Transcript Coastal Ecosystems

Coastal Ecosystems
Include
 Estuaries
 Salt marshes
 Mangrove swamps
 Seagrasses
 Intertidal zones
 Beaches
 Kelp and seaweed
 Coral reefs
Coastal Ecosystems
 Coastal ecosystems are generally highly
productive because they:
 Benefit from nutrient rich runoff from
land
 Are shallow and well lit allowing for a
wide variety of salt tolerant plants to grow
 These plants provide a haven for juvenile
open ocean dwelling organisms
 Allow for a wide variety of different
species to coexist together
Coastal ecosystems
 A major concern is eutrophication which is
an over abundance of nutrients in the water
usually form fertilizer runoff
 It stimulates excessive algae growth
 When the algae dies, degradation
consumes available oxygen
 The depletion of oxygen kills fish and other
sea life
 This creates an imbalance in the ecosystem
which can sometimes take several years to
recover
Estuaries
Estuaries
 Estuaries exist where the tides meet rivers
 They are not found where all rivers enter the sea, but
are common where the tidal range is high
 High tide pushes far up a river flooding the
surrounded area
 They tend to trap and accumulate runoff sediment so
they are rich in nutrients and biological productivity
 They are sensitive to eutrophication because they trap
fertilizers as well
 They are the kidneys of the biosphere because of their
cleansing function
Estuaries
 They have high primary productivity
 Organisms living there must tolerate a wide range of
salinity due to the rising and falling tides which cause
a flush of salt water then fresh water. This limits the
number of species that can live there
 High primary productivity leads to decreased oxygen
levels at times
 This allows anaerobic sulfur bacteria to thrive producing
a rotten eggs smell
 They are excellent nurseries providing nutrients and
shelter for over 75% of commercial fishing juvenile fish
species
Estuaries
 They contribute to the productivity of adjacent marine
ecosystems in at least 2 ways:
 1. Surviving juveniles migrate from the estuaries as they
grow and mature

Therefore contributing to productivity by increasing the
number of individuals that survive the hazardous larval and
juvenile stages
 2. They provide a steady stream of nutrients to adjacent
marine ecosystems while trapping sediment and other
materials in runoff from rain and storms

This will reduce eutrophication and other damage were the
runoff to reach the open ocean
Salt Marshes
Salt Marshes
 Exist in estuaries and along the coast
 They grow were there’s flat, gently sloping , nutrient
rich sediment washed by the tide
 Halophytes are plants that have adaptations that
allow them to survive in salt water
 Some accumulate salt in their roots so water will flow in
to the plant. They transport the salt to glands on leaves
and stem where it gets excreted
 Some store salt in sacrificial leaves. When the leaves are
loaded with salt they fall off and grow another
 Halophytes are not food plants for many organisms.
They are tough and salty making them unsuitable for
herbivores
Mangrove Swamps
Mangrove Swamps
 Found in tropical climates
 They have strong tangled roots that provide habitats
for juvenile fish and invertebrates
 Because of their roots they hold the soil well,
protecting the habitat and coast from erosion
 Without mangroves tropical storms would wash away
many tropical islands and beaches
 They protect coral reefs and other ecosystems by
trapping nutrients and fertilizers and preventing
eutrophication in those ecosystems
 The one huge down side to them is they are swampy
sulfide smelling mosquito havens
Seagrasses
Seagrasses
 Stabilize sediment and provide shelter and habitats for
other organisms
 They are the only submergent plants, some living as
deep as 100 feet
 Their root systems intertwine forming a mat below the
sediment
 Most species release pollen into the current to
reproduce
 They maintain an internally salinity the same as the
surrounding water so they do not need to collect and
excrete excess salt
 They are edible and provide food for fish, turtles,etc
Intertidal zones
Intertidal zones
Intertidal zones
 Include areas above the water line or 10 meters below it
 Organisms living there face 4 huge problems
 1. Drying out
 2. Thermal stress
 3. High salt levels
 4. Pounding surf
 Organisms with habitats here have adaptations to
retain moisture, obtain oxygen from the air or store
enough to endure many hours out of water
 They must also be able to withstanding the pounding
surf
Intertidal zones
 Organisms found living in the intertidal zone are
 1. Barnacles
2. Periwinkles
Intertidal zones
 3.Limpets
4.Chitons
Beaches
Beaches