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Rasmussen, D.E. 1 , Nakamura, R. 1 , Starr, R. 2 , Wendt, D. E. 1 1 Cal Poly, San Luis Obispo

WSN Annual Meeting 2009 Monterey, California. Comparisons of baiting and trapping protocols inside and outside of marine protected areas along California’s central coast. Rasmussen, D.E. 1 , Nakamura, R. 1 , Starr, R. 2 , Wendt, D. E. 1 1 Cal Poly, San Luis Obispo 2 Moss Landing Marine Labs.

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Rasmussen, D.E. 1 , Nakamura, R. 1 , Starr, R. 2 , Wendt, D. E. 1 1 Cal Poly, San Luis Obispo

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  1. WSN Annual Meeting 2009 Monterey, California Comparisons of baiting and trapping protocols inside and outside of marine protected areas along California’s central coast Rasmussen, D.E.1, Nakamura, R.1, Starr, R.2, Wendt, D. E.1 1 Cal Poly, San Luis Obispo 2 Moss Landing Marine Labs

  2. Background info on MPAs • MPAs can harbor more diversity, higher abundance and larger organisms than adjacent fished areas (e.g., Duran and Castilla 1989, Jennings et al., 1996, Bohnsack 1998, Gell and Roberts 2003). • MPAs have been shown to dramatically increase biomass and abundance of non-migratory fish species (e.g., Gell and Roberts, 2003). • Mean density and size of exploited fish species within protected areas can exceed that of fished areas (e.g., Mosqueira et al., 2000).

  3. Nearshore Trap Fishing Projects • 2004-2008 and 2008-2009, two tag and release studies were conducted. • Areas sampled include the waters around Cambria, CA, Piedras Blancas, and Big Creek MPA. • Two different protocols used for the two different studies. Map 1: Locations of Big Creek, Piedras Blancas and Cambria sampling sites.

  4. Why link these datasets? • Linking the datasets would allow for long-term comparisons to be made within and between sampling sites. • Important for stock assessments, resource managers and for MPA evaluation. • Provides important baseline data for Cambria before the MPA was established. • Allows for comparisons to be made to Big Creek MPA which was has not experienced fishing since 1993.

  5. Comparison of Study Protocols • Sampling years and study locations • Commercial Study • 2004, 2006: Cambria • 2006, 2008: Big Creek MPA • California Collaborative Fisheries Research Program (CCFRP) study • 2008, 2009: Cambria • 2008, 2009: Piedras Blancas • Fishing Protocols • Commercial Study • Traps were left in the water for an average of 1:45. • CCFRP Study • Traps left in water for an average of one hour. • Fishermen told to fish within a randomly chosen cell. • Baiting Protocols • Commercial Study • Traps baited with a mixture of chopped squid and abalone trimmings. • CCFRP Study • Traps baited with 1 pint of chopped squid • Bait had to be standardized for MLPA monitoring. Map 2: Location of traps set around Cambria, CA from 2004-2008. Note, different colors denote different trapping periods.

  6. Research Questions • How does the Length of nearshore fish species vary between Trapping and Baiting Protocols? • How is CPUE affected by the different trapping and baiting protocols? • What effect does soak time have on CPUE for nearshore fish species?

  7. CCFRP 1hr Soak CCRP 2hr Soak Commercial 1hr Soak Commercial 2hr Soak Conversion Study • Sampling year and study location. • 2009: Piedras Blancas • Sampling Protocols. • 14 CCFRP traps baited with squid and 10 Commercial traps baited with squid and abalone trimmings were soaked for 1 hour. • 4 CCFRP and 4 Commercial traps soaked for 2 hours. • Goal of conversion study. • Compare trapping and baiting protocols to see their effect on Catch Per Unit Effort (CPUE) and length of nearshore fish species. Map 3: Location of both commercial and scientific traps set in two cells of Piedras Blancas MPA. Note, colors denote different trap types and soak times.

  8. Lingcod Top 5 captured species Gopher Rockfish Black and Yellow Rockfish Cabezon Kelp Greenling Photos: Noelle Yochum. Slosea.org

  9. Total Length between trap types • Length for the top 4 species did not vary between trap type or soak time. • Kruskal-Wallace test with p-value <0.05 • Insufficient length data for Lingcod. Figure 1: Mean length of captured fish species in CCFRP and Commercial traps for both one hour and two hour soak times. Error Bars represent standard error of the mean.

  10. Catch per unit effort between trap types • Cabezon and Black and Yellow Rockfish CPUE were significantly different. • Cabezon showed increase in CPUE with Commercial Trap (2.1x). • Ordinal Multiple Logistic Regression, p-value <0.05. • Black and Yellow Rockfish showed a decrease in CPUE with Commercial Trap (2.3x). • Ordinal Multiple Logistic Regression, p-value <0.05. Figure 2: Mean CPUE for CCFRP and commercial traps with one hour soak time. Error bars represent standard error of the mean. Figure 3: Mean CPUE for CCFRP and commercial traps with two hour soak time. Error bars represent standard error of the mean.

  11. Effect of Soak Time • Soak time had no significant effect. • Approaching significance with the following species. • Cabezon (p-value= 0.108) • Black and Yellow Rockfish (p-value= 0.087) • Kelp Greenling (p-value= 0.085). • Ordinal Multiple Logistic Regression, p-value < 0.05. • Cabezon and Kelp Greenling, trend of increased CPUE with increase in soak time. • Black and Yellow Rockfish, trend of decreased CPUE with increase in soak time. Figure 4: Mean CPUE of CCFRP and Commercial traps for both one hour and two hour soak times. Error bars represent standard error of the mean.

  12. Length between 2004-2009 • No adjustment needed to combine length data from the two datasets. • Lengths don’t significantly vary between trap types. (Kruskal-Wallace test p-value< 0.05) Figure 5: Mean length of captured fish species across all study periods and locations. Error bars represent standard error of the mean.

  13. CPUE between 2004-2009 • Cabezon and Black and Yellow Rockfish CPUE adjusted for Commercial trap study. • Cabezon CPUE decreased by 2.1x. • Most likely due to attractant quality of Abalone. • Black and Yellow CPUE increased by 2.3x • Possibly because Black and Yellow Rockfish are smaller and can exit traps more easily. Figure 6: Mean CPUE of captured fish species across all study periods and locations. Error bars represent standard error of the mean.

  14. Conclusions • Instead of two distinct datasets we now have the ability to compare catch data for three central California MPA’s dating back to 2004. • Includes baseline catch data for Cambria before it was designated an MPA. • Catch data for the waters inside and outside of Piedras Blancas MPA from 2008-present. • Can compare data from recently established MPA’s to Big Creek MPA which has been closed to all fishing since 1993. • Moss Landing Marine Labs is using identical protocols to sample MPAs in the Monterey area. • Cautions. • Conversion study needs to take place over longer periods at both Cambria and Piedras Blancas to fine tune conversion rates. • Possible effect of soak time on CPUE of Cabezon, Kelp Greenling and Black and Yellow Rockfish.

  15. WSN Annual Meeting 2009 Monterey, California Acknowledgements • Cal Poly: DEW Lab (Nate Hall, Erin Nakada, Grant Waltz, Leslie Longabach, Lenora Brewer, Owen Hackleman, Melissa Daugherty, Larissa Ormonde, Helen Dickson) Steve Reinecke, Nic Nesbitt, Genji Nakada • CSU Long Beach: Carlos Mireles • SLOSEA: Leslie Rebik • Moss Landing: Noelle Yochum • Fishermen: Tom Hafer, Roger Cullen • Funding Sources: Packard Foundation, Ocean Protection Counsel, Resource Legacy Fund

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