Mangroves Can Save Coral Reefs: Study
Wed, April 21, 2021

Mangroves Can Save Coral Reefs: Study

According to the World Wildlife Fund, mangroves help in stabilizing the coastline and preventing erosion from waves and storms. / Photo by: Makieni 小林 via 123rf

 

Mangroves were once generally dismissed as an unremarkable bunch of trees in swampy wastelands. That is until scientists discovered that they are actually remarkably diverse and important systems. They keep coastal zones healthy, provide essential habitat for thousands of species, and stabilize shorelines.

However, just like other natural ecosystems, mangroves are also extremely affected by climate change. A 2015 report by the World Resources Institute, a global research organization working around the world to turn big ideas into action at the nexus of environment, economic opportunity, and human well-being, showed that the world lost 192,000 hectares (474,000 acres) of mangroves from 2001 to 2012. This is a total loss of 1.38% since 2000 (or 0.13% annually). 

Asia boasts the world’s largest mangrove area. It’s particularly suitable for mangrove growth because of its significant freshwater sources, high rainfall, abundant islands, and extensive coastlines. However, it is also a hub for global mangrove loss. Using Global Forest Watch (GFW), an online forest monitoring platform, the report showed that Asia has the highest rates of mangrove loss. The continent’s annual loss rates nearly double the global average, particularly in countries like Indonesia, Malaysia, Papua New Guinea, Solomon Islands, Brunei, East Timor, Singapore, and the Philippines.

Why Mangroves Matter

More than 35% of the world’s mangroves are already gone, which poses a negative impact on our environment. For one, mangroves are biodiversity hotspots. They are home to an incredible array of species, particularly marine creatures. In fact, an estimated 80% of the global fish catch relies on mangrove forests. These trees are also prime nesting and resting sites for hundreds of shorebirds and migratory bird species. 

According to the World Wildlife Fund (WWF), a leading organization in wildlife and endangered species conservation, mangroves help in stabilizing the coastline and preventing erosion from waves and storms. In countries where these trees have been cleared, coastal damage from hurricanes and typhoons is much more severe. Also, robust mangrove forests are natural protection for communities vulnerable to intense weather events and sea-level rise caused by climate change.

Like the Amazon rainforest, mangroves sequester carbon at a rate two to four times greater than mature tropical forests. They also store three to five times more carbon per equivalent area than tropical forests. This makes mangroves essential to fighting climate change. At the same time, they are significant in maintaining water quality since they can filter and trap sediments, heavy metals, and other pollutants. 

All of the things that mangroves can do directly affect coral reefs since they function in a symbiotic relationship. For instance, the health and extent of coral reefs are largely dependent on coastal mangrove forests, which remove pollutants, stabilize shorelines, improve water quality, and provide nursery habitat that maintains fisheries. If mangroves are degraded, coral reefs will be adversely affected. This also means that if mangroves are kept healthy, we can save coral reefs from the impacts of climate change.

Mangroves Can Help Coral Fisheries

Coral reefs are one of the planet’s most endangered ecosystems. At least three-quarters of coral reefs across the world are considered under threat due to overfishing, run-off from land, high temperatures, and changing ocean chemistry. Mangroves could help coral species in fighting climate change.

A recent study conducted by researchers from the University of Queensland showed how mangroves can serve as an alternative nursery habitat to the reef. It’s no secret that coral reefs have been bleached as a major consequence of warming seas. Professor Peter Mumby from the UQ stated that many people are worried that reef fishery yields could halve if coral reefs flattened. This could potentially destroy the home that supports thousands of fish in the ocean.

Without coral fisheries, the entire food web can become unproductive since thousands of marine species will have no place to keep safe. As a result, there would be fewer fish that could survive. According to Science Daily, an American website that aggregates press releases and publishes lightly edited press releases about science, the researchers compared and validated model predictions with field data from Belize. They discovered that healthy mangrove forests can help buffer the effects of habitat loss on reef fisheries.

 

Coral reefs are one of the planet’s most endangered ecosystems. / Photo by: blueseacz via 123rf

 

"It's critical that they need to remain a priority as part of the battle to mitigate climate change impacts on coral reefs and their functioning,” Mumby said.

At the same time, the researchers found that mangroves can serve as an alternative nursery habitat for thousands of fish. "Mangroves provide a calm, safe environment with plenty of food and allow fish to grow larger before heading out to the reef as adults. In fact, we discovered that these nurseries could support fisheries productivity that is equal to that in complex reefs that lack nurseries,” Mumby added. 

Thus, in order to save coral reefs from the impacts of climate change, mangroves should be well taken care of first. According to National Geographic, an American pay television network and flagship channel, preserving mangroves can be one in a portfolio of strategies to help corals survive the effects of climate change.

This only shows that our ecosystems are truly connected with each other. If one is damaged, the other is also affected. Mangroves are extremely important in saving not only coral reefs but also other ecosystems. They should be given the huge attention they deserve so they can be protected and preserved.