Odyssey Expeditions - Mangroves 1 NOAA Mangroves By Dave Cabrera.

1Odyssey Expeditions - Mangroves

NOAA

MangrovesMangroves

By Dave Cabrera


IntroductionIntroduction

• Mangroves – Halophytic (salt tolerant) trees that live in areas predominantly saturated with salt water

• Found along coastlines between 32 degrees N and 38 degrees S.

• 16-24 families and 54-75 species (classification dependent)

• Highest diversity in Asia• New world has 12• US has 4 (species we will discuss)• 25% of Caribbean coastline• 75% of continental regions


Adaptations to Salt WaterAdaptations to Salt Water

• Salt pores – located on leaves, root and branches. Excess salt absorbed from soil secreted

• Salt exclusion – roots of some mangroves exclude salt

• Viviparity – seeds germinate while attached. Fully developed seedlings drop from tree.


Adaptations to Low Oxygen in SoilAdaptations to Low Oxygen in Soil

• Prop Roots – roots exposed to air (red mangroves)

• Pneumatophors – pencil-like roots that stick up from the substrate (black mangroves)

• Lenticels – slits in the bark and roots

• Aerenchyma – air spaces that allow gas to reach underground roots

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Pneumatophors Lenticels

Prop roots Odyssey Expeditions


Role of Mangrove EcosystemRole of Mangrove Ecosystem

• Mangroves as a Buffer– Protects coastline from wave action– Prevent erosion, and keep sediments from

reaching coral reefs– Collect and stabilize sediments

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Role of Mangrove EcosystemRole of Mangrove Ecosystem• It has been highly debated as to whether succession

occurs in mangroves. The evidence is inconclusive as to whether this happens and is considered hypothetical.


Role of the Mangrove EcosystemRole of the Mangrove Ecosystem

• Mangroves as a nursery and a habitat– Detritus from leaves –

Bacteria feed off detritus– Bacteria – provide food for

planktonic organisms– Plankton – Serve as food

for larval and juvenile fish and invertebrates

– Shelter – protection from predators

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Odyssey Expeditions


Roll of mangrove ecosystemRoll of mangrove ecosystem

• Diversity of species in mangroves– Trees – 54-75 species in 16-24 families– Poriferans – sponges grow on prop roots– Annelids – segmented worms live in mud and

among prop roots– Cnidarians – anemones occupy prop roots– Molluscs – Gastropods (periwinkles) and bivalve

(oysters) found on prop roots– Echinoderms – Sea cucumbers, sea stars– Urochordates – tunicates attach to roots– Birds – use tree tops– Fish – swim among roots– To name a few

NOAAOdyssey Expeditions

Odyssey Expeditions


Species of MangrovesSpecies of Mangroves• Red Mangrove (Rhizophora

mangle)– Location – found nearest to

water – Leaves elliptical and leathery.

Dark green on top, pale green underneath

– Prop roots – large aerial roots extend from tree into ground

– Roots submerged– Tolerant of low oxygen

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Odyssey Expeditions


Red Mangrove DispersalRed Mangrove Dispersal

• Seedling dropped from tree

• Floats root down in water

• When it comes in contact with substrate it takes root and grows

• Can float around for over a year


Red Mangrove DispersalRed Mangrove Dispersal


Species of MangrovesSpecies of Mangroves

• Black Mangrove (Avicennia germinans)– Location – Shoreward of red

mangroves– Leaves – Oblong. Dark green on

top, pale grey to white underneath. Often encrusted with salt.

– Pneumatophores – Pencil-like root extensions that provide surface area for gas exchange

– Roots submerged only at high tide– Tolerant of low oxygen

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NOAA


Species of MangrovesSpecies of Mangroves• White Mangrove (laguncularia

racemosa)– Location – Terrestrial side of

mangrove stands. Behind black mangroves.

– Leaves – Broad flattened and oval. Leaves branch out from stem opposite to each other

– Salt Pores – Present at base of leaves

– Soil fully saturated with water– Tolerant of salty soils– Less tolerant of high water

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NOAA


Species of MangrovesSpecies of Mangroves

• Buttonwood (Conocarpus erectus)– Location – Terrestrial side of

mangrove stands, behind black mangroves. Not a true mangrove

– Leaves – Elliptical and leathery. Dark green on top, pale green underneath

– Salt Pores – Present at base of leaves

– Soil is damp, but not saturated– Tolerant of salty soils– Not tolerant of high water

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NOAA


Threats to Mangrove EcosystemThreats to Mangrove Ecosystem

• Deforestation– Coastal development– Shrimp farming– Flooding– Charcoal and timber industry

Rice Shrimp and development


Threats to Mangrove EcosystemThreats to Mangrove Ecosystem

• Pollution– Point source pollution – sewers, industrial

discharge, oil spills – Non-point source pollution – agriculture runoff

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Oil

Odyssey Expeditions - Mangroves 1 NOAA Mangroves By Dave Cabrera.

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