Intruder alert! The rising threat of saltwater intrusion

Corns struggles to grow in salty water.

“Going green” are words that are part of many people’s everyday vocabulary as scientists urge the public to take action and protect the environment from the harmful effects of climate change. Many of the recommended strategies to “go green” focus on reducing waste and preserving resources, but there are other ongoing problems associated with climate change that are not as well known. One such concern is with saltwater intrusion.

Saltwater intrusion, described as “the landward movement of sea” [1], is one of the first effects seen from sea level rise. With sea levels rising by 3mm every year in the Northeast United States, saltwater intrusion will become even more of a problem as time goes on [2]. The effects of saltwater intrusion on the ecosystem can be dramatic. Increased concentrations of salinity in soil have been shown to reduce the production of plants, and this can offset the delicate balance between the materials needed and created by the ecosystem [3]. It is vital that work is done to determine the impacts of saltwater intrusion in order to find the best way to combat this urgent problem.

While I had some basic laboratory skills before starting this internship, I have learned and developed many of my skills while working in the Agroecology Lab. Most of my time in the lab has been spent doing Potassium Chloride (KCl) extractions on soils that were collected and archived in November 2020. The purpose of these extractions is to determine the concentration of Ammonia (NH3) and Nitrate (NO3) in the collected samples, which when added together will give the measurement of total inorganic nitrogen in the soil. I performed these extractions by adding 2M KCl to the archived soil samples, mixing the sample for an hour using a shaker table, centrifuging to allow the soil to settle to the bottom, and then filtering the liquid containing the extracted NH3 and NO3. The concentration of these two compounds is determined using a technique called spectrophotometry, which uses light waves to determine the concentration of a substance.