Speaking shortly after the migrants were found, Zapatero said: "Spain and the Spanish government will head a big global mobilisation in support of non-governmental organisations and civil society ... so that the challenge of poverty, hunger, desperation, lack of education, sanitation and food basics becomes the main objective of all developed nations."
Friday's incident was the third such in the span of a week involving migrants dying trying to reach Spain illegally.
Eleven of the survivors of the journey - including three in serious condition - were taken to hospital after arriving on the island of La Gomera, a government spokeswoman said.
The surviving migrants had thrown overboard the bodies of "several" others who died during the trip from Guinea-Bissau, Spain's RNE public radio quotes rescue workers as saying.
The boat had apparently become lost at sea and only arrived at the Canary Islands by chance.
Two days earlier, police intercepted a rubber dinghy carrying 33 African migrants and the body of a woman who had died on board near Almeria in southern Spain.
The survivors said they had thrown the bodies of 14 others, including nine children - all under the age four - who had died during their crossing from Morocco.
Fourteen migrants from Nigeria also died last Monday after their boat capsized off the southern coast of the Spanish town of Motril just as it was being aided by a rescue ship. Twenty-three others were, however, saved.
A total of 921 would-be illegal immigrants died at sea trying to reach Spain last year, according to the Organisation for Human Rights in Andalusia (APDH-A), a Spanish humanitarian group.
Zapatero, during an official visit to Morocco earlier on Friday, said: "The situation is becoming increasingly serious and worrying in some sub-Saharan African countries as a result of the food crisis and deepening of extreme poverty."
Morocco is a common launching point for dangerous migration attempts to Spain and other European countries.
Last year, Zapatero promised to raise the amount of development aid which Spain gives out from the equivalent of 0.5 per cent of gross domestic product to 0.7 percent by 2012.
His government in January approved $8.6bn in international development aid for 2008, a 28.5 per cent increase over last year and its highest amount yet.
The world's richest nations agreed to provide 0.7 percent of their output in development aid by 2015 as part of the United Nations Millennium Development Goals, a series of targets aimed at reducing poverty and living standards around the globe.
Only five nations have so far met or surpassed the target: Denmark, Luxembourg, the Netherlands, Norway and Sweden.