The hospital ship Esperanza del Mar retrieved the bodies, at least some of whom were wearing life jackets, 720km from the Spanish archipelago on Wednesday, a regional government source said.
At least 67 Africans are now known to have drowned since the end of February with thousands setting sail for the Canaries in barely seaworthy boats on a perilous voyage from Mauritania.
Regional prefect Jose Segura said the local authorities "are concerned from a humanitarian point of view, even if they (the bodies) were found on the open sea" some 70 nautical miles off Ras Nouadhibou in northern Mauritania.
Immigration to the Canary Islands has been on the rise in recent months, and only on Tuesday local authorities said the number of clandestine immigrants intercepted there tripled to 2908 in the first quarter of this year compared with the same period in 2005.
Stepped-up coastguard patrols in the Straits of Gibraltar, off northern Morocco and the northern Canaries has forced gangs smuggling migrants to Europe to seek out new routes from points further south, and targeting more outlying islands in the Canary group.
The Mauritanian Red Crescent estimates that between November and the start of March some 1200 to 1300 people died in attempting the perilous crossing.
Smuggling gangs have been
forced to seek out new routes
A government statement said the ministerial delegation would on Thursday propose making patrol boats available for the Mauritanians to bolster coastal monitoring as well as help with provision of reception centres to hold migrants.
The statement added that Madrid hoped to "reactivate" a bilateral accord dating from 2003 allowing repatriation of illegal immigrants and extend the agreement to cover migrants from other African states.
Antonio Camacho, Secretary of state for security, and his foreign affairs counterpart, Bernardino Leon, will meet Mauritanian officials in Nouakchott and then visit the port of Nouadhibou where over the past two months thousands of Africans have concentrated hoping to make it to Spanish soil.
A diplomatic source in the foreign ministry told AFP one difficulty Spain faced was how to show that migrants left from Mauritania as opposed to Morocco or Western Sahara.
Last Sunday, Spanish authorities said they had intercepted 211 clandestine African migrants in boats off the Canary islands over the weekend, some apparently from Mauritania.
In Brussels, a European Commission spokesman said: "We are very seriously concerned about the developments in Mauritania and in particular the loss of life in the Atlantic Ocean between Mauritania and the Canary Islands."
"Migration pressure on the EU is high, has been high for a very long time and will not disappear tomorrow"
Spokesman Friso Roscam-Abbing said that an EU expert would accompany the Spanish delegation "to hear exactly what the problems are, and to see how best the EU can assist".
"We need to be realistic. Migration pressure on the EU is high, has been high for a very long time and will not disappear tomorrow," he added.
"We need a structural approach addressing the roots of migration."
EU and African officials are due to discuss the issue at talks in Rabat on 10 and 11 July, he said.