I start the 2nd to 3rd week in may when I know there are keepers in the herring run up north here, I try to get all my spring chores done first, So I have to say May 15th water temp has nothing to do with it because it is 30 miles up river.
Woods Hole is currently reporting 39 degrees. If 50 is your mark, you're still looking at mid-May for that. In the mean time I'll be focusing on freshwater for trout, smallies, and shad (mid April).
Three-fourths of the Earth's surface is water, and one-fourth is land. It is quite clear that the good Lord intended us to spend triple the amount of time fishing as taking care of the lawn.