The mangroves Now you are going to investigate an environment that you may have experienced the mangrove swamp. You will use this environment to practise writing food chains. To do this, you are going on an excursion to a mangrove swamp. As you go on the excursion, you will be observing, comparing, contrasting and classifying the organisms that live in the swamp. The mangrove environment The mangrove swamp is a special type of environment that has a range of conditions. Mangroves occur where a river meets the sea. They are found in the tropical and sub-tropical regions of the world. The excursion This excursion is to a mangrove swamp. To go on this excursion, you will need the following things: some photographs and drawings of the mangrove organisms the Living things CD ROM containing either an audio file or a slideshow called The swamp and a computer to view the virtual excursion. You will go on the excursion by listening to the audio or watching the slideshow on the Living Things CD ROM. Here are some of the photographs that were taken on the excursion. There are lines beside each picture which you may use to take personal notes while you are on the excursion. Lesson 10/20 What are plants and animals? 1
Photographs of a mangrove ecosystem Pneumatophores at low tide Pneumatophores at mid tide Mangroves at mid tide 2 Living things
Heron on a sand bank Source Jane West Flock of ibises digging for food Seagrass, algae and small fish Lesson 10/20 What are plants and animals? 3
Salt crystals on a mangrove leaf Source Jane West Nipper burrows and oysters Ibises 4 Living things
Soldier crabs Spider close up Burrowing in the mud Organisms seen on the mangrove excursion. Lesson 10/20 What are plants and animals? 5
Excursion sheet for mangrove excursion Small fish Mussel Pelican Blue swimmer crab Mangrove Seagrass Phytoplankton Prawn 6 Living things
Ibis Shark Whiting Soldier crab Leatherjacket Dragonfly Sea horse Spider Now you are ready to more closely study the feeding relationships between these organisms. In this exercise you will be reporting on your virtual excursion to a mangrove. This can be done using the material provided on the Living things CD ROM. Go to the exercises section and complete Exercise The mangroves: excursion notes. Lesson 10/20 What are plants and animals? 7
What did you achieve? Tick what you can do. describe the mangrove environment list some of the plants and animals that live in the mangroves write food chains for the mangrove environment state reasons why the mangrove environment is important. 8 Living things
Exercise Living things Name Teacher Exercise The mangroves Excursion notes Mangrove trees are often found around the shores where rivers meet the sea. They usually form extensive forests because so many of them group together. Sadly, mangrove areas have been used as rubbish dumps and for disposing of factory wastes. Mangroves have also been cut down to be replaced by tourist resorts. First impressions Describe the mangrove environment. List the animals that you have observed on your walk through the mangroves. Lesson 10/20 What are plants and animals? 9
Mangrove feeding relationships The diagram following shows a food web in a mangrove ecosystem. It is an unusual food web because many of the food chains start from a material called detritus. This material consists of the broken down leaves of mangrove trees as well as any other organic material. It forms a rich oozy material that is found on the floor of mangrove areas. These pieces of mangrove leaves become food for molluscs, worms, young fish, crabs and prawns. These animals are then eaten by larger fish, crabs and birds. Circle the producer(s) in the diagram below. The producers are eaten by herbivores. Write down two organisms that are herbivores. The herbivores are eaten by carnivores. Write down two organisms that are carnivores. pelican cormorant mangrove detritus small fish oysters bream prawns oystercatcher seagrass algae Mangrove food web 10 Living things
Write three food chains to represent the feeding relationships in the mangrove environment. Do you think that mangrove environments should be protected? Explain your answer. Lesson 10/20 What are plants and animals? 11