The primary goal of CBRISC is to:

Quantify temporal changes (if any) in the compositions of Southern California rocky intertidal communities during the past one hundred years or so by comparing present day data on species occurrences to those from the past. Similar comparisons in other systems have revealed surprising changes in community composition even over the scale of about half a century in the Monterey Bay area (Barry et al. 1995, Sagarin et al. 1999). However there is very little quantitative information on how present southern California rocky shore communities compare to those from the past when population pressures were significantly lower. Since reliable census data from the past are very rare we will never be able to quantify temporal changes in abundances of species beyond a few localities (such as that by Barry et al. 1995), but data on past species occurrences (i.e. presence/absence data) can be compiled much more easily. Museum collections and the literature provide a rich source of such data and provide us with a comprehensive picture of how species occurrence patterns have changed over the last century or so. In fact, occurrence data may be a better metric for assessing the current health of rocky intertidal communities since absence of species today at a locality where it had been present in the past signifies local extinction. Any sign of widespread local extinctions is clearly more alarming than large changes in species abundances. The results of this project provide quantitative data on the extent of local extinctions in rocky shore populations along the southern California coast. Our database provides information that could be used for conservation decisions and future monitoring of these habitats.

(1) compile a database of the historical occurrences of intertidal species at various localities throughout southern California and the Channel Islands;

(2) undertake extensive surveys of a subset of these localities to compare the compiled historical baseline data to the present day conditions; and

(3) develope and maintain this internet site (http://biology.ucsd.edu/labs/roy/CBRISC/) where other researchers will be able to search our compiled data and eventually update and add to it.

Barry, J. P., Baxter, C. H., Sagarin, R. D. and Gilman, S. E.. 1995. Climate-related long-term faunal changes in a California rocky intertidal community. Science 267:672- 675.

Sagarin RD, Barry JP, Gilman SE, et al. 1999. Climate-related change in an intertidal community over short and long time scales. Ecol Monogr. 69:465-490.