With their tapered snouts lined by formidable teeth, the sawfishes have inspired many a myth and legend. And even today, we're still uncovering details about their mysterious lives. Just recently, a team of researchers conducting a survey off Andros Island in the Bahamas became the first to record a sawfish birth in the wild.
Once abundant in the waters of more than 90 countries, all five sawfish species have suffered extreme declines. Habitat loss and entanglement in fishing gear have emerged as major threats to these shark-like rays. Trade in their unique rostrums, which are still coveted as weapons, trophies and curios, has also taken its toll.
Today, sawfish can be found in just two remaining strongholds: in northern Australia and off Florida's Atlantic coast. They're rare enough to have earned the nickname "ghosts of the coasts", and researchers often struggle to find even lone survivors in much of their original range.
Still, events like this one offer a glimmer of hope.
"When I first saw the little rostra peeking out, I was confused for a second and then ecstatic," recalls Florida State University ecologist Dr Dean Grubbs, who led the expedition. His team was tagging a 14-foot (4.2m) smalltooth sawfish (Pristis pectinata) – one of three critically endangered sawfish species – when the female began giving birth.
Grubbs and his team have been studying these elusive creatures since 2010, with a goal of putting the most vital sawfish recovery habitat on the map. The plan? To sleuth out where the animals mate and where their movements overlap with fisheries. The researchers were also hoping to find their birthing grounds.
"This is a very rare occurrence," Grubbs says. "Something we likely will never witness again. I have tagged about 50 or so adult sawfish, but I never thought I would witness [a birth]. I told my crew this was probably the most exciting research day of my life." Previously, we could only speculate that sawfishes were pupping in the Bahamas.
With only a brief window to act, the team assisted in the delivery of five tiny pups before releasing the mother to birth the rest (likely five to seven more) on her own. Unlike stress-sensitive sharks like hammerheads, sawfish are relatively hardy animals, but research work like this must be quick and efficient to cut down risk to all involved.
"We tag around 3,000 sharks per year and I tell everyone that, when restrained, the sawfish are way more dangerous to work up than any of the sharks," notes Grubbs. Adults can weigh upwards of 1,000 pounds, but with all hands on deck, the team released both mother and pups without any trouble.
Some commenters online have expressed concern that the tagging process itself may have induced the birth. But while it's true that rays can prematurely abort their pups when stressed, several factors indicate this wasn't the case here. For starters, the pups were actively wriggling their way to freedom – the mother wasn't trying to push them out. And the yolk sacs, which provide sustenance to the embryos during development, had been used up – suggesting the youngsters were ready to emerge into the big blue.
"There were actually two pups trying to come out at the same time," says Grubbs. "So I helped those come out so they would exit one at a time. The pups were all 69-70 cm total length, and our sawfish research group in Florida has caught many free-swimming newborn sawfish that were that size or even smaller."
Chemical analysis of the mother's blood also showed her stress levels were low both at the beginning of the workup and at the time of release – a big win for the team.
While giving birth is trying for mothers of all species, there's a whole set of challenges involved when your babies come out "needles first". To avoid damage during their trip down the "life chute", the rostra of sawfish pups are flexible and coated in a thick, gelatinous sheath. After about a week, this tissue disintegrates, leaving the pups ready to stun prey and defend themselves.
The five pups were outfitted with tiny trackers (similar to the chips your pet would get from the vet), and a blood sample was taken from each one. This provides precious DNA that will allow the team to determine the level of interaction between sawfish populations in the Bahamas and Florida. That information is needed for the development of crucial species recovery plans, and it will also help the team to flag – and potentially prevent – genetic bottlenecking.
Sawfishes got some much-needed media attention back in 2015, when research revealed they were capable of sex-free virgin births. Scientists speculated the strategy, formally known as parthenogenesis, was a last-ditch effort by endangered sawfish to reproduce in a shrinking gene pool. After decades of work, however, it's beginning to look like sawfishes are making a slow comeback in the US.
Grubbs and his team credit well-managed protected areas in the region. A large part of potential nursery habitat in Florida falls within the borders of Everglades National Park and the Ten Thousand Island National Wildlife Refuge. Similarly, this new pupping site in the Bahamas was recently protected as West Side National Park. "Areas like these may be critical 'lifeboats' to recovering the species," he says.
