QUALITY ASSURANCE / QUALITY CONTROL LABORATORY GUIDELINES

The following quality assurance/quality control (QA/QC) procedures are routinely followed at Aquatic Biology Associates, Inc. in processing benthic macroinvertebrate samples. Procedures will be altered to fit the needs of the client for specific projects. Alterations in QA/QC procedure may add to the per sample cost.

1. Samples are unpacked upon receipt and preservative levels checked. Labels are checked to make sure they are intelligible and that the experimental design is understandable (e.g. sites & replicates). Non-smear labels are made that go on the inside of sample jars. The client is called if samples have been damaged in shipping and/or if the labeling system is not understandable.

2. The entire sample is floated in water in a white plastic tray. Large debris is rinsed and removed. The sample is then elutriated until all organic matter and invertebrates are floated off the mineral residue. Sieves of a pore size specified by the client are used in this process (500 micron is the most common). The mineral residue remaining in the white pan after elutriation is searched for stone-cased caddisflies and molluscs that have not floated off.

3. Unless otherwise specified by the client, a portion of the sample will be sorted that contains 500-600 organisms. The Caton Tray is normally used to randomly obtain a fraction of the total sample containing 500-600 organisms. Sample data is converted to a full sample basis.

   Other methodologies may be used to split some sample types, such as lake benthic samples.

   If densities are low, Surber and Hess samples are usually processed in their entirety.

   If a sample is subsampled, our normal procedure is to archive the unused sample portion until the project is completed. Unused sample fractions will be returned to the client if requested (shipping charges will be billed to the client). If requested, Aquatic Biology Associates, Inc. will archive unused sample fractions for 1 year at no charge.

4. Experienced technicians are used to remove all invertebrates from the sample residue using dissecting scopes at 6X or 12X power. For small projects, a single technician is assigned. For larger projects, several technicians are given the responsibility for sorting. All invertebrates removed from a sample are placed in a single sorting vial and given directly to Robert W. Wisseman, Senior Scientist of Aquatic Biology Associates, Inc.

   Logs are kept by each technician to record label data, fraction sorted, hours required to complete sorting, and any comments on sample matrix or problems. Our sorting efficacy is well above EPA requirements, as has been determined by an independent lab. Detailed sorting procedures followed by Aquatic Biology Associates, Inc. can be sent upon request.

5. The entire sample residue is saved after sorting to check for sorting efficacy. Sorting efficacy of 95% or better is required on all samples. A 20% aliquot of each residue is thoroughly re-sorted to determine efficacy. The entire residue is re-sorted if 95% or better sorting efficacy has not been achieved, as estimated from the 20% aliquot re-sort.

   All sample residues can be returned to the client for independent checks. The client will be charged for shipping and sample containers.

6. Invertebrate identifications are performed by Robert W. Wisseman and associates.

   For standard level identifications, Robert W. Wisseman performs the initial identifications and counts on all samples, and then determines which specialists will be required to assure accurate identifications to levels specified for a project. He has over 15 years of experience in the identification of freshwater invertebrates. Aquatic Biology Associates, Inc. uses specialists from throughout North America for performing more detailed taxonomy, or to verify questionable identifications.

7. The choices for archiving invertebrate material for QA/QC checks by other experts, are as follows:

   You can trust Aquatic Biology Associates, Inc. to do a competent job, and let us pull out material that we think is significant...e.g. for verification by specialists, to be incorporated into museum collections, or to save for educational purposes. This is our preferred method of operating.

   Save a reference/synoptic series of specimens of each taxa identified. There will be nominal charge for this service.

   All invertebrate material can be saved by each individual sample for archiving or QA/QC checks by another lab. An additional charge per sample will be added for this service, since it greatly slows sample processing.

   The client can request that specific taxonomic groups be archived by individual sample for possible future taxonomic analysis (e.g. all the oligochaete worms). There is usually no charge if one or a few groups are involved.

   Aquatic Biology Associates, Inc. requests permission to remove material from samples that may be of interest to specialists or that we feel would be a valuable addition to museum collections.

8. Identifications and counts are recorded on bench-sheets and then transferred to electronic files. Standardized bench-sheets reduce data entry errors.

   Robert W. Wisseman and Mary Jo Wevers (Aquatic Biology Associates, Inc. senior scientists) perform all data entry and analysis.