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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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EAST LIS CENTRAL LIS WEST LIS NARROWS
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Sampling mud
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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
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Ragweed pollen Onset of hatting industry Chestnut blight 137 Cs 210 Pb 14 C
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HG 137CS
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MEASURES OF ORGANIC PRODUCTIVITY: BURIAL RATE OF ORGANIC CARBON BURIAL RATE OF DIATOM “SKELETONS” (BIOGENIC SILICA) PRODUCTION RATE OF HETEROTROPHS LIKE FORAMINIFERA
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C org, %
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Elphidium excavatum
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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
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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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Core data
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% organic Carbon and 13 C* Year AD CORE A1C1
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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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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
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CONCLUSIONS (2)
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