1. Using sediment cores: Case studies to assess contamination in estuarine environments Brad Hubeny Salem State University

2. Introduction Salem State is adjacent to an estuary that has experienced various human impacts since the early 17 th century Goal of this project is to allow students to investigate how human activities can be preserved in the sedimentary record In-class and take-home assignment

3. Audience Sophomore/Junior level Geology elective: Estuaries and Pollution ~25% are non-geology majors who have taken at least Physical Geology and have an interest in environmental science Most students are from the region, so Salem Sound has a personal connection to them

4. Objectives Investigate the concept of sediment proxy data to reconstruct environmental conditions from the past Quantitatively relate sediment depth to age of deposition Assess a contaminant’s level of impact using sediment quality guidelines Practice formulating and testing scientific hypotheses Final Report: Standard written format with associated figures

5. Data Sources Three sediment cores with age constraints and organic matter concentration; one core with CNS isotope, magnetics, and metals data Two undergraduate theses, which were both presented at NEGSA in 2011 – Ellen Kristiansen – Andrew Danikas More recent analyses associated with a manuscript in prep.

6. Salem Sound

7. Sediment Cores

8. Step 1: Hypothesis Formulation: How might documented population growth show up in the sediment record? Additional Watershed Information: Peabody was “Leather Capital of the World” from 19 th century until mid-20 th century Effluent pipe discharged raw sewage to estuary from 1905-1977 Primary sewage treatment started in 1977 Secondary sewage treatment started in 1998 US Census Data

9. Step 2: Computing Age from Depth Mid Depth (cm)Age14C calibration errorBe-7 (mBq/g)Error (+/-)Cs-137 (mBq/g)Error (+/-) 0.75200710.612.081.010.12 2.252000001.630.31 3.7519931.510.19 5.2519861.950.2 6.7519802.190.23 8.2519730.930.35 9.7519660.370.32 11.25196000 12.751953 14.251946 15.751939 18.751926 21.751913 24.751899 27.751886 74160681

10. Step 2: Computing Age from Depth

11. Step 3a: Test organic matter hypothesis Basic time series How well do they match? Is something else going on?

12. Step 3b: Test organic matter hypothesis Spatial Distribution

13. Step 3c: Test organic matter hypothesis More advanced with CN data

14. Step 4a: Test Contaminant Hypothesis

15. Step 4b: How “bad” are these levels? ERL & ERM from Long et al, 1995 ERM: 370ppm ERM: 218ppm ERM: 410ppm ERL: 150ppm ERL: 34ppm

16. Acknowledgments Ellen Kristiansen, Andrew Danikas, Jeremy Louisos, Bridgette Gillespie, John Strom, Jess Jones, Joe Incatasciato Curtis Olsen and Jun Zhu, UMass Boston Doug Allen, William Hamilton, SSU SSU Dean of the College of Arts and Sciences Massachusetts Bays Program Massachusetts Environmental Trust National Science Foundation Barbara Warren and Salem Sound Coastwatch