The planktonic stages of the salmon louse (Lepeophtheirus salmonis) are tolerant of end-of-century p CO2 concentrations

Cameron R S Thompson; David M Fields; Reidun M Bjelland; Vera B S Chan; Caroline M F Durif; Andrew Mount; Jeffrey A Runge; Steven D Shema; Anne Berit Skiftesvik; Howard I Browman

doi:10.7717/peerj.7810

The planktonic stages of the salmon louse (Lepeophtheirus salmonis) are tolerant of end-of-century p CO₂ concentrations

PeerJ. 2019 Oct 14:7:e7810. doi: 10.7717/peerj.7810. eCollection 2019.

Authors

Affiliations

¹ Institute of Marine Research, Bergen, Norway.
² Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, United States of America.
³ Austevoll Research Station, Institute of Marine Research, Storebø, Norway.
⁴ LEMAR, Institut Français de Recherche pour l'Exploitation de la Mer, UMR 6539 (UBO/CNRS/IRD/Ifremer), Plouzané, France.
⁵ Department of Biological Sciences, Clemson University, Clemson, SC, United States of America.
⁶ School of Marine Sciences, University of Maine, Orono, ME, United States of America.
⁷ Gulf of Maine Research Institute, Portland, ME, United States of America.

Abstract

The copepod Lepeophtheirus salmonis is an obligate ectoparasite of salmonids. Salmon lice are major pests in salmon aquaculture and due to its economic impact Lepeophtheirus salmonis is one of the most well studied species of marine parasite. However, there is limited understanding of how increased concentration of pCO₂ associated with ocean acidification will impact host-parasite relationships. We investigated the effects of increased pCO₂ on growth and metabolic rates in the planktonic stages, rearing L. salmonis from eggs to 12 days post hatch copepodids under three treatment levels: Control (416 µatm), Mid (747 µatm), and High (942 µatm). The pCO₂ treatment had a significant effect on oxygen consumption rate with the High treatment animals exhibiting the greatest respiration. The treatments did not have a significant effect on the other biological endpoints measured (carbon, nitrogen, lipid volume, and fatty acid content). The results indicate that L. salmonis have mechanisms to compensate for increased concentration of pCO₂and that populations will be tolerant of projected future ocean acidification scenarios. The work reported here also describes catabolism during the lecithotrophic development of L. salmonis, information that is not currently available to parameterize models of dispersal and viability of the planktonic free-living stages.

Keywords: Aquaculture; Copepod; Energetics; Growth; Lepeophtheirus salmonis; Lipid; Metabolism; Ocean acidification; Parasite; Salmon lice.

Grants and funding

This research was supported by the Institute of Marine Research, Norway and the Fram Centre, Norway Project # 14591-02 and by the Institute of Marine Research, Norway Project # 81529 to Howard Browman. David Fields also received support from NSF award OCE-1220068. Jeffrey A. Runge and Cameron R.S. Thompson were additionally supported by the National Science Foundation award OCE-1041081. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.