Nearly 50,000 union members working at America's East and Gulf Coast ports have started industrial action, slowing or stopping America’s imports and exports. It could become the country’s most disruptive work stoppage in decades - but it could have a flow on effect to trade around the world, including here in Australia. What the union is asking for, and what the US Maritime Alliance which represents the major shipping lines is willing to give, are miles apart. SBS's Phoebe Daes spoke to international shipping expert Sal Mercogliano, Professor of Maritime History at Campbell University and the host of What's Going On with Shipping on YouTube, and asked him to explain the significance of the strikes and why the strike could be significant for Australia