The gut could reveal effect of climate change on fish

May 14, 2012

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 in fish is much more sensitive to 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 is affected by both rapid and slow changes in water , 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 Gräns,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 Gräns.

Winners and losers

Albin Gräns 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.

Other fish, such as those currently living at the lower extremes of their possible distribution, could instead benefit from a slightly higher temperature. The effects of a rise in water temperature will therefore vary between species, and many of the changes are difficult to predict.

"Our work is largely about trying to identify the physiological bottlenecks, in other words which parts of the body will fail first – whether the heart or the gut is the most sensitive part of the system."

Exploiting temperature differences

Turning food into nutrition requires the gastrointestinal system to function properly. Fish turn out to have guts that are highly sensitive to changes in , and many temperature-regulating behaviours observed in fish can probably be due to that the fish attempts to maintain or maximise gastrointestinal function.

"By eating at one temperature and then swimming off to another temperature to digest the food, fish can exploit areas that might otherwise be harmful to them," says Gräns.

Explore further: Japan to hunt fewer whales in Pacific this season (Update)

add to favorites email to friend print save as pdf

Related Stories

Changing climate can affect fish fertility

Apr 10, 2012

(Phys.org) -- Warmer water temperatures can greatly increase the reproductive capacity of the widely distributed pest fish species gambusia, or mosquito fish, a new study has found.

Fish with attitude: Some like it hot

Dec 03, 2009

Coral reef fish can undergo a personality change in warmer water, according to an intriguing new study suggesting that climate change may make some species more aggressive.

Warm-blooded sea reptiles of the Jurassic

Jun 10, 2010

(PhysOrg.com) -- New evidence shows that reptiles roaming the oceans at the time of the dinosaurs could maintain a constant body temperature well above that of the surrounding water.

Recommended for you

Plants with dormant seeds give rise to more species

11 hours ago

Seeds that sprout as soon as they're planted may be good news for a garden. But wild plants need to be more careful. In the wild, a plant whose seeds sprouted at the first warm spell or rainy day would risk disaster. More ...

Scientists tether lionfish to Cayman reefs

21 hours ago

Research done by U.S. scientists in the Cayman Islands suggests that native predators can be trained to gobble up invasive lionfish that colonize regional reefs and voraciously prey on juvenile marine creatures.

User comments : 0

More news stories

Researchers successfully clone adult human stem cells

(Phys.org) —An international team of researchers, led by Robert Lanza, of Advanced Cell Technology, has announced that they have performed the first successful cloning of adult human skin cells into stem ...

Male monkey filmed caring for dying mate (w/ Video)

(Phys.org) —The incident was captured by Dr Bruna Bezerra and colleagues in the Atlantic Forest in the Northeast of Brazil.  Dr Bezerra is a Research Associate at the University of Bristol and a Professor ...

Researchers develop new model of cellular movement

(Phys.org) —Cell movement plays an important role in a host of biological functions from embryonic development to repairing wounded tissue. It also enables cancer cells to break free from their sites of ...

Impact glass stores biodata for millions of years

(Phys.org) —Bits of plant life encapsulated in molten glass by asteroid and comet impacts millions of years ago give geologists information about climate and life forms on the ancient Earth. Scientists ...