A permit scheme introduced last year is being flouted by trawler owners in many cases, according to figures revealed by RTÉ's Prime Time.
The Atypical Permit Scheme for non-EEA and non-EU fishermen was introduced in 2016 after the Guardian newspaper revealed a range of abuses in the sector.
It was claimed that some fishermen were being treated as slaves, with poor working conditions and low pay.
The industry itself said as many as 2,000 permits could be needed, in order for labour demands to be met.
However figures obtained by Prime Time indicate that less than 200 permits have been issued.
A year later it appears serious issues remain in the sector.
141 inspections of fishing trawlers by the Workplace Relations Commission's Inspection division detected 191 breaches.
Illegal workers were found in 28 cases and a large number of employment rights contraventions were also uncovered.
60 of the inspections were carried out last week under Operation Trident, with ports all over the country targeted.
Despite the large number of breaches only two prosecutions are being pursued through the Court system.
The WRC has not introduced any Compliance Notices or fines despite the issues uncovered.
Only fishing vessels longer than 15 metres are included in the scheme – as a result, many suspect that illegal migrants are being transferred to smaller vessel.
It is believed serious consideration is being given to reducing the size of vessels covered under the scheme to 12m.