PhD Dissertation Defense: Heather Coleman

The Bren School of Environmental Science & Management
at the University of California, Santa Barbara


Heather Coleman
PhD Candidate

Wednesday, Dec. 2, 2009
2:00 p.m.
Bren Hall Dean's Conference Room (2436)


"Ecological Consequences of Natural Oil Contamination"

Faculty Advisor: Hunter Lenihan



Pollution in the marine environment is becoming increasingly common, making its ecological effects and organismal coping mechanisms crucial to understand. Crude oil is a potent cytotoxin and can inhibit primary cellular detoxification mechanisms, such as multixenobiotic resistance (MXR) transport proteins. Purple sea urchins, Strongylocentrotus purpuratus, from the Coal Oil Point oil seep field endow offspring with enhanced MXR activity relative to naïve embryos when treated with transport protein inhibitors. This transgenerational adaptation to improve performance of offspring exposed to oil is somewhat plastic, as embryos of adults removed from the seep show depressed activity from only one of two transport protein types. The only fitness cost of this maternal effect detected in larvae was slightly depressed fertilization success, but adults were affected by reduced fecundity and slightly slowed growth. This adaptation to oil does not predict effects of a secondary, unfamiliar contaminant, as communities may not respond to these stressors in the same manner. The effects of foreign pollution, the synthetic MXR inhibitor musk xylene, on the oil seep community are determined when coupled with natural oil contamination. Low to moderate levels of oil input do not affect or mildly enhance infaunal abundance, depending on taxa, relative to clean sediment. However, moderate levels of musk xylene depress the density of many taxa in sediment trays at the oil seep. Thus, familiar contamination is less detrimental to infaunal density than a foreign MXR inhibitor in this system.




To join the "bren-alerts" mailing list and receive regular announcements about Bren School news and events, or to manage your bren-alerts account, go to

To see a complete list of currently scheduled Bren events, visit

To have an event considered for distribution via bren-alerts, send e-mail to

For more information or for assistance in accommodating a disability, please contact BJ Danetra

To find out how to support the Bren School, please contact Jennifer Purcell Deacon