Proof of concept: efficacy of cleaner fish, cultured juvenile cunner (Tautogolabrus adsperus), for sea lice (Lepeophtheirus salmonis) mitigation and control in Atlantic salmon (Salmo salar)

• Main Author: Chen, Zhiyu
• Format: Thesis
• Language: English
• Published: Memorial University of Newfoundland 2020
• Subjects: Canada; Atlantic salmon; Salmo salar
• Online Access: https://research.library.mun.ca/15071/; https://research.library.mun.ca/15071/1/thesis.pdf

A laboratory-based sea lice culture system was established for hatching and rearing Lepeophtheirus salmonis (from egg strings removed from farmed Atlantic salmon) to the copepodid stage of development, and an enumeration method for estimating the number of sea lice copepodids required for artificial sea lice parasitism was developed. Investigation of the delousing efficacy of cultured juvenile cunner against L. salmonis artificially infecting Atlantic salmon smolts under laboratory conditions indicated that there was no significant effect of cunner stocking density on mean sea lice numbers when held in cohabitation for seven days at stocking densities of 0, 4 and 10% (p=0.143) and they did not exhibit delousing activity. Fin condition (as an indicator of fish welfare) of Atlantic salmon smolts was evaluated during this period. There was no significant effect of cultured juvenile cunner stocking density on mean dorsal fin erosion scores (p=0.463) and mean caudal fin erosion scores (p=0.591) for Atlantic salmon. Additionally, there was no effect of high (18°C) and low (2°C) water temperature on the delousing efficacy of cultured juvenile cunner against Lepeophtheirus salmonis infecting Atlantic salmon smolts during a separate seven-day period of cohabitation (p=0.093), and no economically important pathogens or reportable diseases (within the Atlantic Canada region) (e.g., BKD, IPNv, ISAv, VHSv, IHNv and Nodavirus) were detected in either species during this time.