3rd meeting of young researchers at UP 1 - IJUP - Universidade do ...

Evaluation of the suitability of the marine biotic index AMBI to
assess disturbance in coastal systems: the case of the Douro
estuary
Sérgio, T. and Santos, P.
Department of Biology, Faculty of Sciences, University of Porto, Portugal.
Macrobenthos are animals that disclose the state of the surrounding environment and present
differential sensitivity to disturbance, which portrays in changes in the community space-time
composition when the ecosystem is under stress [1] .
This study aimed to test the applicability of a marine biotic index (AMBI) in the assessment of
the ecological quality of the water in the Douro estuary, using soft-bottom benthic
communities as disturbance indicators.
The Douro river was the site chosen for this project and samples were taken monthly (between
October 2008 and April 2009), in the low-tide period using a 120 mm ∅ core sampler.
Twelve taxa were identified in the course of the study and the resulting value for the biotic
index was 6, which corresponds to a heavily disturbed benthic community. These observations
come to terms with what was expected, thus being consistent with other studies performed with
other methodologies at this location [2,3] .
In addition, the M-AMBI index was calculated to determine the ecological quality status of the
water regarding the context of the Water Framework Directive, but the results obtained were
not consistent with the AMBI index as they were compromised by the reduced number of
species found and samples performed.
In this way, it is concluded that AMBI index is a useful and suitable tool to assess disturbance
in estuarine systems but more studies should evaluate the M-AMBI index results.
References:
[1] Borja A., Franco, J., Perez, V. (2000), A Marine Biotic Index to Establish the Ecological Quality of
Soft-Bottom Benthos Within European Estuarine and Coastal Environments, Marine Pollution Bulletin.
40: 1100 – 1114.
[2] Mucha, A. P., Vasconcelos, M. T., Bordalo, A. (2003), Macrobenthic community in the Douro
estuary: relations with trace metals and natural sediment characteristics, Environmental Pollution.
121: 169 – 180.
[3] Mucha, A. P., Vasconcelos, M. T., Bordalo, A. (2005), Spatial and seasonal variations of the
macrobenthic community and metal contamination in the Douro estuary (Portugal), Marine
Environmental Research. 60: 531 – 550.
3 rd meeting of young researchers at UP 247