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Long Island Sound has suffered from hypoxia for decades: Result of Global Warming? Eutrophication? It has always been like this…...

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Presentation on theme: "Long Island Sound has suffered from hypoxia for decades: Result of Global Warming? Eutrophication? It has always been like this…..."— Presentation transcript:

1 Long Island Sound has suffered from hypoxia for decades: Result of Global Warming? Eutrophication? It has always been like this…...

2 EAST LIS CENTRAL LIS WEST LIS NARROWS

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4 Sampling mud

5 Design “proxies” for paleo- environmental research such as Salinity Temperature Faunal/floral characteristics Oxygen saturation Metals Sewage Calibrate proxies for these parameters on the modern LIS environment

6 Ragweed pollen Onset of hatting industry Chestnut blight 137 Cs 210 Pb 14 C

7 HG 137CS

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9 MEASURES OF ORGANIC PRODUCTIVITY: BURIAL RATE OF ORGANIC CARBON BURIAL RATE OF DIATOM “SKELETONS” (BIOGENIC SILICA) PRODUCTION RATE OF HETEROTROPHS LIKE FORAMINIFERA

10 C org, %

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13 Elphidium excavatum

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15 The  13 C values in foram “shells” are related to mixing of sea and river water (salinity) and to addition of “light carbon” from photosynthetic productivity

16 Estimate  13 C variability not related to mixing of sea and river water (  13 C*) Measure  18 O values in foraminiferal shells Calculate  18 O of water using BWT Estimate salinity from LIS mixing model Estimate  13 C of dissolved inorganic carbonate using the LIS mixing model Subtract calculated - observed values:  13 C * =  13 C carbonate -  13 C calculated in water

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21 Core data

22 % organic Carbon and  13 C* Year AD CORE A1C1

23 The  13 C* value indicates the amount of oxidized C org that was added to the bottom water column. The  13 C* value serves as an indirect proxy for OCI or Oxygen Consumption Index (Level of Paleo Oxygenation)

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27 CONCLUSIONS (1) Major environmental changes in the early 1800’s: Increased C org and Bsi storage Isotopically lighter carbon, lower O 2 levels in bottom waters, sewage indicators, and metal pollutants Increased productivity of benthic foraminifera

28 CONCLUSIONS (2)


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