ABOUT MANGROVE HABITATS
Mangroves are remarkable and unusual trees and habitats with many important functions and benefits!
Mangroves are very unusual habitats because they are essentially trees growing in the edge of the ocean. This creates an important interaction between the land and sea environments, and a rich supply of nutrients to different habitats.
When they fall, around 80% of the leaves of mangroves end up in the shallow waters below the trees. These leaves are then eaten by animals such as crabs or broken down by fungi and bacteria and then eaten by fish. Fallen mangrove leaves and fruits are even eaten by sea turtles.
As the fallen leaves of the mangroves decompose on the sea floor, nutrients are released into the water and the sediment. The roots of the mangrove trees take up these nutrients for further growth. This relationship benefits both the trees and the animals by providing food and protection to animals as well as nutrients for the plants!
Mangroves also help to stop erosion by holding the soil together and reducing wave energy, but unfortunately, we have already lost half of the world’s mangroves. This is making coastal erosion worse!
SPOTLIGHT: MANGROVE ADAPTATIONS
Australia has 41 species of mangroves, and all of them have adapted in incredible ways to deal with the special conditions.
Mangroves have adapted to the muddy environment by having shallow yet spread out roots to help keep them steady and not be pushed over by strong winds or large waves.
The reason why mangroves can be a little smelly is because there are lots of bacteria that help feed and support the animals! The soil in mangrove habitats doesn’t have a lot of oxygen (which plants need), so the trees send up little roots from out of the soil to allow the plant to ‘breathe’ (just like a snorkel).
Even though they live in water, it’s salt water and it is hard for mangroves to get access to the freshwater that they need. The plants have adapted to deal with this by having thick and waxy leaves that hold onto freshwater for as long as possible. They have special glands that remove salt from the water and store the salt in old leaves that then drop off the tree.
Even the animals have adapted:
Crabs (koutan), in mangrove habitats have very long legs to spread their body weight and stop them from sinking in the mud.
The mangrove snapper (a type of fish) can change colour to blend into its surroundings.
Mudskippers are a small fish that have special eyes for living on both land and in water, can breath both in air and in the water, and can swim like a fish in water, skim across the water surface, 'walk' on their fins and 'skip' on the land and sometimes climb trees!
Isn’t nature amazing?!