KS2: Rockin' rockpools

Rockpools are one of the harshest environments on Earth because they are constantly changing as the tide rises and falls, which means the animals and plants that live there have to cope with this or die. To some it is ‘home’, but others may become trapped by accident in this intertidal zone and must tolerate the extremes of temperature, evaporation and predation that occur before the tide comes in again and they can escape.

What you'll need

• Song Bank song: The rockpool rock
• Song Bank song: Top-notcher
• Resource: Sticky labels
• Resource: Reference books/internet
• Resource: Main animal/plant group names on cards
• Resource: Datalogger with temperature probe
• Resource: Ziplock bag

Other: for a rockpool visit:

• Wear: wellington boots/trainers, sun cream/sun hat, warm clothes
• Take: towel, small transparent bucket/sampling trays, magnifying glass/handlenses, camera/macro-lens, homemade ‘observer’ or mask, datalogger, identification chart. (A net is not advisable as it’s awkward to use and can injure animals).
• Aquascopes (underwater viewer) and endoscopes (small underwater camera on end of a flexible cable) are expensive but great if you can afford them.

Reference material:

• National Trust 50 things to do before you’re 11¾. Rockpooling guide for families.
• Karl, Get Out Of The Garden! Carolus Linnaeus and the Naming of Everything by Anita Sanchez
• Where to see rockpool wildlife by the Wildlife Trust.
• The Rockpool by David Bellamy
• Seashore (Usborne Spotters Guide) by Su Swallow

Visiting a rockpool will bring a project on habitats to life and is great fun. The best time of year is late spring or early autumn. Don’t forgo be safe and check the tides – one or two hours before low tide is the safest.

Target vocabulary for KS2

• Vertebrate: mammals, birds, fish, reptile, amphibian
• Invertebrate: sponge, cnidarian (jellyfish, coral, sea anemone), worm, mollusc (mussel, periwinkle, limpet, barnacle), echinoderm (starfish, sea urchin), arthropods (insects, spiders, lobster, crab, shrimp)
• Animal characteristics: spine, warm/cold blooded, babies feed on mother’s milk, fur/hair, breathes air, feathers, lays eggs (with or without a shell), scales, metamorphosis to adult
• Plants: algae, seaweed (kelp, bladderwrack, dulse, coral-weed, sea lettuce

What living things can we find in a rockpool?

Start the topic by singing the song The rockpool rock.

Note all the living things named within the song and make a list of them as a class – add any others you think you might find in a rockpool (even take unlikely ones as these can be removed later).

Watch a clip such as The Wonderful Sea Life of Pembrokeshire Rockpools and add any animals or plants not already on your class list. We will use this list in some later activities.

Classifying living things in a rockpool

This activity will explore the life and work of the pioneering Swedish botanist, physician and zoologist Carl Linnaeus, ‘the organiser of organisms’, and relate it to rockpool life.

Learning outcomes

• Children can find out about the significance of the work of scientists such as Carl Linnaeus, a pioneer of classification.
• Children can describe how living things are classified into broad groups according to common observable characteristics and based on similarities and differences.

We classify living things to help scientists study them and understand the relationships between different organisms. Research the scientist Carl Linnaeus and why we organise living things.

Discuss the main groups of animals (vertebrates and invertebrates) and plants (flowering and non-flowering) then identify and agree on their main characteristics by making a card for each.

Lay these cards out and use the animals from your rockpool list to determine which group each one belongs to.

Living things are adapted to the environment they live in. This means how they are built, their behaviour, appearance and their way of life enables them to survive and reproduce in their habitat. Do any plants or animals have specific adaptations to help them survive in a rockpool environment? Which groups are not represented in a rockpool? Why might this be?

Sing The rockpool rock again and make up other verses to the song about an animal from your list, using their characteristics.

Who am I?

This game will help recall the features of individual rockpool animals and consolidate classification.

Learning outcomes

• Children can ask relevant questions and use knowledge to answer them.

Teachers prepare sticky labels with the name of a rockpool inhabitant. Place one on each child’s back. Children circulate and ask scientific questions to find out who they are. The answer can only be ‘yes’ or ‘no’, so ask carefully. One question each, then move on. Sit down when you know who you are.

Encourage children to ask broad questions to start with – ‘Do I have a backbone?’ will tell them whether they are an invertebrate or not, ‘Have I got an exoskeleton?’ like an arthropod etc.

Measuring change in rockpool habitats

In the summer sunshine, rockpools can be at their most extreme due to changes in temperature and salinity (saltiness) as some of the water evaporates, altering oxygen levels.

In this activity a datalogger is used to measure changes in temperature over time.

If you cannot visit a rockpool, set up your own temperature investigation in the school playground – use a stone, ceramic or terracotta (not plastic) dish to measure the temperature change with a datalogger.

Learning outcomes

• Children can recognise that environments can change and that this can sometimes pose dangers to living things.
• Children can learn how to use dataloggers appropriately.

Before you arrive at the rockpool, set up the datalogger to measure the temperature of the water using a probe. Predict what you think will happen to the temperature of the water during the visit – will it warm up, cool down or stay the same? What are the possible explanations for this? Answers might include transfer of energy (heat) from the rocks around and evaporation.

Once there, find a suitable rockpool and carefully place the probe into the water remembering to leave the datalogger somewhere dry (perhaps in a ziplock bag). Note the time you start the investigation.

In the classroom download the information recorded and note the temperature changes on the graph. Explain what happened. Did the temperature suddenly change during the test? Why?

How do you think these temperature changes affect the animals and plants that live there? Suggest some ways they have adapted to survive.

Observing life in a rockpool

Learning outcomes

• Children can identify and name a variety of living things in the local or wider environment.
• Children can identify how animals and plants are adapted to suit their environment in different ways.
• Children can observe and raise questions about animals and how they are adapted to their environment.

Before your trip make an ‘observer’. Cut out most of the bottom of an ice cream tub, cover it with cling film and you can use this to observe the

living things beneath the water. Remember to move loose rocks slowly to see the creatures that are hiding beneath.

N.B. Don’t forget to replace everything carefully where you found it.

In the classroom discuss the living things you found and research how this might indicate pollution levels in our seas (see PSHE).

If rockpools are too far away, maybe visit an aquarium instead. You will find all the same creatures there, but probably less stressed.

Curriculum links

English

Write a first-hand account by an animal trapped in an intertidal pool of their struggle for survival against the heat and predators, or interview a crab about its latest adventure.

Mathematics

• How many mathematical facts can you find out about rockpools and the animals or plants that live there?
• Find the symmetry in rockpool animals.

PSHE

‘Marine litter is a major problem throughout the world’. Investigate and then debate this problem with particular focus on plastic on our shoreline. Did you find any litter in your rockpool?

Art

Boil seaweeds to extract the dye to paint landscapes of the seashore or make clay models of rockpool creatures.

Geography

Mark some great rockpooling places on a map of the UK.

Caroline is a primary teacher with a passion for inspiring and engaging young children with science. As a Fellow of the Primary Science Teaching Trust and an independent consultant, she supports teachers to develop their own practice, as well as providing activities for children.