Striped Bass  Pages 71 - 83

Striped Bass Life History Notes (Continued)

It appears that reproduction was exceptionally good in 1953 and 1954 with progressively poorer years in 1955 and 1956. Unfortunately, statistical procedures have revealed certain discrepancies in the sampling methods which limit the usefulness of past surveys as indices of abundance. A new approach is being employed which it is hoped will yield more useful data.

Experimental data indicate the fry are usually located nearer the surface than the bottom, although a recent series of tests designed to determine their vertical distribution, showed the reverse to be true on at least one occasion. Chadwick (unpublished data) conducted tests in the summer of 1957 which showed that the smaller fish are found in greater numbers near the shoreline than in mid-channel. As they approach two inches in length, they are found more evenly dispersed throughout the channel. Evidently, even fry less than an inch in length have some control over their movements despite rapid tidal currents. His findings agree with observations made by the writer in 1954 and 1955 while engaged in this work.

Juveniles. By early summer young fish are scattered throughout all parts of the Delta and at least as far downstream as San Pablo Bay. Apparently, all fry are not carried into the Delta because they can be found far up the Sacramento and San Joaquin Rivers in the late summer and fall. It seems rather improbable that they return upstream after having once gone down. Juvenile fish have been seined all along the Sacramento and San Joaquin rivers and at least as far down as Point Wilson in San Pablo Bay.

During seining operations during the fall (October) of 1956 and 1957, throughout the Bay and Delta, fish with mean lengths ranging from 2.9 to 4.0 inches were taken. The overall average is probably about 3.5 inches. There does not appear to be any perceptible difference of growth pattern in any particular part of the area covered. Growth ceases, or at least is greatly diminished from October until the following March. Juvenile fish apparently remain principally in the Delta for two to three years before moving into San Francisco Bay or the ocean. During this period they tend to be gregarious, moving about in scattered schools.

Fish up to 16 inches may be found anywhere throughout most of the year, but certain areas seem to be more favorable than others. Such juveniles are almost always present in San Pablo Bay in the vicinity of Mare Island, the Napa River, Suisun Bay, and in a number of localities in the Delta.

Raney (1952) states: "During the first and second years they remain in small schools or feeding groups, but it has been observed that they exist in large schools by the end of the second summer."

The age at which they first begin their annual migrations between fresh and salt water has not been positively established on the West Coast. Most fish, it is thought, undertake them in the third year though many unquestionably begin in the second and others probably wait until their fourth year or later. Inherent differences between fishes, and sexual differences, are likely factors influencing the age at which they move into salt water. The proportion of adults making these annual excursions is not known; however, since large fish are very scarce in the Delta during the summer, it may be concluded that the great majority are involved.

Migrations. Clark (1934 and 1936) and Calhoun (1952) are responsible for most of our present knowledge on striped bass migrations in California. Both have conducted tagging experiments showing the migratory patterns. A third study, by Chadwick, was underway at the writing of this report.

Clark reported the results of tagging 1,544 bass, mostly small ones (mean length 11 inches), and found that they did not move in a well defined migration but more or less diffused out of the tagging area.

Calhoun's work was with legal sized fish (then 12 inches and over), of which he tagged more than 4,000. He found that unlike the smaller fish, the adults did undertake well defined seasonal migrations. Recoveries of tagged fish by sportsmen and gill net fishermen showed that the adults move upstream into San Pablo Bay and Carquinez Strait in the fall, then into the Delta in the winter, spread out and ascend the tributary rivers in the spring, and move down to the Bay again by early summer.

Their movement to and in the ocean is not yet understood, although a fair number appear to enter the ocean each year. Occasionally, good catches are made by surf casters off San Francisco beaches. Although stripers are seldom taken off shore, the party boat fleet made good catches of striped bass in the ocean during 1956. On the Atlantic Coast extensive north-south ocean migrations are made, presumably for feeding purposes. This phenomenon has not been observed to occur here.

Food Habits. Scofield (1911) found that fish up to four inches, in Napa Creek, relied on marine worms (50 percent) crustaceans (48 percent) and small fish (2 percent). The items are listed in Table 25.

Hatton (1940), in a collection of 76 fish ranging from one to six inches in length taken at Martinez, found that 69.4 percent of all stomachs contained crustaceans. The percentage of stomachs containing each item found is shown in Table 26.

Hatton points out that the items were found during September and November while the water at Martinez was brackish.

Under freshwater conditions in this area, during the spring, the amphipods and isopods disappear, and the small fish were found to be feeding almost exclusively on a species of Mysidacea (Neomysis mercedis).

The writer has on several occasions while checking the stomachs of young-of-the-year bass (2 to 4 inches) from the San Joaquin River and Suisun Bay during the summer also found that mysid shrimp {Neomysis mercedis) was by far the major item in the diet. Some of the stomachs examined were simply packed with them. Each spring and summer the River and Delta abound with these small crustaceans.

Messrs. Fisk and McCammon of the Department, who have studied the food habits of the white catfish in the Delta, observed that amphipods (Corophium spinicorne) were the most important organism utilized by catfish. Hatton's work seems to confirm the importance of it in the diet of small bass. Unfortunately, data are meager on feeding habits of small bass from the time they begin to feed until they are through the first year.

On the East Coast, freshwater shrimp (Gammarus), and Dipterid (chironomid) larvae were found to be major food items.

Striped bass become piscivorous [ Habitually feeding on fish; fish-eating.] at least by thetime they reach 6 inches and perhaps earlier. Their diet from this size on is extremely varied, and appears to depend upon the forage available. The larger fish appear to have a proportionately larger percentage of fish in the diet but even the largest specimens were found to contain crustaceans.

Bay shrimp (Crago sp.) appears to be one of the most common items, along with Neomysis mercedis and the small forage fishes found in the Bay, such as smelt, herring and anchovy. Hatton (op cit) examined 224 stomachs of adult bass taken near Pittsburg between March 13 and May 4, 1939 and found 56.6 percent to be empty (during the spawning season). His findings are summarized in Table 27.

Johnson and Calhoun (1952) examined 387 stomachs of adult bass collected during a period of a year. All fish were over 12 inches in length. One group of 229 was collected between San Rafael and Martinez during the summer and fall, while the other lot of 158 was taken from the Delta portion of the San Joaquin River between Antioch and the mouth of Middle River between November 1947 and June 1948.

Shrimp (Crago sp.) were the most numerous item and comprised the largest volume of all organisms found in the summer group. It occurred in 35 percent of all stomachs examined and formed 53 percent of the volume of all foods. Anchovies, the next most important item, occurred in 11 percent of the stomachs and comprised 39 percent of the food volume Isopods, crabs, mysid shrimp, and other fish were also found but none occurred more than six times or formed more than 2 percent of the total volume. Of this group of fish 28 percent of the stomachs examined were empty.

Their winter sample, the one from the Delta, contained 66 individual fish (42 percent of the sample) with empty stomachs. Neomysid shrimp occurred in more stomachs than any other item and formed, surprisingly enough for large fish, 20 percent of the total volume. Small fish, however, were the most frequent item and accounted for the greatest volume (64 peicent). Bay shrimp (Crago sp.) accounted for 13 percent of the volume.

Shapovalov (1936) examined the stomachs of 47 striped bass taken from the mouth of Waddell Creek, Santa Cruz County. He found a large variety of items, with crustaceans predominating in the small bass, and other fish being the principal food of the larger bass.

Bass are obviously omnivorous feeders; quoting Scofield (1931): "Practically every marine form common to the San Francisco Bay region has been found in their stomachs. Their food includes fishes, such as small Pacific herring, smelt, anchovies, split-tails, striped bass, shad, gobies, carp and perch; crustaceans and mollusks—crabs, shrimps, periwinkles, clams; and various other forms such as worms, copepods and vellella."

Part 5 of 6 |  « Previous |  1 |  2 |  3 |  4 |  5 |  6 |  Next »

Citations

Calhoun, A. J.
1949 California Striped Bass Catch Records From the Party Boat Fishery; 1938-1948. California Fish and Game, Vol. 35, No. 4, pp. 211-253.
1950 California Angling Catch Records from Postal Card Surveys: 1936-1948 With an Evaluation of Postal Card Non-response. California Fish and Game, Vol. 36, No. 3, pp. 177-233.
1951 California State-Wide Angling Catch Estimates for 1949. California Fish and Game, Vol. 37, No. 1, pp. 69-75.
1952 Annual Migrations of California Striped Bass. California Fish and Game, Vol. 38, No. 3, pp. 391-403.
1953a. State-Wide California Angling Estimates for 1951. California Fish and Game, Vol. 39, No. 1, pp. 103-113.
1953b. Distribution of Striped Bass Fry in Relation to Major Water Diversions. California Fish and Game, Vol. 39, No. 3, pp. 279-299.
1957 Striped Bass Fishing Map (Revised by John E. Skinner). California Department of Fish and Game.

Calhoun, A. J., and John E. Skinner
1954 Field Tests of Stainless Steel and Tentalum Wire with Disk Tags on Striped Bass. California Fish and Game, Vol. 40, No. 3, pp. 323-328.

Calhoun, A. J., and C. A. Woodhull
1948 Progress Report on Studies of Striped Bass Reproduction in Relation to the Central Valley Project. California Fish and Game, Vol. 34, No. 4, pp. 171-187.
1950 Striped Bass Reproduction in the Sacramento River System in 1948. California Fish and Game, Vol. 36, No. 2, pp. 135-145.

Clark, G. H.
1929 Sacramento-San Joaquin Salmon (Oncorhynchus tshawytscha) Fishery of California. California Fish and Game, Fish Bulletin No. 17.
1932 The Striped Bass Supply of California, Past and Present California Fish and Game, Vol. 18, No. 4, pp. 297-298.
1933 Fluctuations in the Abundance of Striped Bass (Roccus lineatus) in California. California Department of Fish and Game, Fish Bulletin No. 39.
1934 Tagging of Striped Bass. California Fish and Game, Vol. 20, No. 1, pp. 14-19.
1936 A Second Report on Striped Bass Tagging. California Fish and Game, Vol. 22, No. 4, pp. 272-283.
1938 Weight and Age Determination of Striped Bass. California Fish and Game, Vol. 24, No. 2, pp. 176-177.

Cole, Charles E.
1930 Angling for Striped Bass. California Fish and Game, Vol. 16, No. 4, pp. 286-290.

Craig, J. A.
1928 The Striped Bass Supply of California. California Fish and Game, Vol. 14, No. 4, pp. 265-272. 1930 An Analysis of the Catch Statistics of the Striped Bass (Roccus lineatus) Fishery of California. California Department of Fish and Game, Fish Bulletin No. 24.

Hatton, S. Ross
1940. Progress Report on the Central Valley Fisheries Investigations, 1939. California Fish and Game, Vol. 26, No. 4, pp. 334-373.

Jackson, H. W. and R. E. Tiller
1952 Preliminary observations on spawning potential in striped bass (Roccus saxatilis). Maryland Dept. Res. and Ed., Pub. 93, pp. 1-6.

Johnson, W. C, and A. J. Calhoun
1952 Food Habits of California Striped Bass. California Fish and Game, Vol. 38, No. 4, pp. 531-533.

Morgan, Alfred R. and Arthur R. Gerlach
1950 Striped Bass Studies on Coos Bay, Oregon in 1949 and 1950. Oregon Fish Commission, Contribution No. 14.

Pearson, John C.
1938 The Life History of the Striped Bass or Rockfish, (Roccus saxatilis) (Walbaum). U. S. Department of Commerce Bureau of Fisheries, Vol. XLIX, Bulletin No. 28.

Raney, Edward C, Ernest F. Tresselt, Edgar H. Hollis, V. D. Vladykov and D. H. Wallace
1952 The Striped Bass (Roccus saxatilis). Bulletin of the Bingham Oceanographic Collection, Vol. 14, Article 1.

Scofield, N. B.
1910 Notes on striped bass in California. Biennial Report, Calif. Board of Fish and Game Commissioners for 1909-1910, pp. 104-109.

Shapovalov, Leo
1936 Food of the Striped Bass. California Fish and Game, Vol. 22, No. 4, pp. 261-270.

Skinner, John E.
1955a. California State-Wide Angling Estimates for 1953. California Fish and Game, Vol. 41, No. 1, pp. 19-32.
1955b. Observations on the Shad Gill Net Fishery in 1954. California Department of Fish and Game, Inland Fisheries Branch, Administrative Report 55-3.
1957a. Incidental losses of Striped Bass in the Sacramento River Gill Net Fisheries for Shad and Salmon. California Department of Fish and Game, Inland Fisheries Branch, Administrative Report 57-2.
1957b. Status of the Striped Bass—Sturgeon Study and Suggestions for its Future. California Department of Fish Fish and Game, Inland Fisheries Branch, Administrative Report No. 57-11.

Smith, Hugh M.
1895 The Striped Bass History and Results of Introduction. U. S. Fish Commission Bulletin, Vol. 15, pp. 449-458.

Woodhull, Chester
1947 Spawning Habits of the Striped Bass (Roccus saxatilis) in California Waters. California Fish and Game, Vol. 33, No. 2, pp. 97-101

The entire document is available in Adobe PDF format.
John E. Skinner. 1962. An Historical Review of the Fish and Wildlife Resources of the San Francisco Bay Area.
http://www.estuaryarchive.org/archive/skinner_1962/
San Francisco Estuary and Watershed Archive

Also available StriperSurf.com version Printer Friendly format - ±15 pages

07.02.27, Revised 09.01.14