**3.2 Ecological tools foreseen in the European Water Frame Directive**

In the scope of the WFD implementation, the Guadiana watershed is included in the Mediterranean Region. The Geographical Intercalibration Group for this region (Med GIG) was responsible for establishing boundary values for the Med GiG Member State classification systems. Submitted values were adopted through the European Commission Decision of 30 October 2008 (2008/915/EC).

Ecological Tools for the Management of Cyanobacteria

not support any significant economic activity (Fig. 8).

protection of their drainage basins.

http://snirh.pt/)

**3.4 Methods** 

Blooms in the Guadiana River Watershed, Southwest Iberia 175

doubles and puts water demand at its peak during the high season (June through September), coinciding with low precipitation and high atmospheric temperature. Table 1 presents important features of these two reservoirs, where the most notorious aspects are the ones relative to their catchment area. While other reservoirs from the Guadiana watershed contributed to extensive development of irrigation (eg. Alqueva), promoted by the use of EU subsidies that encouraged high value intensive crop production (Varela Ortega et al. 1998, Varela-Ortega et al. 2003), the catchment areas of these two streams do

Historical reasons linked to deforestation and farming mal-practices, back in the 30s of the XX century, led to extensive soil erosion, agriculture relinquishment and human desertification. Indeed, these catchment areas are the poorest counties in Portugal, with population densities around 20 habitants /Km2. Human settlements are small villages concentrated downstream of the catchment area. In order to rehabilitate the landscape there has been a large investment in replanting pine woods with the objective of developing new soil and future stimulation of natural vegetation. Apart from some small goat herds in the Odeleite watershed and extensive cropping of sparse almond trees, there are no human impacts, no sewages, no pig style farms, no intensive or extensive farming. From a CHAB prevention point of view, it is difficult to point out what could be improved for the

> **Reservoir Beliche Odeleite**  Stream Ribeira de Beliche Ribeire de Odeleite Watershed Guadiana Guadiana

Catchment area (km2) 98 347 Latitude (mean) 37º 16' 35'' 37º 19' 52'' Longitude (mean) -7º 30' 33'' -7º 29' 11'' Year of closure 1986 1996

Max. water column height (m) 30 30 Total volume (x 106 m3) 48 130 Flooded surface (ha) 292 720 Mean annual precipitation (mm) 644 722 Min. stored water volume (x 106 m3) / Date 7 / Sept 2006 40 / Nov 2005 Max. stored water volume (x 106 m3) / Date 46 / May 2010 130 / May 2010 Table 1. Beliche and Odeleite reservoirs location and some main features. (Data source:

These reservoirs have been monitored for standard physical, chemical and microbiological water quality, including, since 2003, determination of phytoplankton biomass and composition. Monthly surface and bottom samples were taken, from 2003 to 2009, at Choça Queimada tower for Odeleite reservoir, and at the extraction tower of the Beliche reservoir. During 2009 and 2010, a new sampling site in the middle of the lake, 500m upstream from the dam wall, was added according to new guidelines from the European Med GIG (INAG, 2009). At each of these sampling sites, vertical profiles were determined *in situ* using a YSI

For their intercalibration exercise, the Med GIG agreed on using chlorophyll *a* and total biovolume as phytoplankton biomass indicative parameters, and elected three phytoplankton composition metrics, namely the contribution of cyanobacteria to total phytoplankton biovolume, the General Algal Index (GAI - Catalàn et al. 2003) and the Mediterranean Phytoplankton Trophic Index (MedPTI - Marchetto et al. 2007). Although recognizing strong limitations of the dataset used and the fact that not all tipologies of Mediterranean lakes and HMWBs were covered, actual law enforcement stipulates that ecological potential of the reservoirs in the Guadiana watershed should be classified, according to the proposed metrics. However, application of such phytoplankton composition metrics to CHABs management has yet to be assessed.

The following case study constitutes an effort to evaluate the Med GIG selected ecological indicators when applied to water management strategies for the Guadiana watershed. Different phytoplankton metrics determined for two reservoirs and compared in order to assess their usefulness in CHAB management, taking in consideration the EPA Guidelines for Evaluation of Ecological Indicators (Jackson et al., 2000)
