Complex sentence: Other parts of coastlines or oceanic islands from Iberian Peninsula and Portugal to Morocco in north to south possibly down to even Mauritania, such as on Dakhla Peninsula and Bay of Arguin were potentially serving as wintering grounds similar to Cintra Bay region.
Split into simpler sentences: Other parts of coastlines or oceanic islands from Iberian Peninsula and Portugal to Morocco in north to south possibly reaching even Mauritania. Locations such as Dakhla Peninsula and Bay of Arguin had been served potentially as wintering grounds similar to the Cintra Bay region.