Hematologic and plasma biochemistry values of an Antarctic seabird at two sites with different histories of commercial fish exploitation

Abstract

Blood parameters are useful to assess the physiological status of wild bird populations. These parameters can be influenced by environmental changes such as changes in the quality and availability of food resources. In this work, concentrations of biochemical (glucose, cholesterol, triglycerides, total proteins) and hematological (leukocyte profile, the heterophil/ lymphocyte ratio, hematocrit) parameters, which are indicators of physiological and nutritional status, were determined for Antarctic Shag (Leucocarbo bransfieldensis) at two breeding sites that differ in their history of commercial fish exploitation: Harmony Point, Nelson Island, South Shetland Islands (62°18’S, 59°12’W) (HP), an area affected by commercial fish fishing, and at the Danco Coast (64°42′S, 62°0′W) (DC), western Antarctic Peninsula during the breeding season. The data showed significant differences between localities for most blood and biochemical parameters. H/L proportion, hematocrit, and monocytes were significantly higher at the historically impacted site, as well as glucose and total proteins. These results suggest that shags from both areas are in different physical conditions during reproduction, with breeding shags from HP experiencing higher levels of physiological stress and poorer health compared to those in the DC, probably related in part to local factors such as climate and, most importantly, food availability. The reported results provide baseline data that can be used for future comparisons among populations and to detect changes in the health status of Antarctic shags.