gray whales in sf bay

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.