Aspects of Fish Welfare in Aquaculture Practices, PhD Thesis
Department of Animal Physiology, Radboud University Nijmegen, Nijmegen, The Netherlands (2009-2013)
Highlighting the negative impact of several common rearing procedure on the welfare of species cultured in recirculating system, providing solution to professional farmers to meet the growing consumer demand for a sustainable aquaculture.
The overall aim of my PhD thesis was to increase knowledge on welfare of farmed fish through study of the effects of relevant and well-defined external stimuli on physiology and behavior. My PhD thesis can be subdivided into two sub-projects detailed below: impact of acute (noxious) and chronic (nitrogenous waste) stimuli on fish welfare.
Supervisors: Prof. Dr. Gert Flik – Dr. Hans van de Vis – Dr. Wout Abbink
Defended on the 20th of December 2013
Pain in fish
The question of the capability of fish to feel pain is a hot topic. In this first part of my PhD thesis, I discovered the presence of pain receptor (nociceptor) in the tailfins of several fish species (Nile and Mozambique tilapia’s, Oreochromis niloticus and Oreochromis mossambicus; Common carp, Cyprinus carpio and zebrafish, Danio rerio) and I showed that fish react to noxious stimuli by mucus secretion, changed plasma composition and altered swimming activity (2 publications).
Effect of nitrogenous waste on growth performance in RAS
Nitrogenous-waste compounds (ammonia, nitrite and nitrate) are limiting factors in recirculating aquaculture systems. In the second part of my thesis, I have determined the safe levels of nitrogenous waste concentrations (ammonium, nitrate and nitrite) at which African catfish and juvenile pike perch can be cultured without negative effect on growth, plasma and gill physiology, thus improving their husbandry in aquaculture (4 publications).