Every year in the late summer, patches of the Columbia River estuary begin to turn red. These patches are blooms of mixotrophic ciliates (Myrionecta rubra or Mesodinium rubrum/major) (MR) that ingest the chloroplast of their prey, the cryptophytes (CR) Teleaulax amphioxeia (Peterson et al., 2013), and use the acquired organs...
The biological transformation of dinitrogen gas (N2) into combined forms(termed N2 fixation) by certain genera of oceanic cyanobacteria represents the largest incoming flux of nitrogen to the global ocean. As such, biological nitrogen fixation
plays a significant role in the regulation of oceanic productivity and the export of
carbon and...
Hypoxia is a naturally occurring phenomenon that happens seasonally off the Oregon coast. As a consequence, there has been a great deal of research focused around analyzing the strength and duration of the hypoxic event during the summer season. This paper, however, takes an innovative approach by looking at the...
Oceanic fronts mark the boundary between two water masses and are often sites of complex bio-physical processes and multi-trophic level interactions, making them particularly important features in marine ecosystems. As global climate change induces multi-scale shifts in the driving physical mechanisms of fronts, spatiotemporal tracking of frontal variability can aid...
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Maria T. Kavanaugh & YvetteH. Spitz
Oceanic fronts mark the boundary between two
Small pelagic fishes (SPF), such as anchovies and sardines, are ecologically important due to their large abundance and intermediate trophic position that links plankton production to upper trophic levels. They are also economically important, supporting large fisheries that contribute to one fourth of the world fish landings. Reproductive success in...
Tropical coral reef ecosystems are very important from both the ecological and economical
points of view. However, they are also particularly fragile, and have been
declining in recent years in most regions of the world, since they are highly susceptible
to anthropogenic stressors operating at global scales (e.g., global warming...
Dynamical assimilation of surface elevation from tide gauges is investigated to estimate the bottom drag coefficient and surface stress as a first step in improving modeled tidal and wind-driven circulation in the Chesapeake Bay. A two-dimensional shallow water model and an adjoint variational method with a limited memory quasi-Newton optimization...
Three-dimensional ecosystem response to wind forcing on the continental shelf off Oregon is studied using a five-component nitrogen-based ecosystem model coupled to a high-resolution circulation model. We investigate, in particular, the influence of timedependent winds and alongshore variations in shelf topography for summer 2001 during the time period of the...
Under conditions of fixed N-limitation, as with most oligotrophic systems, the process of biological N₂ fixation (diazotrophy) is favored, provided the necessary trace elements and vitamins are sufficient. Despite the well understood contributions of N₂
fixation in oligotrophic regions, the nutritional and ecological controls of marine diazotrophs have not been...
Marine microorganisms play a significant role in the cycling of nutrients in the open ocean through production, consumption, and degradation of organic matter (OM). Carbon (C), nitrogen (N), and phosphorus (P) are essential ingredients in every known recipe for life. However, the cycling of each of these elements proceeds at...