Effort to learn more about species may help save smalltooth sawfish
Many years ago, the smalltooth sawfish roamed the coastal waters of the United States, from as far west as Texas to as far north as New York. However, over the years, their range has decreased dramatically.
Today, the species’ current habitat is restricted to South Florida’s shoreline, mainly between Charlotte Harbor and the Keys.
Last week, Gregg Poulakis of the Florida Fish & Wildlife Conservation Commission delivered a presentation entitled “Abiotic Affinities & Movements of the Smalltooth Sawfish in a Southwest Florida Nursery” at the SCCF Nature Center, sharing information related to his sawfish research out of the Charlotte Harbor Field Laboratory and facts about the endangered species that can often be found off the coast of Sanibel and Captiva.
According to Poulakis, the population of smalltooth sawfish off the shores of Florida has severely declined in the last century due to bycatch in commercial and recreational fisheries, but also because they naturally have a low reproductive potential. Their saws, used for hunting, easily got tangled in nets and were sought after for trophies or souvenirs.
“Not surprisingly, an Adams & Wilson study on the species concluded that basically, there aren’t that many smalltooth sawfish left,” said Poulakis.
He called the mouth of the Caloosahatchee River “ground zero” for the few remaining sawfish strongholds anywhere in the world.
Poulakis detailed some of the Florida Fish & Wildlife Conservation Commission’s outreach efforts to help increase awareness of the sawfish’s plight, including providing signage at boat ramps across the region to alert boaters and commercial fishermen to contact the FWC should they catch a sawfish, teaching safe handling techniques and reporting all sightings of the species.
“If somebody calls us and says they have one hanging out underneath their dock, if we can we’ll respond right away,” said Poulakis. “They’re endangered, so we want to know where they are so we can get some tags on them.”
Acoustic satellite tags, which cost about $3,500 each, can be placed on the sawfish without any harm to the marine creature. The device records temperature, depth and location.
Little is known about the history of the smalltooth sawfish, one of two species of sawfish that inhabit U.S. waters, but experts report they may live up to 25 to 30 years, maturing after about 10 years. They can grow up to 18 feet in length, with unconfirmed reports of sawfish growing to nearly 25 feet long. They are ovoviviparous, meaning the mother holds the eggs inside of her until the young are ready to be born, usually in litters of 15 to 20 pups. At birth, they measure approximately two and a half feet.
Poulakis stated that during his research of the species, he has found that younger sawfish tend to remain in upriver areas of the Caloosahatchee for the first two or three years.
Sawfish — like sharks, skates and rays — belong to a group of fish called elasmobranchs, whose skeletons are made of cartilage. Sawfish are actually modified rays with a shark-like body, equipped with gill slits on their ventral side.
Last July, Sanibel Vice Mayor Mick Denham reported that a by-product of the city’s fight against high volume pulse releases might be of great benefit to the smalltooth sawfish. In fact, the city could pursue potential litigation against the U.S.Army Corps of Engineers and the South Florida Water Management District as a means of protecting the sawfish, an endangered species whose habitat in local bays and estuaries could be greatly impacted by these releases.
Poulakis hopes that the ongoing efforts of the FWC to record as much information about smalltooth sawfish will be of great benefit to the species.
“A lot of people have never even heard of the smalltooth sawfish, let alone seen one,” he added. “What we’re doing is very labor intensive, but we have learned a lot about them.”