Dr. Nick Farmer & Andy Strelcheck Southeast Regional Office St. Petersburg, Florida

1. Tab B, No. 4(d)ii Preliminary Results – Pending SEFSC Review Cumulative effects of Amendment 31 regulations upon effective effort impacting sea turtle takes in the Gulf of Mexico reef fish bottom longline fishery Dr. Nick Farmer & Andy Strelcheck Southeast Regional Office St. Petersburg, Florida

2. Introduction Amendment 31: Reduce sea turtle interactions with reef fish bottom longline gear • Action 1:Allow or disallow squid bait in the bottom longline reef fish fishery • Action 2:Restrict the use of bottom longline gear for reef fish in the eastern Gulf of Mexico • Action 3:Longline endorsements to fish East of Cape San Blas • Action 4:Modify fishing practices and gear www.noaanews.noaa.gov

3. Introduction • GOAL: • To evaluate the impacts of endorsement and depth/time closure alternatives proposed in A31 upon ‘effective effort’ in the reef fish bottom longline fishery WWW.NETCRUSADERS.COM www.abcnews.com www.noaanews.noaa.gov

4. Methods and Results • Data: Commercial logbook (SEFSC Miami) • 2007-2008 • Total Hooks = Sets * Hooks/Set • ‘Effective Effort’ • Accounts for probability of sea turtle encounter by depth contour by scaling effort (‘hooks’) to population density • Reduced HooksReduced Sea Turtle Bycatch • Common assumption in sea turtle bycatch studies* WWW.TAMPABAY.COM • *(Johnson et al. 1999, Richards 2006, Walsh and Garrison 2006, SEFSC 2007, SEFSC 2009)

5. Trip Elimination* • Following SEFSC (2009) • Eastern Gulf of Mexico (Areas 1-10) • 1-8 directly impacted by A31 • Gear = Longline • Total landings aggregated at trip level into three general categories: • Reef Fish(50 CFR 622, App. A) • Shark • Other • Trip Eliminated: • If vessel had Shark permit and >66% landings were sharks • If no managed reef fish species were landed • If obvious effort reporting errors

6. Baseline Effort (2007-2008) • Baseline = Average (2007-2008) • most recent complete time series available • most accurate depth reporting • Logbook data summarized by vessel, month, and year • Year and month assigned using date landed • Only effort in areas 1-8 (e.g., east of Cape San Blas, Florida) will be directly impacted by Amendment 31 • Baseline effort in areas 9-10 (~1 million hooks) removed • Added back into grand totals as a constant

7. See Table 1A, p. 9 Baseline Effort (2007-2008)Reported ‘Depth Fished’ Total baseline effort = 28,762 thousand hooks Note ‘unknown’ depth and effort from 1-20 fathoms

8. Misreported ‘Depth Fished’ • Amendment 31, Action 2 establishes seasonal closures along bathymetric contours • Accuracy of reported ‘Depth Fished (ft)’ important • Deepest depth retained for trip level summary • Reef fish bottom longline prohibited <20 fathoms • Approximately 6% effort reported in depths <20 fathoms • Obvious monthly trends by vessels reporting depths in fathoms were adjusted • Also adjusted by comparing species composition and area fished with similar, accurately reported trips by same vessel

9. See Table 1C, p. 9 Baseline Effort (2007-2008)Adjusted ‘Depth Fished’ Total baseline effort = 28,762 thousand hooks

11. Amendment 31: Action 2 (Depth/Time Closure) • 35 fathom closure • June - August • April – August • Annual • Effort from 20-35 fathoms scaled down before being added to the existing effort in 35-50 fathoms Sea turtle sightings during summer 2007 aerial survey (Garrison 2009)

12. Amendment 31: Action 2 (Depth/Time Closure) • What is the appropriate SCALAR to use for redistributed effort? • Garrison (2009)? • Winter ratio? (35-50?50-100?Summer 35-50?) WINTER WINTER SUMMER SUMMER

13. AssumptionsDepth/Time Closure • Movement of fishery from 20-35 to 35-50 fathoms effectively reduces impacts of reef fish bottom longline effort upon sea turtles at a level proportional to ratio of their observed population densities at depth • Sensitivity runs using confidence interval(13 – 66%)around ratio for ‘Summer 2007’ runs (Summer = Jan-Dec) • During other runs, Summer = Apr-Sept, Winter = Jan-Mar, Oct-Dec • Garrison (2009): Winter = Jan/Feb, Summer = Jul/Aug • Impacts of ‘Winter’ assumption only impact annual closure runs • Reef fish bottom longline effort from 20-35 fathoms will not move deeper than 50 fathoms (due to DWG quota) during closure • Not all effort may shift from 20-35 fathoms to deeper water during closure; some vessels may simply not fish • Various levels of effort shifting examined (100%, 75%, 50%)

14. Amendment 31:Action 3 (Endorsement) • Non-endorsed vessels excluded • 40K • 50K • 60K • Endorsements by commercial reef fish permit based on average reef fish logbook landings using bottom longline and/or trap (1999-2007) www.photolib.noaa.gov

15. Amendment 31:Action 3 (Endorsement)

16. 50 Fathom Closure • Evaluated impacts of a closure within 50 fathoms, such as that implemented by the May 18, 2009 Emergency Rule • All effort within 50 fathoms eliminated • Assumption: • DWG and tilefish quota, along with Grouper-Tilefish IFQ, would prohibit any profitable relocation of effort into deeper waters. Observed longline sets 2006-2008.

17. Increased Effort in the Fishery • Proposed alternatives in Amendment 31 eliminate vessels from the fishery and reduce fishable waters, but provide no caps on effort by remaining vessels in available waters • Elimination of competition may provide opportunities for increased landings (and possibly increased effort) • Changes in fishing behavior are influenced by a variety of factors that are difficult to predict and quantify • GOAL:To evaluate the impacts of Amendment 31 given an increase in effort by endorsed vessels

18. Increased Effort in Fishery: Using 2003 Effort as Proxy • Year of highest overall effort in reef fish bottom longline fishery (1999-2007) was 2003 • Effort in 2003 (by vessel) ~ Proxy for increased effort • Effort (2003) partitioned by depth following baseline (2007-2008) by vessel, by month • Trap prohibition did not go into effect until Feb 2007 • Trap-endorsed vessels assigned effort from 2008 • Some vessels that fished in 2007-2008 did not fish in 2003 • Effort remained at 2007-2008 baseline

19. Amendment 31 ImpactsAssuming Constant EffortRatio = Summer 2007 Constant

20. Amendment 31 ImpactsAssuming Increased EffortRatio = Summer 2007 Constant

21. Amendment 31 ImpactsAssuming Constant EffortRatio = Summer 2007 Constant

22. Amendment 31 ImpactsAssuming Increased EffortRatio = Summer 2007 Constant

23. Amendment 31 ImpactsAssuming Constant EffortRatio = Summer 2007 Constant

24. Amendment 31 ImpactsAssuming Increased EffortRatio = Summer 2007 Constant

25. Amendment 31 ImpactsAssuming Constant Effort Varying “Winter” ratio only impacts annual closure scenarios W=“Winter” S=“Summer”

26. Amendment 31 ImpactsAssuming Increased Effort Varying “Winter” ratio only impacts annual closure scenarios W=“Winter” S=“Summer”

27. Amendment 31 ImpactsAssuming Constant EffortNo Ratio Sea Turtle Density

28. Amendment 31 ImpactsAssuming Increased EffortNo Ratio Sea Turtle Density

29. Discussion • Various combinations of Actions 2 and 3 of Amendment 31 may achieve significant reductions in effective effort that impact sea turtle takes by the bottom longline component of the reef fish fishery in the eastern Gulf of Mexico • As with any model, the outcomes are sensitive to the assumptions www.answersingenesis.org

30. Assumption:Misreported Depths were properly adjusted • Corrected for misreported depths to better reflect effort shifting relative to 35 fathom closure • Few vessels (15%) had potentially misreported depth • Even fewer trips (5%) had misreported depths • Correction probably had little impact upon the overall projected percent reductions www.captfredsmarineinc.com

31. Assumption:Constant effort in areas 9-10 • Assumed non-endorsed vessels would not relocate longline effort into Areas9-10 • Bottom longline fishing prohibited < 50 fathoms • Implementation of the Gulf of Mexico Grouper-Tilefish IFQ program • Annual quotas for DWG and tilefish have been consistently met in Apr-Jun in recent years

32. Sensitivity Runs • Sensitivity of model outputs to ratio of sea turtles in 20-35 fathoms versus 35-50 fathoms was investigated using the 95% confidence interval (13-66%) around the mean ratio for ‘Summer 2007’ runs • Mean variability <5% • Also explored different ratios • (All = 0, Winter = 0, Winter = 0.636) • Sensitivity of model outputs to percent of vessels relocating outside 35 fathoms during closure was investigated using effort shifting scalar (100%,75%, 50%) • Mean variability <2%

33. Sensitivity Runs • Variability was surprisingly low, especially for scenarios with longline endorsement criterion • Endorsements removed large amounts of effort from all areas fished prior to shifting effort from 20-35 fathoms out to 35-50 fathoms during area/season closures • 40K ~ 37% reduction without closure • 50K ~ 54% reduction without closure • 60K ~ 74% reduction without closure • Impacts of variability dampened due to effort in 35-50 fathoms prior to redistribution, comparison to large baseline estimate

34. DiscussionIncreasing or Constant Effort? • Increasing effort • Endorsed longliners will have less competition and may be able to land more fish to fill market demand • Constant effort • Several upcoming management actions may prevent landings (and effort) from increasing in coming years • Reduction in commercial red grouper quota • Reduction in commercial gag grouper quota

35. DiscussionIncreasing or Constant Effort? • Grouper – Tilefish IFQ • Endorsed longliners may buy catch shares from other longliners and vertical liners, increasing longline landings • Consolidation may lead to greater efficiency • Reduced competition may lead to increased CPUE • Increased landings ≠ Increased effort SPTIMES graphic

36. Summary • Large reductions in effort, and corresponding sea turtle takes, may occur if longline endorsements and area closures are implemented • Sources of uncertainty are numerous: • Depth of fishing reported • Effort shifting • Sea turtle density estimates • Impacts of quotas reductions upon longline effort • Implementation of the IFQ program

37. Summary • Endorsements result in greater reductions than summer closures inside 35 fathoms • Depending upon assumptions: • 40K + Closure  18-51% reduction • 50K + Closure 41-63% reduction • 60K + Closure 56-79% reduction

38. Questions?

39. Misreported ‘Depth Fished’ Obvious reporting in fathoms • Reef fish longline fishing is prohibited within 20 fathoms • Diagnosing and Correcting Misreported ‘Depth Fished’: • 18 vessels (~1.6 million hooks) reported fishing <20 fathoms • Maximum depth recorded by each vessel by month examined • If vessel’s maximum reported depth by month <120 ft: • Assumed vessel reported in fathoms rather than feet that month • Depth = ‘Depth’ * 6 • Several vessels reporting abundant shallow water grouper (SWG) landings closely examined to validate this approach • Majority reported SWG landings between ‘20’ and ‘25’ • Subsequent adjustment to 120-480 ft appeared appropriate • Adjustment relocated 93% of effort reported within 20 fathoms to deeper waters. • Assumed maximum depths >120 ft were accurate, as reef fish fishery does not extend far beyond 120 fathoms (720 ft)

40. Misreported ‘Depth Fished’ Vessel-by-Vessel Adjustments • Diagnosing and Correcting Misreported ‘Depth Fished’: • Ten records (9 vessels; ~0.1 million hooks) remained with reported fishing depth <20 fathoms • One vessel clearly reported in fathoms Jan ’07 - mid Dec ’08 • Depth = ‘Depth’ * 6 • Two vessels landed snowy grouper (DWG) • Depth = ‘Depth’ * 6 • One vessel never fished >150 ft, and had just completed a fishing trip landing a similar suite of species in 120 ft • Depth = 120 ft • One vessel misreported in Jan ‘07, mostly fished >50 fathoms • Depth = ‘Depth’ * 6 • Four vessels exhibited no obvious trends in reporting • Depth = ‘Depth’ * 6

41. Using 2003 Effort as Proxy for Increased Effort in Fishery • Year of highest overall effort in reef fish bottom longline fishery (1999-2007) was 2003 • Effort in 2003 (by vessel) ~ Proxy for increased effort • Monthly vessel effort (2003) partitioned by depth following monthly percent effort at depth from baseline (2007-2008) • If no fishing during that month (2007-2008), effort from 2003 assigned ‘unknown’ depth • ‘Unknown’ depth by vessel redistributed using aggregated proportional distribution of effort at depth by month across vessels • Trap prohibition did not go into effect until Feb 2007 • Trap-endorsed vessels assigned effort from 2008 • Some vessels that fished in 2007-2008 did not fish in 2003 • Effort remained at 2007-2008 baseline

42. Amendment 31 ImpactsAssuming Increased Effort, No Ratio50% Effort Shift

43. Amendment 31 ImpactsAssuming Constant Effort, No Ratio75% Effort Shift

44. Amendment 31 ImpactsAssuming Constant Effort, No Ratio75% Effort Shift

45. Amendment 31 ImpactsAssuming Increased Effort, No Ratio75% Effort Shift

46. Amendment 31 ImpactsAssuming Increased Effort, No Ratio75% Effort Shift

47. Amendment 31 ImpactsAssuming Constant Effort, No Ratio50% Effort Shift

48. Amendment 31 ImpactsAssuming Constant Effort, No Ratio50% Effort Shift

49. Amendment 31 ImpactsAssuming Increased Effort, No Ratio50% Effort Shift

50. Amendment 31: Action 2 (Depth/Time Closure) • Scalar = Ratio of sea turtle population density in 20-35 fathoms versus 35-50 fathoms from Summer 2007 aerial survey(Garrison 2009) • Reduced effective redistributed effort from 20-35 fathoms by approximately 70%(e.g., 10 hooks become 3 hooks)