Another good article sent from Randy(308).
Sawfish too big for their own good
By SHANNON TOMPKINS
Copyright 2010 Houston Chronicle
April 28, 2010, 9:42PM
Scattered fragments of one of the largest, most viscerally stunning pieces of Texas' coastal history today hang mute, gathering dust on walls in homes and garages or relegated to dark attics, closets and a few museum cabinets.
They are impressive remnants, resembling 3-4-foot broadswords studded along the perimeters with a couple of dozen 1-2-inch ivory spikes. Looking at them, it is wholly understandable that these objects — the dried rostrums, or bills, of sawfish — were the Aztecs' inspiration for their obsidian-edged war swords.
Those old, dried rostrums are all that remain of Texas' sawfish.
The last sawfish documented in Texas was caught (and released) in Aransas Bay in 1984 by Texas Parks and Wildlife Department coastal fisheries staff conducting a gill net sampling. One had been caught in 1979 and another in 1978. They were the last three.
Since then, the only physical evidence these huge, distinctively shaped fish lived — thrived — in Texas bays and near-shore coastal waters are yellowed newspaper clippings telling of behemoth sawfish hauled from the bays, old black-and-white photos of 400-1,500-pound sawfish, and the desiccated “saws” people hacked from the fish and kept as trophies or souvenirs.
Those old saws tell stories. They illuminate their past and, perhaps, can brighten their future.
Ted Bates owns two sawfish rostrums, appropriately called “saws” for their likeness to the blades of double-sided crosscut saws.
“They were from sawfish my father caught,” said Bates, a 70-year-old Palacios native.
The larger of the two saws came from a particularly huge sawfish. That's saying something, as the fish grew to perhaps 18 feet or more.
“He caught it in 1950, when he was shrimping around the mouth of the San Bernard (River),” Bates said. “It got tangled in the old cotton nets they used — tore it up.
“The fish weighed 2,200 pounds. They had to use a double block (and tackle) to lift it.”
The other rostrum is smaller, if a 3-foot saw can be called small. The fish that produced it weighed “only” about 1,000 pounds. Like the larger fish, it was captured when it ran afoul of the senior Bates' shrimp nets near Pass Cavallo.
It was those nets — shrimp trawls, gill nets and trammel nets — that doomed sawfish.
Well, nets and behavior and biology of the fish.
Florida haven
Sawfish are narrowly specialized creatures. Members of the fish family that includes sharks and rays, sawfish look to be a cross between the two. The top part of their body is shark-like in shape. Their underside is flat like a ray's.
That flat ventral side allows sawfish to rest on bottom, like a ray or a flounder. They feed by attacking schools of baitfish, slashing with that studded rostrum and gobbling the killed and wounded.
Their behavior, along with the rostrum, made them especially vulnerable to nets. Although not targeted by shrimpers and netters, sawfish lived in shallow water and were slow, lethargic beasts; they easily became tangled in the mesh.
Sawfish are slow-growing, slow-maturing fish with very low reproductive rates.
“Most of the information we have — and it's not a lot — say sawfish have to reach 10-12 feet long before they become sexually mature,” said Tonya Wiley, a fisheries scientist with TPWD's coastal fisheries division and a long-time sawfish researcher.
Some research indicates it may take as long as 30 years for a female sawfish to reach sexual maturity. Sawfish, which give live birth to their young and seem to do so only every other year, produce only a handful of “pups.”
“They have a dozen or two pups, at the most,” said Wiley, who worked eight years on sawfish research in Florida. “They certainly aren't like other fish that produce millions of eggs.”
Through the first half of the 20th century, sawfish were common in bays along the Texas coast and the rest of the Gulf Coast. A 1943 report termed sawfish “frequently taken” and “plentiful” in Texas bays. As late as 1953, they were “abundant” in Texas, according to another report.
But by the early 1960s, they were fading — fast. Unable to reproduce fast enough to replace the adult fish being inadvertently taken by nets and different habitat, sawfish disappeared.
“It happened so fast, it was al-most like people looked up one day and they were gone,” Wiley said.
A remnant population holds out in far southwest Florida, centered around Everglades National Park, where netting of any kind has been prohibited for decades.
“If it hadn't been for Everglades National Park, we almost certainly wouldn't have any sawfish remaining in this country,” Wiley said.
Those remaining sawfish, placed on the federal Endangered Species List in 2003, and the old rostrums squirreled away along the Gulf Coast coast are being used to learn more about the great fish and, perhaps, show a way to rebuild their numbers and range.
Part of that effort centers on collecting any historic information on sawfish — photos, personal accounts of catches or encounters, articles, etc.
Part of that effort centers on collecting any historic information on sawfish — photos, personal accounts of catches or encounters, articles, etc.
Unanswered questions
It also involves finding owners of some of those old rostrums and soliciting them to allow Wiley to take a small piece of the saw to study the genetics of the fish.
Most pressing, the DNA profile of the “historic” sawfish population can be used to determine if the remaining sawfish are experiencing a genetic “bottleneck,” where there are so few remaining fish and genetic variability is so compromised by inbreeding that the population faces a dire future.
But it can help with other questions, too.
“It can help tell us if there were distinct populations of sawfish in the eastern and western Gulf — if the sawfish in Texas were different, genetically, from the ones in Florida or if they were one population,” Wiley said.
If they were genetically different populations of the same fish, it would mean that the “Texas” population is almost certainly extinct.
But if the sawfish are genetically the same, it could be a ray of hope. If Florida's smalltooth sawfish population can be stabilized and increased and if scientists/fisheries managers can learn enough about their natural history, biology and habitat requirements, it's possible that reintroduction of sawfish might be considered one day.
The two rostrums that have been in Ted Bates' family for more than a half-century are among the handful of Texas sawfish saws from which Wiley has taken tissue samples for the DNA/genetic profile project.
“It's people like Mr. Bates who can play a big role in helping us learn more about sawfish,” Wiley said. “And we can learn so much from just a little piece of tissue and from the historic information people can share.”
Sawfish too big for their own good
By SHANNON TOMPKINS
Copyright 2010 Houston Chronicle
April 28, 2010, 9:42PM
Scattered fragments of one of the largest, most viscerally stunning pieces of Texas' coastal history today hang mute, gathering dust on walls in homes and garages or relegated to dark attics, closets and a few museum cabinets.
They are impressive remnants, resembling 3-4-foot broadswords studded along the perimeters with a couple of dozen 1-2-inch ivory spikes. Looking at them, it is wholly understandable that these objects — the dried rostrums, or bills, of sawfish — were the Aztecs' inspiration for their obsidian-edged war swords.
Those old, dried rostrums are all that remain of Texas' sawfish.
The last sawfish documented in Texas was caught (and released) in Aransas Bay in 1984 by Texas Parks and Wildlife Department coastal fisheries staff conducting a gill net sampling. One had been caught in 1979 and another in 1978. They were the last three.
Since then, the only physical evidence these huge, distinctively shaped fish lived — thrived — in Texas bays and near-shore coastal waters are yellowed newspaper clippings telling of behemoth sawfish hauled from the bays, old black-and-white photos of 400-1,500-pound sawfish, and the desiccated “saws” people hacked from the fish and kept as trophies or souvenirs.
Those old saws tell stories. They illuminate their past and, perhaps, can brighten their future.
Ted Bates owns two sawfish rostrums, appropriately called “saws” for their likeness to the blades of double-sided crosscut saws.
“They were from sawfish my father caught,” said Bates, a 70-year-old Palacios native.
The larger of the two saws came from a particularly huge sawfish. That's saying something, as the fish grew to perhaps 18 feet or more.
“He caught it in 1950, when he was shrimping around the mouth of the San Bernard (River),” Bates said. “It got tangled in the old cotton nets they used — tore it up.
“The fish weighed 2,200 pounds. They had to use a double block (and tackle) to lift it.”
The other rostrum is smaller, if a 3-foot saw can be called small. The fish that produced it weighed “only” about 1,000 pounds. Like the larger fish, it was captured when it ran afoul of the senior Bates' shrimp nets near Pass Cavallo.
It was those nets — shrimp trawls, gill nets and trammel nets — that doomed sawfish.
Well, nets and behavior and biology of the fish.
Florida haven
Sawfish are narrowly specialized creatures. Members of the fish family that includes sharks and rays, sawfish look to be a cross between the two. The top part of their body is shark-like in shape. Their underside is flat like a ray's.
That flat ventral side allows sawfish to rest on bottom, like a ray or a flounder. They feed by attacking schools of baitfish, slashing with that studded rostrum and gobbling the killed and wounded.
Their behavior, along with the rostrum, made them especially vulnerable to nets. Although not targeted by shrimpers and netters, sawfish lived in shallow water and were slow, lethargic beasts; they easily became tangled in the mesh.
Sawfish are slow-growing, slow-maturing fish with very low reproductive rates.
“Most of the information we have — and it's not a lot — say sawfish have to reach 10-12 feet long before they become sexually mature,” said Tonya Wiley, a fisheries scientist with TPWD's coastal fisheries division and a long-time sawfish researcher.
Some research indicates it may take as long as 30 years for a female sawfish to reach sexual maturity. Sawfish, which give live birth to their young and seem to do so only every other year, produce only a handful of “pups.”
“They have a dozen or two pups, at the most,” said Wiley, who worked eight years on sawfish research in Florida. “They certainly aren't like other fish that produce millions of eggs.”
Through the first half of the 20th century, sawfish were common in bays along the Texas coast and the rest of the Gulf Coast. A 1943 report termed sawfish “frequently taken” and “plentiful” in Texas bays. As late as 1953, they were “abundant” in Texas, according to another report.
But by the early 1960s, they were fading — fast. Unable to reproduce fast enough to replace the adult fish being inadvertently taken by nets and different habitat, sawfish disappeared.
“It happened so fast, it was al-most like people looked up one day and they were gone,” Wiley said.
A remnant population holds out in far southwest Florida, centered around Everglades National Park, where netting of any kind has been prohibited for decades.
“If it hadn't been for Everglades National Park, we almost certainly wouldn't have any sawfish remaining in this country,” Wiley said.
Those remaining sawfish, placed on the federal Endangered Species List in 2003, and the old rostrums squirreled away along the Gulf Coast coast are being used to learn more about the great fish and, perhaps, show a way to rebuild their numbers and range.
Part of that effort centers on collecting any historic information on sawfish — photos, personal accounts of catches or encounters, articles, etc.
Part of that effort centers on collecting any historic information on sawfish — photos, personal accounts of catches or encounters, articles, etc.
Unanswered questions
It also involves finding owners of some of those old rostrums and soliciting them to allow Wiley to take a small piece of the saw to study the genetics of the fish.
Most pressing, the DNA profile of the “historic” sawfish population can be used to determine if the remaining sawfish are experiencing a genetic “bottleneck,” where there are so few remaining fish and genetic variability is so compromised by inbreeding that the population faces a dire future.
But it can help with other questions, too.
“It can help tell us if there were distinct populations of sawfish in the eastern and western Gulf — if the sawfish in Texas were different, genetically, from the ones in Florida or if they were one population,” Wiley said.
If they were genetically different populations of the same fish, it would mean that the “Texas” population is almost certainly extinct.
But if the sawfish are genetically the same, it could be a ray of hope. If Florida's smalltooth sawfish population can be stabilized and increased and if scientists/fisheries managers can learn enough about their natural history, biology and habitat requirements, it's possible that reintroduction of sawfish might be considered one day.
The two rostrums that have been in Ted Bates' family for more than a half-century are among the handful of Texas sawfish saws from which Wiley has taken tissue samples for the DNA/genetic profile project.
“It's people like Mr. Bates who can play a big role in helping us learn more about sawfish,” Wiley said. “And we can learn so much from just a little piece of tissue and from the historic information people can share.”
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