There’s a baby whale in the Gowanus and it’s been identified as a Baleen whale. Here’s the skinny on that kind of whale from Wikipedia.

The baleen whales, also called whalebone whales or great whales, form the Mysticeti, one of two suborders of the Cetacea (whales, dolphins and porpoises). Baleen whales are characterized by having baleen plates for filtering food from water, rather than having teeth. This distinguishes them from the other suborder of cetaceans, the toothed whales or Odontoceti. Living Mysticeti species have teeth only during the embryonal phase. Fossil Mysticeti had teeth before baleen evolved.

Baleen whales are generally larger than toothed whales, and females
are larger than males. This group comprises the largest living animal
species, the Blue Whale. Baleen whales have two blowholes, causing a V-shaped blow.

The suborder contains four families and fourteen species. A list of species can be found below and at the Cetacea article. The scientific name derives from the Greek word mystax, which means "moustache".