PINNIPED PREDATION IN THE BONNEVILLE DAM TAILRACE,

Transcription

1 PINNIPED PREDATION IN THE BONNEVILLE DAM TAILRACE, Robert J. Stansell Karrie M. Gibbons Fisheries Field Unit USACE Portland District

2 TOPICS COVERED Objectives, Study Site, Methods Results Predation Estimates Pinniped Abundance Estimates Deterrent Actions Barriers, ADD s, Harassment, Trapping Impact of 3 years of CSL removal program Summary

3 OBJECTIVES Estimate Pinniped Predation at Bonneville Tailrace Monitor Pinniped Abundance Monitor Effectiveness of Deterrent Actions USACE (2008 FCRPS BiOp RPA 49, 69)

4 OBSERVATION AREA, BONNEVILLE DAM, N WASHINGTON Hamilton Island Columbia River Robins Island Bradford Island Cascades Island Spillway PH2 Tanner Creek PH1 Primary Observation Area OREGON

5 LOCATIONS OF PREDATION BONNEVILLE DAM, 2010

6 RESULTS: PINNIPED ABUNDANCE Steller s sea lion Eumetopias jubatus California sea lion Zalophus californianus Harbor seal Phoca vitulina

7 MINIMUM ESTIMATED PINNIPED ABUNDANCE AT BONNEVILLE DAM (Season Total), CSL SSL* HS Total * - SSL now estimated same as CSL, by individuals, not maximum seen in one day as previously reported

8 DAILY AVERAGE AND MAXIMUM PINNIPED ABUNDANCE, Mean (SD) 60 Maximum Daily Pinniped Abundance Year

9 60 DAILY AVERAGE AND MAXIMUM CSL ABUNDANCE, Mean (SD) Maximum Daily California Sea Lion Abundance Year

10 DAILY AVERAGE AND MAXIMUM SSL ABUNDANCE, Mean (SD) Maximum Daily Steller Sea Lion Abundance Year

11 Daily California Sea Lion Abundance Estimates at Bonneville Dam, California Sea Lion Numbers Date

12 Daily Steller's Sea Lion Abundance Estimates, Steller Numbers Date

13 MARCH 1, 2010, 0630 TRAP ONE TRAP TWO TRAPS THREE AND FOUR

14 BUILDING STRONG

15 RESULTS: PINNIPED PREDATION

16 ANNUAL SALMONID PASSAGE AND ESTIMATED CONSUMPTION BY PINNIPEDS, BONNEVILLE DAM Year Bonneville Dam Salmonid Passage Expanded Salmonid Estimated Consumption % of Run (Jan 1- May31) Adjusted Salmonid Estimated Consumption % of Run (Jan 1- May31) ,733 1, % ,185 2, % ,804 3, % ,006 2, % ,063 3, % 3, % ,474 3, % 4, % ,543 4, % 4, % ,060 4, % 4, % ,194 6, % 6, %

17 Year SALMONID CONSUMPTION BY CSL AND SSL AT BONNEVILLE DAM, Expanded Salmonid Consumption CSL Salmonid Consumption per California Sea Lion Maximum # Salmonids Observed Caught by Individual CSL Expanded Salmonid Consumption SSL Salmonid Consumption per Steller Sea Lion , , , * 2, * , , , , , * - Observers not trained on individual ID s due to late start.

18 NIGHT-TIME PREDATION Based on 30 hours night-time observations in 2009 at Bonneville Dam, we can multiply the adjusted salmonid consumption estimate by to account for unobserved night-time predation. Apply to 2006 through 2010 only as previous years night observations (before hazing) saw virtually no night-time predation

19 CLEPTOPARASITISM (Stealing Prey) Year CSL from CSL CSL from SSL SSL from SSL SSL from CSL Other Total Note Figures are expanded estimates, virtually all salmonids.

20 FURTHER SALMONID CONSUMPTION ESTIMATES BY CSL AT BONNEVILLE DAM, Year Expanded Salmonid Consumption CSL Adjusted Salmonid Consumption CSL Night-factor Adjusted Salmonid Consumption CSL Clepto-Adjusted Salmonid Consumption CSL ,010 1,010 1,010 1, ,329 2,329 2,329 2, ,516 3,516 3,516 3, ,904 2,904 2,904 2, ,944 3,312 3,428 3, ,846 4,340 4,492 4, ,294 4,738 4,904 4, ,014 4,353 4,505 4, ,095 5,296 5,481 4,621

21 Expanded Estimated of Salmonids Consumed by Pinnipeds at Bonneville Dam, Adjusted for Unknown Catch, Night-time Catch, and Clepto-parasitism Events, Number of Estimated Salmonids Consumed CSL SSL 0 Year

22 FREQUENCY DISTRIBUTION OF CHINOOK CATCH LOCATIONS AT BONNEVILLE DAM, CSL 2010

23 FREQUENCY DISTRIBUTION OF CHINOOK CATCH LOCATIONS AT BONNEVILLE DAM, SSL 2010

24 Timing of Salmonid Predation by Pinnipeds and Salmon Passage at Bonneville Dam (Averaged Over ) Salmon passing Salmon caught Number of Salmonids Passing Number of Salmonids Caught Jan 15-Jan 29-Jan 12-Feb 26-Feb 11-Mar 25-Mar 8-Apr 22-Apr 6-May 20-May 0.0 Date

25 STURGEON PREDATION AT BONNEVILLE DAM TAILRACE, Year Observed Catch Estimated Catch Adjusted Catch , ,241 1, ,100 1,879 2,172

26 80 Daily Average Estimated Chinook Salmon, Steelhead, and Sturgeon Caught by Pinnipeds at Bonneville Dam (Averaged 2006 to 2010) Average Daily Fish Caught Chinook Salmon Steelhead Sturgeon Date

27 Sturgeon Prey Size Distribution, Bonneville Dam, Number of Sturgeon UNK. <2' 2'-<3' 3'-<4' 4'-<5' 5'-<6' 6'-<7' >7' Size (Feet)

28 FREQUENCY DISTRIBUTION OF STURGEON CATCH LOCATIONS AT BONNEVILLE DAM, SSL 2010

29 Lamprey Predation at Bonneville Dam Tailrace, Year Total Hours Observed Expanded Pacific Lamprey Consumption Estimate Percent of Total Observed Fish Catch % , % % , % , % , % , % , % , %

30 RESULTS: NON-LETHAL DETERRENTS

31 DETERRENT MEASURES AT BONNEVILLE DAM, SLED s and FOG s installed and still effective (No entry into fishways observed after installed). ADD s installed near entrances and activated, no effect noticed. Hazing by USDA (land) and States/CRITFC (boat) continued, limited effectiveness. Concrete blocks appear successful in preventing hauling out on concrete apron, but not resting nearby.

32 RESULTS: TRAPPING AND REMOVAL

33 CALIFORNIA SEA LION REMOVALS: COLUMBIA RIVER, Year Zoo/ aquaria On list Spring capture Accidental mortality Qualified Not qualified Euthanized Fall capture Euthanized Total Total NMFS summary (all listed): 37 USACE analysis (all): 40 and 37 ODFW / WDFW analysis (all qualified): 38

34 COMPARISON OF LISTED AND NON-LISTED CSL Number of CSL Mean Number of Salmon Eaten per Individual Mean Number of Days Observed per Individual CSL ID D CSL on Removal List CSL Not on List CSL Removed (excludes 3 non-listed CSL died on 5/4/08) CSL Remaining on List Note Data as of 10/20/10, using observed data only, not expanded.

35 WEIGHT DATA FOR BONNEVILLE PINNIPEDS 2 Heaviest California sea lions ever weighed on record were Bonneville animals (1,454lbs, 1,151lbs) C319 weight gain recorded (+339lbs in 5 months) C265 weight gain recorded (+484lbs in 2.5 months) C697 weight gain recorded (weighed April 2009, locked up into forebay May 2009, captured/weighed February 2010, gained about 250 lbs.

36 MAY 2008 ~ Astoria, OR Bonneville residents Astoria residents Photo by M. Tennis

37 SUMMARY KEY POINTS 1. Physical barriers effectively block access to fishways years of active non lethal deterrence efforts failed to reduce predation on salmonids and sturgeon at the dam. 3. Trapping and removal program working for CSL abundance, but full benefits not know until after 5 years. Without removal, salmonid predation undoubtedly higher 4. Salmonid catch totals continue to increase (6,081; 2.2% of run in 2010). Higher if unidentified fish, night catch are included. 5. Steller sea lions beginning to become more of a problem with increasing abundance and more predation on both white sturgeon and salmon species and stealing prey. 6. California Sea lions coming earlier each year (some in fall), and having impact on early spring Chinook stocks.

38 PINNIPED IDENTIFICATION PROCEDURES

39 REQUIREMENTS Pinniped/Fisheries Interaction Task Force Requirements for Removal of Pinnipeds Individually identifiable Seen at Bonneville for 5 days Seen to take at least one salmonid Present during non-lethal hazing conditions

40 IDENTIFYING AND DESCRIBING INDIVIDUAL SEA LIONS: BRANDS, CIRCULAR SCARS, NICKS, AND OTHER USEFUL MARKINGS

41 COLUMBIA RIVER BRANDS

42 NON-COLUMBIA RIVER BRANDS

43 COAT PATTERNS AND COLORS

44 CIRCULAR SCARS Dermal caused by the fungus Trichophyton mentagrophytes

45 DENTS

46 SCARS, CUTS, BUMPS

47 FLIPPERS

48 NICKS, FRESH MARKS

49 THE DRYING EFFECT

50 B237/C265

51 B127/C657

52 B242/C643

53 B239/C319 B238/C309

54 CATELOG OF ALL CSL W/PHOTOS AND/OR DESCRIPTIONS ID: YEARS AT BONN: EASE OF ID: ID CATEGORY C643/B Easy HIGH ID: YEARS AT BONN: EASE OF ID: ID CATEGORY B226 02, 03, 04, 05 EASY HIGH DESCRIPTION: Male, large, top spot, 2 large ring marks dorsal right side one posterior and one anterior. Faint elliptical scar on base of neck. Satellite tag, yellow neoprene patch, flipper tags in DESCRIPTION:. DORSAL: VENTRAL: DORSAL: VENTRAL: Key ID Features Estimated age Other Comment Scars ID year to year: Yes Key ID Feature Estimated age Other Comment Brand/ring marks Branded Removed 2009 ID year to year: yes

55 ASSIGNING ID CATEGORIES Highly Identifiable Animals (HIA) Brands Physical features that will be seen for many years and identifies animal as unique individual Possibly Identifiable Animals (PIA) Features may or may not be noticed in future years Non-Identifiable Animals (NIA) Features will likely not be present or observable in future year, possible not even within year

56 BREAKDOWN OF BONNEVILLE CSL INDIVIDUALS BY LEVEL OF ID 420 CSL Identified Branded (including 31 previously B codes) 148 B codes HIA 108 B codes PIA 48 B codes NIA Brands, HIA, and PIA are added to get the minimum number of individual CSL seen each year. Only HIA can qualify for removal list

57 ANNUAL TOTALS OF CSL BY ID CATEGORY CSL at Bonn Brands HIA Total HIA PIA Minimum Estimate of CSL at Bonneville Dam NIA

58 REPEAT SIGHTINGS OF CSL BY ID CATEGORY 1 Year New 2010 Total 1 Year >1 Year Total % >1 Year Brands Only % HIA then Branded % HIA % PIA % NIA % Total %

59 REPEAT SIGHTINGS OF CSL BY ID CATEGORY 1 Year 2 Year 3 Year 4 Year 5 Year 6 Year 7 Year 8 Year Total Brands Only HIA then Branded HIA PIA 36 (16) 6 (6) 98 (28) 103 (10) NIA 48 (4) Total 291 (64)

60 REPEAT SIGHTINGS OF LISTED AND REMOVED CSL 1 Year 2 Year 3 Year 4 Year 5 Year 6 Year 7 Year 8 Year Total Total HIA CSL Listed CSL Removed CSL* Likely** Remaining Listed CSL * - Excludes 3 CSL died on trap but not listed, all were seen 1 year ** - Individuals seen within last year only

61 PERCENTAGE OF HIA CSL RETURNING TO BONNEVILLE EACH YEAR Number of New HIA CSL Number of Repeat HIA CSL NA % of HIA Returning NA 19.2% 51.2% 77.1% 62.3% 65.6% 66.2% 69.8% 34.6%

62 USING BRANDED CSL ONLY 116 Branded CSL ID d at Bonn (86 branded in Astoria, 25 at Bonn, 4 San Miguel Island, 1 Puget Sound) 23 New branded CSL in 2010, 33 branded CSL removed (including 3 new 2010), 4 branded CSL known to have died in early Branded CSL left in wild to return to Bonn. 7 Branded CSL still returning to Bonn. Of 52 Branded CSL not returning to Bonn., 15 (29%) were seen in Astoria subsequently (8 the next year, 2 two years later, 1 three years later, 2 four years later, and 2 five years later)

63 ONE YEAR VS MULTI-YEAR CSL VISITING BONNEVILLE DAM 13 of 88* (14.8%) Branded CSL seen 1 year only at Bonn. 6 of 88 (6.8%) Branded CSL seen 1 year only at Bonn. subsequently seen at Astoria 11 of 75 (14.7%) Branded CSL seen >1 year at Bonn. skipped one year and returned following year. 0 skipped >1 year * - 88 Branded CSL had opportunity to return to Bonn.

64 C287 HISTORY AT BONNEVILLE Branded May 8, 2002 First seen at Bonneville April 25, 2005 Year # Days Observed # Salmonids Observed* Consumed Total * - Not expanded for hours and days not observing

65 SUMMARY Currently able to ID most CSL at Bonn. ID and harassment efforts at odds. ID and restricting haul-out sites at odds.. Can attribute catch to individual 30%-70% 85%-93% CSL will return to Bonn. > 1 year About 70% of branded CSL that do not return to Bonneville are never seen again, 86.5% not seen more than 1 year later

66 Description Challenge 1: How would you describe this sea lion?

67 Description Challenge 2: How many individual sea lions are there?

68 Fish #1

69 Fish #2 Pacific Lamprey

70 Fish #3

71 Fish #4

72 Fish #6

73 I couldn t eat another salmon.i feel sick