Geoff Shester, Ph.D. Presentation to California Fish and Game Commission June 4, 2014 White sharks should be listed under CESA Genetically distinct population Inherently vulnerable: Long-lived (>70 years), slow to reproduce, few young Low numbers of breeding females (47) Overexploitation: Gillnet fisheries kill >200 shark pups per year Over 78,000 public comments supporting CESA listing and protection for white sharks Concerns with Dept Status Review/Recommendation Overly optimistic, flawed interpretation of data Erring against conservation in light of uncertainty Inadequate, unbalanced peer review/ Lack of scrutiny Conclusions and listing recommendation based primarily on speculation, NOT actual evidence Population Estimates at Known Aggregation Sites Photographic mark-recapture is scientifically robust NMFS BRT challenged assumptions and reanalyzed data the current abundance estimates comprise the best available scientific information (Dept at 19) Aggregation Site Original estimate (sub-adults & adults) NMFS BRT re-analyzed estimates (sub-adults & adults) NMFS BRT estimate of mature females Central CA Guad. Isl Total Show us the sharks Dept concluded population much greater 1. Undetected aggregation sites However, someone would have noticed by now We know where all major pinniped rookeries are 2. Far more undetectable sharks are at the aggregation sites However, if they are there to feed, why wouldnt we ever see them Estimates already account for sharks we havent seen yet Central CA and Guadalupe tagged sharks transit ALL locations where white sharks have ever been observed Jorgensen et al (sharks tagged in Central California) No evidence for other major aggregation sites Ao Nuevo sharks WERE assessed (Chapple et al. 2011) 6 of 8 sharks identified at Ao Nuevo were identified at other locations the exclusion of the Ao Nuevo Island data only reduced our estimate by 600%41% Sea lion bite marks 2>29,900%10% Sea otter mortalities %22% * Published max 5%/year Overexploitation: Bycatch in gillnet fisheries Current minimum estimate ~208 white shark pups killed per year [NMFS BRT,p. iii, 48, 90-91] ~192/year in Baja California gillnets ~16/year killed in CA gillnets (28 caught, 12 survive) ~40% already dead upon retrieval [Dept. statement 2013] CA set gillnet halibut fishery Main US contributor to bycatch Managed directly by Dept. and Commission Occurs in white shark nursery (S. CA) Overexploitation: Bycatch Mortality Breeding adult females*50100 Birth events per year2550 Pups per birth event1010 Total pups produced per year Pups killed per year in gillnets* Bycatch mortality80%40% Published pop. estimates Double Published pop. estimates *Estimates rounded for simplicity High Bycatch Mortality Implausible? For reference: Less than 10% mortality is typical for marine mammals and turtles known to be declining due to bycatch 20% bycatch mortality on critically endangered vaquitas [NMFS BRT p. 81] 5 of 7 tagged juvenile white sharks were recaptured in a gillnet within 6 months (Weng et al., 2007; Weng et al. 2012; Dewar et al. 2013) Fishing Mortality on Adults Adult white shark caught and landed in gillnet off Guaymas, Mexico in Sea of Cortez, Rate unknown. Most plausible explanation of data White sharks are far below healthy, historic levels A single catastrophic event could wipe out remaining population Fisheries continue to take severe levels of bycatch, despite current regulations, effort, and protections Preventing recovery High extinction risk from overexploitation Remedy: Manage bycatch, support science Consider new regulations to manage bycatch 1. Limit gillnet soak times 2. Time-area closures 3. Hard bycatch caps Increased observer coverage, outreach, and research (CDFW recommendations) AND pressure on Mexico Lyons et al. (2013): white shark bycatch hotspots in areas of low target species catch rates CA Set Gillnets among dirtiest US Fisheries NMFS observer data: 2007, 2010, % of animals caught were discarded 78% of all sharks/rays/skates discarded (> 20 spp.) 470 pinnipeds 241 seabirds From Oceana Wasted Catch Report Bycatch in CA set gillnets (NOAA) Summary and Conclusions CESA requires best available science, not speculation Cannot rubber stamp Dept. recommendation Best available science strongly warrants listing white sharks as Endangered or Threatened Bycatch is a Top Conservation Priority Its time for the Commission and Department to address bycatch in fisheries under their authority