UMCES INTERNSHIP Summer 2019 - Scott McKinstry WORKING IN A LAB - PowerPoint PPT Presentation

UMCES INTERNSHIP Summer 2019 - Scott McKinstry

WORKING IN A LAB  Safety and appropriate lab wear.  Understanding of materials and equipment used.  Mindfulness of others in the lab.  Communication about supplies and equipment.

CLEANLINESS & NEATNESS YAY NAY

OTHER OPPORTUNITIES  Bird Walks  Ecology Readings  AMJV  Lab Events

INTERNSHIP RESEARCH  Identification of sources of nitrate (NO3) in rivers during storm events.  Isotopic composition differences between sources of NO3 measured using the denitrifier method and IRMS.

WHY WE CARE  Excess NO3 pollution from upland watersheds contributes to algal blooms and the formation of dead zones in the Chesapeake Bay. (Kemp et al. 2005)  Understanding the sources of NO3 can allow us to take steps to decrease the amount of nitrogen entering the Bay. https://mde.maryland.gov/programs/Water/HA /Pages/index.aspx

DENITRIFIER METHOD  First, the bacteria are grown on shaker table overnight.  Next, the bacteria are mixed with a nitrate-free broth and injected into vials.  The vials are then placed on a “purging” rack, where helium is entered into the vials and any atmospheric gases (N 2 and O 2 ) are emitted.  Lastly, the samples collected from the storm events are added into the vials and bacteria convert NO 3 to nitrous oxide (N 2 O). Soto et al. 2015

WATERSHEDS

RESEARCH QUESTION  Does the size of the storm have a correlation with the concentration of total and atmospheric NO3?

Total Precipitation Depth (cm) vs. Event Mean Concentration (mg/L) 3.50 vent Mean Concentration of 3.00 2.50 2.00 NO3 (mg/L) R² = 0.324 1.50 GUN GWN 1.00 0.50 R² = 0.0642 0.00 0.00 1.00 2.00 3.00 4.00 5.00 6.00 Total Precipitation Depth (cm)

TOTAL NO3 LOAD (KG/HA) VS. MAX PRECIPITATION INTENSITY(CM/HR.) Gunpowder Falls Gwynn's Falls 0.90 0.16 0.80 0.14 0.70 0.12 Tot al N03 Load (kg/ha) Total NO3 Load (kg/ha) 0.60 0.1 0.50 0.08 0.40 0.06 0.30 0.04 0.20 0.02 0.10 0.00 0 0.00 2.00 4.00 6.00 8.00 0 5 10 15 20 Maximum Precipitation Intensity (cm/hr) Maximum Precipitation Intensity (cm/hr)

Gunpowder Falls - Storm Event 3 1800 0.12 CONCENTRATION (MG/L) 1600 ATMOSPHERIC NO3 0.10 DISCHARGE (CFS) 1400 1200 0.08 1000 0.06 800 600 0.04 400 0.02 200 0 0.00 12/28/2018 0:00 12/28/2018 4:48 12/28/2018 9:36 12/28/2018 14:2412/28/2018 19:12 12/29/2018 0:00 12/29/2018 4:48 12/29/2018 9:36 DATE & TIME Discharge Atm. NO3 Concentration

Gunpowder Falls – Storm Event 6 1000 0.16 CONCENTRATION (MG/L) 900 0.14 ATMOSPHERIC NO3 800 DISCHARGE (CFS) 0.12 700 0.1 600 500 0.08 400 0.06 300 0.04 200 0.02 100 0 0 5/5/2019 0:00 5/5/2019 4:48 5/5/2019 9:36 5/5/2019 14:24 5/5/2019 19:12 5/6/2019 0:00 5/6/2019 4:48 DATE & TIME Discharge Atm. NO3 Concentration

Gwynn’s Falls – Storm Event 3 1000 0.14 CONCENTRATION (MG/L) 900 0.12 ATMOSPHERIC NO3 800 DISCHARGE (CFS) 0.1 700 600 0.08 500 0.06 400 300 0.04 200 0.02 100 0 0 12/27/2018 19:12 12/28/2018 0:00 12/28/2018 4:48 12/28/2018 9:36 12/28/2018 14:24 12/28/2018 19:12 12/29/2018 0:00 12/29/2018 4:48 12/29/2018 9:36 DATE & TIME Discharge Atm. NO3 Concentration

Gwynn’s Falls – Storm Event 5 1800 0.14 Atmospheric NO3 Concentration 1600 0.12 1400 Discharge (cfs) 0.1 1200 0.08 1000 (mg/L) 800 0.06 600 0.04 400 0.02 200 0 0 3/21/2019 4:48 3/21/2019 9:36 3/21/2019 14:24 3/21/2019 19:12 3/22/2019 0:00 3/22/2019 4:48 3/22/2019 9:36 Date & Time Discharge Atm. NO3 Concentration

Gwynn's Falls - Storm Event 6 800 0.2 CONCENTRATION (MG/L) 0.18 700 ATMOSPHERIC NO3 0.16 DISCHARGE (CFS) 600 0.14 500 0.12 400 0.1 0.08 300 0.06 200 0.04 100 0.02 0 0 5/4/2019 19:12 5/5/2019 0:00 5/5/2019 4:48 5/5/2019 9:36 5/5/2019 14:24 5/5/2019 19:12 5/6/2019 0:00 5/6/2019 4:48 5/6/2019 9:36 DATE & TIME Discharge Atm. NO3 Concentration

CONTINUING RESEARCH  Currently waiting on isotope data from remaining storm samples.  More data will help us better understand the relationship between storm size and sources of nitrate.  Insight on relationships between the urban and rural watersheds.

SPECIAL THANKS TO:  Joel Bostic  Kevin Dodge  Rhonda Schwinabart  Robin Paulman  Pavithra Arachchige  Katie Kline  FRA’s  Graduate Students  Professors  Lab Staff