The volume of goods passing through Dublin Port last year only dropped marginally, despite the impact of Brexit on Irish Sea trade.
Overall, 34.9 million tonnes went through the facility, down 5.2% on the previous year.
Roll-on-Roll-Off, or Ro-Ro units dropped by 9.3%, equivalent to 99,000 trailers, according to the port.
But Load-On-Load-Off containers rose by 10.2% to 43,000, offsetting the Ro-Ro decrease.
This increased the share of Lo-Lo volumes from 29% to 33%.
When the two categories are combined, total unitised volumes decreased by 3.8% or 56,000 units.
Imports of vehicles destined for sale rose by 10.9% over the course of the year, reaching 82,000.
Routes to and from Great Britain made up 52% of the total loads last year, down from 64% in 2020.
Most of that drop was centred on routes between Dublin and Holyhead, Liverpool and Heysham.
In contrast, the volume of goods transported on direct routes to continental Europe rose significantly, by 88,000 to 259,000, as shipping agents and hauliers took steps to avoid the UK land bridge.
Dublin Port also reported that fewer of the Ro-Ro trailers were accompanied by drivers during their sea journey.
"Brexit has caused the make-up of Dublin Port's unitised volumes to change significantly," said Eamonn O’Reilly, Dublin Port’s CEO.
"Ro-Ro volumes were down by 99,000 and, for the most part, this decline was accounted for by a 90,000 reduction in driver accompanied Ro-Ro. By comparison, the number of Lo-Lo containers increased by 43,000," he said.
Ahead of the expiration of the Brexit transition period at the end of 2020, there had been fears or significant delays and backlogs at UK and Irish ports, as those moving and inspecting imports and exports got to grips with new checks and paperwork.
However, Dublin Port claims that the introduction of the changes went largely smoothly.
"The extensive Brexit preparation work completed in 2020 paid off in 2021," said Mr O'Reilly.
"There was none of the catastrophic congestion that had been projected and what disruptions there were in the early days of 2021 were quickly resolved as supply chains adapted to the new realities," he stated.
"Over the course of the year, the average number of trailers called for some physical inspection on services from GB was just 2.5 per ferry," he added.
Last year also saw a modest 2.1% increase in the volume of bulk commodities passing through the port.
These made up 17% of the total volumes using the port.
The number of ferry passengers who used the port last year rose 1.5% compared to 2020 levels, but due to travel restrictions, the number of people travelling through Dublin Port is still half of the 1.9 million who did so in 2019, before the pandemic hit.
The port is now predicting an increase in the total volume of trade this year as trade on direct routes between the capital and continental Europe grows further.