Mangroves for Security and Sustainability of Karachi Coastal Belt

by M. Wasim

UNESCO celebrates July 26 each year as the International Day for the Conservation of Mangroves with the aim of raising awareness about mangroves ecosystems and promote their sustainable management and conservation.

Mangrove forests are significant in balancing coastal ecosystem and bridging between terrestrial and marine environments. They transfer organic matter and energy from land to the sea, forming the base of many marine food webs. Mangroves are the first natural wall of defense against natural calamities including cyclone and sea level rise as they are vital in trapping sediments, thereby stabilizing coastlines and protecting coral reefs and sea grass meadows. They are also important to stabilize shorelines, reduce coastal erosion, protect coasts from storm damage and act as carbon sinks and natural water treatment plants.

Ecological Balance

Pakistan coastal belt is heavily dependent on these mangroves forests to maintain the ecological balance. Besides a source of nutrients, the mangroves provide a diverse habitat for complex and interdependent community of invertebrates, birds and reptiles. However the growing dependency of coastal communities on mangroves for fuel and fodder for their livestock and camels and unchecked mangroves deforestation, misbalancing the marine ecosystem.  Mangroves forests are being continuously degraded further by decreasing fresh water discharges. This degradation is resulting in the loss of important breeding and spawning grounds for marine fisheries.

Nearly 125,000 mangrove trees were planted over last 25 years in different coastal areas of Sindh, with survival ratio of 70%. But release of fresh water that also carries nutrient-rich slit and deposits it into the sea is pre-dominant cause of the rapid worsening state of the mangroves forests and is a stumbling block to the growth of new mangroves trees.

Ecologists therefore recommend strong check on mangroves deforestation through laws and strict control of coastal development besides reforestation of denuded areas to recover the mangroves loss caused over decades. Raising and protecting mangroves forests also require sweat water through Indus river — a minimum 10 million acre feet fresh water discharge into the delta is suggested for sustainable management.

Maintains Biodiversity

Karachi coastal areas are also home to species and habitats that provide many benefits to society and natural ecosystems. It’s mangrove covers and wetlands attract a number of migratory birds, particularly waterfowl. Two species of turtles — the Green turtle and Olive Ridely turtle — are also found in the shores of the Karachi coastline.

However, these coastal areas are being speedily ruined by deforestation of mangroves and now vulnerable to climate change, which could affect in variety of ways and bring cyclone and cause heavy devastation of life and property. Coasts are sensitive to sea level rise, changes in the frequency and intensity of storms, increase in precipitation and warmer ocean temperature.

The impacts of climate change are likely to worsen many problems that coastal areas already facing. Shoreline erosion, mangroves deforestation, coastal flooding, and water pollution affect man-made infrastructure and marine ecosystems. To confront these challenges is already a concern, yet the additional stress of Climate change definitely require modern and global approaches to managing land, water, waste and ecosystems.


Editorial, Infocus

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