According to Freeman (1993) and Matete (2004), "ecological value is estimated from the utility humans derive from using ecological services. […] It then follows that the basis for deriving measures of economic value of the environment and goods and services it provides is their effects on human welfare".
It is easy to take ecosystem services for granted, especially when there is a disconnection between the end product and the services. We rely on ecosystem services to survive and have to recognise their importance in terms of function and economic value.
Economic valuation of ecosystem services allows for the benefits of ecosystem services to be quantified and justified. This is a hotly debated topic with a number of studies providing value estimations for a number of essential services, resulting in a wide range of values for the same services. The table below is a summary of the range of economic values that have been assigned to aquatic ecosystem services on a global scale, and more specifically in developing countries (Forslund et al. 2009).
Table: Economic values of aquatic ecosystem services reported in recent literature.
|
Type of value
|
Service provided
|
Range of economic values reported in the literature
|
|
Global estimate (USD/ha/year)
|
Developing countries (USD/ha/year)
|
|
Direct Use
|
Water for people
|
45-7500
|
50-450
|
|
Fish/shrimp/crabs (non-recreational)
|
20013
|
6-750
|
|
Fertile land for flood-recession agriculture and grazing
|
40-520
|
3-370
|
|
Wildlife (for food)
|
40-520
|
0.02-320
|
|
Vegetables and fruits
|
40-470
|
1-200
|
|
Fibre/organic raw material
|
4513
|
1-40
|
|
Medicine plants Inorganic material
|
25-160
|
0.1-63
|
|
Indirect Use
|
Chemical water quality control (purification capacity)
|
60-6700
|
20-1400
|
|
Flood mitigation
|
15-5500
|
2-1700
|
|
Groundwater replenishment
|
10-90
|
10-90
|
|
Erosion control
|
20-120
|
20-120
|
|
Carbon trapping (sequestration)
|
130-270
|
2-2000
|
|
Microclimate stabilisation
|
|
1026
|
|
Potentially all (direct and indirect use, option, bequest and existence
|
Recreation and tourism (incl. fishing and hunting)
|
230-3000
|
20-260
|
|
Biodiversity conservation
|
|
0.6-3600
|
|
Cultural/religious/historical/symbolic activities
|
30-1800
|
8026
|
|
Total Economic Values*
|
|
120-370
|
30-2900
|
Source: (Emerton & Kekulandala (2002), Turpie et al. (1999), Emerton et al. (2002), Iftikhar (2002), Emerton (1994), IUCN (2001), Emerton et al. (1999), Rosales et al. (2003), Gerrard (2004), De Groot (1992), Kirkland (1988), Thibodeau & Ostro (1981), Schuyt & Brander (2004), Busk (2002), Chowdhury (2003), Rogers et al. (1998), Sadoff et al. (2003), Karanja et al. (2001), Seyam et al. (2001), Acharya (2000), Woodward & Wui (2001), Brown (1991), MRCS (1998), Ringler & Cai (2003), Pyo (2002), Seild & Moraes (2000), Schuyt & Jansen (1999), Christensen (1982), Sathirathai (1998), Bann (1997), Drew et al. (2005), Costanza et al. (1997).) As quoted in Forslund et al. 2009
* Values as assigned by the literature, not a sum of ranges minimums and maximums
