As sea temperatures rise, stocks of some fish species can decline while others may grow, reveals new research from the University of Gothenburg looking at gastrointestinal function in fish.
The gastrointestinal system in fish is much more sensitive to temperature changes than previously believed and may even be a limiting factor for the distribution of species, a thesis from the University of Gothenburg shows.
By looking at how gut function in various fish species is affected by both rapid and slow changes in water temperature, we can better understand what will happen to different species when the climate changes.
"When the temperature of the water rises, the fish's body temperature climbs, activity in the gut increases, and more energy is needed to stay healthy," says researcher Albin Grns,who has studied various species in both saltwater and freshwater environments in western Sweden, California and Greenland.
Ectothermic animals are victims of their environment
Almost all fish are ectothermic, which means that their body temperature is the same as that of their surroundings. When the temperature of the water changes, so does the temperature of the fish, which affects all their body functions.
"Since changes in body temperature affect virtually all of a fish's organs, it's surprising that we know so little about how temperature changes impact on their physiology," says Grns.
Winners and losers
Albin Grns has studied sculpin, sturgeon and rainbow trout at various temperatures. His research shows that some species may find it harder to absorb nutrients as water temperatures rise, while others could profit from the new climate.
"If the water temperature in the Arctic rises further, some sedentary species, such as various types of sculpin, will probably struggle to maintain blood flow in the gut during the summer months, which will affect their health," he explains.
|Contact: Albin Grns|
University of Gothenburg