In the 4th and 5th centuries the Mazarrón salting industry appeared to reach a peak period, which led to considerable economic and trading activity. The wines of Greece and the oils of Bética were brought in and out of Mazarrón Port, but the main player in this trade will be North Africa and the current area of Tunisia.
Between the 4th and 5th centuries it seemed there arrived at the port more products from the rest of the empire and we see at the same time the salting industry at full production. This all reflects a peak period and a flourishing economy without precedents in previous epochs. The conclusions extracted from the Late amphora in Mazarrón Port give us abundant trade information. Wine from the eastern Mediterranean was received during the 3rd and 4th centuries, as well as part of the 5th. The previous relations with Lusitania for the import of garum were interrupted from the 4th century when the Port or Castellar salting factories were at full production. There are trade links with Bética, from where oil was received during the 3rd and 4th centuries.
It is also worth mentioning the role of trade links with North Africa, and specifically the current area of Tunisia, which from the 5th century was virtually the main Mazarrón Port player in terms of trade.
The port dredgings reflect a majority presence of containers for oil. The import of this product in large quantities leads us to believe that it would be for more than local supply and was possibly for redistribution in inland areas. This trading activity would come to a drastic end at the beginning of the 6th century, due to the economic collapse of the North African centres following the Byzantine seizure of Carthage by the vandals in 532 or due to the Byzantine occupation of the south-east of the peninsular after the landing in Cartagena in 555 and the probable return to this city of the monopoly on external trade activity.