ASPIRE is an NSF-funded project that will examine the ecology of the Amundsen Sea during the Austral summer of 2010. ASPIRE includes an international team of trace metal and carbon chemists, phytoplankton physiologists, microbial and zooplankton ecologists, and physical oceanographers, that will investigate why and how the Amundsen Sea Polynya is so much more productive than other polynyas and whether interannual variability can provide insight to climate-sensitive mechanisms driving carbon fluxes. This project will compliment the existing ASPIRE effort by using 1) experimental manipulations to understand photoacclimation of the dominant phytoplankton taxa under conditions of varying light and trace metal abundance, 2) nutrient addition bioassays to determine the importance of trace metal versus nitrogen limitation of phytoplankton growth, and 3) a numerical ecosystem model to understand the importance of differences in mixing regime, flow field, and Fe sources in controlling phytoplankton bloom dynamics and community composition in this unusually productive polynya system. The research strategy will integrate satellite remote sensing, field-based experimental manipulations, and numerical modeling. Outreach and education include participation in Stanford's Summer Program for Professional Development for Science Teachers, Stanford's School of Earth Sciences high school internship program, and development of curriculum for local science training centers, including the Chabot Space and Science Center. Undergraduate participation and training will include support for both graduate students and undergraduate assistants.
In the ASPIRE project we studied phytoplankton (small, unicellular algae that grow in the oceans) in the Amundsen Sea Polynya in Antarctica. Satellite images show a lot of phytoplankton in this region and the major goal of the project was to understand why they grow so well here. In general, phytoplankton in Antarctica need light for photosynthesis and iron as a nutrient. Phytoplankton only need a bit of iron to grow but iron concentrations in Antarctic waters are so low it may still not be enough. The Stanford team joined an international team of researchers on a scientific expedition to the Amundsen Sea Polynya on the icebreaker "Nathaniel B. Palmer". Here, direct measurements of phytoplankton abundance confirmed the satellite observations of high levels of phytoplankton. Moreover, photosynthesis measurements showed they are very active and growing fast. We manipulated the phytoplankton in experiments, we gave them more iron and studied the growth and photosynthesis under light limitation and under a lot of light. These experiments, in combination with the direct phytoplankton measurements, show that if phytoplankton in the Amundsen Sea Polynya would receive more iron than they currently do they would grow even faster. The Amundsen Sea Polynya is adjacent to a major glacier that borders the Amundsen Sea Polynya as the Dotson Ice Shelf. The melt rates of this glacier have increased over the past years and are among the fastest in Antarctica. Melting glaciers release iron in the water and our research suggests that this stimulates phytoplankton growth in the Amundsen Sea Polynya. Potentially, increased glacier melt rates in the future would stimulate phytoplankton growth even more. This is important for the Antarctic ecosystem, since phytoplankton forms the basis of the food web and supports all other life in the water, e.g. penguins, seals, whales, and sea birds. Moreover, phytoplankton take up CO2, which is a greenhouse gas, and take part of it down to the deep sea, or even the seafloor where it gets buried and removed from the atmosphere. Thus, phytoplankton growth has a negative feedback on (it lessens) climate chance. In addition to doing science, ASPIRE researchers participated in outreach activities such as writing scientific blogs and teaching. The female researchers in ASPIRE particularly active and interacted with over 200 girls in 6th and 7th grade to talk about science in general, oceanography, climate change, and the role of phytoplankton in the ocean. This direct interaction with female scientists will help girls of this age continue their interest in science, math, engineering and technologies (STEM) exploration and learning, through the tricky years when new distractions enter their lives. Studies have shown that girls’ interests can be sustained if they are exposed to the careers available to women in science today. ASPIRE provided some of that exposure through talks and blogs. PRODUCTS Commentary Garay, L., A. M. Wotkyns, K. E. Lowry, J. Warburton, A.-C. Alderkamp, P. L. Yager. ASPIRE: Teachers and researchers working together to enhance student learning. Elem. Sci. Anth. 2: 000034 DOI 10.12952/journal.elementa.000034 Presentations Ocean Sciences Meeting, Honolulu, Hawaii, May 2014. Poster presentation. Alderkamp, A.-C., G. L. Van Dijken, K. E. Lowry, R. M. Sherrell, S. E. Stammerjohn, P. L. Yager, K. R. Arrigo. Effects of glacial melt on phytoplankton primary productivity in the Amundsen Sea (Antarctica) Datasets Chlorophyll concentrations of the NBP 13-10 cruise: www.bco-dmo.org/project/2132 Website http://antarcticaspire.org/
