1. OF CAPTIVE HARBOR SEALS (PHOCA VITULINA) IN ALASKA
A COMPARISON OF THE IMPACT OF ENVIRONMENTAL STRESSORS ON THE BLOOD PARAMETERS
OF CAPTIVE HARBOR SEALS (PHOCA VITULINA) IN ALASKA
Maura Allard- University of Rhode Island, Kingston
James Carpenter- College of Tropical and Agricultural Resources, University of Hawaii at Manoa, Honolulu
Shannon Atkinson and Lori Polasik- Alaska SeaLife Center, Seward
Project Objectives
Observe the effects of impending stressors upon an animal’s hepatic system
Identify which blood characteristics are most susceptible to change due to various environmental stressors
Travel to Alaska to observe and partake in research procedures and gain working experience as a researcher with the Alaska SeaLife Center
Introduction
Little research has been established in determining blood chemistry values for harbor seals in Alaska. It has been suggested that various environmental factors can influence the blood chemistry values due to temperature, day length, precipitation, constraint and diet amongst other variables. Currently there are no guidelines for veterinarians and rehabilitators to refer to when analyzing blood chemistry values for sick animals. The hope for this research is that it will aide in establishing guidelines for specific circumstances due to environmental stressors. It is hoped that in the future, this study will be used to create values for which veterinarians can simply refer to in a manual.
Materials and Methods
Eight Alaskan harbor seals (four female pups and four female yearlings) were captured and subsequently put on either low fat or high fat diets. The animals’ consumptions were documented and proximate analysis for nutrient composition of the diet was analyzed in detail.
To determine how the changes in diet effected the animals’ blood chemistry, a series of blood tests were taken to assay the blood characteristics. This study seeks to learn how the effect of confining the animal versus keeping the animal unconfined can also effect the blood characteristic values. During the blood tests, blubber biopsies were also performed.
Because a seal or sea lion’s body functions and metabolism may be effected by the changing seasons, temperature, photoperiod and molt period will be scrutinized as variables in determining the sensitivity of the blood chemistry values. Temperature and photoperiod were found using exterior sources.
Lori Polasik, Alaska SeaLife Center 2004
A harbor seal is restrained in order to obtain blood and blubber biopsies.
A centrifuge machine and chemistry analyzer used in obtaining values for the study.
Acknowledgements
We thank the Alaska SeaLife Center and its staff. We acknowledge Liliana Gonzalez from the University of Rhode Island for helping in the graphing portion of this study. Funding was received by the National Marine Fisheries Service and the Alaska SeaLife Center. Additional support was received by the University of Rhode Island’s Office of the Provost, Student Life Center and the College of Environmental Life Sciences. Research associated with this study are have been authorized under NMFS research permits , ; ASLC IACUC Protocol and University of Hawaii IACUC Protocol
Results and Conclusions
Results of the preliminary analyses indicate that the seals’ blood chemistry values are within normal ranges even after shifts in diet, confinement, photoperiod and temperature. Seals are considered ‘generalists’ which allow them to be very flexible and adaptable to changing conditions within the environment. What we are beginning to see is that their bodies allow them to remain the same even when the animal is subjected to extreme conditions. The seals that are being reported upon have undergone extensive training to aid in making testing and sampling easier on both the research staff and the animals. Our initial results are indicating that indeed, by exposing the animals to humans and testing procedures through training, the animals are physiologically not stressed. This ultimately helps the research scientists, as values will be more accurate, and the animals so that testing is not a traumatic experience for them. Through more extensive results it will be possible to alert other research facilities of the importance that training the animals has on their health and well-being.
There are several trends amongst the data that has been preliminarily analyzed that show that indeed there are some blood characteristics that are particularly sensitive to the variables (diet, confinement, weather, photoperiod, etc.). Because these results are only a byproduct of approximately two year’s data, they are still fairly vague and will become more specific and beneficial in the next few years.
A harbor seal pup being confined for a blood drawing trial.