Detecting Ecological Impacts: Effects of Taxonomic Aggregation in the Before-After/Control-Impact Paired Series Design

Principal Investigators:

Sally Holbrook University of California, Santa Barbara
Mark H. CarrUniversity of California, Santa Cruz
Craig W. Osenberg University of Florida, Gainesville

The second year of this study involved three overall objectives listed and addressed separately below. These objectives include species level identification, database development and data analysis for three separate datasets collected for three studies; the Carpinteria produce water discharge, Gaviota produce water discharge, and the San Onofre Nuclear Generating Station (SONGS) cooling water intake and discharge study conducted by the Marine Review Committee (MRC). The status of each of the overall objectives is presented for each of the three studies.

Objective 1:
Obtaining species level identification and quantification of MRC and MMS/UC SCEI samples

Preparation and shipment of samples for taxonomic identification.

All samples from the Carpinteria study (biocores, emergence traps and re-entry traps) were prepared and shipped for taxonomic identification by Lovell and Associates (San Diego, CA) and Paul Scott (Santa Barbara Museum of Natural History). All Gaviota samples were shipped previously in Year 1.

Cross verification of MRC-SONGS, Gaviota and Carpinteria species lists and voucher collections

To guarantee cross-compatibility of species identifications among the three datasets (MRC-SONGS, Gaviota, Carpinteria), species lists, codes and vouchers were compared by Lovell and Associates, Paul Scott and Henry Channey (SBMNH). This task was completed subsequent to their review and update of the MRC database and voucher collection, which was completed in Year 1 (except molluscs).

Taxonomic identification of Carpinteria and Gaviota samples.

All molluscs collected in the Carpinteria and Gaviota samples (biocores, Gaviota emergence traps and Gaviota re-entry traps) were identified and quantified, and voucher collections were created in Year 1. In Year 2, Paul Scott and Henry Channey (SBMNH) reviewed and updated the mollusc section of the MRC database and voucher collection.

The remainder of Gaviota biocore samples of polychaetes and crustaceans which required identification to species were identified, labeled, stored and recorded into the database. All samples from Carpinteria (biocores, Carpinteria emergence traps and Carpinteria re-entry traps) of all taxa (polychaetes, crustaceans and "others") were identified, labeled, and stored. All samples except for some Carpinteria biocores have been transcribed into Excel databases. The raw data sheets have been sent to Osenberg's lab to finish this process. The number of taxa identified (species, genus and family) are presented below (Table 1). Besides providing us with some minor supplemental support in the future, all tasks required of Lovell and Associates and Paul Scott have been completed.

Table 1. Number of taxa identified from each of the three studies. The lowest taxonomic resolution of some individuals was to the genus and family level. Values for Gaviota include only biocore samples. "Others" may include some species also listed in the other three categories.

StudyGroupNo. of Taxa

Size frequency analyses

Gaviota biocores: Four species of polychaetes (Apoprionospio pygmaea, Levinsenis gracilis, Nephtys cornuta, and Spiophanes missionensis), four species of crustaceans (Apoprionospio pygmaea, Levinsenis gracilis, Nephtys cornuta, and Spiophanes missionensis), and three species of molluscs (Parvilucina tenuisculpta, Tellina carpenteri, and Rochefortia tumida) were removed from the biocore samples for size frequency analysis during Year 1. No species was consistently numerous among the Gaviota emergence or re-entry traps to allow for size frequency analysis.

Carpinteria Biocores: four species of polychaetes (Apoprionospio pygmaea, Levinsenia gracilis, Goniada littorea, and Spiophanes duplex), four species of crustaceans ( Amphideutopus oculatus, Campylaspis hartae, Foxiphalus obtusidens, and Rutidermi rostratum) and three species of molluscs (Parvilucina tenuisculpta, Tellina carpenteri, and Rochefortia tumida) were removed from the biocore samples for size frequency analysis. No species was consistently numerous among the Carpinteria emergence or re-entry traps to allow for size frequency analysis.

All size frequency samples were shipped to Carr's lab at UCSC where size frequency data are being collected. Samples are imaged and digitized with a video camera, frame grabber, and Adobe Photoshop software. Images are measured using NIH imaging software.

Objective 2:
Database development for MRC and MMS/UC SCEI samples

Data acquisition, transcription and database development

Prior to any transcription of species identities and abundance data into any database, a master species list had to be compiled with the original and revised taxonomic designations for the pre-existing MRC-SONGS species list. This master species list includes all molluscs, polychaetes, crustaceans, and miscellaneous species found in all three studies (MRC, Carpinteria and Gaviota). All species have also been assigned the appropriate phylum, class, order, and family designations. All species have also been assigned an individual species code, compatible with the pre-existing codes in the original MRC-SONGS species list. A large number of taxa were new to the existing species list from the MRC surveys, so they have been assigned species-level codes compatible with pre-existing codes assigned to the MRC data. Lovell and Associates supplied the codes, and have reviewed them and the taxonomic classifications to insure that the proper codes were used and the classification of animals is current.

In addition to the master species list, individual databases for both Gaviota and Carpinteria for each sampling method (emergence traps, re-entry traps and biocores) have been compiled as Excel spreadsheets for eventual transformation to SAS datasets. The Carpinteria biocore databases are still being compiled at Osenberg's lab as data are transcribed to the Excel spreadsheets. These databases include appendices with information for interpreting the codes used in each database, a process trail indicating personnel involved in the identifications and data transcription and entry, and any alterations to the databases subsequent to their original formulation.

Ecological functional group assessment.

Ms. Karen Green has provided us with ecological functional group designations for the species included in the MRC species list and has agreed to categorize species in the Gaviota and Carpinteria studies into functional groups. These ecological functional groups are primarily determined by trophic criteria. Additional criteria (e.g., habitat associations, diel activity patterns, dispersal potential) may be incorporated in to the functional group designation in the future.

Objective 3:
Analysis of MRC and MMS/UC SCEI samples

Analysis of each of the three datasets requires complete and updated taxonomic data, as well as functional group designations. This information was not available until recently. We are in the process of adding the information to the master species list at Osenberg's lab. As soon as this is completed, we will begin our analyses of the patterns of spatial and temporal variation and the influence of taxonomic aggregation for the MRC, Gaviota and Carpinteria studies.