Recreational boats and a New York Water Taxi sharing the Shrewsbury River off Bahrs Landing in 2012. Below, the whales as seen in a photo posted on the Bahrs Marina Facebook page Monday. (Photo above by John T. Ward. Click to enlarge)

Three juvenile Beluga whales were seen in the Shrewsbury River Monday, according to multiple reports.

The Facebook page of Bahrs Marina in Highlands, six hours after first reporting the possible presence of dolphins, “confirmed” the presence of three whales just 50 feet off the marina’s dock shortly after 4 p.m.

The Asbury Park Press reported that the marine mammals spent “at least half an hour splashing in the Shrewsbury and Navesink rivers.”

According to the Press, three organizations  – the Marine Mammal Stranding Center in Brigantine, the Riverhead Foundation for Marine Research in New York and Mystic Aquarium in Connecticut — have been tracking the creatures as they’ve made their way south since they appeared off Rhode Island around May 10 and in Long Island waters before Memorial Day.

The Press did not cite any source on its report that the animals had entered the Navesink.

In the past, dolphins have ventured upriver as far as Red Bank via the Shrewsbury and Navesink Rivers from Sandy Hook Bay. Most famously in recent years, a pod of about a dozen dolphins visited in the summer of 2008 and, as the summer turned to fall and winter, became the subject of a debate over whether they were trapped and should be rescued.

Several members of the pod died, though the fate of the rest was unknown.