Long Island Sound has suffered

1

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

2
(No Transcript)
3
(No Transcript)
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
137Cs
Chestnut blight
210Pb
Onset of hatting industry
Ragweed pollen
14C
7
137CS
HG
14C
14C
8
(No Transcript)
9

• MEASURES OF ORGANIC PRODUCTIVITY
• BURIAL RATE OF ORGANIC CARBON
• BURIAL RATE OF DIATOM SKELETONS
• (BIOGENIC SILICA)
• PRODUCTION RATE OF HETEROTROPHS LIKE
  FORAMINIFERA

10
Corg,
11
(No Transcript)
12
(No Transcript)
13
Elphidium excavatum
14
(No Transcript)
15
The d13C 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 d13C variability not related to mixing
of sea and river water (d13C)

• Measure d18O values in foraminiferal shells
• Calculate d18O of water using BWT
• Estimate salinity from LIS mixing model
• Estimate d13C of dissolved inorganic carbonate
  using the LIS mixing model
• Subtract calculated - observed values
• d13C d?13Ccarbonate - d?13Ccalculated in
  water

17
(No Transcript)
18
(No Transcript)
19
(No Transcript)
20
(No Transcript)
21
Core data
22
organic Carbon and d13C
CORE A1C1
Year AD
23
The d13C value indicates the amount of oxidized
Corg that was added to the bottom water
column. The d13C value serves as an indirect
proxy for OCI or Oxygen Consumption Index (Level
of Paleo Oxygenation)
24
(No Transcript)
25
(No Transcript)
26
(No Transcript)
27
CONCLUSIONS (1)

• Major environmental changes in the early 1800s
• Increased Corg and Bsi storage
• Isotopically lighter carbon, lower O2 levels
  in bottom waters, sewage indicators, and metal
  pollutants
• Increased productivity of benthic foraminifera

28
CONCLUSIONS (2)

• Hypoxic events may have occurred since the early
  1800s but were absent before that time. They are
  severe in the late 20th century. Why?
• Enhanced productivitygt more Corg
• Modern global warminggt higher rate of Corg
  decompositon and increased water stratification
• HYPOXIA NEED A COMBINATION OF HIGH BWT AND HIGH
  Corg LOADING