Mangroves have a complex and unique ecosystem, with roots deeply embedded in the water. They thrive in hot, muddy and salty environments where no other plant can survive
These trees benefit everyone, as more than 1,500 species of plants and animals depend on them, which means that they support biodiversity. Mangrove forests also play an important role in protecting coastal communities from natural disasters such as storms and tsunamis.
They combat climate change by sequestering carbon. They are among the most carbon-rich ecosystems on the planet, storing an average of 1,000 tons of carbon per hectare in their biomass and underlying soil, according to the United Nations Environment Program.
Arabian mangrove forests
Mangroves represent an important wealth along the Arab coasts, including the western shores. According to the Food and Agriculture Organization report “Mangroves in the World,” Africa has the second largest area of mangroves in the world, about 2.82 million hectares, representing 19% of the global mangrove area. They are concentrated in the West African region where Mauritania is located, which overlooks the southeastern coast of the Atlantic Ocean.
In Mauritania, the black mangrove grows. They are very hardy trees that adapt to harsh environments where water levels and salinity change, and the black mangrove can penetrate the most inland areas into salt water.
Black mangroves are valuable in saltwater marsh restoration because of their ability to filter and trap sediments. They act as a sink for excess nutrients and pollutants, play a role in reducing wave energy, and are easily adapted to other native plants, according to the United States Department of Agriculture (USDA).
From the west of the continent to the coasts of the Horn of Africa, Somalia has the second longest coastline in all of Africa, which extends along the Gulf of Aden and the Indian Ocean, and mangrove trees are concentrated on the southern coast of the country.
Mangrove forests in East Africa, including southern Somalia, are an ecological area that serves as food traps for river basins and provides shelter for many important species of fish, shrimp, crabs and molluscs.
Shallow mudflats associated with mangrove trees along the coast also provide important sites for migratory birds, and mangrove forests play an important role in preventing beach erosion and sediment flow onto coral reefs, according to the "one earth" website.
In Djibouti, mangrove forests represent a critical ecosystem for addressing the impacts of the climate crisis along coastal areas. The country is highly vulnerable to the effects of climate change, and is at risk of losing part of its coastline due to rising sea levels, putting the lives of most coastal residents at risk.
The United Nations Environment Program (UNEP) is working with Djibouti to restore mangroves within local communities and combat climate change, as these forests provide a natural defense against extreme weather events, a buffer against sea level rise while absorbing carbon, and sustain the livelihoods of coastal communities.
A recent study
Despite the proven great importance of mangrove systems in the Arab world and globally, they are witnessing a worrying decline. The area of mangrove trees in the world has decreased by 284 thousand hectares from 2000 to 2020, due to several natural phenomena, such as: Sea level rise, changes in temperature and precipitation, as well as the impact of human activities such as agriculture and urban expansion, according to the FAO report.
In light of this alarming situation, conservation and forest restoration efforts have become more important than ever, especially within Asia and Africa, where the largest areas of mangrove trees in the world are located, while continuing to conduct scientific studies and research to improve and recover mangroves.
A recent study by researchers at the University of Putra in Malaysia has found that monitoring bird communities living in mangrove forests can serve as useful indicators for measuring the health of the
mangrove ecosystem.
The research team explains that when mangrove planting or restoration projects begin, it is difficult to track or measure the progress of these projects or know what stage they have reached, so the study proposes monitoring bird communities living in mangrove forests using bioacoustics, to get answers to these questions.
The team used audio recording devices to listen to birds in their natural habitats. They installed 20 audio recording devices inside four mangrove forest reserves, at different stages of growth. The newest one is about 10 years old, while the oldest one was planted more than 4 decades ago.
By monitoring and analyzing the recordings, the researchers found that mangrove forests with larger, taller trees and greater tree cover support a larger and more diverse array of birds. They identified 53 bird species, including endangered species, living within the largest and oldest reserve, while the number and diversity of birds are lower in the smaller, newer reserves.
“Monitoring bird communities using acoustics clearly helps track the progress of mangrove restoration in the long term”, says Low Yin Yee, a bioacoustics researcher at Sunway University Malaysia.
She stressed the importance of bioacoustics, which is increasingly being used in Southeast Asia, as it allows researchers to collect long-term, in-depth data across dense forests, which are difficult to survey on foot.
She added that bioacoustics works to reduce the impact of human observers on bird communities, increasing the chance of discovering rare and endangered species without harming or disturbing these communities.
This study demonstrates the potential of using bioacoustics of bird communities to ensure the successful progress of mangrove restoration projects, a simple and effective method that can be exploited in Arab and global mangrove forests to achieve good tree cover that will support biodiversity, climate resilience and overall ecosystem health.
