In early January, then-Gov. Charlie Baker signed a bill that officially designates April 24 as Right Whale Day in the commonwealth. North Atlantic right whales are a critically endangered species that feed each winter and early spring in the waters off of Massachusetts. Several dozen right whales have been spotted in Cape Cod Bay this spring. One scientist said that's extraordinary, as the Center for Coastal Studies estimates that only 340 individual whales are left in the world. In honor of Right Whale Day this coming Monday, the New England Aquarium will host an event featuring lawmakers and community advocates speaking about the importance of protecting the whales. Philip Hamilton, a senior scientist at the Anderson Cabot Center for Ocean Life at the New England Aquarium who's been studying right whales for decades, spoke with GBH All Things Considered guest host Judie Yuill about the importance of protecting the whales. This transcript has been lightly edited.

Judie Yuill: What was the process like for activists to get the legislation for a Right Whale Day on Charlie Baker's desk?

Philip Hamilton: I was obviously not directly involved, but I think it really started with the passion of Matt Delaney, who proposed the legislation. He had his own personal relationship with seeing right whales from the beach, and that really sparked something that grew over a few years into this legislation.

Yuill: Let's discuss the plight of the North Atlantic right whale. Why is it so important that they get their own day? And is it possible that they could become extinct in the coming decades?

Hamilton: It is possible that they could become functionally extinct. They're a very long-lived animal. They live as long as humans, if not longer. Our immediate concern is that there really won't be any reproductive females left, and it is possible that that could happen in the next few decades, given their current trajectory. They've had a downward trend in their population numbers since around 2011, quite steep at some times, and that's really alarming. We can turn it around. Those are human-caused deaths, as well as lower reproduction. The thing we have control over is stopping killing and harming them. As far as Right Whale Day, I think it's wonderful to have them spotlighted in this way. They've been an underdog for most of the time that I have been studying them, since the early eighties, and it's great that they're getting their recognition. I really hope that the enthusiasm and support will really help the species out.

Yuill: How has the situation that the right whales are in changed lately? Has conservation been working? And why does the number remain so low, given that we've seen other whale species such as humpback whales rebound?

Hamilton: Yeah, that's a really good question. The population was improving considerably in the 2000's. The thing that makes right whales different than some of the other species that have been rebounding is, first of all, their numbers started very low, in the low three hundreds, maybe lower. They have a long ways to go before they can get to a really robust population. They also have been impacted by entanglements in fishing gear, vessel strikes and climate change, perhaps more than some other species. Since around 2011, their feeding habits have been disrupted. They've been going to new areas. At least one of those areas has been particularly harmful for them. That's up in the Gulf of St. Lawrence, where there has been a high level of mortality from both entanglements and vessel strikes. It's a combination of a changing habitat, right whales being very coastal and then being already at a reduced number. That makes them particularly precarious at the moment.

Yuill: What can the average person do to make the world a safer place for right whales?

Hamilton: It's a great question, and I love hearing it because it shows people are interested and concerned. It's a challenging question to answer, actually, because when we get to a place where there are such things as, well, safe seafood, then certainly we will encourage people to be purchasing that. For now, it's being aware, sharing with their friends the plight of the right whale, talking with their representatives to say this is an issue that matters to them. And just keeping your your head and your heart open for this species.