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Standardizing Benthic Assessments Across North America and Europe

This study assesses the variability of Benthic Assessment using Best Professional Judgment across regions in North America and Europe. Experts ranked and categorized samples to establish a uniform assessment scale. Findings show high agreement among experts, suggesting the potential for a universal assessment scale.

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Standardizing Benthic Assessments Across North America and Europe

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  1. Sustentabilidade e biodiversidade marinhas Sessão 10C Avaliação da condição ecológica de comunidades macrobentónicas costeiras através de juízo profissional qualificado: Desenvolvimento de consenso entre a América do Norte e a Europa

  2. Sustentabilidade e biodiversidade marinhas

  3. Sustentabilidade e biodiversidade marinhas Benthic Assessments of Large Areas are as important as problematic • Large area assessments have value, e.g.: • U.S. EPA’s National Coastal Assessment • E.U. Directives: Water Framework Directive and future Marine Strategy ecological assessments • But many benthic assessment tools are developed locally • By habitat, not necessarily on uniform scales • Based on distinct premises • Reporting on different aspects of biological communities Differing scales lead to inaccuracy and bias: Affecting management decisions

  4. Sustentabilidade e biodiversidade marinhas Our study:Evaluated Benthic Assessment BPJ Variability Across Regions • Do expert assessments based on species abundances vary by expert home region? • Can expert judgment be used to establish common scaling across geographic regions? • Consistent scales can be used to calibrate benthic indices Using Best Professional Judgment to Develop A Uniform Benthic Community Assessment ScaleAcross North America and Europe

  5. Sustentabilidade e biodiversidade marinhas Approach • Experts from 4 different regions: • 4 experts per region

  6. Sustentabilidade e biodiversidade marinhas 16 Benthic ecologists US East Coast US West Coast EU Mediterranean EU Atlantic Rafael Sardá João C. Marques Daniel M. Dauer David E. Montagne Anna Occhipinti -Ambrogi Steven Degraer Donald B. Cadien Linda C. Schaffner Ioannis Karakassis Jean-Claude Dauvin Ronald G. Velarde Roberto J. Llansó Lawrence L. Lovell Rutger Rosenberg Antoine Grémare Robert J. Diaz

  7. Sustentabilidade e biodiversidade marinhas Approach • Experts from 4 different regions: • 4 experts per region • Provided with data for 48 samples: • 12 samples per region • Species abundances and minimal habitat data • Samples covered the range of impacts

  8. Sustentabilidade e biodiversidade marinhas 12 samples per region

  9. Sustentabilidade e biodiversidade marinhas Approach Experts asked to: • Rank samples from least to most affected • Overall ranking and within region ranking • Assess samples on a 4 category scale • List their: • Assessment criteria, and • Indicator species

  10. Findings of the study…

  11. Across region consistency?

  12. Sustentabilidade e biodiversidade marinhas Samples’ Category Assessments by experts’ home region

  13. Sustentabilidade e biodiversidade marinhas Correlation between Category Assessments Regional mean Spearman rank correlations with the Regional median category: Correlation between Rank Assessments Correlations were generally higher for ranks than categories.

  14. Sustentabilidade e biodiversidade marinhas Category Assessments • Permutational Multivariate ANOVA • Tested expert category assignment patterns • For “Expert Region”, “Sample Region”, & “Expert” effects • 4999 permutations (p=0.05) • Significant differences among experts • - Some experts were tougher graders • - Unrelated to “home” region • US East Coast samples patterns differed from others

  15. Level of agreement on assessments?

  16. Sustentabilidade e biodiversidade marinhas Level of agreement on Category Assessments • Experts classifications’ comparison(weighted Kappa analysis) • “Moderate” to “Almost perfect” Agreement (average kappa = 0.65 ) • 78.5 % of experts comparisons agreeing at Good or higher level Mismatches on > 30% classifications occurred in less than 10 % of the comparisons! Good vs. Bad condition samples – experts agreed on approximately 80 % of the comparisons Level of agreement on Rank Assessments • Expert rank vs. median rank of samples • Average Spearman Rank Correlationcoefficient of0.85

  17. Assessment Variability Ranks ←Disturbance Gradient→ “Good” “Bad”

  18. Assessment Variability Categories ←Disturbance Gradient→ “Good” “Bad”

  19. Sustentabilidade e biodiversidade marinhas Criteria

  20. Sustentabilidade e biodiversidade marinhas Top 10 Indicator Taxa

  21. Sustentabilidade e biodiversidade marinhas Conclusions • A universal assessment scale is a possibility • No differences by expert “home” region • There was good agreement among experts • Agreement was higher towards the ends of the disturbance gradient • There was higher agreement among experts when: • Including indicator organisms • Using more indicators

  22. Sustentabilidade e biodiversidade marinhas Steve Weisberg SCCWRP Ananda Ranasinghe SCCWRP Ángel Borja AZTI Tecnalia Obrigada pela vossa atenção!

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