Abstract
The Pacific halibut (Hippoglossus stenolepis) is a commercially and ecologically significant flatfish species inhabiting the continental shelf of the United States and Canada, spanning the northern Pacific Ocean and Bering Sea.1 This study aims to provide baseline physiological and health parameters, such as bloodwork and morphometric measurements, which are lacking for this species. Various management strategies for this species have been put into place over the years to prevent rapid population decline as seen with its close relative, the Atlantic halibut (Hippoglossus hippoglossus), listed as Near Threatened in 2021 by the IUCN due to overfishing.2 The data collected from this project will aid in informing conservation strategies, habitat protection measures, and sustainable fishery practices. A preliminary study was conducted in 2019 on 27 Pacific halibut collected across Alaska’s Kenai Peninsula with data presented at the 2020 IAAAM conference.3 This current study expands on that data set to include 25 additional samples for a total of 52 individuals. Field surveys were conducted in Alaskan waters to collect morphometric measurements and blood parameters from these individuals. Parameters such as white blood cell counts, hemoglobin concentration, and hematocrit levels provide insights into the overall health and metabolic status of individuals. In addition, the current study includes detailed biochemistry values from plasma samples collected in 2019 and 2023, none of which were previously reported in 2020. In conjunction with bloodwork, morphometric measurements, including length, body weight, heart rate, and body temperature, were also recorded. As a valuable commercial and subsistence species, understanding the physiological health of the population enables the implementation of effective fisheries management practices to prevent overexploitation and ensure the resilience of the species in both wild-caught and commercially farmed populations.
Acknowledgements
We would like to thank the NC State University Robert J. Koller Endowment for funding and the NC State CVM Clinical Pathology Lab for support.
*Presenting author
+Student presenter
Literature Cited
1. International Pacific Halibut Commission. The Pacific Halibut: Biology, Fishery, and Management. Seattle, WA; 2014.
2. Cadrin S, González Troncosos D, Hallfredsson E, Munroe TA. Hippoglossus hippoglossus. The IUCN Red List of Threatened Species. 2022:e.T10097A148035632.
3. Dougherty KA, Gaudette C, Moledo JA, Passingham RK, Law JM, Cannedy AL, Fuller FJ, Goertz CEC, Stacy NI, Lewbart GA. A health survey of Pacific halibut, Hippoglossus stenolepis. In: Proceedings from the IAAAM 51st Annual Conference. 2020. Virtual.