The bream fishing in Ireland seems to have been on constant decline for the past 20 years. Seems that gone are the days of consistant bulging keep nets full of large bream, and they are unlikely to return.
The group of blokes i know who went Ireland every year no longer bother; instead they go to Holland for big bream bags.
However, there is an old timer who still goes Ireland and he's shown me photos of recent 100lb+ bream bags.
His view is that the zebra mussels that got introduced in 90's/00's have been the main factor, as they caused a lot of the waters to become more clear. Due to this the feeding habits of the bream have changed, with them mostly feeding in early morning/late evening or through the night. Fishing for them through the day is a waste of time.
The other factor he mentions is that due to less people fishing, less food is going in, which means the bream shoals are now smaller and more dispersed. To combat this he says he uses like 7-8 times the amount of bait he used to use, and thinks nothing of spending 3 days pre-baiting waters or swims before he even drops a line in the water.
Also, a lot of his big bream catches are from private waters or from others well off the beaten track, where a 2 mile trudge across open fields is the norm.
So, the bream are still there but most people can't be arsed spending the time, effort or the expense to catch them, especially when the bream fishing in places like Holland is better/easier/less expensive.