Bonneville Dam; 83-Years of Spring Chinook Counts

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Bonneville Dam Spring Chinook Counts

The Effects of Fish Run Numbers

There are many ways to measure the success or failure of managing natural resources. In the case of anadromous fisheries many claim to have superior scientific knowledge. Yet even professionals with multiple decades of deep experience and master’s degrees in fisheries admit that predicting results of any management plan for salmon or steelhead is never certain. There are too many factors out of our sight and out of our control. In the case of wild fish, we rarely actually watch eggs being placed in a Redd, incubating in the gravel, or fry emerging from it. Young fish learn quickly that staying out of sight is the best tactic for survival. Then they go to sea where they disappear completely for several years. When they return to fresh water to reproduce, they remain nearly as elusive. Often anglers are nearly surrounded by anadromous fish that refuse to bite. Yet many anglers claim to have superior knowledge about these same fish, and it is hard to prove them wrong (or right). It is only when they have to pass choke points such as fish ladders at dams that we can get clear visions of anadromous fish numbers and physical conditions. The smallest run and largest run were just six years apart.

Facts:

For data collection, the Spring Chinook run timing at Bonneville Dam IS April 1 – May 31.

Total passage of Spring Chinooks at Bonneville Dam since 1938 = 8,555,137 (div) 83-years = 103,074

The average annual Spring Chinook run size is: 103,074

The largest and smallest annual run sizes:
Largest: 2001=393,027 Smallest: 1995=10,293
May 31, 2021 = 66,778 - is less than average>

Bonneville Dam Spring Chinook Counts

Year

Annual Run Size

Totals (Decadal Run Size)

1938

22,379

1939

76,900

1938-1939

99,279

99,279

1940

66,378

1941

72,569

1942

40,502

1943

65,531

1944

30,865

1945

43,741

1946

67,820

1947

134,010

1948

42,728

1949

51,572

1940-1949

615,716

615,716

1950

58,369

1951

135,120

1952

116,192

1953

170,744

1954

136,120

1955

171,895

1956

63,449

1957

139,750

1958

78,272

1959

61984

1950-1959

1,131,895

1,131,895

1960

69,597

1961

90,815

1962

91,253

1963

75,708

1964

91,428

1965

84,489

1966

112,760

1967

85,003

1968

99,187

1969

174,261

1960-1969

974,501

974,501

1970

111,264

1971

126,010

1972

186,140

1973

142,948

1974

135,270

1975

104,615

1976

113,446

1977

120,236

1978

150,749

1979

51,793

1970-1979

1,242,471

1,242,471

1980

53,,100

1981

63,088

1982

70,435

1983

55,255

1984

46,866

1985

83,699

1986

118,614

1987

99,279

1988

90,532

1989

81,577

1980-1989

709,345

709,345

1990

94,487

1991

57,553

1992

88,425

1993

111,581

1994

20,305

1995

10,293 LOWEST YEAR

1996

51,492

1997

114,870

1998

38,497

1999

38,967

1990-1999

626,470

626,470

2000

178,302

2001

393,027 LARGEST YEAR

2002

272,598

2003

197,649

2004

170,308

2005

74,053

2006

96,458

2007

67,504

2008

125,585

2009

116,405

2000-2009

1,691,889

1,691,889

2010

244,204

2011

167,146

2012

158,089

2013

83,345

2014

188,083

2015

220,480

2016

137,215

2017

83.624

2018

87,894

2019

54,657

2010-2019

1,341,197

1,341,197

2020

55,596

55,596

2021

66,778

66,778

83 years total

8,555,137

8,555,137

Average Run Size

103,074

Above Average

34

Below Average

49

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