Celebrating the magic of mangroves on World Mangrove Day

The Mangosuthu University of Technology (MUT) and Triad Scientific presented a discussion on the importance of mangroves and estuaries in celebration of World Mangrove Day at the Beachwood Mangroves Nature Reserve, Durban North, South Africa, on Saturday.

MUT Department of Nature Conservation’s Professor Akash Anandraj and Triad Scientific’s Trevor Govender provided a presentation that explained the importance of mangroves.

They began the presentation by explaining that mangroves are important for the following reasons:

• They maintain water quality. With their dense network of roots and surrounding vegetation, they filter and trap sediment, heavy metals, and other pollutants;
• They provide livelihoods. Healthy mangrove ecosystems mean healthy fisheries from which to fish for local communities, and the surroundings provide for sustainable farming;
• They are biodiversity hotspots. Mangroves are home to an incredible array of species and provide a nesting and breeding habitat for fish, shellfish, migratory birds, and sea turtles;
• They act as a buffer against erosion, storm surge and flooding. They stabilise shorelines by slowing erosion and provide natural barriers protecting coastal communities;
• They increase carbon storage. Mangroves sequestrate carbon at a rate two to four times greater than mature tropical forests and store three to five times more carbon per equivalent area than tropical forests like the Amazon rainforest. Thus, conserving and restoring mangroves is essential to South Africa’s fight against climate change;
• They have direct and indirect uses. Communities have historically used mangrove wood and other extracts for both building and medicinal purposes; and
• They have untapped potential for sustainable revenue-generating initiatives including eco-tourism, sport fishing, and other recreational activities.

“Mangrove tree bark, leaves, fruits, roots, seedlings, and stems are used to treat various conditions. Some of these conditions include wounds, diarrhoea, stomach aches, diabetes, inflammation, skin infections, conjunctivitis (pink eye), and toothache. It can even be used as mosquito repellent,” Anandraj and Govender said.

They both added that the bioactive secondary metabolites obtained from different mangrove species are elaborately studied in terms of their anti-cancer potential. Specific studies related to the application of these compounds in different cell lines of cancer are found to be scanty and scarce.

Mangroves are defined as tropical plants that are adapted to loose wet soils, salt water, and being periodically submerged by tides. Four major factors appear to limit the distribution of mangroves: climate, salt water, tidal fluctuation, and soil type. There are more than 50 species of mangroves found throughout the world.

They shared that studies have revealed that the estuarine habitat has declined due to anthropogenic activities occurring within the estuarine functional zone such as infrastructure development, overgrazing, agricultural activities, and poor water quality.

To advance the management of mangroves, South Africa, as a member state of the Ramsar Convention, supported the implementation of the Ramsar COP13 resolution which seeks to promote the conservation, restoration, and sustainable management of these ecosystems.

The Department of Forestry, Fisheries, and the Environment (DFFE) has embarked on a process to collect data (including from citizen science and indigenous knowledge), map these ecosystems, analyse the information, and make such information publicly accessible to derive evidence-based management interventions to improve the status of mangroves in South Africa.

Anandraj and Govender concluded that the United Nations Educational, Scientific and Cultural Organisation (Unesco) is engaged at the scientific and policy levels to protect, manage, or restore global blue carbon ecosystems (mangroves, seagrasses, and tidal/salt marshes).