Estimates of phytoplankton sticking efficiency (α) were made in the laboratory within a 1500 l annular flume mesocosm over the initiation, maintenance and senescence phases of a bloom of the diatom Thalassiosira pseudonana. The spatially weighted mean turbulence kinetic energy dissipation rate in the annular flume was comparable to values found at the ocean's surface on a calm day. The α of T. pseudonana varied as a result of physiological state, and ranged from 0 ± 0.08 during the bloom initiation to 0.26 and 0.73 ± 0.16, respectively, during bloom maintenance and senescence phases. During the periods of high α, physiological changes included (1) diminished phytoplankton photosynthetic quantum efficiency, (2) an increase in super-oxide dismutase protein expression, reflecting oxidative stress, and (3) the induction of a biochemical cascade initiating autocatalytic programmed cell death. Additionally, during the period of high physiological stress on the diatoms, there was an increase in the presence of transparent exopolymer particles and bacteria. Applying a variable α to a 1-dimensional export flux model shows that carbon export can be increased by at least 2-fold compared to simulations assuming a typically modeled value of α = 1 (100% sticking efficiency). The model using a physiologically dependent α had a low initial sticking efficiency that allowed a significant increase in the critical concentration of algal cells. Such an increase in the number of cells during bloom initiation followed by an increase in α during the maintenance and senescence phases resulted in enhanced export fluxes during the latter, 'stickier', stages of the bloom.

Despite their strong dependence on the pelagic environment, seabirds and other top predators in polar marine ecosystems are generally studied during their reproductive phases in terrestrial environments. As a result, a significant portion of their life history is understudied which in turn has led to limited understanding. Recent advances in autonomous underwater vehicle (AUV) technologies have allowed satellite-tagged Adélie penguins to guide AUV surveys of the marine environment at the Palmer Long-Term Ecological Research (LTER) site on the western Antarctic Peninsula. Near real-time data sent via Iridium satellites from the AUVs to a centralized control center thousands of miles away allowed scientists to adapt AUV sampling strategies to meet the changing conditions of the subsurface. Such AUV data revealed the water masses and fine-scale features associated with Adélie penguin foraging trips. During this study, the maximum concentration of chlorophyll was between 30 and 50 m deep. Encompassing this peak in the chlorophyll concentration, within the water-column, was a mixture of nutrient-laden Upper Circumpolar Deep (UCDW) and western Antarctic Peninsula winter water (WW). Together, data from the AUV survey and penguin dives reveal that 54% of foraging by Adélie penguins occurs immediately below the chlorophyll maximum. These data demonstrate how bringing together emerging technologies, such as AUVs, with established methods such as the radio-tagging of penguins can provide powerful tools for monitoring and hypothesis testing of previously inaccessible ecological processes. Ocean and atmosphere temperatures are expected to continue increasing along the western Antarctic Peninsula, which will undoubtedly affect regional marine ecosystems. New and emerging technologies such as unmanned underwater vehicles and individually mounted satellite tracking devices will provide the tools critical to documenting and understanding the widespread ecological change expected in polar regions.