Surgery for a Sawfish

A small growth

Caring for Shedd’s 32,000 residents includes daily monitoring of their physical condition. Every morning before Shedd opens, Lise Watson, collection manager for Wild Reef, or another aquarist closely checks out Ginsu and the other large fishes at the floor-to-ceiling windows of the shark habitat. From there they can get good views of the animals as they swim along the windows and overhead.

On July 2, Lise noticed a mass on the underside of Ginsu’s left pelvic fin. “It was a flat, thickened area that looked similar to a small pancake.”

“We had assumed this was a papilloma, which is generally a benign growth caused by a virus—basically a wart—and Dr. Matt’s biopsy confirmed our suspicions,” Lise says. “As we observed this growth, we saw that the size fluctuated a bit, so we looked into ways we might be able to help Ginsu’s immune system resolve this on its own, including a vitamin C regimen.”

Intervention needed

The mass stayed about the same for seven months, but in March of this year, Lise observed a rapid surge in growth as the papilloma thickened and spread to the top of the fin. It was time, the Fishes and Animal Health teams agreed, for surgical intervention.

This would be the first time a papilloma was removed from a sawfish, but the procedure had been done on a related group of fishes, sharks. “We talked to other aquariums, and they had tried to debulk the growth—shave it off,” Dr. Matt says. “But like with warts, if you leave any bit of a papilloma behind, it will grow back. We were not sure how Ginsu would handle the procedure, and the restraint required, so the plan was to go in for one surgery—a partial fin amputation.” Based on the outcomes with sharks, the prognosis for Ginsu was full recovery with normal mobility.

Planning and preparing for the one-hour surgery took two months. Colleagues at other aquariums with sawfishes were consulted on the best way to handle and sedate one for surgery. Lise put together a step-by-step plan for handling Ginsu that would work for both the husbandry and veterinary teams. Dr. Matt calculated the anesthetic needs.

From there, nearly 30 people from the Fishes, Animal Health and Facilities departments—call them Team Ginsu—put their heads together to determine what equipment the procedure would require: a 10-foot submersible mesh surgical table; a drop net, 15 feet long, 6 feet wide and 2 feet deep, to catch the sawfish; a hoist to lift and weigh her; and a neoprene wrap to cushion and protect her rostrum, which is calcified cartilage and can fracture. All of this unique equipment was designed and fabricated in-house. In addition, the team used a commercially made 10-foot stretcher for weighing Ginsu and returning her to the shark habitat post-op.

A few days before the surgery, Team Ginsu did two practice runs, one a full-dress rehearsal and a second to fine-tune the restraint procedure.

At 6-foot-5 and 270 pounds, senior curator of fishes George Parsons was a natural stand-in for Ginsu. “My scuba gear added 30 pounds, and I held a 4-foot broom handle tipped with a scouring pad for a rostrum, so I was a reasonable facsimile,” he says. He thrashed realistically as his coworkers maneuvered him into the net and through the water to the surgical table.

Ginsu, on the other hand, was the perfect patient.

“We planned for A, B and C, if not also D and E,” says Dr. Matt, “because you don’t know how things will go. But everything went exactly as planned, mostly because of how calm and gentle Ginsu was. We had contingency plans for if she was crocodile-rolling in the net or thrashing, but she was super calm, which made our job so much easier. She’s a remarkable animal.”

Team Ginsu in action

The day of the surgery, Aug. 17, Team Ginsu, now including Shedd’s videographer, assembled at 5 a.m. at the top of the shark habitat. Lise orchestrated 20 Fishes staff members who were assigned stations to carry out each critical role in handling Ginsu. Dr. Matt was the primary surgeon, assisted by Dr. Mitch Robbins, director of surgery and anesthesia and one of Shedd’s medical advisors at the Veterinary Specialty Center in Buffalo Grove. Five additional members of Shedd’s Animal Health team administered the anesthetic and further assisted with the surgery.

Once Ginsu was unconscious, she had to be ventilated, using a long PVC pipe on a pump, much like a shop vac, that pushed water through her mouth and over her gills. Throughout the procedure, an aquarist in full dive gear was underwater under Ginsu to make sure the tube stayed in the right position.

Finally, before the surgery started, other aquarists had to keep the fish’s bulk slightly tilted on foam pads so that the affected fin was out of water throughout the procedure.

Nothing about this surgery was typical, and that included the tools. “Elasmobranch skin is thick and abrasive, like extra-course sandpaper,” Dr. Matt says. “If we used a scalpel blade, we’d have to change it every few inches because it would dull so quickly.” Instead, he took advantage of a tool designed specifically for this purpose. After he prepped the surgical site with a disinfectant, he used a fillet knife to remove about half of the fin, including a margin of healthy tissue to make sure no papilloma cells were left to regrow and threaten Ginsu’s well-being.

Recovery and success

The final step in the procedure was to make sure Ginsu recovered safely. She was too big to keep in the medical pool, so she was moved back into the shark habitat.

“Using the large stretcher closed around her, six aquarists swam her down to the sand bed,” Lise says. “I removed the rostrum cover and had the team open the stretcher to let her swim out. She swam a few feet, then settled on the bottom for about 20 minutes. The team stayed in the water with jump boards we could use to direct her out of harm’s way if necessary, but she didn’t have any difficulty.” While the opening of Wild Reef was delayed an hour, guests still got to see divers monitoring the sawfish for two hours.

“This was a huge success on a number of levels,” says Lise. “We were fortunate that we planned for the worst-case scenario and got the best. From the husbandry team’s perspective, we are a lot more comfortable handling her now.”

Dr. Matt and Lise’s team did handle her one more time, in a follow-up exam about two weeks after the surgery. “We wanted to take a close look at the incision and make sure it wasn’t infected,” says the veterinarian. “Later I removed the sutures while I was diving, just getting alongside Ginsu at her sand bed. Most of the rechecks were done during dives, which is a fun way to do a house call on your patient!”

Ginsu got a clean bill of health at the end of December. “Sharks are healing machines,” says Dr. Matt. “In the wild, you’ll see them with scars from chunks taken out of their fins by other sharks. Ginsu doesn’t even have a scar. It’s remarkable.”

A species critically endangered and declining

Shedd guests are among the privileged few to be able to see a sawfish outside of diving on a far-off reef. Ginsu is one of only 41 sawfishes in aquariums and zoos worldwide. That small number reflects not only the special care and facilities these animals need but also their scarcity in the wild. All species of sawfishes are listed as endangered or critically endangered by the International Union for the Conservation of Nature (IUCN). Green sawfishlike Ginsu are among the critically endangered.

Scientists estimate that all sawfish populations have declined to less than 10 percent of their historic levels and have been extirpated from at least 80 percent of their historic ranges. In 2007, marine sawfishes were granted the highest level of protection by the Convention on International Trade in Endangered Species (CITES), which banned commerce in all species except for collection for public aquariums with educational and conservation programs.

Sawfish are among the at-risk animals receiving intensive conservation efforts through the Association of Zoos and Aquarium’s SAFE (Saving Animals From Extinction) program, which is supported by Shedd and 231 other AZA-accredited organizations.

Ongoing threats to sawfishes include habitat destruction, entanglement in fishing nets as bycatch, and, despite the trade ban, the targeted and overexploited illegal fishery for their rostrums, fins and liver oil, all of which command high prices, especially as the animals become increasingly rare.

Ginsu is one of 48 species at Shedd, identified by red triangles at their habitats, that are at risk of disappearing from the Earth in our lifetime. She has lived in Wild Reefsince 2003, when she arrived as a mere 6-footer. While she often hangs out on the bottom of the 400,000-gallon shark habitat, far back on the right side and out of view, she’s active in the morning. When she cruises a circuit of the reef habitat, all eyes are on her. You can also get impressive views of Ginsu on our Shark Feeding Tour: Behind the Scenes in Wild Reef.

As Dr. Matt says, “She’s a great ambassador for her endangered species.”

―Karen Furnweger, web editor