The Lummi Intertidal Baseline Inventory (LIBI) project was undertaken in order to document the baseline conditions present on Lummi Reservation tidelands. The intent of the project is to provide a pre-disaster ecological assessment that might be used to contrast with conditions following a catastrophic event, such as a large oil or chemical spill. A PDF-version of the final report and appendices from the LIBI project is available for download/viewing in the Available Documents or in the list of links at the bottom of this page.

Executive Summary

The Lummi Intertidal Baseline Inventory (LIBI) was conducted in order to document the existing diversity, abundance, distribution, and habitats of biological resources that are found on the Lummi Reservation tidelands. The LIBI integrates the results from six field surveys that were conducted in 2008 and 2009 with compatible pre-existing information.

The six surveys were conducted as follows:

• Topographic Survey: this survey used remote sensing with Light Detection And Ranging (LiDAR) to develop a high-resolution digital elevation model of the tidelands.
• Intertidal Biota Survey: this survey documented the diversity, distribution, abundance, and habitat preferences of benthic biota such as clams, snails, and eelgrass.
• Large Bivalve Survey: this survey assessed the distribution and abundance of horse clams specifically.
• Finfish Survey: this survey documented the diversity and monthly abundance of finfish.
• Shorebird and Marine Mammal Survey: this survey documented the diversity and monthly abundance of birds and marine mammals.
• Petroleum Toxicity Baseline Survey: This survey documented present-day concentrations of petroleum-derived chemicals in tideland sediments and clam tissues.

Over 242 separate taxa were documented on Lummi Reservation tidelands during the LIBI. The most abundant benthic taxa encountered were polychaete worms in the family Oweniidae, while the purple varnish/mahogany clam was easily the most abundant bivalve species. The purple varnish/mahogany clam was estimated to number nearly 1.2 billion individuals with a total biomass of 19.9 million pounds. The clam species with the next highest biomass was the butter clam. Butter clams collectively had an estimated biomass of 6.7 million pounds, even though the abundance estimate for this species was only 73 million individuals. The population estimate for Manila clams was 2.4 million pounds of legal-sized clams. This value is not statistically different from existing stock assessment estimates due to large confidence intervals for the LIBI estimate. Maps showing the distribution of selected species are presented in this report. Generally, densities of total benthic biota were highest at tidelands on Brant Island/Brant Flats, Lummi Bay, Point Francis, Hale Passage, and in the lower elevation parts of Neptune Beach. Densities of benthic biota were intermediate in Portage Bay and Lummi Shore Road and lowest on the Nooksack River Delta and the middle and upper elevations of Neptune Beach.

Seasonal and spatial trends in the abundance and diversity of finfish and birds are presented and discussed. Generally, bird abundance and diversity was highest during fall and winter months, while finfish diversity and abundance was highest during spring and summer months. Birds were generally most abundant in Lummi Bay, moderately abundant in Portage Bay, and least abundant at Neptune Beach, Hale Passage, and the Nooksack Delta. In contrast, finfishes were generally most abundant near the Nooksack Delta, followed by Portage Bay, Hale Passage, Lummi Bay, and finally Neptune Beach.

Environmental factors that had biological significance for individual taxa included tidal elevation, beach slope, wind fetch, substrate particle size, and eelgrass coverage. Overall, community structure was responsive to these same environmental factors along with salinity, percent coverage of acorn barnacles, percent coverage of mussels, and percent coverage of red, brown, and green algae. The five environmental gradients that appeared to have the most biological significance for community structure were tidal elevation, beach slope, substrate particle size, surface coverage of Pacific eelgrass (Zostera marina), and salinity.

Petroleum-derivative hydrocarbon concentrations were mostly below detection limits in Manila clam tissues and sediments sampled from 3 tidal elevation strata at sites in Lummi Bay and Portage Spit. However, very low concentrations of Napthalene (15 parts per billion) and Phenathrene (6 parts per billion) were detected in the sediment of the upper elevation sub-sample of the Lummi Bay site. These values are below the 'no effect' marine sediment quality standards criteria adopted by the State of Washington for these compounds.

The results of this project are intended as a pre-disaster reference dataset that can be used to assess the potential adverse impacts from an oil spill or some other disaster, as well as a standard against which post-spill recovery can be measured. In addition, the data are useful for informing resource management decisions, enhancement and aquaculture opportunities, oil spill response planning, vessel navigation, and they improve the current knowledge about the ecology of the Lummi Reservation tidelands. Furthermore, the data can potentially be used to build models that would provide qualitative predictions about changes in community structure resulting from environmental changes.

LIBI Documents:

Please note that many of these files are large documents (up to 24MB in size) and should likely not be downloaded unless you have a broadband internet connection.

Also, these documents were distributed on a DVD with the printed version of the final report. The DVD contained the raw data and several electronic files for various GIS data layers, projects, and Access databases. These files are currently not available for download on this website. Interested parties should contact LNR regarding the availablity of those files.

• LIBI Final Report
• LIBI Appendix A - Intertidal Biota Survey
• LIBI Appendix B - Large Bivalve Survey
• LIBI Appendix C - Finfish Survey
• LIBI Appendix D - Shorebird & Marine Mammal Survey
• LIBI Appendix E - Taxonomic Resolution of Surveys
• LIBI Appendix F - Petroleum Toxicity Baseline
• LIBI Appendix G - Topographic Survey
• LIBI Appendix H - GIS Analysis
• LIBI Appendix I - Ecological Analysis
• LIBI Appendix J - Relational Database Applications
• LIBI Appendix K - GIS Projects
• LIBI Appendix L - Annotated Bibliography