Reasons of degradation of mangrove forests
Reasons of degradation of Mangrove forests in Pakistan and its Management.
Over 600,000 hectares of Pakistan’s coastline is under mangrove forestation. Coastal mangrove ecosystems in Pakistan have been seriously degraded over the last 50 years as a result of freshwater diversion for agriculture, industrial and urban water pollution, over-fishing in Indus delta andoverharvesting of mangroves by the local communities, sedimentation, and coastal erosion.The Indus delta of Pakistan constitutes the most extensive mangrove forestsapproximately 129,000 ha along the coast. The data for this paper was collected from different reports and from WWF Pakistan. The paper focuses on thereasons of ecological damage ofmangroves in Pakistan and their management through sustainable use of mangrove resources, their protection and conservation.There is also a need for the creation of awareness and education among planners and coastal communities regarding the sustainable management of mangrove forests.
The objectives of this paper are:
Determination of causes of degradation of the mangrove forests and quantification of the areas destroyed by various factors specially.
- Decreasing freshwater and silt flows from Indus river.
- Browsing by camels
- Industrial and marine pollution.
Management of mangrove forests by restoration and with training and awareness among people of that area.
Mangroves are the marine tidal forests that include trees, shrubs, palms, epiphytes and ferns (Tomlinson, 1986). The plants and animals community associated with mangroves is referred to as the ‘mangal’ (Macnae, 1968). Mangrove ecosystems have diversity of plants and animals with heterogeneous habitats and adapted to the environmental conditions of highly saline, soft bottomed anaerobic loose mud and silt (Clough, 1992).Amjad and Khan (1983) mentioned the estimated area of mangrove cover in Pakistan is about 283,000 ha consisting of 281,000 ha in Sindh and 2000 ha in Balochistan.It is one of the most productive ecosystems and a natural, renewable resource. Over the last decade, concern has grown over the ways in which human activities have altered the mangrove ecosystems of Pakistan. The rate of degradation of mangrove forests in the Indus Delta has been estimated at 6 percent between 1980 and 1995. At present, only 15 percent of mangroves here are considered healthy (Thompson and Tirmizi, 1995). Freshwater scarcity due to upstream diversions of river flows for agriculture,industrial water pollution and algal bloom, overgrazing, browsing by camels, lopping by villagers along the coasts,erosion caused by tidal current, cutting for fuel wood and timber, and unsustainable fishing levels are seen as the main factors associated with biodiversity loss in the mangrove forests on the coasts of Sindh and Baluchistan (IUCN Pakistan, 2005).The Indus delta is not only one of the longest deltas in the world; it is also the largest area of arid climate mangroves in the world. The natural resources it contains are of significant economic importance to Pakistan, and the time is now to conserve what is left whilst it is still in a viable condition, rather than wait until it is too late. It does this by developing zones where various activities can take place, by regulating the levels of these activities to sustainable limits and by encouraging in the participation of local people. The commitment of the main land-owning agencies in the Indus delta is required to make the concept of the Indus delta Biosphere secures a reality (Macintosh and Ashton, 2002). The management of the different resources of the mangrove ecosystem is handled by different agencies of the government, both at central and provincial levels. Forestry, fisheries and land administration agencies, for example, have specific jurisdiction over specific resources in the area of mangrove (IUCN Pakistan, 2005). It is believed that local people living in the coastal areas have been able to manage mangrove forests for their communities (Qureshi, 1984). A current working plan titled “Working Plan of Mangrove Forests for a 20 year period from 1985-2005 has been prepared with the objectives to protect the coastline from erosion, and to meet the demands of local communities provide them sustained quantities of forest products (Qureshi, 1985). Afforestation and reforestation activities are being undertaken on a small and large scale by IUCN in collaboration with Sindh Forest Department. The International Society for Mangroves Ecosystem (ISME) with its headquarters in Okinawa, Japan is encouraging mangrove studies and plantations along the coast of Pakistan (IUCN Pakistan, 2005). There are also many government and non-government organizations under different projects working for the management of mangrove forests in Pakistan these include the WWF, Pakistan, Sindh Forest Department, World Bank, UNDP and UNESCO.
Historical records indicate that the original extent of mangrove forests has declined considerably under pressure from human activity. National proportions of original mangrove cover lost vary from 4 to 84%. For example, in Southeast Asia Malaysia lost 12% from 1980 to 1990 (Ong, 1995); the Philippines originally had 4,300 km2 but now has 1,200 km2 (Primavera, 2000); Thailand had 5,500 km2 in 1961 but 2,470 km2 in 1986 (Aksornkoae, 1993); and Vietnam 4,000 km2 originally to 2,525 km2 today (Spalding et al., 1997). Mangroves have often been considered as unproductive land and their destruction and degradation have been due to the preference for short-term exploitation for immediate economic benefit like shrim farming, rather than long-term sustainable exploitation (Saenger et al., 1983). Underestimation of the total economic value of mangroves and of the impacts of human activities are major factors contributing to the widespread loss and degradation of mangrove ecosystems (Gilbert and Janssen, 1998). Ong (1995) considers that burgeoning populations are possibly the biggest cause of mangrove destruction and degradation because they rely heavily on marine habitats and resources for food, building materials, building sites and agricultural and recreational areas. They also use coastal areas as a dumping ground for sewage, garbage and toxic wastes.
Pollution and poor land use practices within these watershed areas affect downstream marine habitats because sediments and pollutants are ultimately washed into coastal waters. Mangroves have been over exploited or converted to various other forms of land use, for example agriculture, aquaculture, salt ponds, terrestrial forestry, urban and industrial development and construction of dikes and roads (Macintosh, 1996).
Global warming could be a significant threat to mangrove cover and biodiversity. Rising water (as a result of melting ice caps) could drown coastal mangrove. Projected climate change could have other effects, such as changes in ocean currents, salinity and surface temperatures. These would alter the species compositions and perhaps trigger local and global extinctionʹs (McCarthy et al.,2001). Over cutting is another major factor as Mangrove wood (especially Rhizophora spp.) is good for charcoal production because it is heavy, dense, hard and with a high calorific value (Aksornkoae, 1993). The residents of Keti bunder reported that before the construction of Sukkur barrage, the river water used to flow 9 months in the year. After its construction, this was reduced to 7 months due to decreasing flood water, the mangroves forests are being adversely affected,due mainly to salinity resulting from lack of freshwater inflows (IUCN,2005).
The damage on account of browsing by camels is serious and extensive. During flood season in the River Indus, the camels from the interior of Sindh migrate to mangrove forests in herd (IUCN, 2005). Increasing populations put pressure on the production for food. Mangroves are often converted for salt production, agriculture and aquaculture. Large tracts of coastal mangrove in Asia have been converted to rice farming (FAO, 1982). The creeks represent an important resource for recreation, water sports and ecotourism for Karachi, which has relatively few such amenities nearby. Such development will change the relationship of the local people with the mangroves and will add additional stresses to the environment unless the developments are planned sensitively preservation of the area for viewing wildlife, such as migrating water fowl, dolphins and mangrove jackals is being considered, and the idea of a mangrove national park (IUCN, 2005).
Off-site activities, unrelated to the mangrove ecosystem but detrimental to it, for example oil pollution, diversion of upstream freshwater resources for irrigation and offshore dredging also have detrimental effects on the mangrove ecosystem. Indirect effects of agriculture on mangroves can be seen through diversion of freshwater by agricultural schemes and run-off of agricultural residues. For example, the interception of freshwater for agriculture has severely affected the mangroves in the Indus delta of Pakistan (Hogarth, 2001). Storm damage, coastal erosion, naturally shifting hydrology, climate change and sea level rise. Karachi, which is on the northern edge of the mangrove forests of the Indus Delta, has rapidly grown in population and level of industrial activity. This has increased the pollution load on the mangroves. Along the Korangi creek a number of villages are rapidly growing and their waste is adding to the pollution problem (IUCN, 2005). Governance and institutional failure to effectively manage coastal mangrove resources. Poor planning of coastal land use and implementation of development plans
Issues related to enforcement, realistic design of implementation of laws e.g. Zonation. Lack of involvement of communities in decision making (management, development of legislation, enforcement). Lack of understanding and awareness of the value of mangrove ecosystems among various groups of people including policy makers, officials, developers and local people. Compatibility issues. Timber mafia is a major threat to mangroves involved in illegal trading of fuel wood. Conflicts are common between the various departments involved. Weak coordination between different levels and different sectors of government Availability of infrastructure, manpower and equipment are inadequate for effective control over the utilization of mangrove resources (IUCN, 2005).
Reserves have been established for the preservation of mangroves ecosystems or to enhance the survival of particular species within these ecosystems in atleast thirty-six countries in the world, (Vannucci, 1996). At the International Level, the common approach to major environmental policy issues has been to formulate conventions, treaties and agreements, which all concerned countries become signatories to. Mangroves are today a global issue because more than 100 countries worldwide have mangrove resources (Spalding et al., 1997). Methods for international and regional management of mangroves include Marine Protected Areas (MPAs), Bio-regional management, Transboundary Protected Areas (TPA) and Biosphere Reserves (BR). The use of protected areas for conservation management has many advantages for mangroves and other coastal ecosystems (Spalding et al.,1997). The number of Transboundary Protected Areas (TBPAs) for mangroves is now growing around the world. In 1988 there were only 59 such areas, mainly concentrated in Europe and North America: by 1997 this figure had grown to 136, distributed through all regions of the world (World Conservation Monitoring Centre (WCMC), 1998). Several factors have influenced this growth, including greater support from donors and international assistance for the establishment of TBPAs to enhance biodiversity conservation and sustainable resource use at an ecosystem scale. International cooperation in the Asia-Pacific region has been particularly effective with many countries sharing knowledge from many years experience of mangrove planting for reforestation purposes. International NGOs are the leading agencies in mangrove rehabilitation for example the Danish Red Cross (DRC, 1994) and the UK Save the Children Fund started mangrove planting (Macintosh et al., 1998). At the national level governments should be encouraged to ratify international and bioregional conventions and agreements, and to bring them into law so that they are also legally adopted at national level. The expansion of markets has driven exploitation of natural resources to extremes in some places, where levels of investment create imbalance between alternative uses for the same resource. In such cases the poor can be made poorer.
Sustainable livelihoods for coastal communities are therefore dependent upon effective management of all interrelated activities in coastal areas to achieve sustainable use of both living and non-living resources, and equitable sharing of the benefits arising (Brown, 1997). There are many forms of tourism but ecotourism or nature-based tourism should be promoted because it reduces the negative social and environmental impacts of tourist visits to an area (Clark, 1998). Reforestation in indus delta and the community participation are both very effective tools for management of mangroves in that area. The proper laws and regulations should be implemented to protect the mangroves (IUCN, 2005).
Discussion and Conclusion:
An examination of the literature on mangroves reveals that there is still a need for further descriptive studies in Pakistan. A common need idenitified is to develop and improve the scientific knowledge base on mangrove ecology and biodiversity. Mangrove ecosystems have demonstrated high value for forestry and fisheries. They are however, under severe and increasing human pressure because a large proportion of tropical coastal populations is mangrove dependent. Mangrove ecosystems are being exploited on the basis of inadequate information and there is a growing trend toward the utilization of mangrove areas for various and often conflicting purposes. There is an urgent need to improve and facilitate communication among mangrove scientists themselves and between them and policy makers, planners and mangrove managers. Capacity building should also include assisting stakeholders (local communities and community based organizations, government agencies and departments, university. departments, research institutions, private companies, national and international NGOs) to increase their capability to participate in mangrove management. For example by providing boats, or boat repair facilities to fishermen and enforcement officers, or by providing equipment to monitor water pollution.
People living in an around mangroves should be made aware of the importance of the mangrove ecosystems as a whole. Attempts should be made to make village people understand the environmental and social impacts of large scale exploitation operations on their land; eg. Mangrove fellings for industrialization and urbanization. Moreover active involvement of the community, local government and private industry should be enlisted and harnessed to protect, rehabilitate and conserve mangrove areas. This necessitates a more vigorous extension and information campaign and the participation of the various sectors in planning and implementing of conservation and development program for the mangrove. The coastal areas of the country lack basic amenities such as drinking water, fuel sources, and road infrastructure. Over time, the coastal population has grown as a result of increased returns from fishing, despite the poor physical infrastructure. Consequently, the demand for fresh water for household consumption has increased several fold. Local authorities have not assessed the household demand for water, causing the meager water supplies from seasonal rivers on the Baluchistan Coast, in particular, to be under pressure due to population growth. pollution of the marine environment is another proximate cause of biodiversity loss in the coastal areas of Pakistan. Three areas in the coastal region of the Indus Delta are significantly polluted: Keti Bunder (to the south near Sir Creek), the metropolitan center (Karachi, Port Qasim, and Rehri), and the coastline in the west (extending from Sonmiani to Jiwani). The loss of mangrove species during the last 50 years, besides being consistent with the reduced supply of fresh water to the Delta, is also consistent with the increased volume of untreated wastewater discharges from industries and the city of Karachi and its vicinity. In addition, land clearance for the construction of new sea ports, extension of existing sea ports, and establishment of industrial units near the coast has also contributed to the depletion of mangrove cover, particularly in the northern part of the Delta. Lack of alternate fuelwood aggravated the problem. Alternatives, such as kerosene oil or natural gas, are either not available or too expensive for the local communities and ultimately they fulfill their needs by cutting trees. Responsibility for protecting mangrove forests has lain with the Forest Department since the late 1950s, but only very recently has this department shown any interest in conservation of these forests. A mere expansion of responsibilities, without the requisite resources, will not help the Forest Department implement the existing laws. For example, one forest guard alone is given an area of 20,000 to 25,000 acres of mangroves to monitor. At the national level, weak environmental groups coupled with a general lack of political will to control deforestation allow weak implementation of laws to continue. These environmental groups receive inadequate support from international bodies and NGOs, while the absence of strong conditionalities related to environmental protection in larger economic and financial agreements does not promote political will on the part of the government to control deforestation. The conclusion is that the loss of mangrove species over the last 50 years is highly consistent with the reduction of fresh water and silt supplies to the Indus Delta. There is a need to create awarness among people the local government should stricly implement laws to conserve the mangroves forests.