Can fish feed help farmed salmon adapt to climate changes?
How will salmon farming adapt to predicted climate changes? Can feed formulation be used as a tool to reduce the impacts of rising seawater temperatures? These are underlying questions for a new PhD project conducted by Vibeke Vikeså at Skretting Aquaculture Research Centre, reports www.megafishnet.com with reference to Skretting (world leader in the production and supply of feed for farmed fish and shrimp).
Climate change is predicted to increase seawater temperatures in many important salmon farming areas, resulting in longer periods where they are outside their optimal temperature and oxygen conditions. This becomes apparent in farming operations as decreased feed intake and growth, and therefore lower productivity. Understanding the factors affecting feed intake and the potential for nutritional intervention is the aim for Vibeke Vikeså's PhD project.
The project revolves around well controlled tank-based systems that mimic the effects of elevated seawater temperatures and allow their comparison to more optimal conditions. Nutritional manipulations can then be tested under ideal and suboptimal conditions.
"The project consists of four different trials where I will look at dietary protein and energy utilisation in situations where you either have hypoxic conditions (low oxygen level), elevated water temperatures or a combination of the two," Vikeså explains.
The salmon will be fed experimental diets with different protein:energy ratios for 1-4 months for each trial.
"The point is to identify the effects of different nutrient ratios on nutrient utilisation and feed intake. This will help us give better recommendations to the people formulating feed in warmer climates," Vikeså says.
The project will not only provide critical fundamental knowledge toward coping with climate change, but it is also relevant for current operations.
"In Norway we've seen rising summer temperatures over recent years, while warmer countries like Australia consistently have higher than optimal temperatures over the summer," adds Vikeså.
Vikeså has been working in Skretting ARC for 10 years. She started out coordinating research projects at Lerang research station just after finishing her Cand.scient degree at the University of Bergen in January 2001. After 18 months at Lerang she was promoted to a Researcher position in the Nutrition department.
"The research I've been doing up until now has been very much targeted towards specific areas within fish nutrition. With this project I will have a wider focus and get the chance to become more absorbed in the topic. I look forward to that and to working closely with people from the academic organisations who are guiding the project," she comments.
The PhD project has funding through the Industrial PhD programme, facilitated by the Research Council of Norway. It will be conducted together with the National Institute of Nutrition and Seafood Research (NIFES) and the University of Bergen.