Scope

Scope  Rationale  

Two essential components of any salmon enhancement project are: (1) the acquisition of "brood" fish in order to collect eggs and milt required for artificial fertilization and (2) the subsequent artificial incubation of these fertilized eggs in an appropriate type incubator. By fertilizing and incubating eggs in this way, the survival rate from egg to the fry stage can be greatly increased as compared to that occurring in the natural environment.

The collection of the brood fish involved trapping them in the upstream counting fence that was utilized during the 1993 assessment work. However, instead of holding the fish captive in a stream-side holding pen or raceway, the fish were immediately transported to a secure holding facility constructed at a vacant fish processing plant. The holding facility consists of a 3 metre diameter 1.5 metre deep fiberglass tank equipped with a suitable pump and filter which supplied recirculated water and a flow-through of new water. The brood fish were held in this facility from early September to mid-November until they were "ripe" for the stripping of eggs and milt.

As the fish ripened in early to mid-November, stripping of eggs and milt commenced. Milt was added to the eggs and then this mixture was gently and thoroughly mixed to ensure maximum fertilization. The eggs were then washed and allowed to water-harden for a number of hours before being transported to the incubator. The incubation facility consists of a fiberglass trough-type incubator fitted with a pump, filters, chiller and ultraviolet sterilizer which recirculates clean and temperature-controlled river water through the trough containing the eggs. These eggs will hatch in spring of 1995 and these newly hatched salmon, referred to as alevin, will be held in the incubator until the river water is warm enough for their dispersement throughout the watershed. This process will be continued over the next few years until there is sufficient numbers of adult salmon to sustain the river's population through natural reproduction.

In addition to the enhancement work initiated during 1994, the project also continued with stock assessment activities started in 1993. Since the "upstream" counting fence was used to collect brood fish, it was also operated throughout the season to again enumerate numbers of both anadromous and resident species traversing the lower reaches of the North Arm River. Such a count would be helpful in determining whether numbers had increased from the previous year. As was done in 1993, water temperature, air temperature and water level were recorded on a daily basis at the fence location. Further stream surveying was carried out in the uppermost reaches of the North Arm River's watershed in areas that were not reached during the 1993 survey work. Information collected by these further surveys would be beneficial in providing a better estimate of the salmon production potential of the North Arm watershed.

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