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
Dorsal Fin – shape, nicks & scratches
Saddle Patch
A12, Scimitar, 1941
A33, Nimpkish, 1971
Photos: Jackie Hildering
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 example
Resident killer whales – A30s
A30 female 1947
“Tsitika”
A6
Male
1964-2000
“Strider”
A38
Male 1970
“Blackney”
A39
Male 1975
“Pointer”
A50
Female1984
“Clio”
A72
Female1999
“Bend”
Know female by DNA
A84
2005
No name
A54
Female 1989
“Blinkhorn”
A75
2001
“Cedar”
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
Food Web
Transient killer whale
Seal
Resident killer whale
Salmon
Herring
Zooplankton
Phytoplankton
Humans
Organism
Number Surviving
Resident killer whales
2
Amount of food
energy per animal
(number of
plankton
markers)
Salmon
Salmon #1
Salmon #2
Etc.
Herring
Herring #1
Herring #2
Herring #3
Etc.
Total amount of food
energy for the
species
Organism
Transient killer whale
Number
Surviving
Amount of food energy
per animal (number
of plankton
markers)
1
Seals
Seal #1
Etc.
Salmon
Salmon #1
Salmon #2
Etc.
Herring
Herring #1
Herring #2
Herring #3
Etc.
Total amount of food
energy for the
species
Lesson 4
PCB (ppm)
PCBs in British Columbia's Killer Whales
260
240
220
200
180
160
140
120
100
80
60
40
20
0
1st bar; Northern
resident mature male
2nd bar; Northern
resident reproductive
age female
3rd bar; Southern
resident mature male
4th bar; Transient
mature male
Killer Whale Population
Persistent Toxins
Higher = more
Resident killer whales
Salmon
Transient killer whales
Seal
Salmon
Herring
Herring
Plankton
Plankton
Killer whale calf
Resident killer whale
Salmon
Herring
Zooplankton
Phytoplankton
Organism
Transient killer
whale
Number
Surviving
Amount of food
energy
1
Seals
Seal #1
Etc.
Salmon
Salmon #1
Salmon #2
Etc.
Herring
Herring #1
Herring #2
Herring #3
Etc.
Total number of
marked food
pieces
Survived (S),
Died (D) or
reproduction and
immune system
problems (RI)
Organism
Resident killer
whale
Number
Surviving
Amount of food
energy
1
Salmon
Salmon #1
Salmon #2
Etc.
Herring
Herring #1
Herring #3
Herring #4
Etc.
Total number of
marked food
pieces
Survived (S), Died
(D) or
reproduction and
immune system
problems (RI)
Organism
Herring
Number of toxic
plankton
markers
•
•
•
Less than 3
3 to 4
More than 4
What this means
•
•
•
Salmon
•
•
•
Less then 4
4 to 6
More than 6
•
•
•
Seals or
residen
t killer
whales
•
•
•
Transient
killer
whales
•
•
•
Less than 5
5 to 8
More than 8
•
•
•
Less than 8
8 to 12
More than 12
•
•
•
Survives
Survives but will have reproduction and immune system
problems
Dies
Survives
Survives but will have reproduction and immune system
problems
Dies
Survives
Survives but will have reproduction and immune system
problems
Dies
Survives
Survives but will have reproduction and immune system
problems
Dies
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Slide 1