20 May 2011

Chilko Lake Sockeye Salmon Smolt

Right now the Chilko River is alive with the annual spring migration of baby sockeye salmon. The one year old smolts are heading to the Pacific Ocean. The fry are emerging from the gravel and heading up Chilko Lake. Consequently there are a lot of baby fish in the Chilko system right now! These baby sockeye, are making a lot of other species very fat and happy, including my Dad, Bud’s favorite mergansers, the DFO’s favorite bull trout, and the big bows!

The adult Sockeye salmon show up to spawn in Chilko around the end of August.  In 2010 two million plus sockeye made the journey home to Chilko to lay their eggs in the clean gravel beds of the river bottom.  After laying their eggs, all of these sockeye die.  They feed everything under the sun at Chilko.  Not only do they feed all of the other wildlife such as Grizzly Bears, Eagles, cougars, coyotes, and other fish, but they are a natural fertilizer for all of the plant species in the water system and along the shoreline.  More sockeye means more nutrients, more algae, more bugs, (big hatches) more food, and of course big healthy bows and bull trout. 

Back to the baby fish; the eggs are in the gravel. Once the eggs have been fertilized by the male sockeye, the embryos will incubate and eventually hatch, this stage is called the alevin.  These tiny sockeye will remain in the gravel during the winter time feeding off their egg sacs. In the beginning they look like an egg with an eye, slowly they will develop their fins, gills, and slowly start to look like a small fish with an egg sac on its belly.  As they continue to develop, the egg sac continually decreases in size as they feed off it. Eventually it disappears and the fish skin slowly closes over it. This stage is called “buttoning up” At this point they emerge from the gravel and start to physically feed in the river on plankton.  They have now officially reached the third stage of their development and are called “fry”.  

Right now in the middle of the river they are emerging from the gravel and venturing to the safety of the shallow water … from here they follow the shoreline up Chilko Lake where the majority will live for one year.  Some will stay for two years. Occasionally a few will stay for three years, but this is rare. No one is sure why they stay longer, but at some point everybody has to grow up and head out, so off to the ocean they go.

Currently about thirty million salmon smolt (rough field estimate) are wiggling their way from Chilko Lake to the Pacific Ocean; and so their first big journey begins.  It will take them about seven days tumbling down the Chilko, Chilcotin, and Fraser Rivers to reach the Pacific Ocean. What a journey and so many amazing things to see.   These sockeye smolts leaving Chilko are the off spring of the sockeye who spawned here in the fall of 2009. They will be the Adult Sockeye returning in 2013.

If you believe that our salmon and freshwaters fish species are important, please connect with me through Facebook, my RSS feed, twitter, or my lodge blog…

Karen Mclean owns and operates Tsylos Park Lodge at Chilko Lake in British Columbia, Canada. Karen and her family have operated at Chilko Lake since 1957. In that time she has gained an in depth love and historic knowledge of the Chilko water shed.