Oct 14: Make a Sediment Jar

Issue 198

Mar - Apr 2026

Black-Backed Gulls
Meth & HIV in Fiji
Dung beetles
Centro
Rogaining

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Talking points

Gull spotting

• Editorial

For shame

• In the field

When black-backs attack

• In the field

Two years on Mana Island

• Geo News

Before the flood

• Geo News

A delicious crayfish circle of life

Below are some talking points and activities to pass the time, all relating to today’s story.

Talking points

Discuss the ideas presented in the story with your family—at home or over video conferencing. Find ways to involve as many people as possible, especially those who you know are isolated by the lock-down.

• Do you know the difference between freshwater, wastewater and stormwater – all of which are connected to where you live? 
• “Today the creek is a torrent, the waterfall is brown thunder—a Huka Falls of sediment-filled water.” Have you ever seen a creek rise suddenly in heavy rain? What did you see? Is “brown thunder” a good description?
• Have you seen a sign saying “Dump no waste, flows to sea” on a stormwater drain? Do you think most people know that stormwater drains carry water (and anything else that goes into them) into streams that flow out to sea? What kinds of things do you see in or near stormwater drains? 
• Are you surprised to read that Meola Creek in central Auckland has 450 times the recommended limit of Enterococcus bacteria? What effect might this bacteria have on plant and wildlife? Do you think humans can tell that a creek is ‘sick’ even though we can’t see bacteria? What makes a creek seem sick or healthy?
• Have you seen any projects or places which show that either citizens or local government are trying to become more water-sensitive? If you could do one thing to awhi or care for a creek or estuary near you, what would you do?

Activity: Make a Sediment Jar

When water flows in torrents, everything gets mixed up. Once the heavy flow settles, a creek or river becomes clear again, with layers of material. Make this sediment jar to explore what happens!

You will need:

• A jar with a lid
• Water
• A range of materials from outside – pebbles, soil, potting mix, rocks, grass, dead leaves

Step One: Fill your jar up about ¾ of the way with water. Add your materials.

Step Two: Screw the lid on the jar and give It a good shake.

Step Three: Leave the jar on a flat surface such as a windowsill and watch it for a few minutes to see what happens. Check again in about an hour. What do you notice? What has floated to the top and what has settled at the bottom? Are the contents of the jar similar to a stream in any way?

Send us a picture of your sediment in a jar!