bioaccumulation: a case study of british columbia’s killer whales lesson 1
TRANSCRIPT
Bioaccumulation: A Case Study of British Columbia’s Killer
Whales
Lesson 1
Killer Whales of British Columbia•There are 3 different types of killer whales
•They have different diets, ranges, languages, behaviour & social organization (Bigg, Ellis, Ford)
The three types are Residents, Transients & Offshore killer whales
The different kinds do not mate with one another! (Barrett-Lennard)
So much is known because killer whales can be told apart as individuals thanks to the work of Dr. Michael Bigg
A12, Scimitar, 1941 A33, Nimpkish, 1971
Photos: Jackie Hildering
Saddle Patch
Dorsal Fin – shape, nicks & scratches
Resident Killer Whales
Eat fish – Mainly salmon
The fish can not hear in the range of the calls and salmon has very predictable spawning behaviour
This means that residents can afford to be:•Very social – they don’t leave their mothers, travelling in matrilines •Very vocal – each matriline sounds a little different
•Because each matriline sounds different, they know exactly who is family and who is not. This if very important for mating! It allows them to avoid inbreeding.
Matriline exampleResident killer whales – A30s
A30 female 1947“Tsitika”
A38 Male 1970“Blackney”
A39 Male 1975“Pointer”
A50 Female1984
“Clio”
A54 Female 1989“Blinkhorn”
A75 2001
“Cedar”A72
Female1999“Bend”
Know female by DNA
A84 2005
No name
A6 Male
1964-2000“Strider”
Transient Killer Whales
Eat marine mammals
The marine mammals can hear them!
This means that transients:•Must be very quiet until they are sure they are going to get their prey•Family structure less stable
Lesson 2
Resident killer whale
Salmon
Herring
Zooplankton
Phytoplankton
Transient killer whale
Seals
Salmon
Herring
Zooplankton
Phytoplankton
Transient killer whale
Resident killer whale
Salmon
Herring
Phytoplankton
Humans Seal
Food Web
Zooplankton
Organism Number Surviving Amount of food energy per animal
(number of plankton markers)
Total amount of food energy for the
species
Resident killer whales 2
Salmon Salmon #1Salmon #2Etc.
Herring Herring #1Herring #2Herring #3Etc.
Organism Number Surviving
Amount of food energy per animal (number
of plankton markers)
Total amount of food energy for the
species
Transient killer whale 1
Seals Seal #1Etc.
Salmon Salmon #1Salmon #2Etc.
Herring Herring #1Herring #2Herring #3Etc.
Lesson 4
PCBs in British Columbia's Killer Whales
020406080
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Killer Whale Population
PC
B (
pp
m)
1st bar; Northernresident mature male
2nd bar; Northernresident reproductiveage female
3rd bar; Southernresident mature male
4th bar; Transientmature male
Transient killer whales
Seal
Salmon
Herring
Plankton Plankton
Herring
Salmon
Resident killer whales
Persistent ToxinsHigher = more
Resident killer whale
Salmon
Herring
Zooplankton
Phytoplankton
Killer whale calf
Organism Number Surviving
Amount of food energy
Total number of marked food
pieces
Survived (S), Died (D) or
reproduction and immune system
problems (RI)
Transient killer whale
1
Seals Seal #1Etc.
Salmon Salmon #1Salmon #2Etc.
Herring Herring #1Herring #2Herring #3Etc.
Organism NumberSurviving
Amount of food energy
Total number of marked food pieces
Survived (S), Died (D) or reproduction and immune system problems (RI)
Resident killer whale
1
Salmon Salmon #1Salmon #2Etc.
Herring Herring #1Herring #3Herring #4Etc.
Organism Number of toxic plankton markers
What this means
Herring • Less than 3• 3 to 4• More than 4
• Survives• Survives but will have reproduction and immune system
problems• Dies
Salmon • Less then 4• 4 to 6• More than 6
• Survives• Survives but will have reproduction and immune system
problems• Dies
Seals or resident killer whales
• Less than 5• 5 to 8• More than 8
• Survives• Survives but will have reproduction and immune system
problems• Dies
Transient killer whales
• Less than 8• 8 to 12• More than
12
• Survives• Survives but will have reproduction and immune system
problems• Dies