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THE BOWHEAD WHALE (Balaena Mysticetus) AS a POTENTIAL

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THE BOWHEAD WHALE (Balaena Mysticetus) AS a POTENTIAL THE BOWHEAD WHALE (Balaena mysticetus) AS A POTENTIAL INDICATOR SPECIES FOR MONITORING THE HEALTH OF THE WESTERN ARCTIC/ Spring and fall migration Toxicological sampling of routes of the bowhead whale BERING SEA ECOSYSTEM USING BLUBBER, HISTOLOGY AND blubber sections. in the Western Arctic/Bering Sea region. CONTAMINANT INDICES *Adapted from The Bowhead Whale, Special Publication Number 2, The Society for Marine Mammalogy, 1993 Organochlorines Proposed research to include: Cheryl Rosa1, John E. Blake1, Todd M. O’Hara2, Gerald R. Bratton3, Margaret M. Krahn4 Blubber Indices Analyses will be conducted on select cores (blow- 1 Institute of Arctic Biology, University of Alaska, Fairbanks, Alaska, USA 2 College of Veterinary Medicine, Thickness and girth (quantity) as determined by: hole girth) for deep, middle and outer sections, Texas A&M University, College Station, Texas, USA 3 Department of Wildlife Management, North Slope •blubber core/section measurement at the (three sections per core, nine samples per whale) Borough, Barrow, Alaska, USA 4National Marine Fisheries Service, Seattle, Washington, USA peduncle, anus, umbilicus, one meter • investigate sample site/depth dependent caudal to the blowhole, and axilla differences in OC levels Sampling and depth determination along two INTRODUCTION • consider OC contaminant levels in light girths at ventral and dorsal midline sites, and The bowhead whale (Balaena mysticetus) is an endangered mysticete and an important of overall health assessment a lateral site subsistence species to many native communities in both Alaska and Russia. The Histology •A total of six full thickness cores will be population health of the bowhead whale is intimately tied to offshore/coastal Establish normal histology taken and divided into five equal sections development and other human activities that influence ecosystem health. The native Establish a pathology “scoring” system and create resulting in thirty samples per whale subsistence hunt provides a unique opportunity to examine this rare species and confidence levels for pathology in tissues. likewise the data to investigate the health status of Bering Sea/Western Arctic Document pathology population. The research proposed in this study will provide techniques and baseline •epidermal lesions data that can be applied to other endangered marine mammal populations, such as the •special stains northern right whale. •liver (glycogen, lipid and lipofuscin stores) •pancreas (zymogen granules) OBJECTIVES •intestine (microvilli- document inactivity/ Determine the normal range of values for basic nutritional and health parameters in the atrophy) bowhead whale •thyroid histology and hormone levels (measure •Blubber thickness, chemical composition, and tissue structure serum levels of T3 and T4, relate data to OC •Essential and non-essential elements in liver and kidney levels) Basic blubber indices •Tissue structure related to nutritional status in liver, pancreas, intestine, etc., •adrenal histology (relate data to OC levels) •% lipid, water, and protein; calories and evaluation for evidence of disease •lipid profiles and class composition •Additional serum and tissue assays Serum haptoglobins levels Histology Employ data from above to: We will investigate the acute phase reaction in the •collagen, elastin and reticulin ratios at different •Determine the role of the bowhead whale as an indicator of ecosystem health bowhead whale to assist in evaluating potential stressors depths/orientations (of cut tissue section) •Develop an optimized protocol for assessing mysticete health for the Bering Sea, Western Arctic Sea and other regions Metallothionein Metals/Minerals We propose to investigate and make comparisons in tissues examined for: Protein binding in relationship to heavy metal toxicity We propose to address physiological, clinical, pathological, and •Spring vs. fall harvested animals (specifically Cd) will be investigated histopathological evaluations of whale tissue with comparisons to •Size/age cohorts as determined by morphometrics, aspartic acid racemization Histologic samples for will be stained metallothionein tissue metal/trace mineral concentrations (especially liver and kidney) (eye lens), and collagen/elastin/reticulin aging and it will be measured in tissues Samples from kidney and liver will be analyzed for Hg, •Gender/reproductive stage Cd, Se, As, Cu, Zn, Mn, Mg, Pb, Mo, Co Aging Archived data will be available for inclusion in analysis Aspartic acid racemization (lens nucleus) techniques Special stains will be employed will be employed as a means of aging whales Renal fibrosis has been noted in the kidneys of bowhead We will also test the aging potential of soluble collagen whales (Bratton, pers. comm.) cross linking quantification We will investigate the possible association between age and/or cadmium driving these fibrotic changes A large bowhead whale has Butchering begins with removal A lesion on the maxilla of a Acknowledgements been hauled onto the ice of the maktak (blubber). bowhead whale. We gratefully acknowledge the Cooperative Institute for during the spring whaling season. Arctic Research (CIFAR) for funding support.
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