Threat to mangrove forests
Today, mangroves are one of the world’s most endangered habitats. Between 30% and 50% of mangrove forests and swamps have disappeared. In Indonesia alone, 350,000 hectares of mangroves disappeared in a single year, in the 2010s. It is one of the largest deforestation projects in human history.
Mangroves are destroyed by dredging. This means excavating and sucking up roots, silt and mud, and sometimes filling in with other soil. Other things that destroy mangroves are spills of oil and other toxic substances, which gets to the mangrove roots. Livestock farming, large-scale logging, road building and salt farming are also major threats to mangroves.
Mangrove forest that has been dredged to build ponds for shrimp farming.
Photo: Edmond-OGOWE-CC-BY-SA
Mangrove trees uprooted to be transported to a coal factory in Malaysia.
Photo: udeyismail-CC-BY-SA
When debris and pollutants are washed into the mangrove forest, with high tide from the sea, it gets stuck in roots and branches when the water recedes.
Photo: Sivasothi-CC-BY
Human expansion of cities and roads reduces the mangrove forest. The picture shows Panama City in Panama.
Photo: GRIDArendal-CC-BY-NC-SA
Shrimp farming the biggest threat
The most common reason for destroying mangroves is to build ponds for shrimp and prawn farming. Many tropical shrimp species live naturally in these areas. When the mangroves are cut down to build the dams for the farm, the wild, local shrimp are hit hard. Food, chemicals and pharmaceuticals used in farming leak into surrounding waters.
In addition, the shrimp are fed a diet containing ground, wild fish. This makes the pressure on fisheries even higher, and local fishing families will find it more difficult to make a living. Farming on former mangrove land now accounts for more than half of all shrimp farming on earth.
The biggest threat to the mangrove forest is the expansion of shrimp farms. Here you can see how much of the mangrove that was destroyed in an area in Honduras between the years 1987 and 1999. The shrimp farms are the dark rectangles.
A pond for shrimp farming in Indonesia.
Photo: Herman-Gunawan-CC-BY-SA
Giant shrimp are also known as scampi, king prawns, tiger prawns and giant prawns.
Photo: Fotokannan-CC-BY-SA
Mangrove forests destroyed to build shrimp farms in Malaysia.
Photo: Marufish-CC-BY-SA
Biodiversity changing
As mangroves diminish or disappear, many species of both plants and animals are threatened or become extinct. When sand and soil bound by mangrove roots are carried by the water into the sea, sensitive coastal environments and coral reefs are destroyed. Fish and other animals that spend their early life in mangrove swamps before moving to coral reefs are losing one of their most important habitats. Where the mangroves are cut down, fishing is radically reduced for the local population and many fishermen lose much of their main income. The poorest are hardest hit.
Small-scale fishing is important for many people who live in areas with mangrove swamps. When the trees are cut down, the income of many of the poorest disappears.
Photo: Exagren-CC-BY-SA
New seedlings of mangrove trees planted in Thailand, to get back the important mangrove forests.
Photo: northways-CC-BY
What can I do?
Don’t eat giant shrimp! They are also known as scampi, king prawns, tiger prawns and giant prawns. Even certified giant shrimp are a big problem, so skip them altogether. If you see a restaurant or grocery store selling giant shrimp or prawns, tell them.
Talk to family and friends about the problem of shrimp farming. Ask them to read up about them!
Get involved in associations and organisations working to stop mangroves being destroyed.