A visit yesterday almost precisely at 1:26 pm (exact time of low tide) yielded 24 species between this time and 5pm. A complete list of my sightings can be found at this ebird link
Here’s a few photographs of a 1st Year Common Tern in flight.
In flight, the markings on the underwing (blackish marked feathers in primaries) and upperwing being mostly white with the exception of the outermost primary dark along with the bill being bicolored but thinner and duskier than Forster’s Tern and a forked tail with the outer tail retrices black (clearly visible in this photo) are all good ID points for Common Terns, this being a 1st Year below.
Photo taken at Bolsa Chica Ecological Reserve, Huntington Beach, CA on September 19, 2014