Written by: Haroon Shuaib
Posted on: September 12, 2024 | 
| 中文
Women gardeners gesture for a group photo at an event to mark the start of the Delta Blue Carbon (DBC) project
Globally, mangroves, unique and thriving ecosystems where land meets sea, play a crucial role in protection of ecological balance, disaster risk reduction, reducing climate change impact and providing economic opportunities. These extraordinary habitats act as green lungs of mother earth as they form natural carbon that captures significant amounts of carbon dioxide. They serve as nurseries for fish and crustaceans and safeguard coastlines from storms, tsunamis, rising sea levels and erosion. Their role in protecting coastlines from tsunamis and other eroding factors cannot be underestimated.
Yet mangroves are disappearing three to five times faster than overall global forest losses. Estimates are that mangrove coverage has halved in the past 40 years. Importance of these fast-depleting pegs on which our delicately balanced ecosystem is perched, has been underscored by the fact that the UN Educational, Scientific and Cultural Organization (UNESCO) declared 26 July as the International Day for the Conservation of the Mangrove Ecosystem.
Mangrove forests are important for diverse ecosystems
The soothing scent of rich silt and mud is the prevailing aroma of mangroves. Surreal looking thick tangles of roots, rising above water, provide an excellent breeding ground for numerous marine species, including fish and shrimp. In these safe havens, away from predators, fledgling marine life feeds on leaf scraps and microorganisms.
According to UN estimates, over 100 million people live in proximity to mangroves. Raphaelle Flint of International Union for the Conservation of Nature (IUCN) notes in an essay, “These dynamic ecosystems provide approximately US$33-57,000 per hectare per year of income to national economies in services like coastal protection, food and medicines. Furthermore, although this ecosystem covers less than 1% of our planet's surface, they pack a punch when it comes to dealing with climate change control. For example, a 10km2 area of mangrove forest can store the same amount of carbon as 50km2 area of tropical upland forests, essentially meaning mangroves are five times more efficient at storing carbon; even when compared to one of the most productive ecosystems on our planet.” Those who end up receiving the hardest blow as the world continues to lose mangrove coverage are the same communities dependent on these forest for their livelihoods and their biodiversity.
This photograph shows boatmen travelling on a boat loaded with chopped mangroves along a tributary close to the Arabian Sea in Karachi. (Pic by AFP)
Typically, mangroves plants grow in an equatorial climate along brackish and saline waters of coastlines and tidal rivers. Botanists claim that there are more than 100 different plant species that have adapted to mangrove conditions. These plants have special adaptations to take in extra oxygen and remove salt, allowing them to tolerate conditions that would kill most plants. Mangrove plant families first became widely distributed in part due to the movement of tectonic plates with the oldest known fossils of mangrove palm found dating back to 75 million years ago. With their sophisticated and complex salt filtration systems and complex root systems to cope with saltwater immersion and wave action, they adapted to the low-oxygen conditions of waterlogged mud. As bacteria thrive in these low oxygen areas, they liberate nitrogen gas, iron, inorganic phosphates, sulfides and methane, making the soil much less nutritious. As a result, plants in mangrove biomes developed aerial roots, allowing absorption of gases directly from the atmosphere, and other nutrients such as iron from the inhospitable soil. Mangroves have the ability to absorb four times more carbon dioxide than other trees.
Mangrove roots above and below water
In Pakistan, mangrove forests, often referred to as, ‘Timar’, are found along the Indus river delta region and the coastline of Sindh and Balochistan. The 600,000 hectares of mangrove located along the delta of the River Indus is the largest mangrove forest in Pakistan. Known as the vertebra of Pakistan’s ecology and economy, the Indus delta is the fifth largest in the world and home to the seventh biggest mangrove forest. This system of riverine mangrove forests is threatened by multiple factors, including inadequate freshwater flow from downstream Kotri Barrage, pollution, climate change, deforestation, urbanization, sea-level rise, global warming and overfishing.
Pakistan’s coastline is about 1026 km long and the country’s Exclusive Economic Zone (EEZ) covers an area of about 240,000 sq. km. Besides the Indus Delta, similar mangrove biomes are found in the coastal areas of Sindh and Balochistan along Sonmiani, Miani Hor, Kalmat Hor, Jiwani, and Gwatar Bays. Despite being an utterly important part of ecological system, coastal mangrove forests in Pakistan, just as in the rest of the world, have faced serious threats. Pollution, unabashed land reclaiming, climate change, and deforestation are the biggest challenges faced by coastal mangrove forests.
The Indus Delta mangroves are among the top 10 mangrove forests in the world
Fortunately, concerted efforts have been made by climate activists and authorities with help from international environmental protection agencies to restore these ecosystems. Since 2010, around 55,000 hectares of mangrove forests have been planted and restored in Sindh alone. The Sindh Forest Department along with the provincial and the federal government has created a mangrove resource base spread over an area of more than 150,000 hectares. Rigorous conservation policy and local coastal communities both aided in the restoration of mangrove forests. In June 2013 alone, the Forest Department set the Guinness World Record for the ‘Maximum Number of Trees Planted in a Day’ after planting more than 840,00 mangrove saplings in Thatta and Kharo Chan. The plantation drive was completed within a period of 12 hours with the help of around 300 local volunteers. IUCN and the World Wildlife Fund (WWF) for Nature, also play an important role in supporting these initiatives. The Pakistan Navy launched its widely-hailed ‘2020 Mangroves Plantation Campaign’ to restore the ‘green coastal belt.’
Nipa palms, Nypa fruticans, the only palm species fully adapted to the mangrove biome.
According to the United Nations Framework Convention on Climate Change (UNFCCC), the Clean Development Mechanism (CDM) lets countries that promised to lower their emissions as part of the Kyoto Protocol, work on projects that reduce pollution in poorer countries. These projects can earn them credits called certified emission reductions (CERs), which help meet Kyoto goals. In 2023, Pakistan raised its carbon trading sales by launching a new mangrove plantation project at the Indus Delta that sold $40 million worth of carbon credits. Besides climatic dividends, these mangrove forests also have critical economic importance. An estimated 80% of the fish caught in coastal waters spend at least part of their life cycle as fry in the mangrove creeks, or depend on the food web within these biomes. Shrimp fishery is the major fish export for Pakistan, accounting for 68% of the $100 million of the foreign exchange that the country earns from fisheries exports.
Mangrove forests serve as a breeding ground for various species of fish and shellfish.
Thanks to the realization of the environmental and economic returns of these precious natural settings, coordinated efforts for their rehabilitation have continued. According to satellite data, these actions have led to nearly threefold expansion in mangroves in Pakistan between 1986 and 2020.
In a world facing an ever-increasing shadow of climate-change and its disastrous outfalls, nature-based solutions are increasingly recognized as the preferred approach to meet the needs of people and nature, while addressing climate change risks. Investigations have revealed that a 100 meters thick belt of mangroves has the ability to reduce wave height by two thirds in the case of a tsunami, greatly reducing the damage to an area. On top of that, the protection and maintenance of existing mangroves is five times more cost-effective than the construction of traditional grey infrastructure such as seawalls. Preservation of natural safeguards such as mangrove forests that in return offer effective disaster reduction and great economic benefits, should be made a national and global priority.
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