Water Quality
Created By: James Rothwell
Currently Used By: Emma Shuttleworth, Matt Dennis
Instructions
Top tips for before you start:
- Keep an eye on the weather and stream level. If there has been a lot of rain the river may be in spate and it will be dangerous to run this project.
- Get the kit ready in the equipment store before you find your group.
Part 1 - preamble (usually takes about 30-40 minutes)
Walk the students to the clearing in the woods out the back of the field centre.
Talk them through what influences water quality, why we should care, and how we might measure it (using the handout as a guide). I don't usually give the students the handout till later on so they have to think!
Get them to think about what might be influencing water quality in the stream next to them. They usually mention the field centre pretty quickly (cars, sewers, litter, septic tank, etc).
Head to the equipment store and grab the waders, kick nets and buckets.
Walk back to the clearing and get them to think about how you might design an experiment to test if the field centre is influencing the water quality in the river. Key considerations:
- Take samples upstream and downstream of field centre
- Take the same number of samples at each site
- Sustain kicking effort across all samples
- Kick for same amount of time per sample (two min)
Part 2 - sampling (usually takes about an hour)
Split the students into pairs and get them into the waders. Note - no one will be wearing the correct shoe size, this doesn't matter.
Go through health and safety. Warn that it might be slippery underfoot and that they should leave all phones/electronics in their bags well away from the water. Stress that they shouldn't go in above knee height and to avoid fast flowing water. There are no heroes in water quality!
Get the students in the stream near the clearing in the woods. Unless the level is extremely low, don't let them cross tot he other side.
Get them to do two rounds of kicking each (for consistency). Time them from the safety of the bank so no one risks losing their phone in the water.
After each round of kicking, get them to empty their nets into the buckets. Make sure their's a bit of water in the buckets too to keep everything alive.
When the upstream site is done, walk over to the downstream sampling site just across the road next to the bridge. On the way, drop off the full buckets at the equipment store and grab some empty ones.
Sample as above, then head back to the equipment store and de-wader.
Part 3 - looking at what they've found (usually takes 40 min to an hour)
Grab the remaining kit and all of the samples and head to the picnic area at the back of the field centre. If it's raining, you can stay in the equipment store, but just to warn you it smells of feet.
Pour the samples from the upstream site into the plastic trays and give out the pipettes, tweezers, hand-lenses, petri dishes, handouts, and key cards.
Talk them through the key card and table on the last page of the handout, and set them off looking through the samples for bugs. Make sure they only count things they've extracted and put in the petri dishes so they don't count things twice. Also make sure they count everything rather than just hunt for lots of different things.
After about 20 min, get them to tip the contents of the trays back into the stream and give them a rinse under the tap on the side of the equipment store.
Repeat for the downstream samples.
Part 4 - wrap up (usually takes about 10-15 min)
Gather the students round and go through the questions on the last page of the handout.
When asked if the field centre is impacting water quality, they usually say yes. Get them to think about this in a bit more detail. There are always clean water indicators downstream so there almost certainly isn't a water quality issue. Get them to think about what other things might influence what they find (differences at the two sites - stream bed, speed/depth of flow, veg, land use, etc).
Make sure they tidy everything up then send them on their merry way with firm instructions to wash their hands before they do anything else.
Equipment
For students:
- Waders – one pair per student (pack at least 10 pairs)
- Kick nets – one pair per student (pack at least 6)
- Buckets with lids (pack at least 10)
- Blue gloves – various sizes
- White plastic trays (pack at least 6)
- Plastic petri dishes (pack more than you think you'll need)
- Hand lenses (pack more than you think you'll need)
- Plastic tweezers (pack more than you think you'll need)
- Plastic pipettes (pack more than you think you'll need)
- Freshwater invertebrates key cards (as many as we have)
- Handouts
For staff:
- Stop watch
