Today I helped Mary-Kate prepare her Acetylene reduction Assay to measure N-fixation from her sediment samples.
I also spent some time acid-washing lab equipment that was used in the field this week. We have to acid wash things because the nutrients measured in samples are also present in the air, in tap water, and on our skin, so we need to decontaminate everything to be sure what measure is real and not from us.
After a few rounds of acid washing, I read some scientific papers to learn more background information for my project. I read about the invasive marsh grass species Phragmites australis that out-competes native species because it can grow up to 6 meters tall and shade out smaller native plants. Human activities such as building roads through marshes contribute to the spread of this invasive species by blocking or impeding tides from the ocean. This lowers the salinity and sulfide content of the restricted marsh area -- conditions very favorable to Phragmites australis growth.