Mangroves are best known for their ability to withstand
strong waves and protect the coasts from typhoons, storm surges and even
tsunamis. But more than that, mangroves are capable of doing a lot of things.
Below are some of the ecosystem services and functions provided by mangroves!
- Mangroves are critical spawning areas
Mangroves are critical spawning, nursery, feeding and
transient shelter areas to hundreds of fish species, crustaceans and
invertebrates and support an abundant and productive marine life. Like all
other animals, fish, shrimp, crabs and other marine life in the sea need a safe
place to grow, away from many predators. With their tangled and intricate root
systems, mangroves are excellent nurseries, providing safe hiding places for
young animals. The muddy waters around mangroves are rich in nutrients from
decaying leaves and organic matter produced by the mangroves themselves and
also from the sediment that is trapped around the roots.
Many commercial marine species such as bangus (milkfish) and prawns spend their early life within the mangrove area where they find food and protection from predators. Juveniles of some deep sea fishes also spend some time in the mangroves before moving on to other ecosystems such as seagrasses or coral reefs. In addition, mangroves are also habitats to shore birds, some species of mammals (monkeys, rats, etc), reptiles and insects. These animals utilize the mangroves as places to roost, breed or take shelter from strong winds or heat of the sun.
2. Mangroves provide food for marine species
Marine leaves are a source of food for fish, shrimps and
crabs and other marine animals. When a leaf falls, it breaks up and decomposes
into smaller pieces, until they become too small to be seen with the naked eye.
The decomposing plant matter is collectively known as detritus. Detritus is
covered with large amount of small organisms which take up the nutrients in the
leaves. Individually, these organisms are too small to be of much value to any
larger animal, but together they form a coating around leaf particles which
many different animals use as food.
Leaves eaten by animals are not totally digested. They are excreted almost intact, again coated with organisms, and then eaten by marine animals. This process is repeated several times, so that one leaf can literally nourish a juvenile fish for much of its life in the mangrove area. Mangroves contribute about 3.65 tons of litter per hectare per year.
3. Protect coastlines from storms and wave surges
Mangroves protect coastlines from the onslaught of storms and wave surges. Their crowns, trunks and stems serve as physical barriers that help break the winds and waves, reducing their speed and intensity and subsequently their destructive impact. Scientists say that during such surges, at least 70-90 percent of the energy of wind-generated waves is absorbed, depending in how healthy these ecosystems are and their physical and ecological characteristics (UNEP, 2006).
4. Absorb pollutants such as heavy metals and other toxic substances
Mangroves are also capable of absorbing pollutants such as heavy metals and other toxic substances as well as nutrients and suspended matter. Mangroves therefore serve as natural wastewater filters, preventing many landbased and nearshore pollutants from reaching deeper waters (UNEP, 2006).
5. Mangroves are a source of income
As breeding and nursery grounds for many fish species,
mangrove areas are sources of wild fry and juvenile fish for the
aquaculture/mariculture industry. In addition, mangrove seeds and propagules
can be harvested and sold to reforest denuded areas.