Are Californian Sea Lion pups dying from radiation poisoning?

Californian sea lions may be dying from radiation poisoning.

Nearly 1000 sick and dying Californian sea lion pups have washed up on beaches this year.

Scientists say they are dying of starvation, but don't know why.

Cesium-137 radiation has been leaking into the ocean since the March 2011 Fukushima nuclear disaster in Japan.

Ocean plankton have been contaminated with Cesium-137, according to a Tokyo University of Marine Science and Technology report.

Sea lions eat fish that live on plankton, which drift with ocean currents. 

The Kuroshio current travels north past Japan and joins the North Pacific current. This flows east to join the Californian current heading south.

Tuna caught off the Californian coast have above-average Cesium-137 contamination. Tuna also eat fish that live on plankton.

After the disaster, wind carried fallout clouds across the US east coast. Rains washed radioactive material to the ground, contaminating pastures, crops and dairy milk.

Since the Fukushima disaster, Cesium-137 radiation has been found in Finland, Canada, California and Australia.

Radiation disease symptoms include nausea, vomiting, diarrhoea, loss of appetite, fatigue, cancer, seizures and coma.

Children and young animals are more sensitive to radiation poisoning than adults due to faster cell division. Cesium-137 takes at least 60 years to decay.