Found this spider sitting on my boat lift on my lake in Northern Michigan. It was a very good and fast surface swimmer when I knocked it into the water.
It layed very flat and when I touched it it lifted itself on all legs. It was about 3" in dia from all leg tips.
Should I be concerned?
David
Is it possibly a wolf spider? It looks like one, and they live in your area.
There also is the possibility of it being a fishing/dock/nursery web spider in the closely related family Pisauridae. Some of these, particularly in the genus Dolomedes, superficially resemble wolf spiders. The one sure way of telling them apart is to look at their eye pattern (not seen in your image). Wolf spiders have their anterior median eyes much larger than the rest whereas the eyes of pisaurids afre all pretty much the same size. See http://farm2.static.flickr.com/1386/1120991317_ce2aec27f6.jpg?v=0 for the face of a wolf spider and http://farm2.static.flickr.com/1412/851379560_1617e2f840.jpg?v=0 for a pisaurid.
