Mangroves in Mumbai

Due to rapid urbanization, the native mangroves of Mumbai have experienced massive amounts of degradation over the past few decades. New housing developments and water pollution have destroyed the previously lush mangrove forests along the coast and negatively affected the ecosystem and community as a whole.

We hope that this blog will be helpful in informing the public about the mangroves' current state and what has been done to mitigate the effects of humans on this fragile ecosystem.

Map of Mumbai Area Mangroves (green outline)

N.d. India. Soonabai Pirojsha Godrej Marine Ecology Centre. Web. 26 Nov. 2015.

The Historical State of Mumbai's Mangrove Ecosystem

        Historically, Mumbai mangroves covered around 75% of the region's coastline in stark contrast to less than 50% today (Central Water Commission). The region's mangrove forests consisted of 54 to 75 species of various mangrove trees in inter-tidal coast zones that depended on the forest for sustenance and habitats, many of which still exist but are threatened by current pollution. As any healthy mangrove forest is able to do, Mumbai's mangroves were better able to balance levels of water salinity in the water surrounding their roots much better than they can today because previously there was no "chemical soup" mixed through the water. When the ecosystem possessed a significantly larger amount of mangroves with their distinctive above-ground roots, this allowed for better barriers against ocean waves and storms along the shores of the Mumbai region because the mangroves served as natural sand dykes and berms. The Maharashtra floods of 2005 would not have had such devastating effects (over 1000 people were killed) if the mangroves in Mithi River and Mahim Creek had not been removed.
        The previously expansive mangroves also gave more stable habitats and sustenance to various insects, amphibians, mammals, birds, and other organisms (Mangrove Action Project). The historical state of Mumbai's mangroves also allowed for better removal of harmful carbon dioxide, (carbon sequestration) important in maintaining the ecosystem's chemical balance (Vijayaraghavan). Earlier, the larger mangrove forests meant that there were more of the mangrove trees' specific roots, which gave support structurally to the entire forest, as well as giving more oxygen to the environment (AMNH). All in all, in their historical state, Mumbai mangroves provided better shelter from high ocean tides, sheltered and sustained many varied species, and allowed for a better chemical balance in the ecosystem's air and water.

How Mumbai Mangroves Appeared Historically

N.d. Mumbai, India. Afternoon, Despatch and Courier. Web. 24 Nov. 2015.

Current Appearance of Much-Reduced Mumbai Mangroves

N.d. Chembur-Mankhurd Link Road, India. Mumbai Mangroves. Web. 24 Nov. 2015.

Current Human Impacts

As one of the fastest growing regions worldwide, the population in the Mumbai Metropolitan Region (MMR) skyrocketed from 7.7 million in 1971 to 22.4 million in 2011 (MMRDA,2011). This tremendous population growth brought extreme consequences to its mangrove ecosystem. 

Source: Rafiq Maqbool

The mangroves in Mumbai have been facing biotic pressures due to land use patterns, industrial waste disposal and oil spills.  Between 1995 and 2005, almost 40% of the mangrove ecosystems along the west coast of Mumbai, especially those along the Mahim Creek and Mithi River, have been destroyed and converted to urban areas. As a result, the mangrove ecosystem has become increasingly susceptible to climate change and environmental stress. Due to the reduced capacity of the ground water aquifers, water level has risen up to ground level and submerges the mangrove areas. This not only leads to disturbances in the food web but also causes the loss of endemic mangrove plants. The rising temperatures also exacerbate the death of mass plankton and benthic animals in mangrove areas, leading to a decline in water bird population and thus the reduction in the external nourishment. 

Source: http://www.sciencedirect.com/science/article/pii/S0964569101000552#

The disposal of industrial waste has further contributed to the deterioration of the mangrove ecosystem. Most of the industries in the MMR that manufacture chemical products such as dyes, pharmaceuticals, fine chemicals, plastics, fertilizers, and refined petroleum products discharge the untreated effluents to Thane creek, Ulhas and Patalganga rivers. By comparing various data records over the years, we can see from the increasing water concentrations of Zn, Cu, Pb, N and P that the water quality in coastal areas around Mumbai has deteriorated significantly. These increasing concentrations of pollutants cause depletion of dissolved oxygen and increase in the biochemical oxygen demand (BOD). Oil pollution is also a huge problem for mangroves, as they are highly sensitive to oil exposure and die within a few months of exposure. Due to insufficient oxygen in the soil for the roots, mangrove seedlings will also not be able to survive, and this affects the entire balance of the ecosystem. In 2010, 800 tons of oil spilled in the Arabian seas as a result of the collision of Panamanian vessels and caused a loss of 1273 hectares of reclaimed mangroves.

Source: Vivek Bendre

Source: http://www.sciencedirect.com/science/article/pii/S0964569101000552#

Future Prospects

Fortunately, after the tsunami in 2004, awareness about the importance of mangroves increased significantly in Mumbai because the mangroves protected the villages of Pichavaram and Muthupet from the devastating natural disaster. Despite the current ugly state of mangrove ecosystem (70% of mangroves lost-157 km2 left) and the need for a more integrated effort, the future prospects for Mumbai are optimistic because of the various holistic approaches taken to conserve the mangrove ecosystem.

To mitigate waste disposal problems, as an example, the Thane Municipal Corporation (TMC) has implemented sewerage and waste management schemes. TMC plans to carry out treatment projects and building of sewage networks to conserve estuaries of Thane Creek and Ulhas River, which as mentioned above, are highly polluted. By upgrading sewage treatment plants and improving the sanitation system, the area will be able to alleviate the effects of waste disposal on destruction of mangrove ecosystem.

In 2005, the Bombay High Court cited India’s Forest Conservation Act of 1980 and the Coastal Regulation Zone Notification of 1991 in its new ruling to lessen the destruction of mangrove ecosystems. Under the CRZ-1 protection status, mangroves in Mumbai are disallowed of being cleared, however, mangrove reclamation by private businesses steadily continues. It can be concluded that these inter-related environmental issues cannot be resolved purely by a single authoritative approach. Instead, a centralized coordination between these federal, provincial and municipal governments is necessary because mangrove ecosystem problems require a systematic study of environmental processes, urbanization, legislation and climate change in formulating strategies.

Thoughts on Improving Human Impacts

Mumbai as a whole has already made some progress in improving impacts on the mangrove ecosystem, but further measures can be taken. In regards to legislation, India has the Coastal Regulation Zone Notification, disallowing any new construction in and within 50 meters of mangrove areas, which are classified as ecologically sensitive areas. This was set in place by India’s Ministry of Environments and Forests in 1991 and has since been updated in 2011. Unfortunately, regulations such as these and those prohibiting water pollution are not being properly enforced. Since coastal zones typically encompass many physical, social, and regulatory divisions, it is necessary to adopt a multidisciplinary approach to conservation that takes into account the needs of all stakeholders—including the private sector, individuals, and the government. First, when surveying affected mangrove areas, it’s important for the science and management communities to collaborate and focus on researching the demographic and socioeconomic factors that contribute to marine pollution and coastal degradation. If those in charge of implementing regulations are more aware of the underlying reasons behind the mangroves’ destruction, the agencies will be better equipped to combat those issues.

Nursery at Godbunder, Mumbai

Source: http://mangrovecell.org/nursery.aspx

Afforestation, the replanting of mangroves, should also be encouraged. The Mangrove Cell, part of the Maharashtra Forest Department, aims to create awareness and train individuals on the conservation of mangrove areas. The Mangrove Cell has initiated afforestation programs in Mumbai and established Mangrove nurseries, where saplings will be cultivated and used for replanting mangrove trees along the Maharashtra coast.

Public education about the importance of mangroves to the community is a vital component in reducing human impact on the ecosystem. Awareness is one of the first steps in affecting change, and although awareness alone is insufficient, it can lead to action. The stretch of Mumbai’s west coast along Carter Road is a prime example of how citizens themselves rallied to protect their mangroves. Over the last 10 years, while surrounding mangroves have deteriorated, mangroves there have increased in both area and height. A more recent example of citizen action occurred in November 2015 when residents of Versova marched in protest over the dumping of debris into the mangroves. Their efforts were heeded by the local government and the authorities have promised to punish those dumping waste into the mangroves. These citizens are aware that “unless citizens are out on the road making noise, the authorities supposed to protect mangroves and be alert will not take action.”

Carter Road: Before and After

Source: Mumbai that is and could be (rediff.com)

Different methods can be used for increasing public awareness. Environmental organizations can arrange field trips for schoolchildren to discover the mangroves of Mumbai and even get involved in afforestation. Furthermore, boardwalks can be built in parts of the mangrove forest areas so that visitors can appreciate the beauty of the mangroves rather than viewing them as wastelands. As the people of Mumbai learn more about the importance of mangroves and the deleterious effects of their destruction, they can be mobilized to get involved in afforestation efforts and to pressure authorities to ensure management of the ecosystem.

References

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Elsevier B.V., 23 Aug. 2001. Web. 25 Nov. 2015.

"Frequently Asked Questions on the Coastal Regulation Zone Notification, 2011 and Island Protection Zone Notification, 2011."Ministry of Environment, Forest and Climate Change. Government of India, 2011. Web. 28 Nov. 2015.

Indian Central Water Commission. "Mangrove Forest in India." (n.d.): n. pag. Central Water   Commission. Indian Central Water Commission. Web. 22 Nov. 2015.

Kumar, Arun, and Parveen Nangia. "Population Growth and Changing Land Use Pattern in Mumbai Metropolitan Region of India." 1 Feb. 2004. Web. 27 Nov. 2015.

M, Sengupta, and Dalwani R. "Conservation of Wetlands and Mangroves in Thane
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Murthy, Raj C., Y. R. Rao, and Arun B. Inamdar. "Integrated Coastal Management of Mumbai   Metropolitan Region." Ocean and Coastal Management 44.5-6 (2001): 355-69. Science Direct.

"Nursery." The Mangrove Cell - Maharashtra Forest Department. Government of Maharashtra, 2013. Web. 28 Nov. 2015.

"Ripple Effects: Population and Coastal Regions." Population Reference Bureau. Population Reference Bureau, 1 Sept. 2003. Web. 28 Nov. 2015.

S., Sandilyan. "Impacts of Climate Change on Indian Mangroves: A Review Paper." IDOSI Publications, 1 Oct. 2014. Web. 25 Nov. 2015.

Singh, Virat. "Mumbai: Versova Residents Hit Street against Dumping Debris on Mangrove." DNA India. Diligent Media Corporation, 23 Nov. 2015. Web. 26 Nov. 2015.

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Vaz, Eric. "Managing Urban Coastal Areas through Landscape Metrics: An Assessment of Mumbai's Mangrove System." Ocean & Coastal Management 98 (2014): 27-37. ScienceDirect. Elsevier B.V. Web. 27 Nov. 2015.

Vijayaraghavan, Akhila. "How Mumbai's Mangrove Forests Saved the City Millions of Dollars."

Triple Pundit. Triple Pundit, 22 Dec. 2011. Web. 27 Nov. 2015.

"What's a Mangrove? And How Does It Work?" AMNH. American Museum of Natural History, n.d. Web. 26 Nov. 2015.

Yada, Madhura, and Gaurang Desai. “Transforming Habitats: - Case Study of Mumbai.” 14 July 2008. Web. 26 Nov. 2015.