Intercalibration of the GUADALMED methodology. Selection of a sampling protocol for the determination of the ecological status of the Mediterranean rivers

Abstract:

The development of the Water Framework Directive in European countries needs standard sampling methods to evaluate the ecological status of freshwaters. Methods for use in monitoring surveys, should be suitable for non specialists. Therefore, standard protocols are necessary for the intercomparison of results from different countries. Similarly, the sampling protocols in cooperative research projects should be homogeneous in order to ensure consistent data bases. In the present work, the results of an intercalibration exercise of sampling and sorting protocols between six teams are given. Several indices potentially useful for the evaluation of ecological status of streams in the Mediterranean coast of Spain and the Balearic Islands are compared. The exercise was conducted in a sampling site in the river Argos (Murcia, Spain) and 23 researchers from six research teams from across Spain were involved. The teams formed part of the projects GUADALMED (HID98-0323-C05 and REN2001-3438-C07) and PKP/10/FS/97 funded by the "Seneca Foundation" (Murcia Regional Authority). To perform the intercalibration exercise, the group of researchers was divided into four subgroups, each of them including researchers from the 6 teams participating in the exercise. Each subgroup took samples from a stream 100 m reach. Each sampling reach was separated from the previous by, at least, 200 m. Water physico-chemistry, and macroinvertebrate and riparian habitat information were collected, following two sampling protocols previously agreed upon by all teams. Procedures and other details for sorting and counting of macroinvertebrates in the laboratory were previously fixed, too. The results show that no significant differences exist, between the two sampling, sorting and counting protocols, nor between subgroups in the evaluation of biological quality of the stream using the indices IBMWP and IASPT (former BMWP' and ASPT'). No significant differences existed in number of macroinvertebrate families found using both protocols. When lenitic and lotic habitats were considered separately, no significant differences in the index values were found between protocols or subgroups either, although the lenitic habitat was more diverse than the lotic one. In the laboratory, the value of IBMWP did not change significantly when estimated from 200 or from more than 200 individuals, while 100 individuals were enough to stabilize the value of IASPT. Significant differences were found between subgroups when the riparian habitat quality was evaluated using the index QBR ("Qualitat del Bosc de Ribera" - Quality of Riparian Forest index). However, differences between subgroups were small, suggesting that differences between the four sampling reaches were indeed due to differences in % vegetation cover of the riparian area. This demonstrates that this index is valuable as an indicator of local changes in riparian habitat condition. Using the results of the intercalibration exercise, a sampling protocol for project GUADALMED was established. © Asociación Española de Limnología.

Año de publicación:

2002

Keywords:

• Protocol
• macroinvertebrates
• Ecological status
• IASPT
• IBMWP
• Water frame directive
• Intercalibration
• QBR

Fuente:

scopus