Robertson Hatchery - Background Info

Early Development of Robertson Creek Hatchery

The Robertson Creek project began as a spawning channel in 1959.  When officially opened in 1960, it was the largest artificial spawning channel in North America.  The project was designed to introduce pink salmon into the Somass River system, and although 1.6 million pink salmon eggs were planted in the gravel, very few pink salmon returned as adults to the channel.

In 1971, a successful pilot operation on Robertson Creek led to construction of a full scale salmon hatchery.  Production began with chinook and coho runs in the fall of 1972.  Steelhead trout were later introduced.  An expansion of the facility in 1975 increased the rearing capacity by two ponds.  A second expansion in 1980 increased incubation, rearing and adult fish handling facilities and added a water cooling system for the summer months to reduce stress and disease among rearing coho and steelhead fry.

Present Day Operations

Today, Robertson Creek Hatchery produces 8 million chinook smolts, 1 million coho smolts and 180,000 steelhead smolts each year.  The resulting adult salmon production is 150,000 chinook, 100,000 coho and 10,000 steelhead each year.

To produce these salmon for the various fisheries in the area, Robertson Creek uses state-of-the-art hatchery techniques.  From beginning egg to later smolt stage, salmon are nurtured in a protected environment.  They are safe from predators and environmental pressures that normally, in nature, take a heavy toll on their survival.   Then the hatchery release the smolts into the river where they begin migration to the ocean.  These salmon return as adults in much larger numbers than found in nature.

The Hatchery Process

The hatchery process begins with the capture and sorting of large adult fish as they return through the fishways to spawn.  Once they have ascended the fishway, the fish are lifted into a tank and anaesthetized with harmless carbon dioxide gas.  The fish quickly recover within five minutes of their return to fresh water.  While the fish are sedated, fish culturists stroke their bodies to judge their stage of "ripeness".  If ready, the females are stripped of their eggs and the males of their sperm.  When salmon are not ripe, they are placed in holding ponds until they mature.

If you are visiting Robertson Creek in the fall, there are underwater viewing areas at each fishway where you can see the fish "eye to eye".

Incubation

Eggs and sperm are stirred together in the incubation room.  After fertilization, the eggs incubate in stacked trays for six to seven months.  Each tray hold approximately 7,000 eggs.  Water flows down through the trays at a carefully controlled rate and temperature.

Robertson Creek Hatchery also incubates 2.8 million chinook eggs in Japanese keeper channels.   The eggs begin incubation in "bulk boxes" each of which hold 330,000 eggs.  These eggs are removed to the keeper channels and stacked in single layers on screens above single layers of gravel.  Water flows horizontally through the channels.

Rearing

Once the eggs hatch they are called alevins.  When their yolk sac, a self contained food supply, has been consumed they are moved to rearing channels.  At this stage they are called fry.

Fry are fed a commercially produced diet of fish meal (herring, anchovy and groundfish) with various vitamins and minerals added.

The rearing ponds are supplied with water from Robertson Creek and from a small tributary, Glover Creek.  Water intake for the ponds have a unique self-cleaning device (called a Finnigan Wheel).

When each species of salmonid has been reared to its optimum weight they are released into the river to begin their salt water migration.   At this stage they are called smolts.  Chinook are reared for about 65 days and released at 6 grams in weight.  Coho and steelhead are reared for one year to 25 grams and 60 grams respectively.