NWT RESEARCH DATABASE

Tags: beluga whale, marine mammals, lungs

Objective(s): To study indicators of beluga health, which will lead to increased knowledge about normal function and how disease and human activities may impact belugas in the Western Arctic.

Project Description: The overall goal of this project is to study indicators of beluga health, which will lead to increased knowledge about normal function and how disease and human activities may impact belugas in the Western Arctic. More specifically the lung aspect of the project aims at exploring mechanical and immunological parameters in beluga lungs to gain a better understanding of factors that may negatively impact this species. This proposed lung study has two components. The first part focuses on characterizing the mechanical properties of beluga lungs during normal activities and how lung function may be compromised by respiratory diseases. The second aspect of this study analyzes immune proteins in lung secretions that defend against infections and also how environmental stressors and toxins may inhibit the function of these compounds. The ear aspect of this study aims to characterize the normal ear ultrastructural anatomy of beluga and document any structural alterations of the cochlear cells (inner ear trauma), particularly related to man-made noise. If ultrastructural evidence of injury is detected, laboratory analysis can further determine the frequency range of the sound source that triggered the injury. This study will provide baseline data to establish and compare “acoustic health” of the Mackenzie Delta beluga with other beluga populations. Deafness has been documented in stranded dolphins and porpoises along the eastern seaboard of the United States and in regions of Europe. However, to the best of the team’s knowledge inner ear trauma has not been studied in the Arctic. The sampling procedures for both of the projects involve only the lungs and ears. After the beluga has been landed and the muktuk and muscle removed, sampling will be conducted separately and should not interfere with the normal rendering process. There will be no waste generated or chemicals left on site due to sampling protocols. The sampling process for both of these projects is technically complicated and requires the expertise of specially trained individuals who will be working together to ensure that all tissues are appropriately sampled. Sampling for the lung aspect of the project can be accomplished after the normal butchering process and includes: (1) Intact lungs (n = 5-10) will be excised and the airways will be washed with a salt (saline) solution. This fluid will be collected from the lung and centrifuged at Hendrickson Island for 5 minutes, and then frozen for transport. (2) 1-2 cm diameter samples of trachea (windpipe) will be collected and frozen at – 20C for 24 hours before being places in the cryoshipper for transport south. DMEM culture media, containing 10% DMSO, and antimicrobials including X% Penicillin, X% Streptomycin, and X% fungizone (antifungal) in 2ml screw cap tubes, will be used to store the trachea for shipment. (3) Lungs will be inflated using a rubber bulb hand pump. A 10x10cm area of inflated lung tissue will be injected with 10mL of 1.5% paraformaldehyde / 1.5% glutaraldehyde and then sampled in 0.5x0.5cm blocks of tissue. These preserved blocks will be transported back to University of British Columbia in 5mL vials with 2mL of 0.1M sodium cacodylate buffer. All chemically-infected tissue (original 10x10cm area of inflated lung tissue) will also be collected and transported back to the University of British Columbia (UBC) for appropriate biological waste disposal. At UBC, tissues samples will be further processed for light and electron microscopy. (4) Approximately 3 to 5 intact lungs will be frozen in a chest freezer at camp. Frozen lungs will be transported back to UBC for further analysis of their mechanical properties. Sampling for the inner ear aspect of the project, includes: (1) After the head and lower jaws have been removed, ears from 20 to 25 harvested belugas will be collected and fixed with 2.5% glutaraldehyde or alternatively 10% neutral buffered formalin (see protocol at http://www.lab.upc.es/papers/Ear_extraction_and_fixation_protocol_LAB.pdf). It is easier to extract the ears once the head is removed and this procedure should have little impact on the butchering of the whales. (2) Both the right and left ears from the belugas will be used, except in those animals where gunshot damaged the ears. (3) Preserved ears will be stored at room temperature or in a fridge and shipped immersed in either 0.1M sodium cacodylate buffer or 10% neutral buffered formalin. (4) Once the ears have arrived at the laboratory, they will be processed and examined by scanning and transmission electron microscopy and immunohistochemistry. (5) The person in charge of ear collection, fixation and transport will be the same person responsible for ear analysis at the UBC facilities. Opportunity for natural history education, and biological and pathological sampling involvement of locals will be possible. The research team hope to integrate these proposed studies with Department of Fisheries and Ocean’s (DFO) current sampling protocols and increase the scope of the scientific program on Hendrickson Island. The team wish to involve and work with local harvest monitors, hunters, and youth and to communicate the research objectives and results in a meaningful way to the community of Tuktoyaktuk. The research team would also be willing to participate in presentations and workshops in order to communicate results and importance of the research to the local beluga population. All results will be provided directly to DFO, ARI, hunters, and community members by presentations and reports, and, ultimately, publications will be prepared to share this information with the broader scientific community. The fieldwork for this study will be conducted from June 25, 2014 to August 31, 2014.