>vertical gradient; >fw overlays sw; >fw flow dominates over tides
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>Vertical gradient; >FW overlays SW; >FW flow dominates over tides. >greater vertical mixing; >Moderate tidal action. >Vertically homogenous; >Vigorous tidal action. Turner et al. 2006 – Hurricane sediments. Turner et al. 2006 – Hurricane sediments. - PowerPoint PPT PresentationTRANSCRIPT
>Vertical gradient; >FW overlays SW;>FW flow dominates over tides
>greater vertical mixing;>Moderate tidal action
>Vertically homogenous; >Vigorous tidal action
Turner et al. 2006 – Hurricane sediments
Turner et al. 2006 – Hurricane sediments
Turner et al. 2006 – Hurricane sediments
- Pulsed Flood Events – natural disturbances drive high productivity & diversity in river, floodplain and estuary
Relationship between FW species percentage and tidal influence
Relationship between species richness and salinity
Table of TFW vs SM conditions
Abiotic gradients along a salinity gradient
Coupled response between Chlorophyll, DOC and DO along the salinity gradient
Salinity zonation patterns and the River Continuum Concept
Odum’s 1984 Dual Gradient Concept
Stream orders = marsh dendritic pattern
River ≠ Estuary ≠ Marsh
Dual Gradient Concept: salinity & marsh stream order gradients
DOC input to estuary
POC input to estuary
DOC gradient along marsh stream orders
Dual Gradient Concept: salinity & marsh stream order gradients
POC gradient along marsh stream orders
Main sources of organic carbon along marsh stream gradient
Nekton as carbon sources and movement among subsystems
Gradients in primary production in estuaries
Juvenile menhaden nursery driven by phytoplankton gradients
Relationship between salinity – menhadenabundance - chlorophyll signatures(Neuse River: 2 May 1984)
Relationship between salinity – menhaden abundance - chlorophyll signatures(Neuse River: 15 May 1984)
Relationship between salinity – menhaden abundance - chlorophyll signatures(Pamlico River: 16 May 1984)
Size ranges were nearly similar so fish considered same cohort
The FW/SW gradient & phytoplankton biomass max were correlated;Generally occurred within 4-6 psu in both rivers and shifted seasonally
Neuse River: 4-6 psu @ 60km during early spring freshet & km 60 in summer
Pamlico River: 4-6 psu @ 30km during early spring freshet & km 10 in summer
Spring – high spring flows = high primary production in lower estuary = nursery
Summer – low summer flows = high primary production in upper estuary = nursery
Creeks have salinity gradients with isolated chlorophyll maxima regardless of location
O = predominantly open estuaryM = moderate/large (>10 ha) closed estuaryS = small (< 10 ha) closed estuary
Subtropical & warm-temperate:O - near top leftM - near the middleS - near lower right
ANOSIM = overall difference in community structure in subtropical & warm-temperate; O most discrete.
less clear in cold-temperate estuaries(no differences).
Cold-temperate:O & M - near top leftS – broad spread
Harrison & Whitfield 2006 estuary typology/community structure model
O = species rich; allows access and recruitment form sea.L/M-C = species poor; closed w/limited access and recruitment from sea.S-C = lowest species richness; due to size and limited habitat diversity and isolation from sea.
A = open systemsB = open & L/M closed systemsC = all but L/M closed mainlyD = all systems but mainly in S closed systems.
Large estuaries – increased habitatheterogeneity & increased diversity
Surface area – linked to mouthwidth & depth, geomorphology &runoff.
Mouth conditions & surface area = different fish communities