Joint DFO/DEOS Seminar - February 21, 2018 - Autumn Oczkowski
When: Wednesday,
February 21, 2018
2:30 PM
-
3:30 PM
Where: New Bedford New Bedford, MA
Description: Joint Department of Fisheries Oceanography and Department of Estuarine and Ocean Sciences
How Major Reductions in Nitrogen Loads Have Impacted the Narragansett Bay Ecosystem
Autumn Oczkowski
Research Ecologist
Department of Environmental Protection
Wednesday, February 21, 2018
2:30 pm - 3:30 pm
SMAST-East, rm 101/102
836 South Rodney French Boulevard, New Bedford, MA
ABSTRACT:
Over the past decade, nitrogen (N) loads to Narragansett Bay have decreased by about 65%. These reductions were the direct result of multiple sewage treatment plant upgrades to tertiary treatment, a process which removes bioavailable N. I will describe the ecosystem response to the N reductions and assess how the distribution of sewage N in Narragansett Bay has changed from before, during, and after the upgrades. Comparisons of dissolved inorganic nitrogen (DIN) concentrations and Secchi depth from bay-wide surveys conducted in the early 1980s and 2014-2016 did not yield distinct differences. To look more closely at potential spatial and temporal changes in bioavailable N distribution over time, I used nitrogen (δ15N) and carbon (δ13C) stable isotope measurements of particulate matter, macroalgae, and hard clams (Mercenaria mercenaria). In contrast to comparable studies from other places, the δ15N results indicated that sewage still plays a dominant role in supporting primary and secondary production, while the δ13C data suggested that overall net production in Narragansett Bay has decreased. The sum of these observations is that the Bay is still sewage-supported but may be undergoing some oligotrophication.
To access the live broadcasting, go to https://echo360.org and click on "Alternate login"
you will have to login as smast@umassd.edu with the password: smastumassd
After login you will have to click on ALL CLASSES (MAR 700-01 - DEOS seminar or MAR 700-02 - DFO seminar) and click on the green LIVE streaming.
To view a video of an SMAST seminar (post-October 1, 2014), go to http://www.umassd.edu/smast/newsandevents/seminarseries/ and click on a highlighted title.
For more information, please contact cfox@umassd.edu (DFO) or s1silva@umassd.edu (DEOS)
How Major Reductions in Nitrogen Loads Have Impacted the Narragansett Bay Ecosystem
Autumn Oczkowski
Research Ecologist
Department of Environmental Protection
Wednesday, February 21, 2018
2:30 pm - 3:30 pm
SMAST-East, rm 101/102
836 South Rodney French Boulevard, New Bedford, MA
ABSTRACT:
Over the past decade, nitrogen (N) loads to Narragansett Bay have decreased by about 65%. These reductions were the direct result of multiple sewage treatment plant upgrades to tertiary treatment, a process which removes bioavailable N. I will describe the ecosystem response to the N reductions and assess how the distribution of sewage N in Narragansett Bay has changed from before, during, and after the upgrades. Comparisons of dissolved inorganic nitrogen (DIN) concentrations and Secchi depth from bay-wide surveys conducted in the early 1980s and 2014-2016 did not yield distinct differences. To look more closely at potential spatial and temporal changes in bioavailable N distribution over time, I used nitrogen (δ15N) and carbon (δ13C) stable isotope measurements of particulate matter, macroalgae, and hard clams (Mercenaria mercenaria). In contrast to comparable studies from other places, the δ15N results indicated that sewage still plays a dominant role in supporting primary and secondary production, while the δ13C data suggested that overall net production in Narragansett Bay has decreased. The sum of these observations is that the Bay is still sewage-supported but may be undergoing some oligotrophication.
To access the live broadcasting, go to https://echo360.org and click on "Alternate login"
you will have to login as smast@umassd.edu with the password: smastumassd
After login you will have to click on ALL CLASSES (MAR 700-01 - DEOS seminar or MAR 700-02 - DFO seminar) and click on the green LIVE streaming.
To view a video of an SMAST seminar (post-October 1, 2014), go to http://www.umassd.edu/smast/newsandevents/seminarseries/ and click on a highlighted title.
For more information, please contact cfox@umassd.edu (DFO) or s1silva@umassd.edu (DEOS)
Contact: > See Description for contact information
Topical Areas: School for Marine Sciences and Technology, SMAST Seminar Series