The ‘sheriff of Wall Street’, who took on mafia bosses and terrorists in court, looks back on his career. Plus: Tim Gordon on the silencing of the oceans

Preet Bharara rose to become one of the best-known lawyers of his generation. Nicknamed “the sheriff of Wall Street” after becoming the US attorney for the southern district of New York, he took on Russian oligarchs, mafia bosses and terrorists. He is even cited as the inspiration for the prosecutor in the hit TV series Billions.

Having been appointed by Barack Obama, Bharara was initially told he would be kept on in the job by Donald Trump. But just two months into the new presidency, Bharara was fired. He looks back on his career and at the subsequent investigations into Trump.

Also today: Tim Gordon, a marine biologist at the University of Exeter, talks about realising his childhood dream of diving the Great Barrier Reef but then finding a grey and deathly quiet world.