Most stream insects have an annual turnover—once a species hatches,
the entire population disappears from the water in a short period of time
and doesn’t grow back until the following year. However, in thermally
influenced areas, some of these stream insects are actually producing
two times a year! For example, a certain caddisfly, which emerges from
cold water streams in March or April, is also hatching from the Firehole
River in November!
Doc, our Firehole investigation started when Viola DeRama expressed concern
about the EPT species in Obsidian Creek. How do the Firehole EPT critters
I observed that many mayflies seemed to prefer the cooler areas of the
river, while caddisflies were thriving in the warmer, bicarbonate enriched
zones. Naturally, there was considerable variation within these groups.
I didn’t see certain types of caddisflies at all in the warmer waters,
while several of the smaller-sized species of caddisflies were only found
stream insects reproduce in thermally influenced areas?
3 of 4: Questions 21-30