Presentation on theme: "Killer Whales of British Columbia"— Presentation transcript:
1 Bioaccumulation: A Case Study of British Columbia’s Killer Whales Lesson 1
2 Killer Whales of British Columbia There are 3 different types of killer whalesThey have different diets, ranges, languages, behaviour & social organization (Bigg, Ellis, Ford)The three types are Residents, Transients & Offshore killer whalesThe different kinds do not mate with one another!(Barrett-Lennard)
3 So much is known because killer whales can be told apart as individuals thanks to the work of Dr. Michael BiggDorsal Fin – shape, nicks & scratchesSaddle PatchA12, Scimitar, 1941A33, Nimpkish, 1971Photos: Jackie Hildering
4 Resident Killer Whales Eat fish – Mainly salmonThe fish can not hear in the range of the calls and salmon has very predictable spawning behaviourThis means that residents can afford to be:Very social – they don’t leave their mothers, travelling in matrilinesVery vocal – each matriline sounds a little differentBecause 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.
5 Matriline example Resident killer whales – A30s A30 female 1947“Tsitika”A6Male“Strider”A38Male 1970“Blackney”A39Male 1975“Pointer”A50Female1984“Clio”A54Female 1989“Blinkhorn”A752001“Cedar”A842005No nameA72Female1999“Bend”Know female by DNA
6 Transient Killer Whales Eat marine mammalsThe marine mammals can hear them!This means that transients:Must be very quiet until they are sure they are going to get their preyFamily structure less stable
10 Food Web Transient killer whale Resident killer whale Seal Humans SalmonHerringZooplanktonPhytoplankton
11 Amount of food energy per animal (number of plankton markers) OrganismNumber SurvivingAmount of food energy per animal (number of plankton markers)Total amount of food energy for the speciesResident killer whales2SalmonSalmon #1Salmon #2Etc.HerringHerring #1Herring #2Herring #3
12 Amount of food energy per animal (number of plankton markers) OrganismNumber SurvivingAmount of food energy per animal (number of plankton markers)Total amount of food energy for the speciesTransient killer whale1SealsSeal #1Etc.SalmonSalmon #1Salmon #2HerringHerring #1Herring #2Herring #3
17 Total number of marked food pieces Survived (S), OrganismNumber SurvivingAmount of food energyTotal number of marked food piecesSurvived (S),Died (D) or reproduction and immune system problems (RI)Transient killer whale1SealsSeal #1Etc.SalmonSalmon #1Salmon #2HerringHerring #1Herring #2Herring #3
18 OrganismNumberSurvivingAmount of food energyTotal number of marked food piecesSurvived (S), Died (D) or reproduction and immune system problems (RI)Resident killer whale1SalmonSalmon #1Salmon #2Etc.HerringHerring #1Herring #3Herring #4
19 Number of toxic plankton markers OrganismNumber of toxic plankton markersWhat this meansHerringLess than 33 to 4More than 4SurvivesSurvives but will have reproduction and immune system problemsDiesSalmonLess then 44 to 6More than 6Seals or resident killer whalesLess than 55 to 8More than 8Transient killer whalesLess than 88 to 12More than 12
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