How slow?

How slow do we have to go to protect right whales from harm?

Words by Valerie Shively
Main photograph by Lewis Burnett via Ocean Image Bank

Butterfly is 42 years old. She’s the size of a school bus and was born with the pattern of butterfly wings atop of her head in her callosities patch, which you can see when she gets excited and dances up out of the water. At 42, she’s still got mad breaching skills. Butterfly has had five babies. Every year, Butterfly travels to Florida in the winter and New England in the summer.

There are more vessels than before, faster boats, and her babies don’t know about boats when they migrate with their mama back up north during the summer. When they are tired, they rest near the surface, especially where the warm sun glistens off their black skin but also where they are more likely to be hit by a boat.

Butterfly has been lucky, only entangled in fishing gear four times, but her babies… not so much. Butterfly’s first baby, having survived all the way to age 11, was then struck by a boat, and never seen again. Her second baby made it to 18 and then caught hold in some fishing gear, and such was the case for her third and fourth babies.

Nevertheless, despite all of these dangers, on January 27, 2024, Butterfly was seen with her fifth baby, a 10-year difference since her last calf. Year after year, Butterfly continues her great migrations through speeding boats and fishing ropes. She takes this risk, perhaps because she knows that she is only one of a handful of her kind left. Or perhaps because she is a mother and she loves her children and she wants to protect them and see them thrive, just like us. So just like us, she keeps trying.

As I am writing this, news is circling of a 44-foot whale draped across the front of a cruise ship as it arrived into its Brooklyn port. Last month, as I interviewed the scientists for this article, a dead mother right whale washed ashore on a Virginia beach, having been hit by a vessel. “The loss of a reproductive female is particularly devastating to the population, and this whale had a young, dependent calf. We do not expect the calf to survive without protection and nursing from its mother,” as stated on the NOAA website on April 5, 2024.

Photograph by New England Aquarium observers under NMFS Permit #25739.
Photograph by NOAA Teacher at Sea Program.

With less than 360 left, right whales are critically endangered, and predicted to die out completely in 16 years. “What I’m 100 percent confident about is that no mariner wants to hit a whale.  No captain wants to come in with a whale wrapped around their bow,” says Jessica Redfern, PHD and Associate Vice President at the Ocean Conservation Science, Anderson Cabot Center for Ocean Life at the New England Aquarium in Boston. Yet all the good intentions of mariners aside doesn’t change that an estimated one third of all right whales die because of vessel strikes, boats unknowingly hitting and killing them in the water.

Redfern has been working for more than 20 years on using statistical models to address wildlife conservation issues. In other words, she uses math to figure out the safest ways for us to live well with the animals of the oceans. Her most recent study, Estimating Reductions in the Risks of Vessels Striking Whales Achieved by Management Strategies, published in Biological Conservation in January of this year, has helped us to better understand where and when to slow down and exactly how slow we need to go, so as not to hit a whale.

In 2008, NOAA, the National Oceanic and Atmospheric Administration, set speed rules to protect right whales. They created the Right Whale Ship Speed Rule which set a speed limit of 10 knots for boats larger than 65 feet in whale habitat areas. These areas, called Seasonal Management Areas, are zones where we know whales migrate to and hunker down for a season. “NOAA did an assessment of the effectiveness of this rule and they could see that there’s pretty good compliance,” says Redfern.

Photograph by New England Aquarium observers under NMFS Permit #25739.
Photograph by New England Aquarium observers under NMFS Permit #25739.

However whales were still at risk for being hit outside of these zones, so as a backup, NOAA also created Dynamic Management Areas which were voluntary, “if somebody sees three or more right whales together, they drop a spatial buffer around them in that area and ships are requested to go slow,” explains Redfern.

Key word being ‘requested,’ not required to go slow, and unfortunately many boaters don’t abide, “there has been over a decade of research on the US west and east coast that shows very little cooperation with these requests to go voluntarily slow when whales are spotted.” Since 2020, multiple whale deaths have been caused by vessels smaller than 65 feet.

Because there are so few right whales left, the New England Aquarium in Boston, where Jessica Redfern works, is able to track and name these whales; names like Marilyn Monroe, Butterfly and Juno. When I spoke with Julia Singer, marine scientist at Oceana, she told me about one of those babies, “Juno’s calf was hit by a boat sometime between December and January of this year, the calf was actually seen alive with really deep propeller wounds on the top of its head… we were trying to remain optimistic, but unfortunately that calf was found dead on March 3, 2024.” NOAA performed a necropsy and determined that the size of the boat that killed Juno’s Calf was between 35 – 57 feet, so the speed limits didn’t apply to this mariner. “That boater [that killed Juno’s calf] was not doing anything illegal because boats under 65 feet right now don’t have to follow these requirements,” explains Singer.

“What we see are these rules are not enough, whales are still being hit and the right whale numbers are still really low. We know that our problem still remains and that’s why NOAA has revised the rule, and one of the things they’ve done is to change the seasonal management areas so that they are larger and last for longer periods of time,” shares Redfern in support of NOAA’s new speed limit proposal.

In 2022, NOAA proposed a new Vessel Speed Rule, one that would require all boats 35 feet and larger to slow to 10 knots, when safe to do so, in both Seasonal and Dynamic whale habitats. Amendments to the North Atlantic Right Whale Vessel Strike Reduction Rule, “covers more habitat for whales and it also provides a buffer against climate change and that’s really important,” Redfern explains.

Photograph by New England Aquarium observers under NMFS Permit #25739.

However the proposal did not go over well. There was a lot of pushback from policy makers who questioned the evidence behind the new rule, and that is where Redfern’s latest study comes into play. Redfern’s recent study used AIS data, information originally meant for tracking navigation and communication purposes, but also worked perfectly for tracking patterns in boat speeds and locations, basically like how your iPhone fitness app tracks where you go and how fast. 

Using this data, Redfern’s team was able to create a map of ship traffic, “we know where the ships are, we get that information about time and latitude and longitude and what we do is we use that to draw a line so we know exactly the track that that ship was on. When you put all those tracks together, it’s almost like you can start to see patterns of roads in the data,” like a ship road map in the ocean.

Redfern explained that they then overlaid this map of ship roads on top of where they know whales migrate, “while the math might look really complicated, it’s actually so simple what we’re doing. It takes into account where the whales are and it takes into account how much ship traffic there is in that area.” And all this works to show where and when we need to slow down.

With a smile on her face, Redfern goes on to say, “What type of road do you want near your school? Do you want it to be busy? Do you want cars going fast? You want to go slow, and you want little traffic. You know, these are the sort of questions we’re thinking about when we think about vessel speed restrictions, it’s like setting a slow speed limit by a school.”

Redfern’s study scientifically showed that if boats were to slow to a 10 knot speed limit in core whale habitat areas, whale deaths could be reduced up to 15%, which supports NOAA’s new speed proposal 100%.

When asked her opinion about Redfern’s study, Singer had this to say: “We were happy to see some very sound science that shows these speed limits will help protect the whales. Having this study come out really reassured a lot of people that the new proposal is worth implementing and will be very beneficial for the whales.” Singer continues: “And it is also helpful because there is a lot of misinformation out there right now – a lot of pushback from people who are saying it’s not going to help.” 

Photograph by NOAA News 011811.

Naysayers to NOAA’s speed proposal claim that the new rule would have too many vessels slowing to speeds that could be dangerous in high seas. Singer shares: “It’s a little frustrating to hear how many people are talking about how unsafe this rule is when it is explicitly written into the rule that human safety comes first.” The rule states that 10 knots is the required speed limit only in whale habitat areas, and only when it is safe to do so. Otherwise, if the wind and the waves are high, if there is any threatening weather whatsoever, mariners have every right to move at whatever speed necessary to put human life first. Singer adds: “And the speed zones are definitely not blocking off the entire coast, it’s just during the times and locations where we expect the whales to be.”

I asked Singer what she thought about mariners’ ability to have access to where these zones were on a map, “Boaters can’t really be expected to follow a rule if they don’t know it’s there.” Singer went on to say: “At this point we don’t know how the new rule would be implemented, but that’s something that would be really important, making sure that the government is making sure all this information is getting out there.” She said some of the ideas recently discussed at a NOAA workshop with technology developers, were putting the Seasonal Zones directly into the Garmin fish finders and navigators.

So what can the average person do to help the right whale survive, to help whales like Butterfly thrive? The answer both Redfern and Singer gave was simple: share their story. Spread the word. Talk about how slowing down saves lives. And mostly, talk about right whales. Imagine Butterfly, and imagine that perhaps just by talking about her, you could save her. There is power in what we choose to share. 


Main photograph by Lewis Burnett via Ocean Image Bank

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