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Current State of Our Orcas

Current State of Our Orcas. Highline Community College. Killer Whales- Orcas. Orcinus orca Largest member of the dolphin family, Delphinidae Identifying traits Tall dorsal fin Saddle patch behind dorsal fin White patches on sides, belly and behind eyes. Orca Biology.

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Current State of Our Orcas

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  1. Current State of Our Orcas Highline Community College

  2. Killer Whales- Orcas • Orcinus orca • Largest member of the dolphin family, Delphinidae • Identifying traits • Tall dorsal fin • Saddle patch behind dorsal fin • White patches on sides, belly and behind eyes

  3. Orca Biology • Average Birth Weight: 395 lbs • Average Adult Weight: 2.6 – 9 tons • Males are larger than females • Lifespan: • Males ~40 years • Females >60 years • Sexually mature ~13 years

  4. Orca Natural History • Found in all the world’s oceans • Travel in pods from 3 to >150 members • Feed on fish, squid and marine mammals

  5. Transient vs. Resident Orcas

  6. Resident Orcas • Resident orcas live in coastal areas feeding mostly on fish • Live in extended familial units called pods • Pods are matriarchal • Northeast Pacific resident orcas are found from Puget Sound to Alaska • Puget Sound orcas are Southern Resident Orcas

  7. Southern Resident Orcas • Consists of three pods: J, K and L • Summer in the area around the San Juan Islands feeding on salmon runs • Winter on outer coast, but do not know where

  8. Dead Orcas

  9. State of Southern Resident Orcas • Almost 20% orcas died between 1995 and 2000. • Reproductive females have not produced young in ten years. • Only four adult males in the entire community of 80 whales.

  10. Puget Sound Orcas and PCBs • Highest levels of PCBs in blubber of any marine mammal in the world • Average almost 150 ppm • <10 ppm PCB is known to cause immune problems in seals • Dead female transient orca on Dungeness Spit in May 2002 • 1000 ppm PCB • 12ppm- EPA’s standard for marine sediments

  11. Polychlorinated Biphenyls(PCBs) Cl Cl Cl Cl

  12. PCBs • Highly stable oily fluids and solids • Transformers, pesticides, etc • Fat soluble • Reside in fatty tissue • Block hormone activity • Destroy normal immune function • Cause liver cancer, pituitary tumors, leukemia, and lymphoma • Banned in U.S. since 1977

  13. Ecosystem Review • Ecosystem • Organisms interacting with environment and each other through a food chain • Food Chain • Biomass moves from one organism to another as each eats a lower member and, in turn, is eaten by a higher member

  14. Generalized Ecological Pyramid 3° Cons. 1 g 2° Consumers 10 g Primary Consumers 100 g Primary Producers 1000 g Biomass

  15. Idealized Puget Sound Ecological Pyramid Orcas 1 g Salmon 10 g Zooplankton 100 g Phytoplankton 1000 g

  16. Pollutants • Pollutant • Adversely affects the health, survival, or activities of living organisms • Persistent Organic Pollutant • POP • Stable, Long Lasting • Includes DDT and PCBs

  17. Factors Influencing Impact of Pollutants • Solubility • Water soluble pollutants • Move easily through environment • Fat soluble pollutants • Need a carrier • Long-lasting in body’s fatty tissue • Persistence • More stable • Longer to break down • More harm it can do

  18. Pollutants in the Food Chain • Bioaccumulation • Cells increase the concentrations of molecules relative to the environment • Biomagnification • Concentration of pollutants increases as they move up the ecological pyramid • Only 10% of biomass, but most of the pollutant is transferred

  19. Trophic level Organism DDT in wet weight of whole organism Primary Producer Green Alga 0.08 ppm Primary Consumer Mud Snail 0.26 ppm Secondary Consumer Summer Flounder 1.28 ppm Tertiary Consumer Ring-billed Gull 75.5 ppm (1000x initial concentration) DDT in a Long Island Estuary(from Woodwell, Wurster and Isaccson, 1967)

  20. Trophic Level %PCB Phytoplankton 0.1% Zooplankton 1% Salmon 10% Orcas 100% Idealized Puget Sound PyramidWith PCBs Orcas 1g Salmon 10 g Zooplankton 100 g Phytoplankton 1000 g 1 g

  21. The ‘Double Whammy’ • In blubber, PCBs are not very harmful. • Low salmon runs force orcas to metabolize more blubber to survive. • The blubber releases PCBs into the blood, destroying the immune system. • Therefore, starvation increases the lethality of the pollutant.

  22. Sources of Pollutants in the Environment • Point Source • Specific location of concentrated pollutants • Factory waste • Sewage • Nonpoint Source • Scattered or diffuse sources of pollutants • Golf courses • Agriculture

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