gray whales in sf bay
DESCRIPTION
Gray Whales in San Francisco BayTRANSCRIPT
Gray Whales in San Francisco Bay
Guy 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
0
5
10
15
20
25
30
Jan Mar May Jul Sep Nov
199920002001
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 acidCollision 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.