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Changes in cetacean occurrence in the Salish Sea: anomalous sightings in southern Puget Sound

Changes in cetacean occurrence in the Salish Sea: anomalous sightings in southern Puget Sound. John Calambokidis 1 Jessie Huggins 1 Dyanna Lamourn 2 Steve Jeffries 2 Bethany Diehl 1,2 Josh Oliver 1,2 Brad Hanson 3 1 Cascadia Research Collective, Olympia, WA

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Changes in cetacean occurrence in the Salish Sea: anomalous sightings in southern Puget Sound

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  1. Changes in cetacean occurrence in the Salish Sea: anomalous sightings in southern Puget Sound John Calambokidis1 Jessie Huggins1 Dyanna Lamourn2 Steve Jeffries2 Bethany Diehl1,2 Josh Oliver1,2 Brad Hanson3 1Cascadia Research Collective, Olympia, WA 2Washington Dept. of Fish and Wildlife, Tacoma, WA 3NMFS/NOAA, Seattle ,WA

  2. Common larger cetaceans of the Salish sea Minke Whale Killer whale Gray whale Humpback whale

  3. Common smaller cetaceans of the Salish sea Dall’s porpoise Pacific white-sided dolphin Harbor porpoise

  4. Harbor porpoises are the smallest cetacean in Washington State • Occur widely in coastal waters of the North Pacific and Atlantic • Light gray dorsally with whitish belly • Females (6ft) larger than males • sexually mature – age 3 • average lifespan - 10-15 years • Vulnerable to entanglement in fishing nets Photo by Robin Baird Harbor porpoise Phocoenaphocoena

  5. Harbor porpoise stock boundaries- E North Pacific

  6. Historical occurrence in Puget Sound • “Harbor porpoise are doubtless seen more often than any other cetacean in the (Washington) state” … “We have seen them within 30 feet of shore at Steilacoom and far out in Puget Sound”“In southern Puget Sound the harbor porpoise occurs in all seasons, rarely singly, usually in groups of 2 to 5, occasionally 10 to 12”Scheffer and Slipp (1948) • Declines in latter half of 20th century in other urban protected waters including San Francisco Bay, Waden Sea, and Baltic Sea.

  7. Disappearance in southern and central Puget Sound by 1970s • After the Marine Mammal Protection Act in 1972 more research on marine mammal distribution and abundance in this and other regions • Lack of sighting reports, compiled in the mid-1970s suggested that harbor porpoise had already vanished from most of Puget Sound (Everitt et al. 1979, Osborne et al. 1988) • Dedicated surveys noted no harbor porpoise sighted in south Puget Sound and only a few sightings are made in the main basin (Osmek et al. 1995)

  8. Reasons for decline in Puget Sound • Fisheries interactions • Harbor porpoise known to be vulnerable to entanglement in gillnets • Increased vessel traffic • Harbor porpoise known to avoid boats • Increased noise • Contaminants • High levels of PCBs in high level predators in Puget Sound • Potential impacts on reproduction

  9. Increase in sightings reports in Puget Sound (south and central) Data from sighting reports to Cascadia Research from 2000 through Aug 2011

  10. Winter WDFW aerial surveys for birds reveals shifting distribution

  11. Why is the harbor porpoise population in Puget Sound increasing? Favorable conditions in Puget Sound: Recovery of some prey species (herring) Decreased incidental take in fisheries Lower contaminant levels Growing overall population expanding from other regions Worse conditions in outside areas: 2006-2007 Unusual Mortality Event in coastal waters of Oregon and Washington may reflect unfavorable factors encouraging harbor porpoise to shift into areas like Puget Sound

  12. Increases in harbor porpoise in Strait of Juan de Fuca and San Juans Harbor porpoise population in adjacent waters of the Strait of Juan de Fuca and San Juan Islands has tripled since the early 1990s based pm aerial surveys Closest areas where porpoise immigrated from into Puget Sound

  13. Harbor porpoise strandings in Washington, 1990-2009 Post-UME Pre-UME UME

  14. Northwest harbor porpoise Unusual Mortality Event, 2006-2007 • Strandings were widely dispersed • Included both sexes and all age classes • Did not extend into surrounding regions (BC and California) • No single factor identified

  15. Changes in strandings of harbor porpoise in Puget Sound

  16. Unusual sightings in Puget Sound 2010-11 • 2-3 bottlenose dolphins • 1st animal sighted in 4-13 June 2010, found dead 18 July 2010 • 2nd animal seen15 Dec 2010 – 18 Jan 2011, found dead 31 Jan • 2 Bryde’s whales • Juv. male, seen alive Jan 2010 then found dead in S PS 16 Jan. • 2ndBryde’s whale 1st sighted 13 Nov. 2010, found dead on 4 Dec 2010, ship strike injury • 2 common dolphins • Since June 2011 in S Puget Sound

  17. Bryde’s Whale, January 16, 2010 CRC-1022 • 39 foot juvenile male, seen floating in South Puget Sound on Jan 16th, towed to a secure location for examination on the 18th • Sighting reports that match description of this whale began in early January • No evidence of having been brought in by ship • Thin, dry blubber, no food remains • Tropical species, usually not seen north of Southern California • First sighting or stranding ever recorded of this species in the Pacific Northwest

  18. 2nd Bryde’s whale sighted 13 Nov 2010, found dead on 4 Dec 2010 • Juvenile whale with severe injuries reported in South Puget Sound • Photographed and confirmed species in early December in Totten Inlet • Found dead 4 December near Shelton. • Necropsy showed extensive injuries that were several weeks old, likely cause by collision with a ship.

  19. Bottlenose Dolphin, June-July, 2010 • Repeated sightings 4-13 June 2010 in S Puget Sound • Found dead near Steilacoom, WA 18 July 2010 • Severely decomposed adult female, 300 cm long • No clear cause of death. • Only two other Tursiops stranding on record in Washington was in 1988 and 2004 neither of them from Puget Sound proper (Samish Bay and Strait of Juan de Fuca) Mike Julh, Eld Inlet, 9-Jun-10

  20. 2nd bottlenose dolphin: S Puget Sound 2010-2011 • First seen 15 December 2010 at Port of Tacoma • All sightings in SPS including the last confirmed live sighting of 18 January near Nisqually Delta. • Found dead at Nisqually on 31 January. Necropsy conducted by WDFW and Cascadia Research • Immature male (196 cm) • Thin blubber and very little food remains in its stomach or intestines but did not appear to have starved to death. • There were also indications of trauma around the head that may have been the result of it stranding alive and thrashing around prior to death.

  21. Bottlenose DolphinTursiops truncatus • - Globally the most familiar • small cetaceans, common • in Aquaria and TV shows • Coastal species and offshore • forms seen in small groups • Primary range in E North Pacific • extends north to central California • Generally not seen this far north, only two other Tursiops stranding on record in Washington was in 1988 and 2004 neither of them from Puget Sound proper (Samish Bay. And Strait of Juan de Fuca)

  22. Common Dolphin(Long-Beaked Delphinis capensis)(Short Beaked: Delphinus delphis) Generally known from tropical and temperate waters In E North Pacific seen north to NCalifornia In herds up to 2,000 animals Slightly under 3ft at birth, 8 as adults

  23. 2 June 2011 single dolphin reported off Boston Harbor lighthouse • 5 June- 6 October 1-2 dolphins are reported off Boston Harbor, Burfoot Park and Cooper Pt, occasionally in Eld Inlet and Dana Passage

  24. Sightings off Boston Harbor light house 5 June 2011 11 June 2011 Some reports to Cascadia from public indicated two individuals. Photos here confirm presence of at least two different dolphins present in June.

  25. Common dolphin occurrence – previous sightings in 2003 in WA and BC • Two long-beaked common dolphins sighted July and Aug. 2003, in Budd Inlet and Dana Passage - one dolphin has injured beak • 16 Aug. 2003 a long-beaked common dolphin live stranded near Grayland on the Washington outer coast • Common dolphin reports from British Columbia (Ford, 2005) • 2 Feb. 1993 Mayne Island, dolphin stranded and died • Aug.-Nov. 2002 multiple sightings along southern Vancouver Island • 19 Sep. 2003 dolphins Victoria Harbor, individual with injured beak same as seen in South Sound • 7 Oct. 2003 two dolphins including the one with injured beak entangled off W. Vancouver Island. Dolphin with injured beak released alive, other animal died

  26. Conclusions • Return of harbor porpoise to these regions of Puget Sound provides encouraging evidence that many of the underlying ecosystem components, e.g., forage fish populations, are functioning at a level sufficient to support these and other top predators • Five sightings of three other species in 2010 and 2011, all highly unusual or unprecedented in Puget Sound, suggest a broader underlying common factor bring these southern animals north • The eventual deal of most of the unusual species sighted as well incidental deaths of harbor porpoise suggests such occurrences are not necessarily positive for these species

  27. Assistance with surveys: Observers from NWFSC, WDFW, and Cascadia Research Assistance with porpoise stranding/necropsies: Northwest Regional Stranding Network Bill Walker Steve Raverty Winter wildlife survey data thanks to Joe Evenson, WDFW Common dolphin sighting data compiled by Annie Douglas Acknowledgements

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