Toxins in Our Oceans

Types of ToxinsPCBs

PBDEsMercury

PCBs polychlorinated biphenylsUsed in plastics and electronicsBanned in US in 1979 •Severe liver damage leading to cancer•Hormonal imbalances leading to breast cancer

PBDEs Polybrominated diphenyl ethers

Flame retardants used in:•Computers•Televisions•Cars•Furniture Fabrics•Foam Mattresses

Causes:

•Endocrine Disruption•Developmental defects

MercuryFound in:•Household switches, thermostats•Household lamps•Button-shaped batteries•Latex paint produced before 1992•Coal-burning power plants

Mercury•Neurological Damage

•Immune System Suppression•Minamata Disease

BioaccumulationConservative Pollutants cannot be broken down by bacteria so they

stay in the animal and concentrate higher up the food chain.

Mercury Levels in FishSeafood with mercury levels over 1.0 ppm is considered

unsafe for human consumptionKing Mackerel ~ 0.3-1.67 ppm

Swordfish ~ 0.1-3.22 ppmTilefish ~ 0.65-3.73 ppmShark ~ 0.05-4.54 ppm

Source of data: FDA 1990-2004, "National Marine Fisheries Service Survey of Trace Elements in the Fishery Resource" Report 1978,

"The Occurrence of Mercury in the Fishery Resources of the Gulf of Mexico" Report 2000

BiomagnificationAnimals at the highest trophic

levels obtain the highest levels of pollutants.

Toxic Top 10Bottlenose dolphin

OrcaRisso’s dolphin

Harbor sealBeluga

Mediterranean monk sealCommon dolphin

Gray sealPolar bear

Stellar’s sea eagle

DDT and other contaminants

Oil Spills…