lecture 14 - estuaries. estuary – body of water partially surrounded by land where fresh water...
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Lecture 14 - ESTUARIES
Estuary – Body of water partially surrounded by land where fresh water from a river mixes with ocean water
Last Ice Age
Classification of Estuaries - Geological
1. Coastal Plain Estuary(= Drowned River Estuary)
Classification of Estuaries - Geological
1. Coastal Plain Estuary2. Bar Built Estuary
Classification of Estuaries - Geological
1. Coastal Plain Estuary2. Bar Built Estuary
Bar-built estuary
-sediment deposited by longshore currents
estuary
Longshore current
Bar-built estuary
Sandy Hook, New Jersey
Bar-built estuary
Sandy Hook, New Jersey
Classification of Estuaries - Geological
1. Coastal Plain Estuary2. Bar Built Estuary3. Fjord
Classification of Estuaries - Geological
1. Coastal Plain Estuary2. Bar Built Estuary3. Fjord4. Tectonic
San Andreas Fault
Hayward Fault
Calaveras Fault
Tectonic Estuary
Earthquake causes blocks to shift
Tectonic Estuary
Earthquake causes blocks to shift
Tectonic Estuary
Circulation Patterns of Estuaries
Salt Wedge
Partially Mixed
Mixed
Estuary flow animations
http://oceanservice.noaa.gov/education/kits/estuaries/media/supp_estuar05a_wedge.html
Reverse Estuary
Rare freshwater inflowRestricted tidal mixing
Internal wind-driven mixing
High Salinity Lower salinity
Evaporation
Factors influencing estuary circulation
River dischargeLow High
Maximum Minimum
Strong Weak
Weak Strong
Tidal mixing
Tidal currents
Water stratification
Well-mixed estuary Partially mixed estuary Salt wedge estuary
San Francisco Bay - a salt wedge estuary
St. Croix River- well-mixed estuary
Columbia R. - Oregon - a well mixed estuary
Chesapeake Bay - partially mixed
Colorado River mouth - a reverse estuary
Reverse Estuary
Laguna Madre - Texas
Physical Features of Estuaries
Salinity - Coriolis forces
Physical Features of Estuaries
Salinity - Bottom vs Water column
MudBottom water
Salinity
Time
Physical Features of Estuaries
Substrate -
Flocculation
Turbidity – Rappahannock River
75 mg/l
>5 mg/l
Physical Features of Estuaries
Substrate - Movement by Current
Diversity in Estuaries
Euryhaline
Stenohaline
1. Euryhaline-tolerate
salinites between 15 and 35 ppt
2. Stenohaline-tolerate
salinities above 25 ppt
Diversity in Estuaries
Brackish water Animals-tolerate salinites between 5 and 18 ppt
Nereis Callinectes Hydrobia
Diversity in Estuaries
Transitional Animals-pass through estuary
American eel
Atlantic salmon
Diversity in Estuaries - Vegetation
Chaetomorpha Cladophora
EnteromorphaUlva
Adaptations to Estuaries
Coping with salinity
Adaptations to Estuaries
Coping with salinity
Internalsalinity
Environmental salinity
0 10 20 30 40
40
30
20
10
Adaptations to Estuaries
Coping with salinity
Internalsalinity
Environmental salinity
0 10 20 30 40
40
30
20
10
Perfect osmoconformer
Adaptations to Estuaries
Coping with salinity
Internalsalinity
Environmental salinity
0 10 20 30 40
40
30
20
10
Perfect osmoconformer
Perfect osmoregulator
Adaptations to Estuaries
Coping with salinity
Internalsalinity
Environmental salinity
0 10 20 30 40
40
30
20
10
Adaptations to Estuaries
Coping with salinity
Internalsalinity
Environmental salinity
0 10 20 30 40
40
30
20
10
Adaptations to Estuaries
Coping with salinity
Internalsalinity
Environmental salinity
0 10 20 30 40
40
30
20
10
Ecological Relationships
Primary Productivity
Algal mats
Benthic diatoms
Ecological Relationships
Primary Productivity
Classification scheme for estuaries - based on primary productivity
EuropeanAmerican
Estuarine Food web
From river and ocean
Detritus
Detritus feeders
BirdsLost
Salt marshLight
Phytoplankton
Zooplankton
Fish Lost
Algae
Grazers
Invertebrate Predators
Death
Microbial Decomposers Scavengers
Filter Feeders
Estuarine Food web
From river and ocean
Detritus
Detritus feeders
BirdsLost
Salt marshLight
Phytoplankton
Zooplankton
Fish Lost
Algae
Grazers
Invertebrate Predators
Death
Microbial Decomposers Scavengers
Filter Feeders
Allochthonous sources of Carbon
Salt Marsh - Importer or Exporter?
Factors Influencing the relationship of the salt marsh and estuary
1. Latitude
800
600
400
200
0
FloridaTexas Louisiana Georgia North Carolina
ChesapeakeBay
NewEngland
Dry
wt –
g/m
2 /yr
Turner, 1976
Allochthonous sources of Carbon
Salt Marsh - Importer or Exporter?
Factors Influencing the relationship of the salt marsh and estuary
2. Nitrogen
N-fertilized
Control
M J J A S
700
400
0
Dry
wt –
g/m
2 /yr
Vince et al, 1981
Allochthonous sources of Carbon
Salt Marsh - Importer or Exporter?
Factors Influencing the relationship of the salt marsh and estuary
2. Nitrogen
Sippiwisset Marsh
- 10 year nitrogen enrichment study
• increased above and below ground production
• increased N content in plants
• consumer populations increased
Allochthonous sources of Carbon
Salt Marsh - Importer or Exporter?
Factors Influencing the relationship of the salt marsh and estuary
Others
• geomorphology
• oceanographic conditions
• marsh age
• primary productivity