In South-western Atlantic waters, individuals of the southern right whale (SRW) Eubalaena australis spend part of the year (the austral winter and spring) in northern inshore waters where they breed and then migrate to southern feeding grounds during the summer. Mar del Plata (MDP) is located between two main reproductive areas (Península Valdés-Argentina and Santa Catarina-Brazil). The purpose of the present study is to report the presence of SRWs on their journey off the coast of MDP based on sighting records during the past half century. We carried out whale observations through systematic weekly coastal marine mammal surveys in different points of the MDP area from 1966 to 2016. The first SRW sighting was recorded in 1970; since then, sighting frequency has gradually increased, reaching a peak of 28 sightings (N = 63 whales) in 2016. These are unique long-term sighting records of SRWs in Argentina and the first on their journey off the shores of Buenos Aires province. We expect that these results will help local authorities to regulate tourism and other activities in the area and thereby contribute to the conservation of the species.

Between the years 1996 and 2006 the Threatened Marine Species Recovery Centre (CREMA) detected 14 strandings and sightings of hooded seals in the coasts surrounding the Strait of Gibraltar. Five strandings and the only three sightings occurred on the Spanish coasts of the Mediterranean Sea. CREMA or its stranding report network did not deal directly with the stranded or sighted individuals but there were good descriptions and photographs to confirm identification. The frequency of stranding and sighting of hooded seal individuals on the southern coast of Spain indicate that the migratory movements of this species are performed by groups of young animals less than one year old.