Unusual mortality of Tufted puffins (Fratercula cirrhata) in the eastern Bering Sea.

Mass mortality events are increasing in frequency and magnitude, potentially linked with ongoing climate change. In October 2016 through January 2017, St. Paul Island, Bering Sea, Alaska, experienced a mortality event of alcids (family: Alcidae), with over 350 carcasses recovered. Almost three-quarters of the carcasses were unscavenged, a rate much higher than in baseline surveys (17%), suggesting ongoing deposition and elevated mortality around St Paul over a 2-3 month period. Based on the observation that carcasses were not observed on the neighboring island of St. George, we bounded the at-sea distribution of moribund birds, and estimated all species mortality at 3,150 to 8,800 birds. The event was particularly anomalous given the late fall/winter timing when low numbers of beached birds are typical. In addition, the predominance of Tufted puffins (Fratercula cirrhata, 79% of carcass finds) and Crested auklets (Aethia cristatella, 11% of carcass finds) was unusual, as these species are nearly absent from long-term baseline surveys. Collected specimens were severely emaciated, suggesting starvation as the ultimate cause of mortality. The majority (95%, N = 245) of Tufted puffins were adults regrowing flight feathers, indicating a potential contribution of molt stress. Immediately prior to this event, shifts in zooplankton community composition and in forage fish distribution and energy density were documented in the eastern Bering Sea following a period of elevated sea surface temperatures, evidence cumulatively suggestive of a bottom-up shift in seabird prey availability. We posit that shifts in prey composition and/or distribution, combined with the onset of molt, resulted in this mortality event.

Application of heated inlet extensions to the TSI 3306/3321 system: comparison with the Andersen cascade impactor and next generation impactor.

Pharmaceutical aerosol size distribution analysis based on multi-stage inertial impaction is well accepted, though laborious. The TSI 3306 Impactor Inlet/3321 time-of-flight (TOF) Aerodynamic Particle Size Analyzer (APS) has been evaluated for its ease of use and potential for time savings during product development. However, instrument inlet modifications may be necessary for increased correlation with equivalent measurements obtained by inertial impaction following pharmacopeial methods. A heated inlet extension tube was located between the USP/Ph.Eur. throat and the Single-Stage Impactor (SSI) to promote evaporation of residual ethanol from aerosol droplets, generated from two formulations containing ethanol as semi-volatile solubilizer (8 and 20% w/w) for the active pharmaceutical ingredient. As temperature and extension length increased, the SSI-measured fine particle fraction (aerosol < 4.7 microm aerodynamic diameter) also increased, for the aerosols used in this study. These values correlated quite closely with equivalent measures made by multi-stage cascade impactor equipped with the same throat. Particle size distribution profiles measured with the APS for either formulation did not significantly change utilizing the heated extensions, suggesting that ethanol evaporation was largely complete at any condition by the time the aerosol entered the measurement zone of the TOF analyzer. The addition of a heated inlet extension may be useful to facilitate evaporation of residual semi-volatile species, especially when an agreement of APS-derived particle size mass distribution data from the SSI with multi-stage cascade impactors is desired. However, complete evaporation of the semi-volatile species may not be necessary for SSI-generated mass distribution to match conventionally used cascade impactors.