Ecological Integrity of Wetland, Their Functions and Sustainable Use
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Journal of Ecology and Natural Environment Vol. 1(3), pp. 045-054, June, 2009 Available online at http://www.academicjournals.org/JENE © 2009 Academic Journals Review Ecological integrity of wetland, their functions and sustainable use N. Jafari Department of Biology, Faculty of Basic Sciences and Nano and Biotechnology Group, Mazandaran University, Babosar, Iran. E-mail: [email protected]. Tel.: +98-9111184973. Fax: +98-1125242161. Accepted 11 May, 2009 It is estimated that 90% of sewage in cities in developing countries are today discharged untreated into water bodies. The physical, biological, chemical and geologic interactions among different components of the environment that occur within a wetland. Anzali wetland complex is a good example of a natural wetland, characteristic of the South Caspian lowlands. It supports an extremely diverse wetland flora and fauna. Anzali wetland supports over 1% of the regional Middle East wintering populations of several species of waterbirds. Anzali wetland complex as a large and freshwater lagoon fed by several rivers, separated from the Caspian Sea by a dune system; supports extensive reed beds and abundant submerged and floating vegetation. It is vital life support system for many biological communities as it has so many different fishes like caviar that is the best in the world and supports a major commercial fishery. It has marvelous climate and beautiful views for tourists’ attraction as an important recreation center in the north of I. R. Iran. Key words: Wetlands, function, environmental problem, Caspian sea, Anzali wetland. INTRODUCTION The largest wetland in the Middle East and Western Asia brackish or salt, including areas of marine water, the is situated in southern Iraq and adjacent Iran. This paper depth of which at low tide does not exceed six meters". is an overview of the wetland ecosystems in I. R. Iran, in- This is a very broad definition that recognizes the often cluding the North of Iran and along the Caspian Sea (Fi- dynamic nature of wetlands and allows the consideration gure 1). A particular focus of the paper is to review what of the place that they have within the broader context of the author terms “heritage values” of wetlands which in- the landscape. This is crucial as wetland management clude natural history, ecological information storage, ha- needs to take into account the hydrological linkages, tem- bitat for rare and endemic species, archeological uses poral cycles and changes and the terrestrial components and the current human uses of wetland systems for con- of wetlands. There are more than 70, 000 constructed sumptive and non-consumptive uses. Particular attention wetlands around the world at present (Vymazal and Kröp- will also be paid to human uses that degrade wetland felová, 2008; Kadlec and Wallace, 2008). ecological integrity and sustainability. Literature which ad- dresses human use values and functions of wetlands. Wetland function With the emergence since 1971 of the Ramsar Con- vention (The Convention on Wetlands) as a powerful tool Constructed wetlands for water pollution control are be- for promoting the sustainable use and conservation of coming an accepted technology worldwide. Recent inven- wetlands, the functions and values of wetlands are incre- tories have indicated that there are more than 7,000 con- asingly recognized in local, regional and international structed wetlands in Europe and North America, with the land-use planning and management processes. There number increasing in central and South America, Austra- are many different definitions of wetlands, probably as lia and New Zealand as well as Africa and Asia (Water many as there are user or interest groups. The Ramsar 21, 2000). Constructed technology is popular because Convention defines wetlands as "Areas of marsh, fen, these systems serve money and works well. They require peatland or water, whether natural or artificial, permanent none or small energy, can be constructed from native or temporary, with water that is static, flowing, fresh, soils with minimum concrete and steel. Operator skills 046 J. Ecol. Nat. Environ. and training requirements are minimal. Constructed wet- sound management of wetlands can only be achieved lands are therefore appropriate technology for remote through inter-sectoral land-use planning, integrating the and developing areas where regular supply of energy development options and constraints offered by each as may not be available and operating requirements are of- well as the combination of specific wetland functions and ten ill matched to local skills (Mara et al., 1992). Succes- resources, within the overall context of the hydro-ecolo- sfull case studies indicate that constructed wetlands sig- gical wetland processes and the socio-economic situa- nificantly reduce suspended solids (SS), biological oxy- tion. This means that the values placed on wetlands will gen demand (BOD), pathogens, heavy metals and exces- be central in policy development and management deci- sive nutrients from wastewater (Gersberg et al., 1984; sions. Hence the increased recognition to involve from Rogers et al., 1991; Ojo and Mashauri, 1996; Mashauri et the outset of wetland development and management al., 2000). planning all stakeholders and particularly the people that Globally, forested wetlands occupy more than 330,000, depend on these areas for their livelihood. 000 ha (Matthews and Fong, 1987). These wetlands are During the last century many human impacts on wet- vital habitats that harbor high levels of floral and faunal lands have occurred drainage (Fojt, 1994), fragmentation biodiversity including critical bird and mammal habitat (Marrs, 1993) and overgrazing (Bardgett et al., 1995). An (Saenger et al., 1983), significantly contribute to fisheries important impact is enhanced nutrient input into wetlands, productivity, and act as nursery sites for fish and crusta- either directly through application of fertilizer in order to ceans (Robertson and Duke, 1987). They also regulate increase the biomass production, or indirectly, through run-off quantity and quality (Lugo et al., 1988), mitigate runoff of higher concentrations of nutrients caused by flooding (Saenger et al., 1983), control erosion and modi- more intensive agricultural use of uplands and through in- fy geomorphological processes (Carlton, 1974). Wetlands creased atmospheric deposition. are also important as sources of timber (Putz and Chan, Wetlands are increasingly recognized as valuable natu- 1986), firewood and food (Saenger et al., 1983); and ral systems providing useful services to society such as when used wisely, provide numerous recreation, tourism flood abatement, water purification, groundwater re- and educational opportunities (Saenger et al., 1983). charge, erosion control and biological diversity (Ewel, The concept of wetland functions is relatively new in 1997). International recognition of the value of wetlands both the regulatory and scientific arenas. For many years is apparent through collective action in the Convention on wetlands were considered nuisances and wastelands wetlands of International Importance (Mitsch and (Washington State Department of Natural Resources, Gosselink, 2000). 1998). The functions found within a wetland were not A number of studies have addressed the restoration of considered important enough to study and understand. wetlands on a large scale to minimize the impacts of agri- Today, however, we know that the functions performed cultural and urban runoff on coastal bodies of water. Most by wetlands are important and interacts with other as- wetland ecologists do not have a difficult time defining (in pects of the landscape around it. some manner) just what constitutes function in a wetland Wetlands are multi-functional; they provide services, (Table 1). However, very few attempts are made to di- such as water purification and regulation of water flows, rectly measure function. fishery and other resources for human and non-human Kentula et al. (1992) suggest using indicators or those uses, habitats for plants, animals and micro-organisms variables seen as closely related to a particular function. and opportunities for recreation and tourism. Their intrin- However, with wetland mitigation monitoring, Kentula et sic hydrological processes buffer against extremes as al. (1992) noted that “Measures of wetland structure, e.g. droughts and flooding. During rainy periods, wetlands ab- site morphology or species present, are readily available sorb water and therefore reduce flood risks. In the dry and more often meet the requirements of expediency and seasons wetlands gradually release their water and thus economy than do measures of function.” In effect, bio- ensure water is available even in the non-rainy periods. physical structure is assumed to correlate highly with This is important for people as well as to maintain basic function, even though that might not always be true (and ecological processes. In a broader perspective, the wet- is rarely shown directly). lands are important water reserves feeding into and re- Measurement of function is complex and expensive plenishing ground water reserves and sub-soil aquifers. and as a result, is not often the objective of wetland site Largely because of water, wetlands are a source of life: assessments. If function equates to a process or a rate, much of the world's biodiversity depends on or is linked to then analyzing function requires at least two temporally it. This includes many endangered and or migrant