Black Carbon: A Silent Threat to Marine Biodiversity

Kartik Srivastava 

MSc Zoology, NET (Env Sci), MEd (pursuing)

The Maharaja Sayajirao University of Baroda,

Vadodara, Gujarat-390002

ABSTRACT/ SYNOPSIS 

        Living in the 21st century, a civilized world as we call it, we have modernized almost everything, every aspect of our lives with technological advancements but have actually forgotten or rather ignored our duties towards mother nature of which we are an integral part. The human race has till date caused a lot of devastations to the natural environment and its ecosystems and, oceans and marine ecosystems are not something untouched. A lot of marine biodiversity across the world has already declined due to anthropogenic pressures and a lot more are on verge of extinction. However, in the recent past, with the coming up of environmentalists, conventions and policies directed towards sustainable future, we have begun focussing on global environmental issues like climate change, pollution, deforestation, coral bleaching, sea-level rise, etc and have talked about various causes too like Carbon emissions, tropospheric ozone etc. but one silent and unnoticed threat to the environment, especially marine environment is Black carbon, which is quite less discussed.

             Black carbon, a primary pollutant emitted from incomplete combustion of fossil fuels and various other anthropogenic activities, can travel to long distances in the atmosphere and can block and absorb sunlight thus increasing the temperature and accelerating climate change. Particularly talking about marine biodiversity , black carbon can land on ocean surfaces changing the chemical composition of its surface water and accelerating acidification of oceans thus killing marine biodiversity like shellfish and corals. Also, due to blocking of sunlight it can hinder photosynthesis in phytoplanktons, thus disrupting the ecological chain in the marine ecosystem.

            This article aims to discuss the potential threats of black carbon to marine biodiversity and the adverse consequences. The article will also highlight the possible mitigation strategies in order to combat this silent killer of marine biodiversity- the black carbon.

Keywords - Black carbon, anthropogenic, ocean-acidification, coral-bleaching, climate change 

Black Carbon 

Black carbon which is also referred to as soot in common terminology, is basically a primary anthropogenic pollutant which is released in very fine particle form from incomplete combustion of fossil fuels , burning of agricultural biomass , from diesel engines etc. Even indoor daily activities like gas stove burning and lighting an incense cone can release black carbon. 

Black carbon is solid in nature and black in colour composed of pure carbon particles and could be released in fine aerosol forms and when inhaled it could enter into the respiratory tract and cause distress and respiratory disorders.

Adverse effects on environment with special emphasis on marine biodiversity 

• Global climate change: Black carbon can act as a major contributor to global climate change. When it's present in atmosphere it absorbs more and more heat from Sun unlike other aerosols,  causing air around it to warm thus causing global warming and significantly accelerating the issue of  global climate change. The global climate change has got devastating effects on biodiversity including marine biodiversity.

• Glacier melting and sea levels rise: Black carbon can travel to long distances and can settle on glaciers and snow surface thus rendering the surface as black , hence reducing its reflectivity and thus causing more heat entrapment and melting of snow that leads to sea level rise again a major threat to sensitive flora and fauna of the marine ecosystem.

• Ocean acidification and coral bleaching: The global climate change being brought by black carbon can lead to acidification of oceans. Also, the black carbon aerosols which land on sea surface can alter the surface chemistry of sea water . This acidification of sea water with climate change leads to coral bleaching and devastation of this varied ecosystem which is home to many.

• Hindrance in planktonic photosynthesis: Since black carbons can absorb sunlight, thus they block the light to reach phytoplanktons in the sea thus affecting photosynthesis process and causing their death,  in this way disturbing the entire ecological food chain.

• Changed monsoon and cloud pattern: Black carbon can interfere with cloud forming process by interacting with sunlight and altering the way sunlight interacts with air masses. This causes changed monsoon pattern , even marine weather cycles too.

Source:- Climate and Clean Air Coalition

Mitigation

Relating with the saying ‘Prevention is better than cure’ it's always better to prevent black carbon from being released rather than keep on searching and incorporating different treatment methods even when they are not cost effective.

Some of the mitigation strategies could be use of cleaner cooking alternatives like LPG etc rather than burning fossil fuels for cooking, use of electrical vehicles in place of diesel vehicles, reduced open burning of wastes and proper disposal of wastes, use of scrubbers or filters by industries before discharging exhaust gases with black carbon, etc.

    At last but not the least , we should remember that nothing will really work unless and until we realise that nature is not someone's private property but a collective responsibility of we all  to work upon to make it a better place to live in not only for us but for all organisms of Earth.