Pond planting and Sampling with Coed Eva Primary School

Working with year 4 of Coed Eva has been amazing fun and really inspiring for our small group. Most of the plants in the pond look great and Class 4RP (Ms. Payne) did a great job of sampling. Here's a little report including the results of their work...

Twenty Eight volunteers from Friends of Henllys LNR and Coed Eva Primary School’s Class 4RP came along to sample macroinvertebrates from the two adjacent ponds.

Look at the concentration

Year 4 were studying water quality in class and we decided it would be good idea investigate the pond water quality by recording the macroinvertebrates caught. The class learnt from the Friends that some bugs like very clean water and some live in dirty water and looking at the range and average of these bugs caught can give clues to water quality.

Dragonfly nymph (likes good quality water)

Moreover, they could scientifically test to see if there are any differences between the two ponds which are only 40 metres apart from each other. After a quick demonstration of pond dipping and how to look at what they’d caught using sample trays, the children split into three groups which they called themselves , dragonflies, fireflies and cased caddis flies. Armed with a crib sheet and tally chart prepared beforehand by the Friends, the children set to their tasks admirably. After a suitable length of time, they cleaned their nets, but all the bugs back and headed over to the second pond. They carried on sampling in this pond noting that some of the pond was green and there was some plantlife inside this one, which was not present in the first one.

Greenish growth in pond 2

 

The data was summarised with loads more dragonfly larvae found in the planted up pond (Class 4WWs) compared with the top pond.

	Planted Pond	Top Pond
Caught	Sum Planted	Sum top pond
Pondskater (BI 5)	11	12
Water boatman (BI 5)	16	14
Dragonfly nymph (BI 8)	9	2
Water beetle (BI 5)	2	2
Pond snail	6	0
Frog	1	0
Tadpole	1	0
Caddisfly larvae (BI 5)	2	0

 Using the calculated Biotic Indices and an unpaired t-test the probability of a difference between the 2 ponds was p = 0.118.  From this, with a 0.05 confidence limit, they are not significantly different. However, the numbers of dragonfly larvae caught were quite a bit larger than at the top pond (I'd be tempted to do it again with a smaller group to minimise errors).

NOT BAD FOR 9 YEAR OLDS DOING SOME PROPER SCIENCE EH?

We were supported again with equipment and experience by TCBC’s ranger Jon Howells.

 

For more pictures, have a look at http://flic.kr/s/aHsjGZ9YUJ Many thanks to all the teachers who were really encouraging and positive with the kids, a real credit to Coed Eva and brilliant for Henllys Local Nature Reserve.