ASSESSING FISH QUALITY STATUS IN TRANSITIONAL WATERS, WITHIN THE EUROPEAN WATER FRAMEWORK DIRECTIVE: SETTING BOUNDARY CLASSES AND RESPONDING TO ANTHROPOGENIC PRESSURES

Validation of the AZTI's Fish Index (AFI), proposed for the Basque Country (northern Spain), in assessing fish quality within the Water Framework Directive (WFD), is undertaken. The response to anthropogenic pressure is investigated, in setting the boundaries between the different quality status classes. Hence, 12 estuaries were sampled, at different frequencies, between 1989 and 2007, by means of a beam trawl. Significant (p < 0.0001) correlations were found between the AFI and oxygen saturation and ammonia. Oxygen quality standards are used to set boundaries between quality classes. Then, the AFIs obtained are compared with different anthropogenic pressures, including urban and industrial discharges, engineering works and dredging. The effects of the removal of some of these pressures are also studied. The total number of pressures within an estuary shows significant (p < 0.009) negative correlation with AFI, explaining between 51 and 62% of the variability in fish quality. The impact of pressures upon fish and demersal assemblages is detected as required by the WFD. Nonetheless, further investigation and intercalibration of the methods used, are necessary.

[1]  Juan Bald,et al.  Implementation of the European water framework directive from the Basque country (northern Spain): a methodological approach. , 2004, Marine pollution bulletin.

[2]  Linda A. Deegan,et al.  Regional application of an index of estuarine biotic integrity based on fish communities , 2002 .

[3]  P. Jones.  Water quality and fisheries in the Mersey estuary, England: A historical perspective. , 2006, Marine pollution bulletin.

[4]  Á. Borja.  The new European Marine Strategy Directive: difficulties, opportunities, and challenges. , 2006, Marine pollution bulletin.

[5]  Á. Borja,et al.  What does 'good ecological potential' mean, within the European Water Framework Directive? , 2007, Marine pollution bulletin.

[6]  Larry B. Crowder,et al.  Habitat degradation from intermittent hypoxia: impacts on demersal fishes , 2005 .

[7]  Benjamin S Halpern,et al.  Interactive and cumulative effects of multiple human stressors in marine systems. , 2008, Ecology letters.

[8]  M. Elliott,et al.  Fishes in Estuaries , 2001 .

[9]  J. Maes,et al.  A fish-based assessment tool for the ecological quality of the brackish Schelde estuary in Flanders (Belgium) , 2006, Hydrobiologia.

[10]  F. Eddy.  Ammonia in estuaries and effects on fish , 2005 .

[11]  Michael Elliott,et al.  The guild approach to categorizing estuarine fish assemblages: a global review , 2007 .

[12]  J. Maes,et al.  Modelling the migration opportunities of diadromous fish species along a gradient of dissolved oxygen concentration in a European tidal watershed , 2007 .

[13]  T. D. Harrison,et al.  A multi-metric fish index to assess the environmental condition of estuaries , 2004 .

[14]  Michael Elliott,et al.  Fishes as indicators of environmental and ecological changes within estuaries: a review of progress and some suggestions for the future , 2002 .

[15]  Á. Pérez-Ruzafa,et al.  Changes in benthic fish assemblages as a consequence of coastal works in a coastal lagoon: The Mar Menor (Spain, Western Mediterranean). , 2006, Marine pollution bulletin.

[16]  J. González‐Oreja,et al.  Assessing the improvement of the Bilbao estuary water quality in response to pollution abatement measures. , 2006, Water research.

[17]  S. Madon.  Fish community responses to ecosystem stressors in coastal estuarine wetlands: a functional basis for wetlands management and restoration , 2008, Wetlands Ecology and Management.

[18]  Ángel Borja,et al.  The European water framework directive: A challenge for nearshore, coastal and continental shelf research , 2005 .

[19]  P. Franzoi,et al.  Structure and functioning of Mediterranean lagoon fish assemblages: A key for the identification of water body types , 2008 .

[20]  Pat Hutchings,et al.  Overview of integrative tools and methods in assessing ecological integrity in estuarine and coastal systems worldwide. , 2008, Marine pollution bulletin.

[21]  Á. Borja,et al.  Preface (to: Oceanography and marine environment of the Basque Country) , 2004 .

[22]  M. Elliott,et al.  Transitional waters : A new approach, semantics or just muddying the waters? , 2007 .

[23]  Ángel Borja,et al.  Paradigmatic responses of marine benthic communities to different anthropogenic pressures, using M-AMBI, within the European Water Framework Directive , 2009 .

[24]  M. Robson,et al.  Efficacy of a multi-metric fish index as an analysis tool for the transitional fish component of the Water Framework Directive. , 2007, Marine pollution bulletin.

[25]  Manfred Ehrhardt,et al.  Methods of seawater analysis , 1999 .

[26]  I. Priede,et al.  Behaviour of adult Atlantic salmon, Salmo salar L., in the estuary of the River Ribble in relation to variations in dissolved oxygen and tidal flow , 1988 .

[27]  W. P. Williams,et al.  Fish assemblages as indicators of water quality in the middle Thames estuary, England (1980–1989) , 2000 .

[28]  J. Moore,et al.  Fish Communities as Indicators of Environmental Quality in the West River Watershed , 1995 .

[29]  M. J. Costa,et al.  Assessing anthropogenic pressures on estuarine fish nurseries along the Portuguese coast: a multi-metric index and conceptual approach. , 2007, The Science of the total environment.

[30]  I. Muxika,et al.  Long-term recovery of soft-bottom benthos following urban and industrial sewage treatment in the Nervión estuary (southern Bay of Biscay) , 2006 .

[31]  Rachid Amara,et al.  Environmental factors structuring fish composition and assemblages in a small macrotidal estuary (eastern English Channel) , 2008 .

[32]  J. Cooper,et al.  GEOMORPHOLOGY, ICHTHYOFAUNA, WATER QUALITY AND AESTHETICS OF SOUTH AFRICAN ESTUARIES , 2000 .

[33]  Peter Goethals,et al.  A fish-based index of biotic integrity for upstream brooks in Flanders (Belgium) , 2004, Hydrobiologia.

[34]  John Buonaccorsi,et al.  Development and validation of an estuarine biotic integrity index , 1997 .

[35]  J. Gerritsen,et al.  Estuarine and Coastal Marine Waters: Bioassessment and Biocriteria Technical Guidance , 2000 .

[36]  Juan Bald,et al.  Using multiple ecosystem components, in assessing ecological status in Spanish (Basque Country) Atlantic marine waters. , 2009, Marine pollution bulletin.

[37]  H. Cabral,et al.  Efficacy of adapted estuarine fish-based multimetric indices as tools for evaluating ecological status of the marine environment. , 2008, Marine pollution bulletin.

[38]  Ibon Galparsoro,et al.  The European Water Framework Directive and the DPSIR, a methodological approach to assess the risk of failing to achieve good ecological status , 2006 .

[39]  C. A. Gray,et al.  Sampling estuarine fish and invertebrates using demersal otter trawls: Effects of net height, tow duration and diel period , 2008 .

[40]  T. D. Harrison,et al.  Application of a multimetric fish index to assess the environmental condition of South African estuaries , 2006 .

[41]  M. Elliott,et al.  The structure and components of European estuarine fish assemblages , 1995, Netherland Journal of Aquatic Ecology.

[42]  M. Pardal,et al.  Assessing estuarine environmental quality using fish-based indices: performance evaluation under climatic instability. , 2008, Marine pollution bulletin.

[43]  Angel Borja,et al.  An approach to the intercalibration of benthic ecological status assessment in the North Atlantic ecoregion, according to the European Water Framework Directive. , 2007, Marine pollution bulletin.

[44]  I. Muxika,et al.  Assessing reference conditions and physico-chemical status according to the European Water Framework Directive: a case-study from the Basque Country (Northern Spain). , 2005, Marine pollution bulletin.

[45]  M. Elliott,et al.  The Need for Definitions in Understanding Estuaries , 2002 .

[46]  H. Cabral,et al.  Does the Tagus estuary fish community reflect environmental changes , 2001 .

[47]  Helen Wake.  Oil refineries: a review of their ecological impacts on the aquatic environment , 2005 .

[48]  M. Best,et al.  Dissolved oxygen as a physico-chemical supporting element in the Water Framework Directive. , 2007, Marine pollution bulletin.

[49]  J. Karr.  Assessment of Biotic Integrity Using Fish Communities , 1981 .

[50]  A. Cearreta,et al.  Chapter 2 - Human activities along the Basque coast during the last two centuries: geological perspective of recent anthropogenic impact on the coast and its environmental consequences , 2004 .

[51]  M. E. Gill,et al.  The response of estuarine fish and benthos to an increasing discharge of sewage effluent , 1997 .