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 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 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 Transient vs Resident Orcas Transients Residents Habitat Offshore Nearshore Food Marine Mammals Fish Pod Size 3 5 20 Vocalization Quiet Very Vocal 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 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 Dead Orcas 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 Polychlorinated Biphenyls PCBs Cl Cl Cl Cl 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 1g 10 g 100 g 10 0 0 g Bioma ss n 3 Co 2 C s ers m u s on ary m i r P rs e m u Cons ar Prim ce u d o y Pr rs Idealized Puget Sound Ecological Pyramid 1g 10 g 100 g 10 0 0 g s Orca on m l a S on t k n la Zoop to y h P to n k n pla 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 Organism DDT in wet weight of whole organism Primary Producer Primary Consumer Secondary Consumer Tertiary Consumer Green Alga 0 08 ppm Mud Snail 0 26 ppm Summer Flounder Ring billed Gull 1 28 ppm 75 5 ppm 1000x initial concentration Idealized Puget Sound Pyramid With PCBs 1g 10 g 100 g 10 0 0 g 1g Trophic Level Phytoplankton Zooplankton Salmon as c r O on m l a S on t k n pla o o Z on t k n pla o t y Ph PCB 0 1 1 10 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