Fishy consequences of transplanting trout, salmon, whitefishes

Jan 26, 2011
Dylan J. Fraser, a Concordia University biology professor, led a new study that found relocating fish is not always a good option. In this photo, Professor Fraser holds an Atlantic salmon. Credit: Dylan J. Fraser

Not all trout are created equal. Those swimming up the streams of British Columbia might resemble their cousins from Quebec, yet their genetic makeup is regionally affected and has an impact on how they reproduce, grow and react to environmental stressors.

Such regional variance makes transplanting – to bolster dwindling populations – tricky business. These are some of the findings of a compelling review published in Heredity, a journal from the Nature Publishing Group, which examined the adaptability of trout, salmon, charr, whitefishes and graylings across North America and Europe.

The investigation, which compared 93 wild and aquaculture fish populations, was led by Concordia University in collaboration with Simon Fraser University, the Université Laval and the University of British Columbia in Canada and Aarhus University in Denmark.

"We can't treat a species as something that is homogeneous throughout its range. Fish of the same kind are distinct, whether they grow in lakes, ponds or streams," says first author Dylan J. Fraser, a Concordia University biology professor.

"A salmon from Quebec isn't the same as a salmon from the Atlantic provinces or an individual of the same species from Europe," he continues. "There's considerable variation within species. That genetic diversity can allow a specific type of fish to thrive in one region – to better adapt to stressors such as climate change or habitat changes – while of the same species introduced from another region can dwindle."

Economic implications

Since , salmon, charr, whitefishes and graylings are important for commercial fishing, recreational fishing and aquaculture industries, Fraser says this review has economic implications for business or conservation programs looking to transplant species into new habitats for a variety of purposes.

"Salmon from Quebec, for instance, should not be reintroduced into British Columbia streams," says Fraser. "For fish to successfully adapt to a new environment, they should be selected by geographic proximity."

Natural selection is what drives local adaptation of fish stocks. "Natural selection may have favored faster growth in certain populations," he says. "If these same populations can also deal with higher temperatures, they may be better suited for new aquaculture initiatives in the face of climate change. This is another benefit of considering local adaptation."

The research team examined other factors that caused fish stocks to thrive or abate: environmental factors, temperature, geology, water chemistry, migration distance, pathogens, parasites, prey and predators.

The result? "Climate change will have a profound effect on species," says Fraser. "And understanding why local populations outperform foreign populations in their home environment may help to predict which populations within species are most likely to persist in the future.'"

Explore further: Decrease of genetic diversity in the endangered Saimaa ringed seal continues

More information: The paper, "Extent and scale of local adaptation in salmonid fishes: review and meta-analysis," was published in Heredity. www.nature.com/hdy/journal/vao… ull/hdy2010167a.html

Provided by Concordia University

not rated yet
add to favorites email to friend print save as pdf

Related Stories

Climate threatens trout and salmon

May 17, 2010

Trout and salmon are among the world's most familiar freshwater fishes, but numbers have fallen over recent decades - in some areas, dramatically.

Recommended for you

How can we help endangered vultures?

4 hours ago

Zoologists from the School of Natural Sciences at Trinity College Dublin are proposing an ingenious idea to help conserve populations of African white-backed vultures. The iconic birds, which play a critical ...

Scientists work to save endangered desert mammal

5 hours ago

Amargosa voles, small rodents that inhabit rare marshes of the Mojave Desert, have faced dire circumstances in recent years. Loss of habitat, extreme drought and climate change brought this subspecies of ...

Sex-loving, meat-eating reptiles have shorter lives

6 hours ago

The health risks and benefits of vegetarianism have long been discussed in relation to the human diet, but newly published research reveals that it's definitely of benefit to the reptile population. That, ...

US charges safari owners with illegal rhino hunts

18 hours ago

Two South African men were charged Thursday by the US government with conspiracy to sell illegal rhinoceros hunts to American hunters, money laundering and secretly trafficking in rhino horns.

User comments : 0