Catherine Drake began working in Dr. Bowler’s lab in her third year at UC Irvine, and came to love working in the local freshwater marsh. She has come to appreciate the rarity of the southern California marsh ecosystem, and has been grateful for the opportunity to work toward protecting its unique collection of plants and animals from invading exotic species. Catherine graduated from UC Irvine in 2010 and is planning to attend graduate school, continuing her education in ecology and marine biology.

Owen Goldsworthy considers his time conducting research to be one of the most valuable experiences he gained during his undergraduate years at UC Irvine. He particularly appreciated the opportunity to collect field data in the San Joaquin Freshwater Marsh Reserve, doing important research in such a beautiful natural setting. Having graduated, Owen plans to seek out a position in a research laboratory or hospital and start to put the skills he learned through his research to use.

Paula Nuguid was instantly interested in this project because of the frequent opportunity to visit the vernal pools. She particularly enjoyed being a part of an experiment that is relevant for many people in different disciplines. This experience has increased her awareness of the interconnectedness of things and how small changes can lead to greater outcomes. After graduation, Paula hopes to continue her education and build upon the experience and knowledge she has gained through her research.

Linda Patterson considers the privileges to study within the San Joaquin Marsh Reserve to be one of the best experiences she has have ever had. The most rewarding part was the faith her faculty mentors had in her to make a creative project come to life. She appreciates the opportunity to make a difference at UC Irvine by calling attention to how sensitive the local marsh environments can be. Linda intends to continue her studies in environmental toxicology, eventually entering a specialized field in medicine.

From 1999 to 2002, six vernal pools were created in the University of California Natural Reserve System’s San Joaquin Freshwater Marsh Reserve. The pools were inoculated with dried benthic samples from a series of vernally filled basins. Resilient populations of Brachinecta lindahli and other indicator species developed and have been appearing annually as the pools fill with winter rain. The pools also sustain mosquito larvae, and the application of BTI, a larvicide derived from Bacillus thuringiensis israelensis, was suggested. Before using BTI, however, we tested its impact on B. lindahli individuals recovered from the vernal pools. BTI has been reported to have no impact on other species of fairy shrimp, but toxicity effects for B. lindahli had not been investigated. A sequence of nine tests was conducted in which the recommended dosage of liquid BTI was applied to microcosms containing vernal pool water and ten individuals of the fairy shrimp, mosquito larvae and other invertebrates from the pools. Our results indicate that BTI kills mosquito larvae within hours but does not appear to be toxic to B. lindahli. In most of the tests, no mortality occurred during the first four days after treatment, and subsequent mortality followed the general pattern of natural mortality in the controls. Thus, BTI is a safe method of selectively killing mosquito larvae in sensitive ecosystems, such as vernal pools.

Peter A. Bowler School of Biological Sciences

Many species of fairy shrimp that inhabit vernal pools are endangered or threatened. Mosquitoes use vernal pools, and the primary mosquito species in our pools is Culex tarsalis. Prior to treating sensitive habitats such as vernal pools with larvicides to reduce mosquito presence, it is prudent to determine their possible impact upon fairy shrimp and other vernal pool invertebrates. This study examined the influence of the larvicide BTI (Bacillus thuringiensis israelensis) upon Brachinecta lindahli and other invertebrates from our vernal pools. BTI had no significant effect upon the fairy shrimp or other vernal pool invertebrates at levels that quickly killed mosquito larvae. This finding allows the option of using BTI treatment to control and reduce C. tarsalis without concern about the fate of fairy shrimp or the other invertebrate fauna in the pools.