More than 580 vessels from states other than Ireland were inspected at sea during 2017 by the Naval Service.
In all, some 3,600 inspections took place at sea, inshore and on landings of both Irish and foreign vessels in 2017, according to the Sea Fisheries Protection Authority (SFPA), the State's regulator for the sector.
Fishing vessels from Russia, Belgium, Denmark, France, Germany, the Netherlands and Britain were among those inspected.
It said there are continued "low levels" of non-compliance with regulations in the Irish fleet. Twelve vessels were detained and 24 cases in total were referred to the Director of Public Prosecutions (DPP). Infringements detected included under-recording of catches and exceeding quota.
A total of 23 legal notices were issued to food business operators by the SFPA last year, during the course of over 700 inspections of food businesses. Its staff also undertook 710 inspections and 1,337 official control checks in response to food incidents and complaints.
"The majority of fishermen, producers and processors want to work within the law and the low levels of non-compliance that we are detecting are evidence of that," said the authority's chairwoman Dr Susan Steele.
“We recognise too that compliance isn’t always easy,”she said. “The new EU Landing Obligation regulations, which require fishermen to land what they catch, have meant significant changes in fishing practice in recent years.
“ However, these are vital changes to ensure a sustainable industry, with fish stocks capable of providing higher and more profitable catches in the medium- to long-term. This will ultimately benefit the industry and the many coastal communities around Ireland that rely on it for a living,”she said.