marshes

marshes - Transcript

Coastal Ecosystems Salt Marshes and Mangroves Salt

Marine Biology Dr Ouida Meier

Latitude

Factors Driving Coastal Ecosystems Ecosystems

temperature light seasonality

Tidal cycles Tidal
amplitude amplitude frequency

Wave energy Degree of riverine input
freshwater input alluvial sediments and deposition turbidity

Geological characteristics Geological
rock sand sediment

Factors Driving Coastal Ecosystems Ecosystems cont

Hydrological characteristics Hydrological
nearshore currents transport

Continental proximity Continental
nutrient input anthropogenic impacts

Recap Rocky Intertidal Recap
Our example Pacific Northwest high latitude so Cold Pacific waters strong seasonality Tidal cycle high amplitude semi diurnal Wave energy high Freshwater input riverine characteristics modified Freshwater by bay estuary by Geology rocky cliffs interspersed w sandy beach Hydrology strong nearshore currents transport Continental edge input via interaction with Continental terrestrial systems terrestrial

Salt Marsh Ecosystems Salt
Our example southeastern U S Gulf and Atlantic Our
coasts moderate latitude so coasts Warm Atlantic and warmer Gulf and Gulf stream Warm waters moderated seasonality waters Tidal cycle low amplitude Wave energy low Freshwater input often critical deltaic riverine input Freshwater can result in extensive marsh systems abundant alluvial sediment input Salt accumulation a challenge alluvial Geology long term alluvial sediment accumulation Hydrology nearshore currents transport important Continental edge nutrient input via runoff rivers

Salt marsh and tidal channels in coastal Georgia

Plants of the Salt Marsh Community Plants
Spartina alterniflora marsh cordgrass
height depends on riverine or tidal flushing export of dried mats during winter storms exclude salt from roots Salt pans

Salicornia a succulent Salicornia succulent Fresher water and soils higher ground other Fresher grasses Spartina patens rushes Juncus grasses Juncus romerianus sedges romerianus Zonation based on topography inundation of Zonation freshwater fresh salt fluctuation tidal flushing relative stresses anoxia of soils latitudinal gradient e g east coast U S

Salt marsh replanted after a break in an oil pipeline

Animals of the Salt Marsh Community Animals
Geukensia demissa dominant mussel Geukensia dominant
lives in sediment physiological variation with tidal cycles

Crassostrea virginica oyster
dense beds in well flushed tidal channels

Littorina irrorata salt marsh snails pulmonates Thais haemostoma oyster drill Uca pugnax other Uca spp fiddler crabs other Uca Sesarma cinereum marsh crabs
These examples are particularly for south Louisiana and coastal Georgia other species These will occur elsewhere filling slightly modified niches depending upon range region and local conditions and

An herbivore in the salt marsh community

Salt Marsh Communities Salt
Highly productive Very stressful Trap sediment Stabilize and extend coastlines especially those Stabilize with fluvial input with Food webs detritus based herbivory may be Food more important than previously thought trophic relays convey biomass to adjacent ecosystems Low diversity high productivity Low

Wetlands Loss Salt Marshes Wetlands
Coastal erosion and wetland loss due to channelization Coastal and levees along the Mississippi dams on its tributaries land settling from groundwater pumping and use and channels cut through the marsh for offshore drilling platforms platforms Estimates of Louisiana coastal wetland loss for 1978 90 Estimates indicate a loss of about 35 square miles a year of freshwater and non freshwater marshes and forested and scrub shrub wetlands From 1978 90 that equalled a 12scrub shrub year loss of about 420 square miles an area twice the year size of the populated greater New Orleans area size http www lacoast gov news press 1997 10 27 htm http www tulane edu bfleury envirobio saltmarsh html http www bonitanews com 03 10 naples e1631a htm

Example of salt marsh decline in south Louisiana http www brownmarsh net

Mangrove Ecosystems Mangrove
Our example south Florida subtropical latitude so Warm Atlantic and warmer Gulf and Gulf stream Warm waters limited seasonality moving toward rainy dry seasons seasons Tidal cycle low amplitude Wave energy low Freshwater input important can be sheetlike Freshwater Everglades rather than distinctly riverine alluvial sediment input High tannins from leaf input sediment Geology long term alluvial and peat accumulation Hydrology more inundated than salt marshes Hydrology nearshore currents transport important nearshore Continental edge nutrient input via runoff rivers

Red mangroves low tide south Florida

Plants of the Mangrove Community Plants
Rhizophora mangle red mangrove
prop roots extrudes salt

Avicennia germinans black mangrove
pneumatophores extends to coastal Louisiana pneumatophores where it unusually coexists w Spartina Spartina

Laguncularia racemosa white mangrove These have viviparous propagules Much higher diversity in the Indo Pacific

Zonation and Distribution of mangroves is affected by flooding salinity temperature fluctuations air soil water and soil

Animals of the Mangrove Community Animals
Prop roots of red mangroves provide substrate for Prop benthic organisms algae sponges hydroids tunicates bryozoans tunicates Mangrove swamps provide critical protected Mangrove nursery areas for fishes crustaceans and shellfish Dense mangrove branches serve as rookeries for many coastal species of birds many Organisms reared in mangrove swamps become Organisms food for fish snook snapper tarpon jack sheepshead red drum oysters and shrimp

Prop root communities

Wetlands Loss Mangrove Swamps Wetlands
Many acres of mangroves in south Florida Many have been lost to development and to anthropogenic changes in hydrology anthropogenic Globally many areas of mangroves are Globally being cut for wood or converted to aquaculture or mariculture ponds e g aquaculture fish shrimp prawns for seafood restaurants restaurants Concomitant declines in offshore fisheries Concomitant can be expected and have been seen can

Mangrove swamp in Mexico