More science!

During Science Week we carried out a practical investigation exploring how a filter lets water through but traps some of the things that are mixed in with it.  This shows us how the ‘sand sausages’ are used at St Clair’s beach in Dunedin.  The ‘sausages’ are used to help keep the sand on the beach.  They let water pass through, but they stop the beach sand, so it isn't dragged away.  This helps stop the waves from eating away at the land.