Biological Samples Collected

GeneticsSurvey personnel are currently working with the NWFSC Genetics & Evolution Program to develop separate indices of abundance for vermilion and sunset rockfish by analyzing the finclips collected from each of the vermilion rockfish complex specimens during sampling (Figure 9). This genetic information is used along with age and biological data collected during the survey for use in a biological profile of the two species to support stock assessments.

AcknowledgementsThe hook and line survey would like to acknowledge the captains and crew of the F/V Aggressor and Mirage for their hard work and dedication over the last 11 years, and the F/V Toronado for last year’s work with us. We also recognize Ian Stewart, now with the IPHC, for his ingenuity in developing the first GLM-based approach for modeling rod and reel data. We thank Anna Elz, Jennifer Hempelmann, and the NWFSC Molecular Genetics Lab for their work analyzing the thousands of tissue samples we have collected. Curt Whitmire consulted on GIS and mapping issues. Victor Simon configured and coordinated the scales and oceanographic sensors used during survey operations. We also thank Aimee Keller for her guidance and suggestions that have significantly improved this project. Melissa Head analyzed all of our maturity samples. The PSMFC Ageing Lab analyzed our otolith specimens.

Example of mature vermilion rockfish ovary at macroscopic stage 2 (vitellogenic), and its corresponding histological image (microscopic ova stages 1-7 present)

600 bp800 bp

300 bp

S V S V S V S V V V V V

Figure 9. Gel electrophoresis analysis of a Restriction Fragment Length Polymorphism (RFLP).

S = Sunset rockfish, V = Vermilion rockfish

Underwater VideoA towable camera sled (Figure 7) was developed to provide visual observations of the seafloor at survey sites. In 2014, a GoPro camera was added to sled to provide a second visual observation, and improve video quality. Data is used to analyze habitat attributes, and compare habitat with catch information.

Figure 7. Custom-designed camera sled, winch, and A-frame as mounted on the F/V Aggressor.

Figure 8. Images from GoPro of the seafloor off 60 Mile Bank, CA, showing rockfish, brittle stars, and complex rocky habitat.

MaturityHook and Line staff annually collect ovaries from vermilion/sunset rockfish, bocaccio, greenspotted rockfish, cowcod, and canary rockfish. We assist scientists from the SWFSC collecting ovaries from chilipepper, yellowtail, swordspine, squarespot, speckled, and rosy rockfish.

Sinker: square shape with rounded bottom; 1,2,3,4, & 5 lb. sinkers can be used

Sinker Breakaway: 30 lb. monofilament; can be changed if greater strength is needed

24’’ between swivel & sinker

Barrel Swivel: Size 1/0

16’’ between tippets

16’’ between bottom tippet & barrel swivel

Shrimp Flies:

•Red and yellow bucktail bristles w/ red collar

•VMC long shank, kirby style “J” hook, size 5/0

•Bait: 1 frozen squid strip per hook

Mainline: 80 lb. spectra

Barrel Swivel: Size 1/0

Gangion: 60 lb. monofilament

6” tippet

Tippet/Leader:

•6” long

•Tie a 6” dropper loop; cut loop at midpoint to form 2 strands, & then remove one of the strands

•Tie the shrimp fly directly to tippet

Figure 2. Diagram of the sampling gangion used during the hook and line survey.

Figure 3. Deckhands and biologists engaged in typical sampling operations aboard the F/V Aggressor.

Introduction

We conduct an annual fishery-independent hook and line survey to monitor groundfish within the Southern California Bight (SCB). The survey targets rocky, high-relief habitats that are generally not well-sampled using other survey techniques such as bottom trawls and acoustic backscatter.

The primary objective of the hook and line survey is to collect catch-per-unit-effort (CPUE) data and biological information to generate annual abundance indices for several species of shelf rockfish within the SCB, including bocaccio (Sebastes paucispinis), cowcod (Sebastes levis), the vermilion rockfish complex (e.g., S. miniatus and S. crocotulus), and greenspotted rockfish (S. chlorostictus). The survey was developed in 2003 and is a collaborative effort among Pacific States Marine Fisheries Commission (PSMFC), Northwest Fisheries Science Center (NWFSC), and southern California’s sportfishing industry.

Methods

• The survey employs a fixed site design with 121 sites sampled annually throughout the SCB. The region is subdivided into 20 sampling areas to ensure sampling coverage throughout the region (Figure 1).

• The depth range sampled is 37m – 229m.

• The survey gear is hook and line gear deployed by rod and reel. A sampling rig (or gangion) is affixed to the end of each line (Figure 2).

• Sampling consists of three deckhands each making five coordinated drops of a five-hook gangion at each site (Figure 3). Maximum possible catch of all species is 75 fish per site.

• Deckhands use stopwatches to measure the amount of time the gangion spends on the seafloor available to demersal rockfish. Maximum fishing time is five minutes per drop.

• Biologists record species, length, weight, sex, age (via otolith), and genetic (via finclip) information for each rockfish caught. A subset of this information is collected from non-rockfish species, and these fishes are discarded when possible.

• A variety of environmental and sampling information is collected to help develop probabilistic models used to predict species presence/absence on survey hooks.

• Catch data are modeled within a Generalized Linear Model (GLM) framework to help generate abundance indices for various species (see Results).

Figure 1. Map of the SCB showing hook and line survey sites from 2014, and boundaries of 20 sampling areas and two CCAs. Red dots represent 121 fixed sites, and yellow dots indicate 42 new sites sampled within CCAs.

Bocaccio Length FrequencyLength frequency analysis of survey data suggest a bocaccio population characterized by a few strong or moderately-strong year classes (Figure 5). The large 1999 year class that dominated catch in 2004 has diminished in size over time due to natural and fishing mortality as well as emigration to depths and latitudes not sampled during the survey. The emergence and progression of the 2003 and 2005 year classes are also visible along with the sharp spike of the 2010 year class. This information can provide analysts with an early confirmation of year class strength before cohorts are fully recruited to the sport and commercial fisheries. The ability to track specific cohorts over time suggests the survey maintains generally constant selectivity over a broad range of sizes.

Figure 6. Index of relative abundance for bocaccio from 2004 – 2014.

Catch ModelingTo generate species-specific abundance indices, catch data were modeled at the level of the individual hook in a GLM framework using a binomial distribution: either a hook caught the species of interest, or it did not. Based upon our experience with the survey in the field and some relationships identified in earlier statistical analyses, we examined several sampling and environmental parameters as potential explanatory variables within the model. We used Akaike’s Information Criteria (AIC) to assist in selecting the final model. This model selection process is re-visited for each species and with each new year of data. Some of the covariates in the final model for the 2013 bocaccio index included site, fishing time, vessel, hook position, angler, and wave height. After back-transformation, the index is presented as the probability of any random survey hook capturing the species of interest (bocaccio) (Figure 6). Per our 2012 CIE (Center for Independent Experts) review and 2013 SSC (Scientific and Statistical Committee) review, we are reviewing our methods of analysis. Future work will be further exploring catch rate information to a number of covariates that might provide us with a more informative means of determining an index of abundance then we have historically been providing.

Vermilion rockfish(Sebastes miniatus)

Sunset rockfish(Sebastes crocotulus)

Seabird 19plus CTD and R.M. Young anemometers record oceanographic and weather conditions during each sampling event.

Determining the Distribution and Abundance of Shelf Rockfish:A Cooperative Research Study in the Southern California Bight

Colin Jones1, John Harms2, Jim Benante1, Aaron Chappell3, Allan Hicks2, and John Wallace2

1 Pacific States Marine Fisheries Commission, Seattle, WA2 Fishery Resource Analysis and Monitoring Division, Northwest Fisheries Science Center, NOAA, Seattle, WA

3 Fishery Resource Analysis and Monitoring Division, Northwest Fisheries Science Center, NOAA, Newport, OR

Catch Rate by Species

The figures to the right show the median proportion of hooks deployed at each site which caught a bocaccio, vermilion/sunset rockfish, and greenspotted rockfish. While greenspotted and the vermilion complex show a relatively flat trendline, the bocaccio data track the abundance indices generated for the 2013 and 2015 stock assessments and show the strength of the 2010 year class.

Cowcod Conservation Areas (CCAs)

• Implemented within the SCB in 2001 to protect shelf habitat where cowcod are most abundant, and prohibit most bottom-fishing deeper than 20 fathoms.

• Two boundary areas were developed, CCA West (4,200 sq mi) and CCA East (100 sq mi) (Figure 1).

• Upon request from Pacific Fishery Management Council (PFMC) and other governing bodies, the hook and line survey started sampling 42 fixed sites within CCAs in 2014 (yellow dots, Figure 1), and will add 40 more sites in 2015.

• These new sites will allow us to determine the efficacy of CCAs for not only cowcod, but other important rockfish in the region (bocaccio, vermilion, etc.).

Figure 5. Bocaccio length frequency from 2004 to 2013.

Point Conception Santa BarbaraSanta Barbara Channel

San Miguel Isl.Santa Rosa Isl.

Santa Rosa Flats

Santa Cruz Isl.Anacapa Isl.

Pt. Hueneme

Harrison Reef

Santa Monica Bay

San Pedro Bay

14 Mile Bank

Central Coast

South Coast

9 Mile Bank

125 Fathom Bank

60 Mile Bank

CCA East

CCA West

San Clemente Isl.

Santa Catalina Isl.

Inde

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0.10

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0.25

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nts Year

002004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014

Figure 4. Deckhands and biologists displaying cowcod caught during hook and line survey.