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Benthic Community Condition Indicators. Ananda Ranasinghe Southern California Coastal Water Research Project (SCCWRP) AnaR@sccwrp.org. Overview. Response to Comments on Revised Workplan First SSC review in August 2004 Revised Workplan in October 2004 Comments received March 2005
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Benthic Community Condition Indicators Ananda Ranasinghe Southern California Coastal Water Research Project (SCCWRP) AnaR@sccwrp.org
Overview • Response to Comments on Revised Workplan • First SSC review in August 2004 • Revised Workplan in October 2004 • Comments received March 2005 • Report on Progress and Schedule • Work accomplished since August review • Including a few preliminary results
Overview of Comments • Mainly requests for clarification • We are glad to provide them • No task or subtask additions or deletions were suggested • Some adjustments are appropriate • A comment or two addressed issues we had not considered
Today’s Talk • Is Organized by Task • For each Sub-Task • Progress • Anticipated completion milestones • Preliminary results • If available for the task • Comments and Clarifications
Benthic Indicators Workplan • Develop Benthic Community Condition Indicators • Task 1: Identify Naturally Occurring Assemblages • Task 2: Refine Existing Indicators • Task 3: Compare and Evaluate Indicators • Identify Effective Field and Lab Methods • Task 4: Evaluate Field Sampling Methods • Task 5: Develop Taxonomy QA
Task 1: Identify Naturally Occurring Communities Defines habitat strata for benthic indicator development Sub-Task 1.1 Assemble database Complete Sub-Task 1.2 Analyze Data In Progress; Completed by end of April 2005 Sub-Task 1.3 Report Expected June 2005
Assemblage Analysis Methods • Data from 8 Regional Projects • 1131 taxa from 1164 stations • Habitat, sediment chemistry and toxicity data available • Collected using 1-mm sieve • Methods and taxonomy reviewed and, if necessary, adjusted • Eliminated potentially contaminated sites and singleton taxa • Analyzed 881 taxa from 714 stations • Cluster Analysis • Cube-root transform, Bray-Curtis dissimilarity index, Flexible sorting β=-0.25
Task 1: Responses to SSC • Why are sediment chemistry and toxicity data necessary? • To eliminate contaminated sites • The products should include more than a map • We agree. Publication in a peer-reviewed journal and project-specific reports are planned
Task 2: Refine Benthic Indicators • The scope of this task has expanded • Six indicator approaches will be improved, developed and assessed • Three approaches are currently used in CA • BRI, IBI, RBI • Three other possibilities • RIVPACS, BWI, Conventional measures • Taking advantage of the availability of experts
Task 2 Sub-Tasks 2.1 Assemble southern California and San Francisco Bay Index Development database • Compiling the data base from different sources, and reviewing methods and taxonomy for compatibility has been more time consuming than expected • In progress; Completion expected by April 30, 2005 2.2 Data Analysis to develop and refine benthic indicators • Habitats defined in Task 1 determine Index Refinement Strata • Indices will be developed and refined separately in each stratum • Scheduled to begin April 2005 2.3 Present Results • Scheduled for June 2005
Task 2: Responses to SSC • Does “refine” mean recalculate with the improved and expanded database? • Yes • Will all indices carry forward to Task 3 • Yes
Task 3: Compare and Evaluate Benthic Indicators • Develop a benthic indicator development strategy based on • Validation using independent data • Comparison of the indicators • Magnitude of season and habitat effects • Magnitude and sources of uncertainty • To begin in June 2005
Comparisons in Southern California • 155 samples Mexico to Pt. Conception • 78.1% agreement • Assessment error is low relative to measurement error Percent ofsamples
Task 3: Responses to SSC • Task 3 should include an evaluation process leading to a single state-wide index • Unlikely to be a single index because multiple habitats require separate index development • Indices for all habitats will be normalized to the same scale • Any indices used in any area should be on a common, easily understandable scale • We agree and this is our goal • Are “ecologically appropriate thresholds” sensu Smith et al. 2001? • Yes
Task 4: Evaluate Field Sampling Methods Identify gear and sieve size effects on benthic indicator results Sub-Task 4.1 Assemble database Samples collected, laboratory processing in progress, existing data compilation in progress Sub-Task 4.2 Data Analysis Will begin September 2005 Sub-Task 4.3 Report Anticipated December 2005
Task 4: Responses to SSC • Will this task lead to a set of required protocols, as in Puget Sound? • Our initial focus is on gear effects on assessments • It will lead to recommendations • Will recommendations be state-wide or region-specific? • Ideally they will be state-wide
Task 5: Develop Taxonomy QA Procedures • Develop procedures to assure repeatability of indicator measurements • We plan to build on existing EMAP and SCCWRP models • Model include • Achieving completeness measures for sorting • QA re-identification of a percentage of samples by a different lab • Completion June 2006 • Necessary accuracy will depend on indicator approach(es) selected
Task 5: Responses to SSC • How will partial organisms be treated? • Usually, heads are counted for mobile animals and bases for sessile animals • How will epifauna be treated? • Epifauna are typically eliminated • They have reduced exposure to sediments • They may be more indicative of habitat structure (e.g., shell hash) than sediment condition
Benthic Indicators Workplan • Develop Benthic Community Condition Indicators • Task 1: Identify Naturally Occurring Assemblages • Task 2: Refine Existing Indicators • Task 3: Compare and Evaluate Indicators • Identify Effective Field and Lab Methods • Task 4: Evaluate Field Sampling Methods • Task 5: Develop Taxonomy QA