Benthic macroalgae contribute to intensely productive near shore ecosystems and little is known about the potential effects of ocean acidification on non-calcifying macroalgae. Kübler and Dudgeon will test hypotheses about two macroalgae, Ulva spp. and Plocamium cartilagineum, which, for different reasons, are hypothesized to be more productive and undergo ecological expansions under predicted changes in ocean chemistry. They have designed laboratory culture-based experiments to quantify the scope for response to ocean acidification in Plocamium, which relies solely on diffusive uptake of CO2, and populations of Ulva spp., which have an inducible concentrating mechanism (CCM). The investigators will culture these algae in media equilibrated at 8 different pCO2 levels ranging from 380 to 940 ppm to address three key hypotheses. The first is that macroalgae (such as Plocamium cartilagineum) that are not able to acquire inorganic carbon in changed form will benefit, in terms of photosynthetic and growth rates, from ocean acidification. There is little existing data to support this common assumption. The second hypothesis is that enhanced growth of Ulva sp. under OA will result from the energetic savings from down regulating the CCM, rather than from enhanced photosynthesis per se. Their approach will detect existing genetic variation for adaptive plasticity. The third key hypothesis to be addressed in short-term culture experiments is that there will be a significant interaction between ocean acidification and nitrogen limited growth of Ulva spp., which are indicator species of eutrophication. Kübler and Dudgeon will be able to quantify the individual effects of ocean acidification and nitrogenous nutrient addition on Ulva spp. and also, the synergistic effects, which will inevitably apply in many highly productive, shallow coastal areas. The three hypotheses being addressed have been broadly identified as urgent needs in our growing understanding of the impacts of ocean acidification.
Broader Impacts This project has broader impacts in 2 major areas: the dissemination of biological knowledge to applied science and nonscientists, and inspiring careers in science among underrepresented minority students. The investigators are committed to facilitating the transfer of biological information to nonscientists who can put that information to practical use in human technologies. The lead PI is actively involved with transfer of biological knowledge to professionals in engineering, design and architecture, through her work with the Biomimicry 3.8. That is a nonprofit organization dedicated to expanding the conscious emulation of nature's genius through formal and informal education. The research results will be made accessible to nonscientists through the AskNature.org database for nonbiologist design professionals and through CSUN ScholarWorks-a database management system. The results of this project will be relevant to resilience to changing chemistry and evolvable designs. The research will also build on the investigators existing collaborations with private sector partners. JEK with will continue collaborations with The BID (Biologically Inspired Design) Community on biological resilience and robustness in systems with the goal of applying aspects of the knowledge gained here to systems of human technology, and SRD will continue collaboration with K. Jones of Gene Identification Services. CSUN is a certified minority serving and Hispanic serving, primarily undergraduate, institution with an outstanding record of moving students into careers in science. Kübler and Dudgeon will mentor 2 graduate students and 2-3 undergraduate students, from CSUN?s diverse student population, in macroalgal physiology and ecology with the goal of addressing global and ecosystem level issues. The PIs have a record of 100% of recruited MSc. students continuing to Ph.D. programs. All of the PI?s graduate students are expected to do some community service or educational outreach, usually to K-12 schools.
