Estuaries
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Lecture 14 - ESTUARIES Last Ice Age Classification of Estuaries - Geological 1. Coastal Plain Estuary (= Drowned River Estuary) Classification of Estuaries - Geological 1. 2. Coastal Plain Estuary Bar Built Estuary Bar-built estuary Longshore current estuary -sediment deposited by longshore currents Bar-built estuary Sandy Hook, New Jersey Bar-built estuary Sandy Hook, New Jersey Classification of Estuaries - Geological 1. 2. 3. Coastal Plain Estuary Bar Built Estuary Fjord Classification of Estuaries - Geological 1. 2. 3. 4. Coastal Plain Estuary Bar Built Estuary Fjord 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 Evaporation Rare freshwater inflow Restricted tidal mixing Internal wind-driven mixing High Salinity Lower salinity Factors influencing estuary circulation River discharge Low High Tidal mixing Maximum Minimum Tidal currents Strong Weak Water stratification Weak Well-mixed estuary Strong 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 Bottom water Mud Salinity Time Physical Features of Estuaries Substrate Flocculation Physical Features of Estuaries Substrate - Movement by Current Physical Features of Estuaries Other features Temperature Waves and Currents Turbidity Oxygen Turbidity – Rappahannock River 75 mg/l >5 mg/l Diversity in Estuaries 1. Euryhaline -tolerate salinites between 15 and 35 ppt 2. Stenohaline -tolerate salinities above 25 ppt Euryhaline Stenohaline 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 Enteromorpha Cladophora Ulva Adaptations to Estuaries Coping with salinity Adaptations to Estuaries Coping with salinity 40 Internal salinity 30 20 10 0 10 20 30 Environmental salinity 40 Adaptations to Estuaries Coping with salinity 40 Internal salinity 30 Perfect osmoconformer 20 10 0 10 20 30 Environmental salinity 40 Adaptations to Estuaries Coping with salinity Perfect osmoregulator 40 Internal salinity 30 Perfect osmoconformer 20 10 0 10 20 30 Environmental salinity 40 Adaptations to Estuaries Coping with salinity 40 Internal salinity 30 20 10 0 10 20 30 Environmental salinity 40 Adaptations to Estuaries Coping with salinity 40 Internal salinity 30 20 10 0 10 20 30 Environmental salinity 40 Adaptations to Estuaries Coping with salinity 40 Internal salinity 30 20 10 0 10 20 30 Environmental salinity 40 Ecological Relationships Primary Productivity Algal mats Benthic diatoms Ecological Relationships Primary Productivity Classification scheme for estuaries - based on primary productivity European American Estuarine Food web From river and ocean Salt marsh Light Detritus Algae Phytoplankton Detritus feeders Grazers Lost Birds Filter Feeders Zooplankton Invertebrate Predators Fish Death Microbial Decomposers Scavengers Lost Estuarine Food web From river and ocean Salt marsh Light Detritus Algae Phytoplankton Detritus feeders Grazers Lost Birds Filter Feeders Zooplankton Invertebrate Predators Fish Death Microbial Decomposers Scavengers Lost Allochthonous sources of Carbon Salt Marsh - Importer or Exporter? Factors Influencing the relationship of the salt marsh and estuary 1. Latitude Dry wt – g/m2/yr 800 600 400 200 0 Texas Florida Louisiana Georgia North Carolina Chesapeake New Bay England Turner, 1976 Allochthonous sources of Carbon Salt Marsh - Importer or Exporter? Factors Influencing the relationship of the salt marsh and estuary 2. Nitrogen 700 Dry wt – g/m2/yr N-fertilized 400 Control 0 M J J A S 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
