BPA Fish and Wildlife FY 1997 Proposal

Section 1. Administrative
Section 2. Narrative
Section 3. Budget

see CBFWA and BPA funding recommendations

Section 1. Administrative

Title of project
Food Limitation and Density Dependent Growth of Salmon in the Open Ocean

BPA project number   5517800

Business name of agency, institution or organization requesting funding
TBD

Sponsor type   Placeholder

Proposal contact person or principal investigator

BPA technical contact   ,

Biological opinion ID   Research M&E Progarm, Hypothesis D.2.2.

NWPPC Program number   

Short description

Project start year   1997    End year   2007

Start of operation and/or maintenance   0

Project development phase   PLANNING

Section 2. Narrative

Related projects

Project history

Biological results achieved

Annual reports and technical papers

Management implications
While experimental modification of the environment is difficult, apart from modifications in numbers of hatchery smolts recruited to the sea and certain aspects of fishery management, it is imperative for managers to better understand the offshore region and its influence upon salmon production. Recent papers have noted the importance of interdecadal cycles in marine productivity. Other work on mean size in salmon suggests that carrying capacity of the sea may be exceeded for some species. The abundance of pink and chum salmon in the Pacific Rim has approximately doubled in the last 20 years. Sockeye abundance has been enhanced with artificial culture, spawning channels, and lake fertilization. Steelhead output from hatcheries has increased dramatically (Burgner et al. 1992). Chinook enhancement has expanded. These factors should be placed in perspective with oceanographic factors and interpreted historically and currently.

U.S. oceanic tagging efforts were confined to the period before 1982, operated under auspices of the INPFC. Those programs, in conjunction with tagging by other nations, yielded limited information on ocean destinations and distribution of Columbia River salmon. They should begin anew, in cooperation with other nations, and coupled with ocean purse-seining to assess distribution of fish marked from various natal areas. They are too costly for support by individual groups, and should be funded nationally and internationally.

Today, very little is known about the ocean distribution of ESA-listed salmon produced in the Snake River, or of steelhead proposed for listing in the mid-Columbia region. Recoveries of coded wire tags are few, confined largely to the areas of ocean trolling for salmon and to limited ocean seining. Funding is a major obstacle. Ocean sampling and tagging is very expensive, and could easily consume all available funds for study. This study will probably have to "piggy-back" on any oceanic work funded by entities not directly connected to Columbia River management. For cost reasons, the ocean tagging program should be considered as having lower priority than other components of this overall marine effort.

Specific measureable objectives

Testable hypothesis
HYPOTHESIS D.2.2: GROWTH OF SALMONIDS IN THE OPEN OCEAN IS NEITHER FOOD LIMITED NOR DENSITY DEPENDENT.

Underlying assumptions or critical constraints

Methods
Analysis of historical information and correlation work can be done. Field effort in ocean tagging would be prohibitively expensive in time and money.

Brief schedule of activities

Biological need
Recent papers have cautioned that the carrying capacity of the sea for salmon fluctuates over time, and that fishery enhancement programs may have led to excessive recruitment of salmon to marine rearing areas (Beamish and Bouillon 1993). The ocean area actually used by salmon may be smaller than originally thought as fish respond to thermal limits (Welch et al. 1995), and to patchy distributions of prey (Thomson et al. 1992). Some papers report a decline in mean size of salmon, and infer that carrying capacity has been exceeded (Bigler and Helle 1994). Columbia River data were a small part of information used to document the decline. This project would examine historical trends in growth in salmon produced in the Columbia River and nearby systems, and any available information on early marine survival before and after the advent of major increases in hatchery-produced recruitment.

One study of Fraser River sockeye demonstrates reduced size at adult return for sockeye that spend three years at sea, when Bristol Bay sockeye catches are high (McKinnell 1995). The same work showed no such relationship for sockeye that spent two years at sea. The authors noted that 4-year-old sockeye require as much food in April-July in the year of maturation as in the preceding 34 months of life.

Critical uncertainties

Summary of expected outcome

Dependencies/opportunities for cooperation

Risks

Monitoring activity

Section 3. Budget

* For most projects, Authorized is the amount recommended by CBFWA and the Council. Planned is amount currently allocated. Contracted is the amount obligated to date of printout.

Funding recommendations

CBFWA funding review group   System Policy

Recommendation    Tier 2 - fund when funds available

Recommended funding level   $1,000,000