A report has found that two crewmen died after being exposed to toxic fumes from a trawler's fish tank.
The men were carrying out checks on the FV Oileán an Óir in Killybegs Harbour, which had been out of use for some time, when they were overcome by the fumes.
The report says that although two of the three crewmen on board were experienced, a skipper did not accompany them on the day of the incident in August 2015.
The report says that the death of both crewmembers was caused by the inhalation of lethal levels of hydrogen sulphide accompanied by elevated levels of ammonia that were present in the atmosphere in the port side RSW tank.
When the first crewmember entered the port side RSW tank and was immediately overcome by toxic gas. The second crewmember attempted to help him and subsequently became overcome by toxic gas.
Neither the vessel, nor the crewmen had equipment to monitor the atmospheres within the tanks.
The source of lethal levels of hydrogen sulphide and elevated levels of ammonia was the dormant water that existed in the RSW system.
The hazards associated with the generation of toxic gases from the decaying of organic matter and the consequent hazard that these toxic gases and or the depletion of oxygen in the atmospheres in confined spaces is well known in the broader marine industry.
The understanding and recognition of the dangers associated with these toxic gases does not appear to be as well known within the fishing industry.
The report concludes that International developments and increasing awareness of issues with the dangers of enclosed space entry in vessels indicate that there is need for greater awareness and guidance in this regard specifically for fishing vessels.