To eat and be eaten

Scientist Darren Stevens talks about how the researchers are following krill and zooplankton, while Peter Mc Millan explains that the Antarctic silverfish is one of the very abundant types of fish they find in the Ross Sea. Darren Stevens then has a closer look at the contents of a fish stomach.

Points of interest

• What are the contents in the fish stomach?

• Consider what would happen if the numbers of krill were reduced?

Transcript

DARREN STEVENS

To estimate the number of krill out there really we’re doing - getting effectively images like a sounder, of particular types of aggregations of fish or these krill in particular and we need to know what type of image actually goes with what type of fish or in this case krill. So we’ve got images that we believe are schools of krill so we put the net down to actually determine that’s what they are.

PETER MCMILLIAN

It’s one of the most abundant species in the Ross Sea so you expect – it’s eaten by quite a lot of species so it’s important in the food chain. So there, there are lots of them here.

DARREN STEVENS

Wow, would you look at that, you can quite clearly see pleurogramma through the side of the stomach here – it really is full – and some krill in the side. The amazing thing about these is we get a lot of them back to look at dietary work but they’re almost always averted, so there’s no prey in the stomach, so to get one this full is really quite nice.