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Mangrove Biology

Mangrove trees are a very important part of estuary ecosystems. They filter water by removing toxins and stabilize silt that enters into estuaries from rivers and coastal runoff. They provide habitat and nursery grounds for many species of vertebrates and invertebrates. The trees absorb wave energy and prevent erosion. Their leaves are a food source for many organisms. They also build new land from the accumulation of fallen decomposed leaves.

Oil that infiltrates mangrove ecosystems by washing into mudflats during high tides is a major threat to the health of mangrove forests. Oil can clog the pores on the snorkel roots of black mangrove trees, causing them to suffocate and die.

Mangrove trees are tropical/subtropical plants. There are three different species of mangrove trees that live on the shorelines and in the estuaries of Mississippi, Alabama, Louisiana, and Florida: red, black, and white mangrove trees. These trees have specific niches that they occupy. Red mangroves grow in the water and directly on the shoreline. Black mangrove trees grow in the mudflats set back from the water. White mangrove trees grow the farthest away from the water on dry land that is occasionally flooded by salt water.

These trees have evolved specialized strategies to survive in salty environments. Red mangrove trees are salt excluders. They have specialized roots that prop them out of the salt water. They keep salt out of their systems through root filtration. Red mangroves can live submerged in salt water due to their ability to exclude salt. Any salt that does get into the system of this tree species is sent to sacrificial leaves. When these leaves are full of salt they are dropped from the tree, eliminating the salt from tree’s system.

Black and white mangrove trees have a different strategy for living in a salty environment. They are salt excreters. Black mangroves live in anoxic mudflats that are often flooded by the tides. When salt enters through the roots of the tree, it is then filtered up the trunk and out through pores onto its leaves. The salt is then eliminated from the tree’s system and the leaves are coated with salt, providing the leaves with a natural sunscreen.

Due to the lack of air in the sediment, black mangroves have specialized snorkel roots called pneumatophores to help them breathe. Each black mangrove tree sends up hundreds of pneumatophores from its root system. Each snorkel root has special pores called lenticels. These pores enable the mangrove to get the air that it needs to thrive in an otherwise airless environment.

Read the background information below independently or in small groups.

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Mangrove Biology, continued

Part of Speech DefinitionWord(s)

anoxic

drop roots

ecology

lenticel

pneumatophore

prop roots

salt excluder

salt excreter

substrate

adjective

noun

noun

noun

noun

noun

noun

noun

noun

no oxygen in the environment

roots that drop down from the branches of red mangrove trees and set shoots into the ground

the study of the environment and its related communities

Eqios= the home, ology= the study of (the study of the home)

a small opening on the exposed roots of a tree that allows the plant to take in air to send to the rest of the root system

the snorkel root of a tree

roots of the red mangrove that keep the trunk of the mangrove out of salt water

an organism that will not let salt enter into itself

when an organism pushes salt out through its pores

underlayer; something to hold on to or attach to

sediment noun underwater soil

dispersants

skimmers

noun

noun

Dispersants are chemicals that are sprayed on oil to cause it to break up and sink.

Skimmers use a floating boom system to sweep oil across the water surface, concentrating the oil to make the skimming process more effective and efficient.

Part of Speech DefinitionWord(s)

Mangrove Vocabulary

Oil Spill Cleanup Vocabulary

boom noun A boom is an oil-containment device that floats on the surface of the water and is used as a barrier to keep oil in or out of a specific location.