet shells – eat crown-of-thorn starfish, other shells, tube worms
Drupa shells – feed on coral
Sea slugs, nudibranchs and sea hares – shell-less gastropods – live on or under
coral slabs – feed on algae, seaweed, sponges, anemones, soft corals – eaten by
cone shells, some fish – may be toxic or have an unpleasant taste to escape
predators – bright colours of nudibranchs warn off predators – colours may blend
with brightly coloured neighbouring sponges, corals etc….
Bivalves: (two hinged shells like clams, mussels, pipus) – filter plankton and small animals
from the water currents – burrow into the sand or are attached to coral rock
Giant clam – contains Zooxanthellae in its tissue like coral does, which feeds the
clam – also filters plankton from the water
Cephalopods: (octopus, squid, cuttlefish) – including the very poisonous blue-ringed
octopus – hides in crevices – eats crab and shrimp – eaten by some large fish and sharks
BIRDS:
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Mostly live outside the reef, but sometimes enter a lagoon – eat jellyfish, sponges, soft
coral, crabs, squid, fish, seagrass, seaweed – eaten by humans and sharks
Heron: wade in reef flats – eats fish and crabs
Terns: nest on trees – their droppings fertilize the soil on coral islands allowing other plants
to grow – eat fish
Boobies (gannets): eat fish – nest in the trees – their droppings fertilize the soil on coral
islands allowing other plants to grow