Poster Details
DETERMINING THE IMPACT OF INCREASED PH ON CHIRONOMID GROWTH RATES IN NEOTROPICAL STREAMS
Stream pH can play a key role in determining ecosystem structure and function. In the Neotropics, some streams undergo episodic acidification seasonally or due to individual rainfall events. However, some streams are resistant to pH declines due to high levels of geothermally-derived solutes (especially bicarbonate) that serve as buffers. In this study, we explored the impacts of artificial alkalinization on chironomid growth rates in two Neotropical streams. One stream had a natural pH gradient and included both naturally low-solute and naturally high-solute reaches, and the other (a naturally low-solute stream) included a control reach and a reach artificially alkalinized by a calcium carbonate addition. We predicted that chironomids in higher-solute (buffered) reaches would have higher growth rates than chironomids subjected to the lower pH of low-solute (unbuffered) reaches. We collected chironomid larvae from leafpacks in each of the four reaches and conducted 48-hour in-stream growth trials. Chironomid growth rate and survival did not differ significantly between the reaches, suggesting that these chironomid communities may be resistant to changes in stream pH.
Carissa Ganong (Co-Presenter/Co-Author), Missouri Western State University, carissa.ganong@gmail.com;
Chris Watson (Primary Presenter/Author), Missouri Western State University, cwatson12@missouriwestern.edu;