Apr 4-10, 2009

These were two samples from Fish Creek. The first was taken while it was still partly covered in ice, but had melted on the sunnier side, where a boatsman was noticed. The second was a few days later, when the whole stream had become higher, swifter, and brownish. It was taken from a small dip where leaves were caught.

Both samples were sparse in some parts and richer in others, with a variety of creatures swept downstream. The most common were Strobilidium, with some vorticellids, flat spirotrichs, and scattered centric and pennate diatoms. The first also had some flagellates like Synura and small dinoflagellates, and a cluster of Carchesium.

A mayfly larva was found in the second sample, and its droppings may have promoted the appearance of films along the bottom, carrying vorticellids and round suctorians, with some clumps of Anthophysa nearby. Settled debris also had a few roundworms, Actinophrys, and extremely fast Askenasia, along with smaller protozoa.