CBRISC:  methods

Methods jump to:
Project scope
Modern data
Historical data

Project Scope

Taxonomic scope

For this project, we focus on two groups of invertebrates, mollusks and echinoderms, with the bulk of the work to date done on mollusks. These groups were chosen because they are diverse, ecologically important, well-sampled and commonly harvested in the rocky intertidal.

Geographic scope

At present, CBRISC is limited to the five most southern coastal counties in California (San Diego, Orange, Los Angeles, Ventura, and Santa Barbara). These counties encompass all of coastal California south of the important biogeographic break at Point Conception.

Temporal scope

No limits are placed on the temporal scope of this project. In practice, we are limited to the last ~ 100 years, as natural history records earlier than this are generally too sparse.

Modern Data

Intertidal surveys are being conducted at a number of intertidal sites throughout Southern California to establish the present day patterns of species occurrences. Since one of our aims is to quantify the effects of anthropogenic disturbances, the surveys include sites that experience a range of human impact from very low (protected marine reserves) to very highly impacted (unprotected high-traffic areas).

Historical Data

Historical data on species occurrences come from three sources: museum collections, private collections, and published literature.

Museum collections

We are collecting occurrence data from the following seven natural history museums: The California Academy of Sciences, The Los Angeles County Museum of Natural History, The National Museum of Natural History, The San Diego Natural History Museum, The Santa Barbara Museum of Natural History, The Scripps Institution of Oceanography Benthic Invertebrate Collection, The University of California Museum of Paleontology.

Example of a museum occurrence of the owl limpet, Lottia gigantea, collected in 1949 (from University of California Museum of Paleontology).

Private collections

Some private collections contain very important records of species occurrences in Southern California. We are grateful to Carole and Jules Hertz for providing us access to their collections.

Published Literature

Published papers, including dissertations and government reports, sometimes record relevant information on species occurrences over time at various localities (click here to open in a new window a partial list of published references used as CBRISC data sources).