Save our saltmarshes

Lesson overview

Visit the saltmarsh of the Solent in the UK and learn about how life is connected through food chains and webs, before thinking about how these amazing blue carbon habitats can be promoted as tourist destinations. This is the third of three lessons in this unit that look at an individual blue carbon habitat in more detail.

Learning outcomes
  • List the importance of saltmarsh for nature and communities
  • Describe food chain relationships using science terms
  • Map food chains in saltmarsh habitats
  • Create a poster to showcase saltmarsh habitats as tourist destinations

See the Fact Sheet All about saltmarshes for background information on saltmarshes. There is also a Teacher Update How to teach food chains and food webs to support teacher who are unfamiliar with this topic.

Lesson steps

1. Introduction to saltmarshes and the Solent (15 mins)

Use slides 2 to 5 to connect to the previous lesson’s learning if you have taught this, then­ introduce the learning objectives to the class. This section then moves on to an overview of saltmarshes. This is the third blue carbon habitat that students will study in depth.

Slides 8 to 10 give a basic overview of mangroves as well as their global range shown in the green outline on the map. Slides 11 to 13 introduce the location for this lesson, the Solent in the UK, and some teachers may wish to reinforce students’ use of geographical descriptions using compass points. An atlas or map of the UK may be needed to show the location of the Solent in the context of the UK in more detail.

A writing activity on slide 11 and reviewed on slide 12 gives students the opportunity to use the information presented in this section to practice writing geographical descriptions.

2. Food chain vocabulary (15 mins)

This section focuses on the vocabulary used to describe food chains. This is an important step to enhance science literacy and to enable students to describe relationships within the saltmarsh.

The explanation starts, like nearly all food chains and webs, with getting energy from the sun. Using slide 17, ask students about the kind of living things that get their energy from the sun. Students should be able to name plants as an example. Some students may also point plant-like living things such as algae (seaweeds). Some students may know that the process of creating food using the sun’s energy as photosynthesis.

Introduce some of these plants (and algae) using slide 18. At this level, the distinction between plants and algae does not need to be made.

Introduce the key terms activity using slide 19 and hand out the cut-up food chain domino cards to groups of four students. Give them five minutes to match the key terms with the definitions and then review as a class.

3. Saltmarsh food chains (20 mins)

Introduce this activity using slides 21 to 23. This shows the basic idea of a food chain, connecting feeding relationships between living things using arrows. The arrows point in the direction of the transfer of energy. Some students have a misconception that the arrows in a food chain point to the food of a living thing, and it is important to clarify this using the examples given.

Ocean food chains often include two groups of living things that students may not be familiar with. These are phytoplankton and zooplankton. These are tiny, often microscopic, groups of life that drift on the ocean currents and tides. Phytoplankton are a collection of algae that photosynthesise, and zooplankton are small animals (such as the copepods) shown, as well as the eggs and larvae or larger animals.

Sort students into groups of four and hand out the saltmarsh life cards and review each of the living things as a class using slides 24 to 35 and the information on the cards.

Students should then work to create as many different food chains as they can, as well as looking to create the longest food chain possible. As an extension, student groups may wish to create a food web, placing the saltmarsh life cards on a sheet of poster paper and drawing lines linking the different living things.

The food chains and optional food web activities can be reviewed using the food web diagram on slide 37. The dotted line shows how dead and decaying plants form part of the food web by forming detritus. This is a complex process for this age group and can be mentioned if appropriate.

Slide 38 contains key words from earlier in the lesson and this is an opportunity to recap these words in the context of students’ food chains or food webs.

4. Reflection (10 mins)

Reflect on the learning using slide 39 to prompt a whole class discussion. Students may pinpoint living things at the bottom of the food chain as the most important (saltmarsh grass, phytoplankton, and detritus) as without these none of the other life would be possible. Other students may highlight highly connected life such as ragworms.

Emphasise to students that without the plants and muddy detritus all the other wonderful living things would not have any food.

Extension or home learning

Saltmarsh tourism poster

This extension or home learning activity asks students to enhance the view of saltmarshes. Through the food chain activity, they will have seen how important this habitat is to a wide range of life. The tourism poster activity seeks to show how the future of saltmarshes could be boosted through their promotion as a tourism destination. Brief this activity using slide 41 and the Activity Overview and supply student groups with the template and photo sheets. This could form a second lesson on the topic, extension or home learning, with students working independently or in small groups.