April 5: Inferring species presence using environmental DNA

One of the great challenges with aquatic conservation is knowing what species are present below the water’s surface.  This is particularly true for rare species such as newly arrived non-indigenous species and threatened and endangered species. A new approach to species detection, coined environmental DNA (eDNA), uses the telltale genetic signature of aquatic species in the form of tissue, cells, organelles, and DNA fragments in the water that are captured and extracted to infer presence.  First generation applications of the eDNA methodology were applied to early detection of invasive species, but now the approach is being used to identify entire communities. In this discussion, we will explore the evolution of inferring species presence using environmental DNA, from the original detections of Bighead and Silver Carp in the Great Lakes to the attempts at estimating species richness. Throughout the development of eDNA approaches, mathematical and statistical models have motivated the sampling design and quantification of errors, and these models have ultimately driven inferences of species presence. The resulting growth in eDNA applications is leading to a new era in globally mapping the distribution and identity of species for improved aquatic conservation and management.

Christopher Jerde
Marine Science Institute, University of California Santa Barbara

Christopher Jerde grew up fishing and camping among the prairie pothole lakes of northeastern South Dakota. He completed his B.Sc. (2008) and M.Sc. (2002) at Montana State University surrounded by open spaces and trout. While Montana cultivated a keen interest in ecology, his experiences studying bison population dynamics motivated him to build a broader quantitative background, and he migrated north to the Centre for Mathematical Biology at the University of Alberta where he completed his Ph.D. (2008).  As a postdoctoral fellow and a research assistant professor at the University of Notre Dame, Chris led the development of an environmental DNA surveillance program for invasive species, most notably searching for Bighead and Silver Carp. Now at UCSB’s Marine Science Institute, Chris’s research program emphasizes the application of novel quantitative, field, and laboratory approaches coupled with emerging technology to address pressing environmental problems.

March 1: Observing carbon cycle climate feedbacks from space

Carbon cycle climate feedbacks remain one of the most uncertain and complex aspects of the Earth System. Considerable theory exists, but in situ observations are sparse and using them to test alternative hypotheses and to quantify the strength of feedbacks has proved challenging. Satellite observations of XCO2 provide greater coverage spatially, particularly in some crucial but undersampled regions and have the potential to complement more accurate in situ CO2 and more process-relevant local flux observations. We report early analyses of OCO-2 and GOSAT data showing evidence for satellite constraints on both positive and negative feedback mechanisms in the carbon-climate system. Satellite CO2, by providing greater resolution on land in over the oceans, in the tropics, allows linking both growth, and drought-related emissions from ecosystems to be better quantified, allows better linkage of fluxes to mechanisms of disturbance and CO2 fertilization, and provides a new and complementary constraint to others currently used. We show that the tropical continents differ in their responses and explore why they may differ, based on their prior disturbance, soil and functional diversity. Extratropical feedbacks may also now be becoming evident in observations, and we discuss the role of satellite CO2 in constraining positive and negative feedbacks to climate in the extratropics.

Speaker: David Schimel, Jet Propulsion Laboratory

Dr. David Schimel is currently a Senior Research Scientist at the Jet Propulsion Lab, leading research focused on carbon-cycle climate interactions, combining models and observations.  For the previous five years, Schimel led the National Ecological Observatory Network project, was responsible for the top-level science design, site selection and observing system simulations.  From 2001-2007, Schimel was at the National Center for Atmospheric Research as a senior scientist, with research focused on assimilation of carbon cycle data in land and atmospheric models. From 1998-2001, Schimel served as founding Co-Director and Managing Director of the Max Planck Insitute for Biogeochemistry in Jena, Germany.  From 1990-1998, Schimel was at NCAR.  Schimel served as convening Lead Author for the first IPCC assessment of the carbon cycle, and has served as an IPCC CLA four times, and as a Lead Author twice. From 1988-1989, Schimel was an NRC Fellow at NASA Ames. Dr. Schimel obtained his PhD in 1982 from Colorado State University, studying atmosphere-ecosystem exchange of nitrous oxide and ammonia.

Feb. 15: Evidence for competition among salmon at sea

Pink salmon

Salmon scientists frequently focus research on the link between salmon production and oceanographic conditions, but there is growing evidence that intraspecific and interspecific competition are also important. Pink salmon represent nearly 70% of all adult salmon returning from the North Pacific Ocean (~670 million fish in 2009) and their abundance has doubled since the mid-1970s ocean regime shift. The fixed two-year life cycle of pink salmon and their strong alternating-year pattern of abundance provides a unique opportunity to test hypotheses about competition at sea. In this presentation, I review evidence for competition, including its effects on salmon growth, age-at- maturation, and survival. Much of the evidence involves sockeye salmon, which typically spend two or three winters at sea and have high diet overlap with pink salmon. There is also evidence that pink salmon impact the growth, age, and survival of other species, such as Chinook salmon. Finally, I conclude that this evidence has important implications for large-scale hatcheries, which may contribute to a Tragedy of the Commons.

Dr. Greg Ruggerone
Natural Resources Consultants, Inc.

Dr. Greg Ruggerone has investigated population dynamics, ecology, and management of Pacific salmon in Alaska and the Pacific Northwest since 1979. Much of his earlier experience stems from activities as Project Leader of the Alaska Salmon Program, University of Washington. His research typically involves factors affecting growth, age at maturation, and survival of salmon in freshwater and marine habitats. Lately, this research has focused on species interactions in the ocean, especially competition between pink salmon and other salmon. He is past Chair of the Columbia River Independent Scientific Advisory Board and past Chair of the Independent Scientific Review Panel, and he currently serves as an independent science reviewer for the California WaterFix Project.

Wed. Jan. 25 – Summer fog patterns of Santa Barbara County

Sunrise 3-15-13

During the dry summer months, coastal shrubs in California receive little to no rain. However, shrub-dominated plant communities can be inundated by periodic fog events. I will be sharing my dissertation work examining the patterns of summer fog deposition, chemical make-up of fog and plant uptake of fog water. Come on by and let’s talk fog while reminiscing about those sunny summer months.

Nate Emery
Doctoral candidate
Department of Ecology, Evolution, and Marine Biology
University of California, Santa Barbara