The importance of salmon estuaries
January 13, 2017 - Campbell River, B.C.
Picture this: a single French horn sitting in the middle of the soccer pitch at Wembley Stadium. The horn’s tubing is a meandering river, the bell is a brackish estuary, and the rest of the stadium is the open ocean. Now, picture a tiny salmon starting its life at the horn’s mouthpiece, then navigating the tiny river and coming to rest and acclimatize at the estuary, before venturing off into a massive open blue.
This visualization helps underpin the importance of salmon estuaries in a salmonid’s lifecycle, and retired biologist, Dr. Colin Levings, was determined to help raise their profile as vital habitat for anadromous fish (fish that migrate from salt water to spawn in fresh water).
Ecology of salmonids in estuaries around the world (Levings, 2016) is an important collection of what we know about salmon estuaries, as well as a look into critical knowledge gaps that can further assist conservation efforts.
And recent conservation efforts by dedicated local groups on Vancouver Island are proving fruitful.
In 1969 the Comox Valley Chapter of the Steelhead Society began to ask why fish were not rebuilding in the Comox Valley’s Tsolum River. After decades of discussion, in 1997, funding was received from Fisheries and Oceans Canada for the Tsolum River Restoration Project. As a result of restoration efforts, the Tsolum River has recently had a return of naturally spawning salmonid species. The 2015 pink salmon return was estimated at 129,000 fish – as high as any historical record.
The Campbell River Estuary was once an “industrial mud pit” according to Nature Conservancy Canada. But in recent years, the estuary has undergone a dramatic transformation back into an area of rich diversity and beauty. These days, looking down into the shallow river water swirling lazily past the rocky shore, it is easy to spot dozens of finger-length Chinook fry milling about the weeds and algae. The river has hosted several historically-high salmon returns in the last decade.
Perhaps the words of angler/writer Roderick Haig-Brown (1908-1976) best summarize the importance of the freshwater phase for salmonids, stating “Take care of the rivers and streams and the rest will take care of itself.”