Benitez, Ezel Anne R.

Dizon, Jhulien C.

Bernardino, Mark Adrian P.Estuaries as Ecosystems

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

Open WaterMudflatsSalt MarshesMangrove ForestsOther Estuarine Communities

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

Open WaterLots of suspended sediment → murky water → poor light penetration → limited primary production by phytoplankton

Small estuaries – planktons are flushed in and out

Large estuaries – have own estuarine species

Good nurseries for fish and invertebratesAbundant food

Fewer predators

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

Open Water

The Atlantic Menhaden (Brevoortia tyrannus)

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

Open Water

yellow-eyed mulletflatfish

anchovies

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

Open WaterSome organisms move through estuaries during migration

Anadromous Fishes - migrate from the sea to spawn in fresh water.

Salmon Smelt Shad

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

Open WaterSome organisms move through estuaries during migration

Catadromous Fishes - migrate from fresh water to spawn at sea.

European eelLong-fin eel

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

Open WaterFew spend entire lives in estuaries

Killifish ( Fundulus )

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

MudflatsBottoms of estuaries that are exposed at low tides

Extensive in large tidal range

Sand - accumulate near river mouth & tidal creeks

Fine, silty – in calmer central part of mudflat

Low tides expose organisms to dessication, temperature change, & predation

Regular variations in salinity

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

MudflatsPrimary producers: not usually evident

EnteromorphaSea lettuce (Ulva)

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

MudflatsPrimary producers:

Diatoms forming golden-brown patches

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

MudflatsPrimary producers:

Bacteria decompose organic matter

Production of H₂S by some bacteria

H₂S is used by sulfur bacteria to produce energy

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

MudflatsInfauna

Most dominant

Burrow on sediments

Feed on detritus

EpifaunaLive on sediment

Some are sessile

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

MudflatsMeiofauna

A.k.a interstitial animals

Most are deposit feeders

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

MudflatsDeposit feeders – eat organic materials in sediments

Suspension feeders – feed on suspended materials in water

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

Mudflats

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

MudflatsPredators:“Resource

Partitioning”

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

MudflatsPredators:

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

MudflatsPredators:

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

Salt MarshTemperate and sub-arctic regions

Partially flooded at high tide

Salt / tidal marshes

In N. Hemisphere, more extensive on the left side

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

Salt Marsh: Communities are dominated by grasses & land plants

A salt marsh near Atlantic Beach, North Carolina

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

Salt Marshzonation of plants in salt marshes

Zone location is related to height of tide

Varies accdg. To geographical location, substrate etc. Ex. Soil Salinity

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

Salt MarshCordgrasses – most common where it meets mudflats

Soil is drained , richer oxygen, less salty

May gradually invade mudflats

Stabilize soils by decreased wave action

California cordgrass (Spartina foliosa),

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

Salt MarshHome to decay bacteria, diatoms, green algae, & cyanobacteria.

Bacteria decompose – major source of detritus

Some bacteria are nitrogen fixers –enrich sediment

Animals: burrowing animals in mudflats

Nematodes, small crustaceans, larvae of land insects

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

Salt MarshAnimals:

Fiddler crabs – burrows along mudflat edge → increase oxygenation

Scavengers:

SesarmaHemigrapsus

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

Salt MarshAnimals:

Air breathing snails that feed on detritus, algae, fungi that grow on marsh plants

Coffee bean snails (Melampus) Marsh periwinkles (Littorina)

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

Salt MarshAnimals:

Horse Mussel Juvenile Silverside American coot

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

Mangrove ForestTropical equivalent to salt marshes

Mangroves → Mangals

75% of sheltered tropical shores are surrounded by mangroves

Need fresh water for growthBlack Mangrove leaf

Mangrove Forest

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

Mangrove Forest

mangrove forest on the southern coast of Puerto Rico.

Mangrove ForestRed Mangrove

Lives right on the shore

Roots branch downward

along the shores of southern

Florida, the Caribbean, and the gulfs of California and Mexico

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

Rhizophora mangle

Mangrove ForestBlack Mangrove

Along the Caribbean and Atlantic coasts of the Western Hemisphere

Seedlings can survive high salinity

Develop pneumatophores -aerate the plant

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

Avicennia germinans

Mangrove ForestWhite Mangrove

Found only along the land ward edge of the forest

Sweat glands

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

Laguncularia racemosa

Mangrove ForestAnimals:

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

Sesarma Cardisoma mudskipper(Periophthalmus)

Indo-West Pacific mangrove forests and mudflats

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

Mangrove ForestAnimals:

Sponges – provide nitrogen compounds. Protect the roots from isopods

polychaetes, mud shrimps, and clams at the muddy bottom

rich nurseries for many species of commercially important shrimps, spiny lobsters, and fishes

Rawr!

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

Mangrove ForestAnimals:

Birds, snakes, frogs, lizards, bats & other land animals

Detritus are broken down by bacteria

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

Other Estuarine CommunitiesMuddy bottoms below low tide

Seagrasses:

Roots help stabilize sediment

Leaves shelter many organisms

Source of detritusEelgrass(Zostera)-temperate

Turtle grass(Thalassia)-warm

Estuaries as Ecosystems• TYPES OF ESTUARINE COMMUNITIES

Other Estuarine CommunitiesOyster reefs:

Form beds in temperate waters

Provide 3-d surface for many

organisms

Oyster-reef community:

seaweeds, sponges,

tubeworms,

barnacles,

Estuaries as Ecosystems• FEEDING INTERACTIONS

Human Impact on Estuarine Communities

Salt marshes in Southern California and in many other locations around the globe havebeen obliterated with reclamation.

dredging of navigation channels destroys salt marshes

Human Impact on Estuarine Communities

Mangrove forests converted to Shrimp mariculture, and causes pollution

Clearing of Mangroves for urban development, roads, garbage dumps

Mangrove forests once fringed around 75% of all sheltered tropical coastlines, but 35 to 50% of these mangrove forests have been destroyed.