“…However, NRDAs are often calculated in human terms as the loss of specific services, such as decreased catch rates of fish following releases of wastes (Iadanza et al, 1999;Morey et al, 2002), loss of drinking water because of oil spills (Clark et al, 1990), and loss of groundwater for residential, industrial or commercial use (Dunford, 2000). These ecological services are often valued in terms of replacement costs, willingness to pay, willingness to accept compensation (Brown and Gregory, 1999;Dunford et al, 2003), demand functions (Dunford, 2000), contingency valuation (Montesinos, 1999;Dunford, 2000), and existence values (McConnell, 1997).…”