A Co Cavan man said he "doesn't accept" that a prolonged spell of hot weather was the sole cause of significant fish kill in Lough Sheelin.
Inland Fisheries Ireland (IFI) said it's continuing to monitor the Mountnugent River and Captain's Bay area of Lough Sheelin after detecting several hundred additional mortalities there at the weekend.
This follows a fish kill last week, and it is believed these fish died during that initial incident at the lough in Co Cavan.
Michael Callaghan is from the Lough Sheelin Trout Protection Association.
Michael, who has been involved with the Lough Sheelin Trout Protection Association for over 40 years believes hot weather may have been a factor, but is not the sole reason, adding that he is "very suspect" when it comes to incidents of this nature.
Speaking to Northern Sound, he said it's "very frustrating" for groups like Lough Sheelin Association who put so much effort into maintaining the popular amenity.
He hopes that Inland fisheries Ireland can come up with a definite answer to the cause of this: "I'm very familiar with the work of IFI and I praise them for it. I know that very often they struggle due to limited resources but I hope they can find the real, definite cause of this and establish it once and for all. I hope that the public in general can learn from this and realise how fragile our whole eco-system is in relation to the affects of effluence and possible spills and to be careful and vigilant. I just hope IFI can come up with a definite cause to this and I know that they're trying."
