A killer algae has killed more than half a million fish in a US lake over the past 10 days.
Fisheries scientists are currently investigating the algal bloom at Lake Texoma, which straddles Oklahoma and Texas, in an attempt to determine why it has killed so many fish.
The golden algae is causing fish to bleed from their gills, but is currently confined to a localised part of the lake.
It is hoped that the algae will recede as the water temperatures increase and won't continue to spread.