California Department of Fish and Wildlife

Kelp Bass Studies

Biologist collecting biological data and tagging a kelp bass during a hooking mortality study, CDFW photo by Dianna Porzio

The State Finfish Management Project was created in July 2006. In 2011 the Project was re-organized and the Southern California Fisheries Research & Management Project assumed all work for kelp bass and other basses. Bass project staff are based in Los Alamitos. The fishery data collected include length-at-age, catch per unit-of-effort, seasonal maturity, fishing gear effects on undersized fish, and relative species composition within habitats. These data are collected in order to manage fisheries with the best available information and ensure their long term resource sustainability for economic and recreational benefits.

Historical Length and Catch Data

Marine Recreational Fisheries Statistics Survey (MRFSS) and California Recreational Fisheries Survey (CRFS) kelp bass length and catch data from 2000 to 2008 were analyzed by project staff to determine trends in length and angler catch (or bag) frequencies. All data analyzed were obtained from anglers interviewed by MRFSS and CRFS field technicians. These data will be used to assist in future kelp bass population evaluations. Summaries of data are provided below.

Length frequency data

The total length (TL) data summarize the total number of kelp bass measured from interviewed anglers each year. The TL data were grouped into four length intervals: less than 12 inches (sub-legal), 12 to 12.99 inches, 13 to 17 inches, and greater than 17 inches to provide a better understanding of length distribution. Average percentages were calculated for the 9-year period and results indicated that almost 86% of all kelp bass measured were from the 12- to 17- inch TL interval.

2000-2008 Kelp Bass Length Frequency Data by Year

Year Number of Fish & Percentage Total Length of Kelp Bass (in inches)
<12 12 to 12.99 13 to 17 >17
2000 Number of Fish 34 234 704 120
Annual Percentage 3.11 21.43 64.47 10.99
2001 Number of Fish 41 227 514 55
Annual Percentage 4.90 27.12 61.41 6.57
2002 Number of Fish 83 503 896 133
Annual Percentage 5.14 31.15 55.48 8.24
2003 Number of Fish 91 814 1431 233
Annual Percentage 3.54 31.69 55.70 9.07
2004 Number of Fish 152 1071 3306 566
Annual Percentage 2.98 21.02 64.89 11.11
2005 Number of Fish 134 828 2473 589
Annual Percentage 3.33 20.58 61.46 14.64
2006 Number of Fish 146 1103 4214 878
Annual Percentage 2.30 17.39 66.46 13.85
2007 Number of Fish 107 722 2615 544
Annual Percentage 2.68 18.10 65.57 13.64
2008 Number of Fish 184 1045 2933 450
Annual Percentage 3.99 22.66 63.59 9.76
Combined 2000-2008 Total Number of Fish 972 6547 19086 3568
Average Percentage 3.55 23.46 62.11 10.87

Note: MRFSS and CRFS kelp bass length measurements were collected as fork length in millimeters.
All fork lengths presented here were converted to total length in inches as California regulations are written in this manner.

Catch frequency data

The kelp bass catch frequency data summarize the number of fish caught (also called daily bag and possession) per individual interviewed angler from 2000 to 2008. The table below provides annual summaries of total fish caught, total number of anglers sampled, and the average number of fish per angler. Data summarized include all angler trips that targeted kelp bass, which means that bags over the legal 10-fish limit and bags with zero fish caught were included. The average annual catch of kelp bass per angler for the 9-year period was 0.8 fish. If bags with zero fish were eliminated from the summary, the average annual catch of kelp bass per angler for the 9-year period would be 2.1 fish.

2000-2008 Kelp Bass Average Angler Catch (or Bag) by Year

  Year
  2000 2001 2002 2003 2004 2005 2006 2007 2008 Combined
Number of Fish 1496 1077 1842 3394 9834 4547 6253 5075 4837 38355
Number of Anglers 1474 1269 2253 3669 8944 6393 7666 7907 7650 47225
Average Fish per Angler 1.01 0.85 0.82 0.93 1.10 0.71 0.82 0.64 0.63 0.81