The consequences of moving fish from one habitat to another


Researchers from Canada and Denmark have discovered that the genetic makeup of fish can have a significant impact on whether conservation efforts are successful or not.

The study compared the adaptability of trout, salmon, char, whitefish and graylings in 93 wild and aquaculture fish populations across North America and Europe.

The biologists found that even fish of the same species will not necessarily thrive if transplanted from one part of the country to another and that this even holds true of fish from different parts of the same waterway.

The principle author Dylan Fraser from the University of Concordia said:
"We often view fish species as homogeneous; but a fish is a fish is a fish isn't actually true."

Fraser cited the example of taking trout from rivers in northern Quebec, Ontario and British Columbia and putting them in a river near Montreal (for those of you unfamiliar with Canadian geography, this is equivalent of roughly 500 miles, 900 and 2000 miles).

He said: "The Quebec population would do the best, the Ontario guys second and the B.C. fish next best. For fish to successfully adapt, they should be selected by geographic proximity."

This is because the genetic diversity of fish from different areas has evolved to cope with different stressors, such as climate and habitat, found in that area.

Fraser believes that this study can have implications for both aquaculture where fish are selected that are better adapted to the location of the fish farm, conservation and presicting effects of climate change.

Similar studies have also been done on killifish which range from Canada down to Argentina and have found that some are adapted to warmer temperatures, while others can survive frigid Canadian winters.