Acronym NA
Category
Aquaculture
Title Local effects of global warming: Effects of period of higher temperature than the normal range for Atlantic salmon Programme National Programme
Instrument (FP6)
Contact Type (FP7)
Strand (Interreg)
NA
Theme (FP7)
Activity Area (FP6)
Regional Area (Interreg)
Action (COST)
NA
Specific Programme (FP7)
NA
Funding source National Coordinator Rune Waagbø Coordinator email rune.waagbo@nifes.no
Coordinator institution
NIFES - National Institute of Nutrition and Seafood Research (Norway)
Institutions involved
UiB - University of Bergen (Norway) ,
Start year 2010 End year 2014 Funding (€) € 793,220 Website https://prosjektbanken.forskningsradet.no/en/project/FORISS/199683?Kilde=FORISS&distribution=Ar&chart=bar&calcType=funding&Sprak=no&sortBy=date&sortOrder=desc&resultCount=30&offset=180&ProgAkt.3=HAVBRUKS-Havbruk+-+en+n%C3%A6ring+i+vekst Summary Longer and more frequent periods with seawater temperatures above the optimum for growth for salmonids cause unfavourable farming conditions along the Norwegian coast. Historically large temperature fluctuations have been observed; however, the mean seawater temperature has increased and is predicted to continue to increase. Temperature affects appetite, metabolism and growth in fish, and temperatures above the optimum for growth results in a number of physiological and fitness consequences. During the summer months, when the seawater temperature is above the optimum for growth, both appetite and growth are reduced in farmed fish. Due to the changing climate, it is important to investigate how Atlantic salmon tolerates high temperature, and how production strategies and tailored feeds can contribute to increase coping and performance. The aim of the present project was to investigate in depth the underlying mechanisms for the observed physiological responses, with special focus on the effect of elevated temperatures on appetite, growth regulation, metabolism and antioxidant defence system. Several short-term and long-term experiments with mainly Atlantic salmon of different sizes were performed, where the fish was exposed to either high temperature (19°C) or reared at optimum temperature (13°C). The results indicate that larger Atlantic salmon are more affected by high temperature resulting in both reduced appetite and growth. Appetite is stimulated by the hormone ghrelin, which was shown to increase prior to an expected meal. Atlantic salmon of below 1 kg appears to tolerate periods of high temperature, and compensates for an increased metabolism by increasing the feed intake, in contrast to reducing the feed intake as in large fish. The retention of nutrients was lower at high temperature, suggesting that the dietary nutrients were used for energy instead of growth. Atlantic salmon of all sizes exposed to different periods of high temperature had a down-regulated growth stimulation mediated through the growth hormone (GH) ? insulin-like growth factor (IGF) axis. In addition, high temperature resulted in an increased oxidative pressure, and therefore a higher requirement for the antioxidant vitamins E and C. High temperature also results in hypoxia, which alone or in combination with high temperature was shown to result in lower appetite, growth and nutrient retention. Knowledge from the present experiment will be important to form a strategy to maintain production and welfare in periods when the seawater temperatures increase.
Keywords
Impacts;
Fish biology;
Climate change;
Salmon;
Fish;
Marine Region
14
Skagerrak, Kattegat (27.IIIa)
41
Norwegian Sea (27.IIa)
42
Barents Sea (27.I)
13
Northern North Sea (27.IVa)
4
Marine Region Map
