(WPRI) — Cape Cod’s seasonal residents have started to arrive in the bay.

(Courtesy: Center for Coastal Studies)

According to the Center for Coastal Studies’ (CCS) Right Whale Ecology Program, 21-year-old North Atlantic Right whale Porcia and her new calf were spotted Saturday.

Vessel speeds are restricted between March 1 and April 30 to protect the endangered species.

Within Cape Cod Bay, vessels less than 65 feet in length must keep speeds at 10 knots, according to the CCS. Boats and aircraft are also banned from approaching within 500 yards of the animals.

Boat strikes and rope entanglements have been known to threaten the species, according to CCS.

The species is protected under federal law with less than 350 animals remaining, according to the National Oceanic and Atmospheric Administration.