How do they find their way about? Migration, orientation, and navigation of Pacific Salmon
Pacific salmon perform a number of incredible migrations during their life cycle. They can travel downstream or upstream for large distances after emerging from the gravel, move hundreds of kilometres through large lakes and then downstream to the ocean as one-year olds or smolts.
Their migrations in the ocean can encompass thousands of kilometres as they move between feeding and wintering grounds, and then when the time for spawning arrives they find their home river again and unerringly return through estuaries, rivers, lakes and creeks to their ancestral spawning sites.
Thus, during their life cycle Pacific salmon make a number of habitat changes or migrations; about five for pink salmon and about 10 for sockeye salmon. The migrations are performed, within certain time windows, to move from habitat to habitat.
To maintain healthy and productive salmon it is important that the string of habitats is in good shape. Any weak link in the string or chain can break the cycle.
The interesting question I will be discussing in some detail is how do these fish find their way about during their long-distance migrations. That is, how do they orient and navigate in space and time?
In this discussion I will use some information from bird migration studies to illustrate the techniques that have been used to study orientation in the laboratory and also to identify the difference between orientation and navigation.
It will become apparent that fishes, birds, and many other animal groups, have a number of orientation mechanisms available using cues like the sun, the polarized light pattern of the sky, the earth’s magnetic field, star patterns , and odour of a home stream to move about in the world.
The question of how they navigate, that is to return to the place on earth where they have been once before, is still open.
Dr. Kees Groot to speak in Whistler
What: How do they find their way about? Migration, orientation, and navigation of Pacific salmon.
When: Wednesday, May 26 at 7:30 p.m.
Where: Millennium Place
For decades Dr. Kees Groot has been a leading authority on Pacific salmon, studying the problems of Pacific salmon migration – how fish find their way during long journeys – the problems related to salmonid enhancement, and the potential effects of global climate change on Canada’s west coast fisheries.
Groot was born in Modjokerto on Java, Indonesia in 1928. He spent three years in a concentration camp during the Second World War before heading to Holland in 1946 to study biology at the University of Amsterdam and University of Leyden.
He immigrated to Canada in 1956 and a year later joined the Fisheries Research Board of Canada (now the Department of Fisheries and Oceans) as a fish behaviourist and was based out of the Pacific Biological Station in Nanaimo.
While there he worked under the guidance of Dr. J.R. "Roly" Brett, studying a proposal to build multiple hydroelectric dams along the main stem of the Fraser River, which would threaten the local salmon. After successfully proving that the migrating salmon stocks would be destroyed, the plan was scuttled.
After that point Groot concentrated his studies on the long distance migration, orientation and navigation of Pacific salmon, and used that data to obtain his PhD. Degree at the University of Leyden in 1965.
Soon afterwards Groot was appointed as the biological director for the Netherlands Institute of Sea Research in Holland, and in 1968 he was invited back to Canada to again join the staff of the Pacific Biological Station.
During his tenure there Groot acted as research supervisor for several M.Sc. and Ph.D candidates for Canadian and Dutch universities, and taught as a visiting professor at Simon Fraser University and Bamfield Marine Station. He has also conducted animal behaviour workshops at the Pacific Biological Station and Malaspina Unviersity College, both in Nanaimo and the Rajamangala University in Trang, Thailand.
In 1993 he retired from the Department of Fisheries and Oceans, became the scientist emeritus at the Pacific Biological Station and started his own biological consulting business, Yellow Point Bio-Research.
He has completed a number of fisheries and fish farm related studies under contract with both the government and private industry.
Groot now lives on Gabriola Island with his wife Donny, an artist. Groot’s hobby is growing tropical orchids.
Dr. Groot will be in Whistler this Wednesday as a guest of the Whistler Naturalists Speaker Series to discuss his life’s work and discoveries related to Pacific Salmon migrations. Admission is by donation.
Written by: Dr. Kees Groot