12:00 AM, May 31, 2014 / LAST MODIFIED: 01:53 AM, March 08, 2015

Biodiversity in peril

Biodiversity in peril

Md. Asadullah Khan

WHILE observing the World Bio-diversity Day on May 22, environmental scientists as well as environmental groups in the country called for invigorating the tree plantation programme and preventing the enemies of trees from carrying on their onslaughts on forests. Because of human greed and insensible activities, the world is losing a marvelous diversity of genetic materials that has enabled the plant kingdom to overcome pests, blights and droughts throughout the ages. Consequently, many potential food and medicinal sources are being lost forever. Forests also temper climate and store water and 40% of the carbon dioxide in the atmosphere.
Just about 50 years ago, forests draped almost one-fourth of the country's land, nourishing and protecting wildlife and other species. Today, they are in tatters, slashed by human interests, covering only 6 %. We have failed to understand that the earth is an intricate system of links by which all life is shaped. Lose one species, and a thousand others will be on the brink, threatening our survival.
Reports say that an estimated 20% of Brazil's forest is gone. So is the case with Indonesia, Malaysia and Bangladesh. According to a handout released by the forest department in the country, the total forest area in Bangladesh comes to about 25 lakh and 20 thousand hectare. A FAO report revealed that beginning from the year 2000, forest plundering came to about 37 thousand hectares every year. In 2005-06, a joint survey conducted by CIDA and USAID suggested that 50% of the forest land of Bangladesh will disappear in about the next 20 years, should the present slashing process continue unabated.
In the southwestern part of Bangladesh, rivers were dammed for farming through control of salinity intrusion. These polders caused huge deposit of silt in the Sundarbans. Naturally, the natural ecosystems of the Sundarbans have been greatly destroyed, causing extinction of 64 species of vertebrate animals, 40 species of mammals, 38 species of birds, 21 species of reptiles and 23 species of fish. This loss of biodiversity has serious implications on human health and survival.
Scarcity of fresh water, the most crucial of all ecosystems, has caused suffering on a wider scale. Fish resources are under threat from over-fishing and pollution. Studies say that human water consumption rose six-fold in the last two decades, double the rate of population growth. Because of water scarcity, pollution load has increased and now fertilizers, silts, sewage and other effluents have killed rivers, lakes haors and baors. Consequently, agricultural land has been degraded vastly around the world by the build-up of salts and loss of nutrients.
Leaders and policy makers of our country must try to understand how various ecosystems interact. Deforestation in mountains can worsen floods in grass lands or agricultural land below, as was the case with China, India and Bangladesh in 1998 and 2004. Humans have hurt coastal/marine ecosystem by draining wetlands, fishing and destroying reefs and lagoons. We also damage these ecosystems indirectly as rivers transport effluents and by-products of agriculture to the coast.
All these result in man-made climate change, and threaten all coastal areas as melting glaciers send more water seaward, causing sea levels to rise. Coastal cities now face the risk of being inundated and islands may be swept under the waves of water ripped off by cyclones and hurricanes. The inundation and damage to our coastal areas by Sidr and Aila are mostly linked to our insensible actions.
The earth's most important elements move in cycles, circulating from sky to land and sea and back again. Human presence has disrupted the most basic mechanisms of the planet and the biggest assault has come on the carbon cycle. We are pumping carbon dioxide into the atmosphere much faster than land and sea can absorb it. In consequence, the incoming gas is trapping heat and upsetting the climate. The result: apart from rising seas and fiercer storms, droughts and floods in cyclic ways, there is change in the world's ecosystems as the boundaries of forest and grasslands shift. Ultimately many animals and plant species may not be able to adjust to sudden changes in the habitats.
On the other hand, the havoc caused by nitrogen cycles is also taking its toll on humans. Indiscriminate use of fertilizers, burning of fossil fuels and elimination of forest zones has doubled the levels of nitrogen that can be used by living things. These excess nitrogen compounds enter fresh-water as well as salt-water systems where they produce dead zones by stimulating suffocating growths of algae. Paradoxically, since meeting the global food gap is invariably linked with the aggressive use of fertilizer, restoring the balance in the nitrogen cycle poses a daunting challenge.
Around the globe, water cycle poses a more threatening prospect with increasing demand for fresh water for humans. Large rivers like the Yellow river in China, the Nile in Egypt, and Ganges, Brahmaputra etc., in India and Bangladesh are drying up. Because of the construction of 40,000–plus large dams and many other smaller obstructions, the world's rivers have now become a series of interconnected lakes, making life harder and creating a disastrous situation.
Bangladesh is now faced with a critical situation of water-logging and salinity intrusion over vast areas of southwest part of the country because of unplanned construction of polders, bridges and culverts without taking ecological factors into consideration. Shrimp cultivation there has caused salinity to spread over vast areas, destroying farmland.
We are destroying part of the creation, thereby depriving future generations of what we ourselves were bequeathed. The most unsettling prospect is that even the world's richest nations may not have the wherewithal to restore the vital balance in our ecosystems. That only underscores the fact that it is far less expensive to halt the destructive practices before an ecosystem collapses than it is to try to put things back together later. Evidently, the new kind of environmentalism values the world's flora and fauna not just aesthetically as the natural heritage of humanity but also as a source of wealth and economic well-being.
With the world's population at 6 billion plus now, and sure to keep on growing with every passing year, humanity may have entered a dangerous bottleneck. But there perhaps is seen a silver lining behind an enveloping dark cloud.  An infant bio-industry is now taking shape along several fronts. More than 20 pharmaceutical companies have forged contracts with private and national organisations to push chemical prospecting for new medicines in rain forests and other habitats. Such collaborative actions are now most urgent and crucial.

The writer is a columnist of The Daily Star.  
E-mail: aukhandk@gmail.com


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