Mangrove Ecosystems
What are Mangroves?
• Mangroves are plants
that grow in tidal areas.
• The word mangrove can
describe a single plant
or it can refer to a
whole community of
plants .
• They are halophytes
(‘salt loving”). Most
plants can not survive
in salty conditions.
Where Do Mangroves Grow?
Look at the Map Showing the World Distribution
of Mangroves? Is There Anything That You
Could Infer About Mangroves by Looking at the
Map?
Where do Mangroves Grow?
• Mangroves grow
only in the tropics
and subtropics. They
do not tolerate cold
temperatures well,
and freezing
temperatures will kill
them.
•
Picture of mangroves in Sarasota Bay. K
Broderick
Where do mangroves grow?
• Mangroves grow best in
sheltered areas with low
wave energies. High
wave energies destroy
the shallow root
systems of Mangroves.
They also prevent
seedling establishment
and the build up of fine
sediments needed for
growth.
•
Picture of Longboat Key Mangroves,
Florida. K. Broderick
Stop and think!
• What impact do you think that
hurricanes might have on a Mangrove
community?
Effect of hurricanes
• Hurricanes have a
profound impact on
Mangrove communities.
Severe erosion and
wind damage can
severely restrict growth.
In severe cases areas of
mangroves can be
destroyed. The picture
shows damage to
Florida mangroves by
Hurricane Charley.
•
Picture courtesy of USWF
Did you know?
• There are about 100 types of mangrove
plant around the world. This includes
some palms and ferns.
• In Florida there are four main
mangrove plants.
• There are approximately 47,000 acres
of mangrove in Florida.
Types of mangrove in Florida
• Florida mangroves include 4 tree
species.
– The Red mangrove
– The Black mangrove
– The White mangrove
– The Buttonwood
Each mangrove has its own level of salt
tolerance and this determines its location.
The Red Mangrove
• Tall arching roots called
prop roots. These
supply air to the
underlying roots and
provide stability.
• Found closest to the
water as they have the
highest salt tolerance.
• Dark green elliptical
leaves, which are paler
underneath.
Red Mangroves
• The pictures show the
flowers of the red
mangrove and also its
leaves, seeds and
developing prop roots.
Notice that the prop
root develops from the
seed and grows
downward.
Black Mangroves
• Black/brown bark
• Numerous breathing
tubes called
pneumatophores
project from the soil
beneath.
• Grows on high tide
shores.
White Mangroves
• White mangroves
are usually found
upland of the red
and black
mangroves. The
bark is pale and
they do not have
prop roots or
pneumatophores.
Buttonwoods
• Buttonwoods occupy
the same zone as
white mangroves.
Mangrove Adaptations
• All mangrove plants
have special
adaptations that allow
them to survive in their
salty environment.
– Their unusual root
systems give them
support and stability in
the loose soil.
– There is little oxygen
present in these soils and
prop roots and
pneumatophores allow
them to get oxygen from
the air.
Mangrove adaptations
• Did you know that
mangrove plants are
unique in that they
have live young
(viviparous). The seed
remains attached to the
parents plant until it
germinates. It then falls
from the tree and drifts
on the water until it
finds somewhere to
take root.
•
Red mangrove fruits courtesy of Selby Gardens
Mangrove adaptations
• Mangroves do not
have to live in salt
water. They tolerate
the salt water and
so out-compete
other plants. They
excrete salt through
pores in their roots
and leaves.
Why are mangroves
important?
• Mangrove plants form a unique ecosystem.
• An ecosystem consists of living organisms
and non-living factors such as soil and water.
• Mangroves are essential to the first link in the
food chain. When their leaves fall into the
water and are decomposed by bacteria many
valuable nutrients are released that are
essential to the growth of plankton. Plankton
are the producers in this and oceanic
ecosystems.
Why are mangroves
important?
• The leaf detritus
also provides food
for animals such as
worms,
snails,mussels,
oysters,shrimp,
clams and mullet.
The Mangrove Ecosystem
• These detritus
eating animals are a
source of food for
carnivores such as
crabs and fish .
These in turn
provide food for
larger fish, reptiles
and birds.
Picture – Mangrove Crab
The Mangrove Ecosystem
• Mangrove wetlands
provide habitat,
feeding, breeding
and nursery areas
for a wide variety of
plants and animals,
including
endangered species.
Picture shows a Snowy Egret
Wildlife in the Florida mangroves
Pictures from left to right horseshoe crab, sheepshead, tree snail, mangrove water snake.
Mangrove wildlife
pictures show from left to right: blue crab, blue heron,
fiddler crab, mangrove snapper
Mangrove wildlife
From left to right Florida fighting conch, mangrove buckeye, periwinkle,American
crocodile
Habitat
• The roots of the
mangrove provide
shelter for many fish
and other animals. They
also provide an
attachment site for
many creatures such as
sponges and anemones.
In addition the trees
themselves provide
nesting site for many
birds.
•
Picture shows a Snook.
Habitat
• Other creatures
such as bats,
snakes, insects and
frogs also live in
mangrove habitats.
•
Picture shows a Mangrove Cuckoo
Breeding Grounds
• Mangroves are an
important breeding
ground for many
animals, including
fish and birds.
•
Picture shows a roseate spoonbill
Nursery
• The mangroves
serve as a nursery
to many animals,
such as mollusks,
crustaceans, and
fish. The picture
shows a juvenile
Tarpon.
Feeding grounds
• Mangroves are a vital
source of food to many
animals . Some live in
the mangroves
permanently, some only
part of their lives and
some just come to visit.
•
Picture shows a young Lemon Shark courtesy of
J.Stafford-Deitsch- Shark Foundation
Endangered Species
• Florida mangroves
support a number of
endangered species
such as
– The west Indian
manatee
– The brown pelican
– The eastern indigo
snake
– The hawksbill turtle
Besides being an extremely productive
ecosystem mangroves also……..
Act as a buffer against the
high winds and eroding
waves of storms.
The mangroves trap
sediments and prevent
them from building up
further out to sea,
which is damaging to
other ecosystems like
coral reefs and sea
grasses.
Amazing mangroves
• Did you know that
mangroves can filter
out pollutants like
nitrates, phosphates
and petroleum
based products that
are present in runoff? The microbes in
the sediment break
the pollutants down.
Fisheries
• Mangroves contribute to
our economy;they have
a big influence on our
fisheries, because so
many commercially
fished species breed or
develop there. The
mangroves also provide
an important source of
food for other marine
life.
•
Picture shows Florida Stone crab
Food for thought …
• If mangroves were removed what
impacts would this have? How many
can you think of?
Man and mangroves
• Mangrove communities
have been significantly
reduced as coastal
areas have become
more developed. This is
especially true in
Florida. The picture
shows development
encroaching on an area
of mangroves.
Man and Mangroves
• Dredging floods
mangroves. This
submerges their air
breathing roots and
they can not get
enough oxygen and
nutrients.
•
Picture courtesy Army Corps of Engineers
Pollution
• Although mangroves
filter some
pollutants, they can
be irreparably
damaged by oil spills
and herbicides in
particular.
•
Picture shows Mangrove clean up after
an oil spill, picture courtesy of NOAA.
Mangrove conservation in
Florida
• The Mangrove trimming and
preservation act is a piece of legislation
which protects Florida mangroves. It
regulates the trimming and alteration of
mangroves and bans the use of
herbicides and other chemicals to
defoliate mangroves.
Mangrove conservation in
Florida
• Mangroves can
reestablish in 15-30
years if conditions
are right. This can
be achieved by
planting mangrove
seedlings.
Mangroves around the world
• It is estimated that the
world has lost 20% of
its mangrove forests
since 1980.
• This could have
alarming effects on
biodiversity, due to loss
of habitat.
• It could also result in
the silting of coral reefs,
shipping lanes and
ports.
•
Picture shows mangroves destroyed by
pollution. Photo credit T.Wilke
Mangroves around the world
• Loss of mangroves
could also severely
impact economies that
rely on tourism and
fisheries.
• Without a barrier of
mangroves low lying
countries such as
Bangladesh, are more
susceptible to flooding
and devastation by
cyclones.The dark areas
in the satellite image
show mangrove areas
Present status of Mangroves
• Although mangroves
are decreasing the rate
is slowing down as
more countries pass
laws to protect them.
More projects to replant
mangroves are
underway around the
world, but there is still
along way to go before
this ecosystem is
protected.
Bibliography
•
Environmental Protection Agency, (2006). Mangrove swamps. Retrieved August
5, 2008, from Wetlands Web site:
http://www.epa.gov/owow/wetlands/types/mangrove.html
•
U.S Fish and Wildlife Service, Hurricane Charley. Retrieved August 5, 2008, from
J.N. Ding Darling wildlife refuge Web site:
http://www.fws.gov/dingdarling/HurricaneCharley.htm
•
Lee County government, Mangroves. Retrieved August 5, 2008, from
Community development
•
Newfound Harbor Marine Institute, (1998). Ecology. Retrieved August 2, 2008,
from Mangroves Web site: http://www.nhmi.org/mangroves/eco.htm
•
(2007). International society for mangrove ecosystems. Retrieved August 5,
2008, from ISME Web site: http://www.mangrove.or.jp/isme/english/index.htm
Bibliography
•
(2006). Facts about mangroves in Florida. Retrieved August 5, 2008, from
Florida department of environmental protection Web site:
http://www.dep.state.fl.us/southwest/erp/mangroves.htm
•
Importance of mangroves. Retrieved August 5, 2008, from Florida Museum of
natural History Web site:
http://www.flmnh.ufl.edu/FISH/southflorida/mangrove/Importance.html#threat
•
Riley, Robert W. (2001). Ecological importance. Retrieved August 5, 2008, from
Mangrove.org Web site: http://www.mangrove.org/sect1.htm