The costs of habitat utilization of wild, farmed, and domesticated juvenile Atlantic salmon (Salmo salar)

Abstract

We compared morphometry and total swimming costs of wild, farmed (first-generation hatchery progeny of wild progenitors) and domesticated (seventh-generation progeny of the Norwegian aquaculture strain) juvenile Atlantic salmon (Salmo salar). Respirometry experiments were performed to assess total swimming costs of fish ranging in size from 4.0 to 16.1 g wet mass at a water temperature of 15 °C. Fish were subjected to flow conditions of low and high turbulence. Total swimming costs increased significantly with intensity of turbulence and were, on average, 1.4 times higher at high than at low turbulence. Total swimming costs were 2.4- to 4.0-fold higher than predicted by forced swimming models developed under conditions that minimize flow heterogeneity. Total swimming costs of wild and farmed fish were not statistically different (average difference = 6.7%). Hence, swimming costs models developed using farmed fish may be used to estimate swimming costs of wild fish. However, domesticated fish had total swimming costs 12.0% to 29.2% higher than farmed or wild fish. This may be related to domesticated fish having deeper bodies and smaller fins.