I estimated that there were about 180 spread over the top and sides of the jetty. This is a small portion of the flock. This group did not want to move when I approached to pass, whether because they are used to foot traffic or because they did not want to give up their sheltered roosting places.
Meanwhile, other Dunlin were feeding among the mussels attached to the rocks.
The many mussel beds along the sides of the jetty made it easy to understand why so many waterfowl and shorebirds were gathered in the location.
Here are some of the Dunlin with a Purple Sandpiper in their midst.