New figures from the Central Statistics Office show that Irish ports handled over 12 million tonnes of goods in the first quarter of 2021, down 3.2% compared with the same time last year.
The CSO said that goods forwarded from these ports amounted to just over 4 million tonnes in the first three months of the year.
A total of 8.1 million tonnes of goods were received during the same period.
Today's figures show that the total number of vessels arriving during the first quarter of the year in the seven main Irish ports - Bantry, Cork, Drogheda, Dublin, Rosslare, Shannon and Waterford - increased by 73 (2.6%).
The gross tonnage of all arriving vessels increased by 5.1%, the CSO added.
Dublin Port accounted for 60.1% of all vessel arrivals in Irish ports and for 46.2% of the total tonnage of goods handled in the first three months of the year.
The CSO said that Great Britain & Northern Ireland accounted for 29.4% of the total tonnage of goods handled in the main ports by region of trade in the first quarter of 2021, compared with 39.5% the same time last year.
Other EU countries accounted for 43.2% of the total tonnage of goods handled in the main ports, an 8.6 percentage point increase compared with the first quarter of 2020.
The tonnage of goods handled increased in three of the five traffic categories - dry bulk, lift-on lift-off and break bulk & other goods. But there were year-on-year percentage decreases in liquid bulk traffic (down 21.3%) and in roll on/roll off traffic (down 12.9%).