Happy Orcas. Dead Orcas State of Southern Resident Orcas Almost 20% orcas died between 1995 and 2000. Reproductive females have not produced young in.
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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.
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
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
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
Generalized Ecological Pyramid 2° Consumers 3° Cons. 1000 g Biomass 100 g 10 g 1 g Primary Producers Primary Consumers
Idealized Puget Sound Ecological Pyramid 1000 g 100 g 10 g 1 g Phytoplankton Zooplankton Salmon Orcas
Pollutants Pollutant –Adversely affects the health, survival, or activities of living organisms –Persistent Organic Pollutant POP Stable, Long Lasting Includes DDT and PCBs
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
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
DDT in a Long Island Estuary (from Woodwell, Wurster and Isaccson, 1967) Trophic level OrganismDDT 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 (About 1000x Initial Concentrations!)
Idealized Puget Sound Ecological Pyramid With PCBs 1000 g 100 g 10 g 1g Phytoplankton Zooplankton Salmon Orcas 1 g Trophic Level%PCB Phytoplankton0.1% Zooplankton1% Salmon10% Orcas100%
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.
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