The federal government will make it harder for international students to bring their families with them to Australia, among other changes.

The Nationals leader said he’ll do ‘whatever it takes’ to beat the Labor government – including not ruling out a move to the lower house before the next election.

Tony Burke was late to announce the government’s migration policy which will be wedged between those who think the changes don’t go far enough and critics who believe they’re draconian.

Sea urchins eat kelp – but new research shows their diets and relationships with kelp forests are more complex than commonly thought.