This work was performed as Northern California Marine Sport Fish Survey, Dingell-Johnson Project F-12-R. The State of California is responsible for regulating, protecting, enhancing, and assessing the fish and game resources of California. Estimating the existing and potential take of marine resources is one of the tasks of the Marine Resources Operations unit of the Department of Fish and Game. Basic life history information on important species, total catch estimates by species, and enumeration of boats, angler effort, and facilities are compiled and published by this unit. Commercial catch records are gathered, compiled, and published for each year, and give data by month and port of landing. All commercial landings are recorded by species or major groupings at the time of sale to fish buyers. These landings are submitted monthly to the Terminal Island statistical unit. The sport catch, however, has not been assessed except for the partyboat catch which is recorded on logs. An ever-increasing demand placed on marine resources by expanding commercial and sport operations has necessitated a more complete evaluation of all segments of the sport fishery. Popular species such as king salmon, striped bass, and lingcod were known to be important in central and northern California. Information on catch of all species was needed so research funds could be allocated more intelligently and recommendations could be made as to future marine sportfishing improvements projects. Upon completion of the Ocean Salmon Study (Dingell-Johnson project F-12-R) the project was amended to assess total sport catch and effort from Oregon to Point Arguello. Although a routine annual tabulation of catch and effort, as has been conducted on partyboat and commercial catches, could not be perpetuated, one "base" year's data were gathered. Thus, future surveys could reveal trends of effort and catch for any or all segments of the sport fishery. Short-cut methods could be adopted using basic data gathered during the base year survey. The objectives of this assessment survey, the Northern California Marine Sport Fish Survey, were: (1) To estimate the total average annual fishing effort, in angler days, for each fishing method (i.e. party boat, skiff, pier, skindiving, and shore fishing, including surf casting, rocky shore fishing, fishing from jetties, and surf netting). (2) To estimate the total catch by numbers and species for each fishing method. (3) To estimate the total catch by weight for certain fisheries. (This objective was added to the project in 1959.) (4) To compute catch-per-unit-of-effort values for each fishing method. (5) To record length composition of all species taken by partyboat fishermen, skiff fishermen, and skindivers. (6) To enumerate and describe all marine sportfishing facilities. (7) To develop sampling techniques and fish identification guides. All catch and effort data were grouped by monthly intervals at each port or fishing locality, and then summarized into yearly totals for each unit of area. Originally, the objectives included an economic survey of the sport fishery, including amount of money spent per trip, distance traveled, etc., such as was conducted in Florida (Ellis, Rosen, and Moffett, 1958). Also, a survey of San Pablo and San Francisco bays was included. The first 6 months of shore coverage, wherein all fishing methods were sampled, revealed the usual array of ensuing problems, and led to re-evaluation of objectives and methodology. The economic survey was discontinued because, though valuable, it was not essential in a biological approach to management. In addition to estimates of annual average effort and catch, biological information, usable in setting up research programs and as "base year" information, was needed. Since the total shoreline of the many bays of the study area was extensive, only skiff facilities, partyboat operations, and certain piers were included. Shore fishing, skindiving, and fishing from small piers were not surveyed in bays and estuaries. Night surf netting and night pier fishing were not included because the project was unable to provide coverage for night work. The need to collect several series of data per fishing method precluded simultaneous survey of all fishing methods. A complete study in 1 year covering all methods was highly desirable, but our limited budget would not permit such an approach. Thus, pier, shore (primarily surf casting), and surf net fishing were surveyed in 1958; skiff fishing in 1959; and partyboat, rocky shore fishing, and skindiving in 1960–61. Some series' of data were collected throughout the 3 years to make it possible to evalute yearly variations in catch and effort. No exceptional physical environmental changes, which may have materially altered biological relationships between species, occurred during the survey. The data from several consecutive years have been collated to represent average annual estimates for all parameters. Had this study been conducted during the 3 previous years (1955–1957), the sudden warming of ocean waters in 1957, and concurrent influx of southern forms, would have presented unique problems in treating the data in this way. From 1958–1961 there was gradual cooling and a return to a more normal physical environment, with consequent reduced occurrences of southern forms in central and northern California, such as barracuda which, in 1957, ranged as far north as Canada. Results of this survey have been summarized in three different ways: (i) as an administrative report, which included a complete set of typed raw data tables along with a narrative description of each fishery and methods used at each locality; (ii) as this report, which includes much of the original data, but in several cases annual summaries have been given in lieu of monthly summaries, and length frequency data are summarized; (iii) as four fishing maps covering 10 counties from Oregon to Santa Barbara County, Calif. These maps list all fishing facilities, public camping sites, and areas where shore fishing, skindiving, clamming, abalone picking, and surf netting are conducted. Also included are details as to the best times of year to fish, gear and bait to use, and notes on life history and behavior of certain fishes.