Not a great week for new ideas.
I’ve based the new Year 8 Ecology topic around brine shrimps and the wonderful resource developed by Stephen Tomkins and Michael Dockery for the British Ecological Society. You can find a pdf of the full booklet here:
It’s just brilliant – full of superb ideas for practical Ecology based on studies of animals in the lab. My idea was to start with brine shrimp bottles – little self-contained eco-systems – that the students could set up, use for various lessons, and then take home to keep. I also wanted them to carry out the brine shrimp egg hatch investigation, looking at the effect of key variables (pH, temperature and salinity) on hatch rate. There are so many important skills being developed here and it’s a great differentiator as they get to research brine shrimp ecology and make predictions.
In addition, I wanted them to look at the splendid Dunlaliella flagellate algae through microscopes as a route into primary producers.
Better still, I had already used these ideas in other schools and felt the whole thing was pretty much bomb-proof.
Well, starting with the positives, they had a lot of fun. And various skills were certainly developed, particularly that of perseverance when they came to count the 100 brine shrimp eggs for each treatment of the hatch experiment.
But the algal microscopy was a complete failure – nobody could find the startling view of 1000s of tiny green dots gyrating wildly under the lens. I suspect our samples were too old and the alage had all died. Plus the algae really are very very small – even on HP you can’t make out much detail. Next year I plan to buy a few more binocular microscopes and look at the brine shrimps themselves – where you also get to see the algae, crammed into the digestive tract.
Worse, for the hatch experiment, nothing hatched. Under any conditions. For any of the 4 classes. All that work and no results! (my technician would like me to add: all that sea salt! all that marine sand! all that dechlorinated water!). It was all crushingly disappointing and I currently have no idea why – I mean, I’ve done all of this before with primary school children and, as I say, it works. Every time.
Except this time.
So, I’ll have to go and trouble shoot that. Any suggestions? It can’t be a dodgy batch of eggs because they DID hatch when added to the main display brine shrimp tank (well worth setting up one of these if you have space – instructions in the booklet….). They also hatched in the brine shrimp bottles (these do seem to have worked well, and the girls were suitably excited at the sight of the 100s of tiny nauplii swimming around). Perhaps the lab just got too cold – though that doesn’t explain the lack of success at 30’C in the water bath.
All very frustrating and disappointing – but despite all that, the girls were suitably philosophical. They recognised that we were trying to do something interesting and worthwhile and appreciated the effort, even if it hadn’t quite gone to plan. They had enjoyed the lessons setting everything up and we could still talk about the dynamics of an ecosystem in a bottle.
I suppose what I’m getting round to saying is: don’t be afraid of trying something new just because it might not work.
To end on a completely different note – I highly recommend showing this astonishing film on CTLs to your 6th form.