Tags: Seminars

Detailed information on vegetation phenology in salt marshes is useful for understanding patterns in plant production and carbon sequestration. I used high-frequency PhenoCam imagery to characterize the phenophases of Spartina alterniflora, the dominant macrophyte in eastern U.S. salt marshes. These observations showed differences of > 1 month in the timing of spring green-up in plants located only meters apart. I found that green-up could be…

Elasmobranchs typically occupy higher trophic levels in food webs and, consequently, have a propensity to accumulate high organochlorine contaminant (OC) concentrations. However, not all sharks accumulate the same types of contaminants or at the same rate, making use of OCs a potential ecological tool.  Bioaccumulation with respect to ontogeny was examined among three species of pelagic sharks (Shortfin Mako Isurus oxyrhincus, Common…

Estuaries provide critical habitat for eelgrass, oysters, and other species, and also serve as natural sediment traps. The sediment regimes of many modern estuaries are evolving, however, in response to land use changes, shoreline alterations, dredging, and other human impacts. In order to assess hydrodynamics and sediment dynamics in the Coos Bay Estuary (Oregon), we used an unstructured finite-volume model (FVCOM) and multi-year measurements…

Andreas Thurnherr will present observations showing where and how AABW is transformed to lighter density classes and upwells and will also discuss how these two requirements for closing the overturning circulation relate to the observed vertical gradients in turbulence levels and to the hypothesized role of bottom boundary layers for upwelling of bottom water.

ABSTRACT: Sediment transport processes affect oxygen and carbon dynamics in coastal environments through a variety of processes.  Seabed resuspension, for example, can vertically mix sediment and water, facilitating decomposition of organic matter and oxygen consumption. Redistribution of inorganic and organic particles among coastal environments, e.g. between marshes and estuaries, can also affect biogeochemical budgets. The relative…

Processes that either promote growth or cause mortality drive the abundance of all organisms. For microbes that have a lifespan measured in hours to days, small changes in growth and mortality rates can have significant impacts on their population dynamics. While factors that influence phytoplankton growth are often examined, it has been difficult to parameterize phytoplankton population dynamics due to incomplete estimates of phytoplankton…