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 ButtonwoodEach 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 mangrovesPictures from left to right horseshoe crab, sheepshead, tree snail, mangrove water

snake.

Mangrove wildlifepictures show from left to right: blue crab, blue heron,

fiddler crab, mangrove snapper

Mangrove wildlifeFrom 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 run-off? 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 in Bangladesh.

• Picture courtesy of NASA

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