But it doesn't show any signs of stopping.
Since 2015, Europe has scrambled to cope with the arrival of around 1.5 million people by sea.
In an effort to stem this flow, many European countries have tightened their policies and borders. In 2016, the European Union forged a controversial 'one in, one out' deal with Turkey to stop the tide of migrants and refugees fleeing to the continent from the Middle East. And, this year, Italy has adopted an aggressive approach to halting migration across the Mediterranean from North Africa, backing the Libyan coast guard's rescue efforts and cracking down on nongovernmental organizations (NGOs) operating off the country's coast.
With each new twist and turn, the number of arrivals has dropped. But new migrant routes keep cropping up. People seeking alternative passages have moved westward -- seen in the recent spike in migrants arriving in Spain from northern Morocco -- while others are turning in desperation to new destinations such as Yemen.
Footage that surfaced on social media in early August showed stunned sunbathers watching as a dinghy packed with dozens of African migrants landed on a Spanish beach -- the latest sign of an evolving crisis.
Here's what has been happening in the Mediterranean:
Why are NGOs suspending migrant search-and-rescue (SAR) operations in the Mediterranean?
Three aid groups operating in the Mediterranean -- Doctors Without Borders (MSF), Save the Children and Sea Eye -- suspended their rescue operations in August, citing security concerns after Libya blocked foreign vessels from a stretch of sea off its coast. The MSF said an increasingly 'hostile environment' had made their efforts untenable, while Sea Eye alleged that the Libyan government had issued an 'explicit threat' against NGOs.
What is the Libyan coast guard doing?
Libya has extended its SAR zone into international waters, restricting access to humanitarian vessels. The Libyan navy, emboldened by its agreement with Italy, has recently fired warning shots at humanitarian aid vessels patrolling in this area. Libyan Navy spokesman Brigadier Ayoub Qassem told CNN: 'We are fed up with these organizations. They increased the number of immigrants and empowered smugglers. Meanwhile, they criticize us for not respecting human rights.'
Libya has asserted its right to operate beyond the territorial limit of 12 nautical miles from the coast. According to Save the Children, Libya has extended its SAR zone to 70 nautical miles from its shoreline. The move has led to clashes with NGO vessels at the edge of Libyan waters.
What assistance is Italy providing to the Libyan coast guard and why?
In August, Italy announced it would deploy two naval ships to Libya -- a patrol vessel and a technical and logistical support unit -- in an effort to deter illegal migration and human smuggling into Europe. The move came after Libya's UN-recognized government of national accord requested help. The initiative has been widely panned by NGOs, which have warned that the move will expose migrants to far more danger and abuse.
What restrictions has Italy imposed on NGOs?
In late July, Italy's Parliament passed a controversial 'code of conduct' for NGOs operating search-and-rescue missions in the Mediterranean. Among the measures are:
• Ban on entering Libyan waters except in situations of grave or imminent danger
• Ban on phone calls to help migrant departures
• Ban on transferring rescued migrants to other vessels
• Commitment to allow armed police onto vessels to monitor activities
Three of the eight humanitarian groups operating in the Mediterranean agreed to the terms, while Doctors Without Borders refused to sign, saying it could increase deaths at sea. The mayor of Catania, Italy, told CNN that he believes the code of conduct is behind the recent drop in migrant arrivals there; critics say it is too early to tell.
What is happening to migrant arrivals in Italy?
Migrant arrivals to Italy dropped in July -- cut in half from the same month last year -- figures from Italy's interior ministry showed. According to the International Organization for Migration (IOM), 94,802 migrants have reached Italian shores so far this year -- 85% of all arrivals in Europe.
How is that affecting migrant arrivals elsewhere?
The UN says over 9,000 migrants have arrived in Spain so far this year, most of those in the past two months. It's the most the country has seen since the start of the crisis. And it's flared in August -- with a staggering 604 migrants rescued in just 24 hours. Increasingly, African migrants are seeking a cheaper and easier path to Europe, setting sail for Spain from Morocco in toy dinghies and on jet skis. The average price to cross from the Moroccan coast to Spain is around 500 euros (about $590), according to Frontex.
Why has the Italian government shifted its strategy on refugees?
Italy's beefed-up approach to tackling the flow of migrants into the country followed local elections in June, which saw a wave of anti-immigrant mayors and local councilors ushered into office. Critics say the result has left the governing center-left party reeling, forcing Italian leaders to seek short-term solutions at the cost of migrants' lives.
'Our goal is to govern the migration flows,' the Italian interior minister, Marco Minniti, said in an August news conference. 'A big democracy, a big country, doesn't endure migration's flow, but tries to govern them.'
What is happening to migrants intercepted by the Libyan coast guard?
Migrants intercepted by the Libyan coast guard are being returned to the north African country. Human Rights Watch, and other humanitarian organizations, have warned against returning migrants to Libya, a war-torn country where migrants are exposed to torture, slavery and detention, they say.
A report published in June by the UN Panel of Experts on Libya contained serious allegations that factions of the coast guard were colluding with smugglers, and abusing migrants they intercepted. The same report detailed inhumane conditions in multiple migrant detention centers. It echoed another report by the UN support mission in Libya and the Office of the High Commissioner for Human Rights, published in December last year, which included similar claims.
What is the EU's strategy to address the refugee crisis, and how has it changed?
Since the height of the crisis in 2015, governments across Europe have sought to fortify their countries' borders. In February 2017, EU leaders outlined plans to stem the flow of migrants traveling across the Mediterranean from Libya to Italy, and boost the ability of the EU to send people back.
'The key priority is reducing the flow without any consideration for the causes of migration,' Nando Sigona, an expert in migration at Birmingham University's School of Social Policy, told CNN.
What about the anti-immigrant patrols in the Mediterranean?
An anti-immigrant vessel has underlined just how fraught the debate on refugees has become in Europe. The Defend Europe group deployed its C-Star vessel to the Mediterranean this summer, vowing to stop the 'invasion' of refugees attempting to sail to Europe.
'It's created pressure, pressure for the NGOs as we were here, always watching them, documenting them and basically paralyzing them. We've seen it, I think during our operation time, the whole thing has turned against the NGOs. They've lost most public support; many have given up,' Martin Sellner, one of the group's leaders told CNN. 'We came and they went so definitely a success.'
Though the C-Star has been allowed to continue operating in Libya's SAR zone, the Libyan Navy's Qassem told CNN that the coast guard would not work with them directly.
'They combat immigration through a spiteful, racist standpoint,' Qassem said. 'We don't work with racism.'
What is happening to the charities that are continuing their missions?
The Spanish aid group Proactiva Open Arms is among several NGOs that have continued to conduct rescue operations in the Mediterranean despite restrictions. Its crew recently reported that the Libyan coast guard fired warning shots while the vessel was in international waters.
'They were warned and told that they could be detained. We gave them a chance to leave and they did,' Libyan navy spokesman Qassem told CNN. 'They have to respect our sovereignty. They consider themselves above the law and Libyan sovereignty.'
According to Italian coast guard figures, nongovernmental groups were responsible for rescuing a quarter of all those saved in 2016, and a third of those pulled from the Mediterranean in the first three months of 2017.