Cases of bird flu in farm workers in the US may be going underreported, due to supposed poor surveillance and lack of testing. We hear from Amy Maxmen of KFF Health News who has been reporting on a study in Texas.

We hear from Bradley Moore, Professor of Marine Chemical Biology at University of California, San Diego about marine algae using massive enzymes, dubbed PKZILLAs to biosynthesize fish-killing toxins.

BBC Science Correspondent Jonathan Amos gives us the latest on the two American astronauts who blasted off on a test mission to the International Space Station on 5 June, expecting to be back home in a matter of days. But the pair are still there, floating high above the Earth two months later - stuck indefinitely - now facing the sudden prospect of missing the summer entirely and even spending Christmas and New Year in space.

And sea lion camera crews are helping researchers explore previously unmapped ocean habitats in southern Australia. Nathan Angelakis of the University of Adelaide tells us about working with the animal camera operators and what we can learn from viewing their movements.

Presenter: Roland Pease Producer: Jonathan Blackwell Production co-ordinator: Jana Bennett-Holesworth

(Image: Young Farmer and Cows on Dairy Farm. Credit: EyeJoy via Getty Images)