The planktonic stages of the salmon louse (Lepeophtheirus salmonis) are tolerant of end-of-century pCO(2) concentrations

Cameron R. S. Thompson (1) , David M. Fields (2) , Reidun M. Bjelland (3) , Vera B. S. Chan (4, 5) , Caroline M. F. Durif (3) , Andrew Mount (6) , Jeffrey A. Runge (7, 8) , Steven D. Shema (3) , Anne Berit Skiftesvik (3) , Howard Browman (3)

1 IMR - Institute of Marine Research [Bergen]
2 Bigelow Laboratory for Ocean Sciences
3 IMR - Austevoll Research Station
4 LEMAR - Laboratoire des Sciences de l'Environnement Marin (LEMAR)
5 IFREMER - Institut Français de Recherche pour l'Exploitation de la Mer
6 Department of Biological Sciences [Clemson]
7 University of Maine
8 GMRI - Gulf of Maine Research Institute

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 pCO(2) associated with ocean acidification will impact host-parasite relationships. We investigated the effects of increased pCO(2) 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 mu atm), Mid (747 mu atm), and High (942 mu atm). The pCO(2) 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 pCO(2) and 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.

Mots clés: ACL; behavior; Growth; responses; Metabolism; ocean acidification; impacts; Parasite; Aquaculture; infection; respiration; Ocean acidification; calanus-finmarchicus; Copepod; Energetics; copepod; Lepeophtheirus salmonis; Lipid; Salmon lice; sea lice; threat

Domaines: Biodiversité et Ecologie

Cameron R. S. Thompson, David M. Fields, Reidun M. Bjelland, Vera B. S. Chan, Caroline M. F. Durif, et al.. The planktonic stages of the salmon louse (Lepeophtheirus salmonis) are tolerant of end-of-century pCO(2) concentrations. PeerJ, 2019, 7, pp.e7810. ⟨10.7717/peerj.7810⟩. ⟨hal-02920510⟩