However, authorities said a €75m investment plan for 2009 was still on course.
Research, conducted under the National Development Plan 2007-2013, highlighted important conclusions in relation to Dublin Port and the wider port sector.
Transport Minister Noel Dempsey acknowledged the port's future had been the subject of much discussion in recent years.
"The future of this port is not just a local or regional matter it is of major strategic importance to the country as a whole," he said.
"The National Development Plan recognised this fact by providing for this study.
"This report is an important analysis not just of the future of Dublin Port but also provides a useful insight into the capacity challenges that face the sector as a whole."
Over 40% of national tonnage passes through the port, which plays a particularly important role in terms of fast moving high value cargos.
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Dublin port has a 75% market share for roll on roll off trucks (RoRo) and 64% for lift on lift off containers (LoLo). The port is also vital in terms of the State's energy supply, handling 45% of national oil imports.
The study found there is a need to develop significant additional port capacity by 2025 - 2030 as a result of future capacity constraints in existing port facilities.
There are two significant projects at different stages of the planning process at present.
Dublin Port's proposed expansion is currently with An Bord Pleanála and the proposal for a new port at Bremore is at the pre-planning stage.
The study identified considerable uncertainties with regard to both projects. It concluded that nothing should be done at a policy level to hinder either.
A cost benefit analysis of seven different future scenarios identified potential benefits relating to the relocation or partial relocation of Dublin Port.
This was looked at in terms of city sustainability issues arising out of increased urbanisation, greater usage of public transport and a related reduction in congestion.
However, the report said costs of such a relocation are "very significant" in terms of the capital costs of building alternative capacity, the inevitable business disruption caused by such a relocation and increased traffic movements.
An important finding of the cost benefit analysis was in relation to the scale and value of the port estate if it were to be redeveloped.
The study concluded that such redevelopment would have to take place over a considerable length of time, which could realistically reach a century.
The Ports Sub-Programme of the National Development Plan 2007 -2013 estimates port infrastructural expenditure of between €300m and €600m over the period of the programme.
Some €120m has been invested in the first two years of the programme, with a further €75m budgeted for 2009.
(PR/JM)
