Veterinary Medicine International potassium concentrations below detectable limits of the VetScan analyzer (2.0 meq/L) and below concentrations rou- tinely associated with adverse peri-operative events including serious arrhythmias and death in human surgical patients [10]. Potassium depletion can cause decreased intracellular ﬂuid volume, changes in membrane potential, intracellular pH, and potassium dependent enzymatic reactions [11]. Such changes could aﬀect survival during and following anesthesia and surgery [12–15]. Internal potassium balance is aﬀected by acid-base status, exercise, and catecholamine release [16]. Catecholamine release routinely causes an initial mild hyperkalemia followed by hypokalemia because of beta adrenergic receptor responses [17–19]. A rapidly developing, profound hypokalemia can occur with reduced dietary intake [16]. Conservation of potassium by adjustments in renal ion management can be delayed for several days when animals that are normally on a high potassium diet are suddenly taken oﬀ feed or develop anorexia [20, 21]. We postulate that the serum chemistry diﬀerences in serum potassium, glucose and cholesterol observed after the three-day storm event can be readily explained by an inability of the birds to feed during the storm, and to an increase in physical exertion by the birds to cope with high winds and waves. 5. Conclusions (1) On-site evaluation of serum chemistry parameters for pre-surgical screening of waterfowl in remote locations is feasible and oﬀers the advantage of access of key data prior to making decisions on anesthesia and surgical risk for patients. (2) Serum potassium and glucose concentrations of Harlequin ducks can be impacted by environmental conditions in ways that may increase the risk of anesthesia and surgery. Acknowledgments The authors thank Abaxis for providing instrumentation and supplies. These data were collected under studies supported by the Exxon Valdez Oil Spill Trustee Council. However, the ﬁndings and conclusions presented by the authors are their own and do not necessarily reﬂect the views or position of the Trustee Council. Mention of trade names does not imply government endorsement. References [1] E. A. Driver, “Hematological and blood chemical values of mallard, Anas p. platyrhynchos, drakes before, during and after remige moult,” Journal of Wildlife Diseases, vol. 17, no. 3, pp. 413–421, 1981. [2] R. Hemm and W. W. Carlton, “Review of duck hematology,” Poultry Science, vol. 46, no. 4, pp. 956–962, 1967. [3] R. C. Mulley, “Haematology and blood chemistry of the black duck Anas superciliosa,” Journal of Wildlife Diseases, vol. 15, no. 3, pp. 437–441, 1971. [4] H. J. Shave and V. 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