One potential alternative food source – both for humans and the animals we eat – is algae. Could the green stuff that appears on ponds and lakes after a particularly warm spell be the answer ...

Toxic algae has been found in the Waihopai River ... and stable river flows and can be identified as dark brown or green slime on rocks or dark brown/black mats at the water's edge.

Now Argentina's beloved giant rodent, the capybara, has been coated in Hulk-green slime as pollution turns ... partly driven by livestock farming, causes the algae to spread.