What is plankton?

  • Plankton is a word used to describe tiny, mostly microscopic plants and animals that float in our seas along the currents.
  • There are two groups of plankton; tiny plants, phytoplankton, and weak-swimming animals, zooplankton.

Why is plankton so important?

  • Phytoplankton (tiny plants) produce over 50% of the total oxygen present on earth!
  • Plankton forms the basis of all marine food chains and is vital to the life in our seas.

Did you know it takes 100 tonnes of plankton to grow 1 tonne of blue whale!

All the above facts taken from ‘The Plankton Guide’ by Torbay Coast and Countryside Trust.

For the children visiting dailycialisuse the marine centre today, in order for them to meet some of Wembury’s plankton, we first needed to make our own plankton nets.


We made the plankton nets using wire coat hangers, old tights, and recycled juice bottles.


The children then came with us down to the shore and we dragged the nets through the water, keeping our fingers crossed for some peculiar plankton!


With the microscope set up and connected to the big screen, everyone could see what was in the small samples of seawater.


Due to the quite choppy conditions today there was quite a lot of seaweed in our samples. Not tiny phytoplankton, but its still great to see under a high magnification. Especially the delicate, almost feathery red seaweeds.

I really enjoyed finding all of the different plankton species and having a good look at them. The children that took part all had a great time. There were cries of excitement at anything that moved or wriggled, and the occasional ‘yuck!’ at anything that looked remotely like a bug.

I think my favourite thing spotted amongst the plankton is the shed exoskeleton of a barnacles feeding legs. Called a barnacle exuvium. Its in the picture above, looking like a group of tiny delicate feathers. The large dark, and striped mass is a species that we were unable to identify, that rested temporarily amongst the barnacle exuvium.

One of the children’s favourite things under the microscope, was a small prawn, measuring just a few millimetres. Seeing a creature that they recognised magnified like this caused great excitement. There were cries of “I caught that!”, shortly followed by her brother, “No you didn’t! That was in my pot!”.

I think its really important that children understand the significance of these tiny organisms, and what they mean to all the creatures living in our oceans. After all, most people know what a basking shark is, and looks like. But not everyone knows that it feeds on plankton, let alone what that plankton is, or looks like. Without these simple microscopic plants and animals, all of the oceans iconic species, could not survive.