Population biology of a long-lived rhodolith: the consequences of becoming old and large

Life history characteristics of long-lived organisms make them particularly vulnerable to disturbances. Demographic studies of such populations are essential for evaluating susceptibility to disturbance and recovery potential, especially for ecosystem engineers supporting many dependent species. This type of demographic information, including population structure and mortality risk, is limited for long-lived rhodoliths (unattached non-geniculate coralline algae), which harbor a high biodiversity of cryptofaunal organisms. Population structure, in situ seasonal growth rates, age, and mortality estimates were determined in 2003–2004 for the subtidal rhodolith Lithothamnion muelleri in the Gulf of California, México. Individuals ranged in size from 0.5 to 16 cm diameter and the population was dominated by those