Towards The Application of Specific Exergy as an Integrated Indicator For Transitional And Coastal Waters
Ecological indicators are used increasingly to assess the health condition of ecosystems. However, the vast majority of indicators are based on a particular species or components, for example: phytoplankton, zooplankton, macrophyes, macrobenthos, etc. Even though such indicators have provided useful indications on ecosystem status, they are not broad enough to reflect the real complexity of ecosystems. It is therefore necessary for the indicators to include structural, functional, and system-level features. To cope with these aspects, new indices have been developed (for recent reviews see Rapport, 1995 and Jørgensen et al., 2005a). Among them exergy and specific exergy have been recently used to assess ecosystem health in freshwater (Xu et al., 1999; Silow and In-Hye, 2004), transitional (Jorgensen et al., 2002; Marques et al., 2003 and Salas et al., 2005) and coastal ecosystems (Jørgensen, 2000; Vassallo et al., 2006). Furthermore, exergy and specific exergy have been used to assess changes due to eutrophication (Marques et al., 1997; Fabiano et al., 2004).