What does the Mediterranean journey actually entail?

Migrants leaving from north Africa for Italy do so overwhelmingly from Libya, though there are also routes to Italy from Egypt and Morocco, and from Turkey to Greece. A 2013 report for the United Nations High Commissioner for Refugees (UNHCR), by Altai consulting, estimates that the cost of getting to Libya varies from about $200 to $1,000 from west Africa, and from about $1,000 to $6,000 from the Horn of Africa. Subsequent transit by sea runs from a few hundred dollars to a couple of thousand. At the coast passengers are either loaded onto rigid inflatable boats with limited fuel and no captain or guide to help them or are herded onto rickety fishing boats which do have a skipper and crew. The journey from Libya to Italy is a couple of hundred kilometres—less than a day's sail—but the boats are not necessarily intended to get all the way. Once clear of the Libyan coast, a distress call is made in the hope that the migrants will be picked up either by a passing merchant ship or fishing boat or by the Italian or Maltese coast guards. In cases where the vessel is crewed, the crew members flee or try to pass as migrants, often successfully.

Why are people risking this awful journey?

Because they are fleeing some mixture of war, oppression, civil disorder and poverty. Most of the migrants are young men. They make their journeys in sections, stopping and working at various places along the route. According to Italian estimates there are between 500,000 and one million currently in Libya awaiting passage; living conditions are usually bad, but most migrants have no way back to where they came from.

Where are most migrants coming from?

The make-up of the flows has changed over the years. Migrants currently come mainly from west Africa, the horn of Africa and, since 2013, Syria. Last year, according to the UNHCR, 31% of arrivals were Syrians, and 18% were fleeing Eritrea. So far this year the flow to Italy is dominated by migrants from the Gambia, Senegal and Somalia. There are routes through the Sahara from both west Africa and the Horn of Africa; there are also some routes along the Mediterranean coast. For many of the communities along the way the traffic in would-be migrants is now a dominant part of the local economy. (Story continues below the chart)

Where do they end up?

The vast majority of those who leave Libya end up in Italy—often the small island of Lampedusa. Greece and Malta are also common destinations. The European Union's Dublin regulation says that the first EU country a migrant gets to must take responsibility for him; southern countries say this puts puts a great deal of the burden of border management on them. Germany, France and Britain, though, say they end up taking more refugees and migrants, both because of migration along other routes (for example, through the Balkans) and because southerners encourage migrants to move northwards. Reaching an agreement on an equitable distribution of the burden has not yet proved possible, largely because of political sensitivity to immigration in northern countries. On a per capita basis, Sweden has taken by far the largest share of Europe’s Syrian refugees.

Why is the journey so dangerous? Don't people sail around safely on the Med all the time?

The boats used are old and often of dubious seaworthiness; their crews often abandon them. They are also severely overcrowded. The boat that sank on April 19th was about 20 metres long and carrying more than 900 people, many of them locked below decks; it appears to have capsized when those on deck rushed to one side, seeking to board a ship offering to rescue them.

Is migration becoming more dangerous over time? Why are more people dying?

The UNHCR estimates that 26,165 migrants have reached the shores of Italy this year, a similar number to the 26,644 who arrived in the first four months of 2014. However in the first four months of 2014 only 96 are thought to have died, as opposed to an estimated 1,700 so far this year. The main difference in circumstance is that in early 2014 the Italian navy was operating a thoroughgoing interception operation called Mare Nostrum, which was set up after an earlier wreck off Lampedusa in which hundreds died. Mare Nostrum intercepted ships carrying migrants in international waters and became the de facto last stage of most migrants’ journey to Europe. More than 140,000 people were taken on board its ships from October 2013 to October 2014. At that point it was replaced by an operation called Triton, run by the EU’s border agency, Frontex, which only operates within 50km of the Italian coast. Among the arguments for this new, cheaper option was the idea that, if shutting down Mare Nostrum made the passage riskier, then fewer would attempt it. This appears not to have been the case; the change of policy seems simply to have driven the death toll up. (Story continues below the chart)

What could reasonably be done to reduce the number of deaths?

Reinstating a programme along the lines of Mare Nostrum would almost certainly reduce the number of migrants lost at sea. At an EU summit convened in late April, in response to a growing death toll, leaders agree to triple funding for Operation Triton. A full reintroduction of Mare Nostrum was ruled out, however.

For something more ambitious to work, a better way of distributing the refugees around Europe will be necessary. Operations aimed at destroying the smugglers’ ships have been mooted, but pose several risks: military action might increase instability in Libya while encouraging the smugglers to use smaller yet less-seaworthy boats. Peace and a return to effective government control along the Libyan coast could bring with it the sort of stability that lets people earn their living from work other than smuggling, as well as a police presence capable of reining in illegal migration. Yet bringing peace to North Africa and the Middle East is an even harder problem than ending the migration crisis. Doing more for Syrian refugees in other Arab countries might help, but given the large number of migrants already in Libya it would take time to have any effect. It is also possible that applications for European asylum could be processed in north Africa, but although this idea has been gaining support there has been no concrete progress. Again, it is unlikely to be workable without a resolution to the impasse over the distribution of refugees across Europe.

This piece has been updated to reflect news.

Dig deeper:

Europe's disastrous migration policy is a moral failure (April 2015)

Europe's boat people: a briefing (April 2015)

Australia's uncompromising solution to migration (April 2015)