HATCHERIES
III. C. 259 Draft Statewide Strategy to Recover Salmon – Volume
2 Hatchery Management to Meet the Needs of Wild Fish III. D. HATCHERY MANAGEMENT
TO MEET THE NEEDS OF WILD FISH
Section 1: Overview
A Historical Perspective
To understand why hatcheries are operated and managed as they are
today, one must understand the role hatcheries have played in the past,
currently play and will play in the future. As the management objectives
have varied, so have hatchery practices. The two, although different, cannot
be thought of separately. For example, practices which have been used to
produce legal size trout for opening day, which require over one year of
rearing, have always been very different from those used to rear fall chinook,
which are released after only 90 days of rearing. While the trout may have
an average life expectancy of only a few days, the salmon may live four
or five years and travel thousands of miles from its hatchery of origin.
Different expectations for the product of a hatchery require different
hatchery practices.
Since the construction of the first hatcheries before the turn
of the century, the main objective of most fish management programs was
to maximize consumptive utilization of the resource - similar to an agricultural
model of “crops”. Fish not harvested were considered a “wasted” resource.
The early efforts to offset declining wild fish runs (caused mostly by
habitat loss and overfishing) involved collecting large quantities of eggs,
hatching a very high percentage of these and then transplanting the fry
into areas with declining runs, areas where fish had become extinct, or
into bodies of water where increased catch was the primary objective. Because
of the lack of basic life history information and an understanding of the
stock concept (e.g., adaptive differences between stocks, homing behavior,
the lack of understanding about carrying capacities, rudimentary knowledge
of fish behavior and poorly developed culturing practices), many of the
transplants failed; others had various levels of success. Those that were
successful, no doubt had some negative effects on any naturally spawning
populations existing in the same habitat. During this time, hatcheries
were promoted as effective substitutes for natural fish habitat, leading
to complacent attitudes about habitat conservation and large-scale habitat
degradation.
The Recent Past
As scientific knowledge expanded to include the stock concept and
the values of biological diversity, importance of wild salmonid stocks
became more recognized and attention was focused on specific hatchery practices
(and related fish management objectives). The genetic changes that can
result from various hatchery practices and the value of local adaptation
of stocks received increased attention. The ecological impacts of large
scale hatchery releases also began to be understood. The effects of not
allowing salmon above hatchery racks, which had always been justified on
the basis of protecting the hatchery population from disease, was questioned.
In