PROVINCETOWN — A 21-year-old North Atlantic right whale known as Porcia was observed in Cape Cod Bay on March 18. The whale was seen swimming with her 2023 calf by her side. And last week, before this first mother-calf pair of the season was spotted, Scott Landry, director of the disentanglement team at the Center for Coastal Studies, estimated there were already between 30 and 40 right whales in the bay.