mackerel in april??

Hi all, very surprised, yesterday, to catch mackerel at this time of the year.
Decent size too.
They showed up in a little bay around teelin and we were still catching them four hours later.
Seemed to be in among herring as we were catching them too.
Amazing to see the water boiling for hours.

Is it normal for herring and mackerel to shoal together?

Still waiting in Donegal Town for them to appear but if they are at Teelin not long now!
Last year they arrived in to the Hassans near Mountcharles pier around this time last year in the last week or so of April.
Later in the summer they came right in to the pier in Donegal Town feeding on shoals of sprat in so maybe that's something similar to what you are seeing but right enough it's early.