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 our 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. There are two aspects of this project which focus on respiratory and acoustic disease respectively. Beta defensins from beluga will be characterized and their expression in response to polycyclic aromatic hydrocarbons (PAH) and crude oil exposure will be analyzed. 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 at mid-high frequencies. 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 our 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 technical 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: 1-2 cm diameter samples of trachea (windpipe) will be collected and frozen at – 20C for 24 hours before being placed in the cryoshipper for transport south. 2ml screw cap tubes will be used to store the trachea for shipment. 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. 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. (4) Once the ears have arrived at the laboratory, they will be processed and examined by scanning and transmission electron microscopy and immunohistochemistry. There is opportunity for natural history education, and biological and pathological sampling involvement of locals will be possible. The research team will integrate these proposed studies with Department of Fisheries and Oceans (DFO’s) current sampling protocols and increase the scope of the scientific program on Hendrickson Island. The team will involve and work with local harvest monitors, hunters, and youth and communicate the research objectives and results in a meaningful way to the community of Tuktoyaktuk. The research team would like 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 20, 2015 to August 1, 2015.