Post on 08-Jun-2020
Humpback Whale ContaminantResearch
Cristiane ElfesFISH 475: Marine Mammalogy
April 11, 2007
Outline
Persistent Organic Pollutants
Marine Mammals and Contaminants
Humpback Whale Research
Persistent Organic Pollutants (POPs)
“Human-made chemicals that remain in theenvironment for long periods of time and have theability to bioaccumulate”
Common Characteristics:• Volatile• Lipophilic• Resistent to Degradation
4 Classes:• DDTs• PCBs• HCHs• PBDEs
Bioaccumulation
Large fish
Toothed whales
DDT
INSECTICIDE used against disease vectors, crop andhousehold pests
First reported in Marine Mammal tissues in 1960s Regulatory status:
Banned in most countries Still used in some developing countries to prevent malaria
Potential Health Effects: Neurotoxic Developmental and reproductive effects Carcinogenicity
PCBs
HEAT RESISTANT OILS used in electrical transformers andcapacitors; also used in plastics, inks and other minorapplications
Regulatory Status: Banned in most countries in the 1970s and 1980s
Potential Health Effects: Estrogenic effects Alteration of thyroid metabolism
HCHs
Two forms: Technical HCH - Insecticide Lindane - Seed Dressing, Medication (Lice, Scabies)
Regulatory Status Technical HCH - banned Lindane- still in use (including US, Canada)
Potential Health Effects- Neurotoxic- Liver and kidney damage- Carcinogenicity- Estrogenic Effects
PBDEs FLAME RETARDANT chemicals used in plastics, electronic
equipment and textiles Three forms: penta-, octa-, deca- BDEs Regulatory status:
Penta- and OctaBDEs banned in Europe California: ban on penta- and octa-BDE beginning in 2008. Washington: proposed ban on penta-, octa- and deca-BDE
Potential Health Effects: Developmental neurotoxicants Influence thyroid metabolism Estrogenic effects
PBDEs continued…
PBDEs detected in sperm whales (Boer et al., 1998)
PBDEs detected in Arctic food chains, including beluga whales,ringed seals and polar bears (Wolkers et al., 2004)
Killer whales in northeastern Pacific show high levels of PCBsand PBDEs (Rayne et al., 2004; Ross, 2005)
PBDE concentrations in ringed seals in the Canadian Arcticincreased an order of magnitude in 20-years (Ikonomou et al.,2002)
Marine Mammals and Contaminants
Susceptibility:
Long lived species
Often top level predators
Female transfer of contaminantburden to calves during gestationand lactation (through placentaand later milk)
Diving physiology increasingsensitivity to toxic substances?
Health Implications
Direct MortalityNo evidence for direct mortality
Reproductive Impairment Experimentally verified in harbor seal (Phoca vitulina) (Reijnders, 1986) Other field studies: some pinniped populations and St. Lawrence
beluga whales
Immune Dysfunction/Disease Observed occurrences of tumors, lesions, chromosomal aberrations Occurrence of disease - morbillivirus (phocine distemper virus)
Cause and Effect Relationships are difficult to establish in wildpopulations!
Contaminant Variation
Age, sex, reproductive statusIncrease with age, differences between male and female,female transfer to offspring
GeographicHigher in proximity to point sources, sink areas
Feeding ecologyVaries with position in food chain, differences in feeding ecology
TemporalIncrease over time, changes in DDT/DDE ratios
Humpback Whales(Megaptera novaeangliae)
Baleen whale
Status: Endangered(ESA), Depleted(MMPA)
Can be individuallyidentified my flukephotographs
Feed on euphausiidsand small schoolingfish
Humpback Whale Migration
Migrate fromwinter breedingareas to summerfeeding areas
High degree ofsite fidelity tofeeding areas
Can serve asbioindicators
References
O’Shea, 1999. Environmental Contaminants and MarineMammals - Biology of Marine Mammals. Editors Reynolds andRommel. Smithsonian Press.
O’Shea and Brownell.1994. Organochlorine and metalcontaminants in baleen whales: A review and evaluation ofconservation implications. Science of the Total Environment154:179-200.