NEW YORK CITY — One of the last seals of the season was spotted waving goodbye on the beach in Rockaway Park on Monday morning.

Thanks for visiting! The seal on Beach 116th street this morning was a gray seal. The Riverhead Foundation received... Posted by Rockaway Times on Monday, April 27, 2015

Springtime marks a changing of the guard in marine wildlife, as many seals move north out of our inlets and bays and Humpback Whales arrive from more southern waters.

Over the weekend, a seal, this one entangled in some kind of netting, was spotted in Brooklyn near Kingsborough Community College, according to the Riverhead Foundation for Marine Research and Preservation, an organization that aids injured marine animals.

The Brooklyn seal darted back into the water before Riverhead workers could get to it.

The foundation encourages anyone who spots the injured seal or any other whale, seal or turtle to report it to its 24 hour hotline and help determine whether or not the animal is injured.

"If the seal is healthy, they’ll let us know that it is in good condition," Rachel Bosworth from the foundation said. "If it starts to look aggressive that usually means its very healthy."

Whether or not a seal appears healthy, anyone who spots one should report it to the Riverhead Foundation and let the experts decide, Bosworth said.

While most of the seals will head north to Canada and Maine for the summer, our humpbacked friends are just starting to arrive.

Paul Sieswerda, a longtime aquarium worker, turned "citizen scientist" with the organization Gotham Whale, tallies whale spottings and runs whaling tours out of Staten Island.

This year he's anticipating a fruitful season, he said.

His faithful network of fisherman informants who scour the city's harbors have already spotted a number of whales this year, earlier than usual, he said.

Sieswerda said that during the Humpback whale season last year that runs from late May into October, he counted 106 whales, more than the three prior years combined, he said.

He suspects the combination of cleaner waters and less commercial fishing has led to higher Menhaden fish populations in New York waters, which is the humpback whales' main source of food, Sieswerda said.

"We’re encouraged," he said. "[We're expecting] an even better season than we had last year."