Benbow Dam Fish Counts

Benbow Dam
Location: South Fork of Eel River near Garberville.
Length: 270 ft.
Height: 16 ft.

BENBOW DAM FISH COUNTS

Each year the Bureau of Fish Conservation, of the Department of Fish and Game, counts the salmon and steelhead which ascend the fishway at Benbow Dam, on the South Fork of Eel River near Garberville. These counts have been made each year since the season of 1938-39. The purpose of this bulletin is to inform anglers and other interested persons of the objectives and results of this work.

Objectives

We count fish at Benbow Dam for the same reason that a population census is made, or an inventory is taken, by a storekeeper. Counts are the most effective way to determine fluctuations in the stocks of the steelhead and two kinds salmon in the Eel River. Such knowledge provides the basis for evaluating the results of regulation and management practices.

There is another reason for making the counts. Large dams have been proposed for construction within the Eel River system. Whether or not such dams are built will be determined in large part by there estimated effects on the samon and steelhead runs and the monetary value of these runs. The monetary value can be determined only if we know the size of runs. The size of the runes can best be obtained by counts such as those at Benbow Dam.

Results

Fluctuations in the size of the runs are to be expected and are normal. They are generally of two types: short term fluctuations from year to year and long term cyclical fluctations extending over a period of years. Fluctuations depend upon such things as: food, temperature, stream flows, and other environmetial conditions in fresh water and salt water, intensity of angling, and intensity of commercial fishing(salmon). We can control some of these factors, but as yet have no control over others, such as the survival of young in the ocean. Survival in the ocean is undoubtedly a factor of considerable importance. Small runs in 1938-40 and 1949-50 may not have much significance in the long run.

When sufficient data have been obtained so that we can state why the numbers of salmon and steelhead fluctuate so widely we may be in a position to increase the runs. Until such a time as the facts are available we must avoid actions based on guesswork that may do more harm than good.

Season 1938-39 1939-40 1940-41 1941-42 1942-43 1943-44 1944-45 1945-46 1946-47 1947-48 1948-49 1949-50 1950-51 1951-52 Total Average

King Salmon 6,051 3,425 14,691 21,011 10,612 7,264 13,966 12,488 16,024 13,160 16,312 3,803 14,357 12,476 165,639 11,831

Silver Salmon 7,370 8,629 11,073 13,694 15,037 13,030 18,309 16,731 14,109 25,289 12,872 7,495 12,050 11,441 197,129 13,366

Steelhead 12,995 14,476 18,308 17,356 25,032 23,445 20,172 13,626 19,005 18,225 13,963 13,715 15,138 13,774 239,230 17,088

Total 26,416 26,529 44,072 52,061 50,618 43,739 52,447 42.845 49,138 56,674 43,147 25,013 41,545 37,691 591,998 42,286

Please cooperate in making the counts a complete sucess. If you have any questions, consult the local representative of the Department of Fish and Game or write to the:

California Department of Fish and Game, Ferry Building, San Francisco.
6/25/52-L.S. & G.I.M. -100