Glacier Salmon, Part 2

by Bill Hauser and Richard Nelson

WHY IT MATTERS — A LOOK AT THE PAST

For 35 years, Sandy Milner has carefully documented the progression of streams — from torrents of icy water (i.e., cold, sterile meltwater), devoid of all life, to the home waters for thousands of spawning salmon. When I asked Sandy about the significance of his work, he smiled self-consciously, then said he’s published at least 25 scientific articles based on his studies, and nine of his students have done related PhD research on Glacier Bay streams and more young scientists keep adding to this remarkable accumulation of knowledge. The combined result is a powerful and important exploration of how salmon streams develop from the very moment of their birth.

During the last continental glaciation, which ended about 12,000 years ago, much of North America was covered by an immense sheet of ice extending all the way to the north Pacific Coast. As the climate warmed (very slowly compared to the rate of warming today) the glaciers retreated, and this gave birth to thousands of new creeks, streams, and rivers, some as large as the Columbia and Frazer. Eventually salmon colonized these waters in such abundance that salmon have come to define the entire Pacific Coast ecosystem.

Today in Glacier Bay, scientists can witness and document the same process on a much smaller scale. In this sense, Glacier Bay’s salmon streams are a natural scientific laboratory and a window into the history of North America’s great salmon runs.

WHY IT MATTERS — A LOOK AT THE FUTURE

The rapid colonizing of Glacier Bay by straying salmon demonstrates the resilience and adaptability of these remarkable fish. This is important in a time when thousands of salmon runs in the Lower 48 and Canada have been depleted or completely extinguished by human activities. Studying the biological development of newly born streams in Alaska may help us learn how to rebuild these damaged or lost salmon runs.

Recently, we’ve seen this process of recolonization happening in places like the Elwha River on the coast of Washington, where a major dam, which was a barrier to fish migration, was removed and salmon (all five species of Pacific salmon spawn here now) are quickly returning to their upstream spawning grounds after a 100 year absence.

Climate change is a more daunting problem for some salmon runs, especially in places like California, where warming streams threaten the survival of spawning and hatching fish. On the other hand, Glacier Bay shows us how receding ice creates new, cold streams where adult and young salmon thrive. Similar processes seem to be happening farther north, as straying salmon are beginning to apear in Arctic streams where they were not previously known.

THE SCIENCE OF HOPE

On our last afternoon together, Sandy Milner guided us along yet another new and developing salmon stream. Going through a now-familiar routine, the crew weighed, measured, and tallied the catch of young salmon. Sandy pitched himself into the work alongside Leoni and Jessica, and I couldn’t help noticing how tenderly he handled every fish.

Then Sandy led us farther upstream, to a broad sweep of gravelly outwash and braided river channels, backed by a long, steep, formidable ridge. Once again, he explained how the glacier that once buried this land had retreated and how salmon followed in its wake. To me, this place was exquisitely wild and glorious. To Sandy, I’m certain it was all this, plus a lot more. He seemed utterly contented to be in a place he so obviously loved, delighted with the work at hand, grateful for the good company, and certain about what this place — and its living community — had taught him.

Sandy Milner’s studies show us the remarkable adaptability and resilience of salmon — when they’re given a suitable home. And they remind us, yet again, where there are salmon, there is always hope.

By Richard Nelson for SalmonWorld

Learn more about SalmonWorld and read the original report by Richard Nelson as well as other stories and videos at: http://www.aksalmonworld.org/ (BTW… Sandy and I are former work colleagues.)