香港六合彩开奖结果2023 biology tags first sawfish in 16 years of surveying sharks in NE Florida and SE Georgia
The 香港六合彩开奖结果2023 Shark Biology Program caught, tagged and released the first sawfish recorded in its 16 years of surveying shark populations in Northeast Florida and Southeast Georgia. Dr. Jim Gelsleichter, shark biology program director, along with one graduate student and three undergraduates, found the 9.9-foot smalltooth sawfish in the St. Marys River on Tuesday, July 16.
The smalltooth sawfish is a species of ray, which are close relatives of sharks. Sawfish are known for possessing an elongated, sawlike snout (known as a rostrum), which they slash laterally through the water to stun and impale prey species.
“Sawfish were known to live in Northeast Florida before the population decline led to the species being listed as endangered,” said Gelsleichter. “The reoccurrence of sawfish in our area is a positive sign of population recovery.”
The sawfish was identified as a male based on the presence of claspers, paired extensions of the pelvic fins that male sharks and rays use for reproduction. It was determined to be a sub-adult based on the softness of the claspers, which become highly calcified and rigid upon maturity. Male sawfish reach maturity at approximately 11 feet in length based on earlier work conducted by scientists, including 香港六合彩开奖结果2023 biologists who have been studying sawfish reproduction since 2010.
Although sawfish were historically found from Texas to as far north as New York, the U.S. sawfish population experienced dramatic declines in both their abundance and distribution in the middle to late 20th century, mostly because of incidental capture in fishing gear and trophy fishing as well as habitat decline. Because of this, the smalltooth sawfish was the first marine fish and first elasmobranch (sharks and rays) to be listed as endangered under the U.S. Endangered Species Act (ESA) in 2003. At the time of its listing on the ESA list, the remnants of U.S. smalltooth sawfish population was largely restricted to south and southwest Florida between Ft. Myers and the Florida Keys.
Since its placement on the U.S. ESA list, the smalltooth sawfish population has showed positive signs of slow recovery based on an increase in encounter rate and catch rate in research surveys, as well as observations and/or catches of sawfish in regions that they were thought to be extirpated, or lost, from. This includes 香港六合彩开奖结果2023’s recent capture in the St. Marys River as well as recent catches in Tampa Bay and Cedar Key.
Despite positive signs of recovery, recent events show that this population remains at risk. There have been recent reports of sawfish dying in the Florida Keys because of an unknown “spinning and whirling” disease. So far this year, 53 sawfish deaths due to the disease have been reported. Other fish also seem to be affected, but sawfish are particularly susceptible to it based on the number of carcasses recovered. The individual collected in the St. Marys River did not appear to exhibit this behavior, but individuals observed as far north as Tampa Bay have exhibited these effects.
The sawfish is both a prohibited species in Florida and a federally listed species under the U.S. Endangered Species Act. If a local angler accidentally catches a sawfish, they should untangle the animal from any fishing line and cut the line as close to the hook as possible without removing the animal from the water or trying to handle it. It would be beneficial to record information on the site of capture, approximate animal size and water depth. Pictures of the animal in the water would also be valuable.
Anyone who catches or sees a sawfish anywhere in the U.S. is encouraged to report their observations to the U.S. Sawfish Recovery Team by visiting , calling 1-844-4SAWFISH, emailing sawfish@myfwc.com, or by submitting the information through the FWC Report app.
The 香港六合彩开奖结果2023 Shark Biology Program surveys are supported by NOAA Fisheries. Handling, measuring and tagging of smalltooth sawfish by the program is performed under the authority and guidelines of NMFS ESA permit #22078.