Lecture 14 - ESTUARIES

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

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

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

Physical Features of Estuaries

Substrate - Movement by Current

Physical Features of Estuaries

Other features

TemperatureWaves and CurrentsTurbidityOxygen

Turbidity – Rappahannock River

75 mg/l

>5 mg/l

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

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