Gray whales in sf bay
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Gray Whales in San Francisco Bay

Gray Whales in San Francisco Bay

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  • This is a satellite photo of San Francisco Bay. The Bay is approximately 100 km long and up to 20 km wide and most of it is surrounded by highly developed urban areas. Over 6 million people live in the Bay area. San Francisco is located here San Jose and Silicon Valley form a horseshoe surrounding the southern end of the Bay with the Five bridges span the Bay and it is a major port. Many large tankers enter and depart through the Golden Gate each day and ferries crisscross the Bay on an hourly basis. Clearly, this is a place heavily dominated by mankind. While there are many reasons why millions of travelers visit the Bay area each year, I would venture to guess that not a single one of them came to go whale watching within the Bay. This may change, for gray whales are increasingly coming into San Francisco Bay. But let’s step back for a moment
  • 1994 California Gray Whale was first cetacean species to be removed from U.S. Endangered Species List. Only the eastern population was delisted, for as Dave Weller reported the western population remains critically endangered. Current population estimate is 26,000 whales. Undertakes long migration between breeding lagoons along Baja California and foraging grounds off coasts of Alaska and Russia. Not all members of the population make this full migration as work of Darling, Calambokidis, Goley, their students and others has clearly shown. Indeed numerous individuals greatly shorten their migration by stopping at locations off the coast of northern California, Oregon, Washington, British Columbia and Alaska where they forage throughout the summer. Many of these same individuals have been observed to return to the same foraging site year after year.
  • 1994 California Gray Whale was first cetacean species to be removed from U.S. Endangered Species List. Only the eastern population was delisted, for as Dave Weller reported the western population remains critically endangered. Current population estimate is 26,000 whales. Undertakes long migration between breeding lagoons along Baja California and foraging grounds off coasts of Alaska and Russia. Not all members of the population make this full migration as work of Darling, Calambokidis, Goley, their students and others has clearly shown. Indeed numerous individuals greatly shorten their migration by stopping at locations off the coast of northern California, Oregon, Washington, British Columbia and Alaska where they forage throughout the summer. Many of these same individuals have been observed to return to the same foraging site year after year.
  • 1994 California Gray Whale was first cetacean species to be removed from U.S. Endangered Species List. Only the eastern population was delisted, for as Dave Weller reported the western population remains critically endangered. Current population estimate is 26,000 whales. Undertakes long migration between breeding lagoons along Baja California and foraging grounds off coasts of Alaska and Russia. Not all members of the population make this full migration as work of Darling, Calambokidis, Goley, their students and others has clearly shown. Indeed numerous individuals greatly shorten their migration by stopping at locations off the coast of northern California, Oregon, Washington, British Columbia and Alaska where they forage throughout the summer. Many of these same individuals have been observed to return to the same foraging site year after year.
  • 1994 California Gray Whale was first cetacean species to be removed from U.S. Endangered Species List. Only the eastern population was delisted, for as Dave Weller reported the western population remains critically endangered. Current population estimate is 26,000 whales. Undertakes long migration between breeding lagoons along Baja California and foraging grounds off coasts of Alaska and Russia. Not all members of the population make this full migration as work of Darling, Calambokidis, Goley, their students and others has clearly shown. Indeed numerous individuals greatly shorten their migration by stopping at locations off the coast of northern California, Oregon, Washington, British Columbia and Alaska where they forage throughout the summer. Many of these same individuals have been observed to return to the same foraging site year after year.
  • 1994 California Gray Whale was first cetacean species to be removed from U.S. Endangered Species List. Only the eastern population was delisted, for as Dave Weller reported the western population remains critically endangered. Current population estimate is 26,000 whales. Undertakes long migration between breeding lagoons along Baja California and foraging grounds off coasts of Alaska and Russia. Not all members of the population make this full migration as work of Darling, Calambokidis, Goley, their students and others has clearly shown. Indeed numerous individuals greatly shorten their migration by stopping at locations off the coast of northern California, Oregon, Washington, British Columbia and Alaska where they forage throughout the summer. Many of these same individuals have been observed to return to the same foraging site year after year.
  • Public reports of sightings Expand public sighting network Investigate reports to confirm sightings Photo-ID Systematic surveys
  • This graph represents the number of days gray whales were reported in San Francisco Bay during 1999, 2000 and 2001. In 1999 whales were reported in the Bay on 39 days with the peak in April when they were reported on 9 days. In 2000 whales were reported on 69 different days with peaks in April and May and in 2001 they were reported on 98 days.with the peak in March. Typically the first whales are reported in late January as occurred in 1999 or early to mid February as occurred in 2000 and 2001
  • 1999
  • 1999
  • All age classes 15-40’ Singles and groups of up to 5 whales Foraging, traveling and milling Some whales photo-ID and resighted, but photo-ID difficult due to surfacing behavior.
  • All age classes 15-40’ Singles and groups of up to 5 whales Foraging, traveling and milling Some whales photo-ID and resighted, but photo-ID difficult due to surfacing behavior.
  • All age classes 15-40’ Singles and groups of up to 5 whales Foraging, traveling and milling Some whales photo-ID and resighted, but photo-ID difficult due to surfacing behavior.
  • All age classes 15-40’ Singles and groups of up to 5 whales Foraging, traveling and milling Some whales photo-ID and resighted, but photo-ID difficult due to surfacing behavior.
  • Problem of determining whether died as result of being in Bay. Problem of photoID for identifing stranded whales
  • Problem of determining whether died as result of being in Bay. Problem of photoID for identifing stranded whales
  • Problem of determining whether died as result of being in Bay. Problem of photoID for identifing stranded whales
  • Problem of determining whether died as result of being in Bay. Problem of photoID for identifing stranded whales

Gray whales in sf bay Gray whales in sf bay Presentation Transcript

  • Gray Whales in San Francisco BayGuy Oliver1, Jamie Gilardi1, Caitlyn Toropova1,Pieter Folkens2, Kate Cronin1, Natasha Bodorof3 Kristen Sanchez3, Damon Wolf4, Kathryn Zagzebski5 and Birgit Winning1 1 Oceanic Society; 2 Alaska Whale Foundation; 3 UC Santa Cruz, 4 Sanoma State University 5 Marine Mammal Center
  • • 1994 California Gray Whale was first cetacean species to be removed from U.S. Endangered Species List.
  • • 1994 California Gray Whale was first cetacean species to be removed from U.S. Endangered Species List.• Current population estimate is 26,000 whales.
  • • 1994 California Gray Whale was first cetacean species to be removed from U.S. Endangered Species List.• Current population estimate is 26,000 whales.• Long migration between breeding lagoons along Baja California and foraging grounds off coasts of Alaska and Russia.
  • • 1994 California Gray Whale was first cetacean species to be removed from U.S. Endangered Species List.• Current population estimate is 26,000 whales.• Long migration between breeding lagoons along Baja California and foraging grounds off coasts of Alaska and Russia.• Not all members of the population make this full migration as the work of Darling, Calambokidis, Goley, their students and others has clearly shown.
  • • 1994 California Gray Whale was first cetacean species to be removed from U.S. Endangered Species List.• Current population estimate is 26,000 whales.• Long migration between breeding lagoons along Baja California and foraging grounds off coasts of Alaska and Russia.• Not all members of the population make this full migration as the work of Darling, Calambokidis, Goley, their students and others has clearly shown.• In late 1990’s reports of gray whales in San Francisco Bay were occasionally received by the Marine Mammal Center.
  • • Public reports of sightings• Expand public sighting network• Investigate reports to confirm sightings• Photo-ID• Systematic surveys
  • Historic Use of Bay by Gray Whales• Only one gray whale found in middens surrounding San Francisco Bay.
  • Historic Use of Bay by Gray Whales• Only one gray whale found in middens surrounding San Francisco Bay.• One report by Spanish missionaries of whale spouts seen in the Bay.
  • Historic Use of Bay by Gray Whales• Only one gray whale found in middens surrounding San Francisco Bay.• One report by Spanish missionaries of whale spouts seen in the Bay.• Neither Yankee nor modern whaling records indicate whales killed in the Bay.
  • Gray whale occurrence in SF Bay 30 25 20 1999 15 2000 2001 10 5 0 Jan Mar May Jul Sep Nov
  • Sightings 1999 - 2001
  • Sightings 1999 - 2001
  • Sightings 1999 - 2001
  • Whales in the Bay• All age classes 15-40’
  • Whales in the Bay• All age classes 15-40’• Singles and groups of up to 5 whales
  • Whales in the Bay• All age classes 15-40’• Singles and groups of up to 5 whales• Foraging, traveling and milling
  • Whales in the Bay• All age classes 15-40’• Singles and groups of up to 5 whales• Foraging, traveling and milling• Some whales photo-ID and resighted, but photo-ID difficult due to surfacing behavior.
  • San Francisco Bay• Prey• Shipping• Shallow tidal areas• Noise• Future major construction of East Bay Bridge and airport expansion
  • Living in the Bay can be dangerous• In 2000 between 17 and 29 whales stranded in SF Bay.
  • Living in the Bay can be dangerous• In 2000 between 17 and 29 whales stranded in SF Bay.• Causes of death Domoic acid
  • Living in the Bay can be dangerous• In 2000 between 17 and 29 whales stranded in SF Bay.• Causes of death Domoic acid Collision
  • Living in the Bay can be dangerous• In 2000 between 17 and 29 whales stranded in SF Bay.• Causes of death Domoic acid Collision Drowning
  • Future Work• Identification of individuals whales• Residence time• Prey of foraging whales• Is prey contaminated
  • Acknowledgements• Funding provided by Oceanic Society• Vessels provided by Pieter Folkens and Robert and Kay Harrington• Survey members other than the authors include Marianne Tucker, Steve and Heidi Petersen, Nicholas Dentant & Sam Denimon• Dr. Francis Gulland, Marine Mammal Center, for stranding information• USCG, Pilots Association, SF Ferry System, Whale Watch captains and many fishermen and board sailors.