A bottlenose dolphin, nicknamed Filly, swims free in Sarasota Bay after its release in Sarasota Bay Wednesday morning. To help monitor Filly’s whereabouts and condition, the dolphin sports a small VHF radio transmitter on its dorsal fin that will help staff monitor its recovery.
SARASOTA BAY – A bottlenose dolphin, nicknamed Filly, was released in Sarasota Bay Wednesday morning after spending two months in rehab at Mote Dolphin and Whale Hospital after becoming entangled in monofilament fishing line.
The young female bottlenose dolphin was first seen trailing the fishing line from its tail in December 2006 by scientists with the Sarasota Dolphin Research Program, which regularly monitors the 150 resident dolphins of Sarasota Bay.
On Jan. 18, the dolphin was spotted again, and algae had attached to the line and was creating additional drag, making the line cut deeper into the dolphin’s flesh.
Mote applied for and received permission from NOAA Fisheries Service – the federal agency that regulates the protection of wild marine mammals - to try and help the dolphin.
Led by Dr. Randall Wells, Sarasota Dolphin Research Program manager, a 30-member team including NOAA Fisheries Service staff, set out on Jan. 30 to try and free the dolphin from the line. When the team caught the dolphin, they saw that the entanglement was too severe to remove in the field and that the animal likely suffered from other health problems. So the dolphin – nicknamed “Filly” because of her entanglement in monofilament fishing line – was brought to Mote’s Dolphin and Whale Hospital so the line could be removed and she could be treated.
Dr. Charles Manire, Mote’s chief veterinarian, performed two surgeries to remove the monofilament line that had embedded into the dolphin’s skin near the tail and wrapped around the bone. He removed a segment more than a foot long that was encircling the spinal column three times.
Manire also treated the dolphin for infection at the wound site and found a series of other injuries, showing that the animal had additional encounters with humans.
“We found that Filly had ingested plastic and had obvious scars from a boat strike, as well as a scar from a shark bite,” Manire said. “She came in underweight, but has gained weight and grown. I’m hopeful she can survive on her own.”
Filly’s case illustrates a serious issue facing resident dolphin population, Wells said. “Cases of dolphins being negatively affected by humans are becoming all too common on Sarasota Bay,” he said. “In 2006, at least three adult dolphins clearly died as a result of recreational fishing gear entanglement and a fourth dolphin died with a large fishing lure in its mouth. A fifth dolphin was entangled in a man’s bikini bathing suit that had begun cutting into its pectoral fins.
Now this young dolphin would likely have died from having its tail cut off if it had not been rescued. While the loss of an additional three or four dolphins in one year and another injured from human interactions may not seem like a lot to some, our models show that continued unnatural dolphin deaths at this level will lead to the demise of the long-term resident Sarasota dolphin community.”
After eight weeks of treatment, NOAA Fisheries has granted a conditional release for Filly, meaning that contingencies are in place to return her to rehab if she needs additional help. At just 18 months old, Filly had already separated from her mother. Bottlenose dolphins typically stay with their mothers - learning crucial survival skills - anywhere from three to six years after birth.
“This dolphin is unique in many ways,” Wells said. “In 37 years we’ve never seen a calf separate from its mother at so young an age, and we don’t know why that happened. We continue to see the mother in the bay behaving normally otherwise.”
A routine exam while Filly was at Mote found that her hearing is impaired at high frequencies.
“The things we expect to matter most to her - hearing boat noise, the sounds made by prey fish and other dolphins’ whistles - are within her hearing range,” Wells said.
Filly is a candidate for release because she has already shown that she can survive on her own and because Mote will be monitoring her very closely upon her return to the wild.
“Filly represents an unfortunate example of the extent of harm caused by human interactions,” said Stacey Carlson, Bottlenose Dolphin Conservation coordinator for NOAA Fisheries Service. “We are confident in the steps that have been taken to ensure her continued survival, especially given the research and monitoring capabilities of the Sarasota Dolphin Research Program.”
To help monitor Filly’s whereabouts and condition, she was outfitted with a small VHF radio transmitter that will help staff follow her upon her return to the wild, Wells said. After release, she will initially be tracked for 30 minutes and then tracked daily for two weeks. Follow-up monitoring of Filly will be included as part of the program’s regular studies.
“While we are hopeful that Filly is on the road to recovery, the injuries she’s had with fishing line and the boat strike are serious and indicate the potential for ongoing problems because she seems to be associating with humans,” Wells said. “We hope that she will stop pursuing contact with humans and adjust her behaviors, and we’ll be watching closely to make sure there are no additional problems.
Sarasota Bay boaters and anglers can also help us keep Filly and her fellow dolphins safe. Stowing used fishing line in closed containers, not fishing in areas where dolphins are frequenting and staying more than 50 yards away from wild dolphins, can help us all ensure that we’re keeping the waters safe for dolphins while still enjoying our waterways.”
The public can help avoid future interactions by following the list of best practices and responsible viewing techniques.
For avoiding interactions with wild dolphins, the following “Best Fishing Practices” were developed collaboratively by the National Marine Fisheries Service and other research groups, including Mote Marine Laboratory, the Chicago Zoological Society and Hubbs-SeaWorld Research Institute. They were developed after researchers reviewed information gathered from observations at fishing piers and elsewhere, and interviewed recreational fishing guides and anglers. The guidelines re-emphasize current conservation efforts and existing regulations.
1. Never feed wild dolphins – it is against federal law and is harmful to the dolphins.
2. Avoid tossing leftover bait to dolphins if they are nearby. Make use of leftover bait by taking it home to freeze for later or by giving it to a fishing neighbor.
3. Check gear and terminal tackle to make sure they are in good shape and will not break too easily, resulting in a lost fish with a hook that could be eaten by a dolphin.
4. Avoid fishing in an area where dolphins are actively feeding – dolphins may mistake your bait or catch for food.
5. Do not release caught fish in the presence of dolphins – this reinforces the association of recreational fishing activities with a food source. Anglers should try to release the fish as far from the dolphin and as quietly as possible.
6. Change fishing locations if dolphins are showing interest in your bait or catch. Some fishing guides and anglers have reported that fishing success may decline at a site where dolphins are actively feeding. If the dolphin does not leave, or if it follows your vessel, we recommend ceasing fishing activity for a short time to discourage the dolphin’s behavior.
7. Do not cast your line toward a dolphin.
8. Use corrodible hooks – any hook other than stainless steel. It may take anywhere from a couple of days, to weeks, or more for a corrodible hook to dissolve. Hooks are made from different alloys, with different coatings, that all affect how long they last. Using corrodible hooks in combination with other preventative measures may help reduce the chance of these interactions, as well as the degree of serious injury caused to the dolphins.
9. Use circle hooks – it is believed that they reduce injuries to fish and dolphins.
10. Never try to reel in a dolphin that may be hooked – if a dolphin is hooked and the hook is set, cut the line as close to the dolphin as safely possible. If the hook is not set, put slack on the line and give the dolphin time to release itself.
11. Stay at least 50 yards away from wild dolphins while boating or using personal watercraft.
If a recycling bin is not available, please discard in a secure bin. It’s against Florida law to intentionally discard monofilament into area waters because such line can kill or injure marine mammals, birds and sea turtles.
13. If you encounter an injured, entangled, or sick dolphin or sea turtle, contact Mote’s Stranding Investigations Program at: (941) 988-0212.
Mote Marine Laboratory also is treating a rough-toothed dolphin that was brought in to the Dolphin and Whale Hospital on March 24.
The dolphin was found stranded on Egmont Key at the mouth of Tampa Bay by members of the public who contacted the proper authorities on Saturday. Staff from Clearwater Marine Aquarium and Mote Marine Laboratory responded to the stranding and transported the dolphin to Mote for care.
Mote Chief Veterinarian, Dr. Charles Manire, reports that the animal, nicknamed “Dancer,” appears to have gastric and intestinal problems.
Animal care staff performed a gastroscopy on Sunday morning and removed several marine sponges, which can damage dolphins’ stomachs. The dolphin is being given fluids and treated with antibiotics for the gastric issues and because of infection. Dancer began swimming on her own and eating fish Sunday evening.
Dancer will continue to be monitored around-the-clock at Mote. Visit www.mote.org to view the hospital’s online medical journal and updates of the dolphin’s condition.
Rough-toothed dolphins are found in tropical latitudes around the world in the open ocean. This species, Steno bredanensis, has a long beak with no crease at the melon, large flippers and a tall pronounced dorsal fin.
The color pattern is complex, with a dark dorsal cape, white lips and throat and irregular spots or blotches on the ventral surface of the body.
What to do if you encounter a stranded sea animal
• Do not push the animal back into the water, they have stranded for a reason and pushing them back into the water is both illegal (under the federal Marine Mammal Protection Act) and will prevent the animal from receiving proper care.
• In Sarasota or Manatee County, call Mote Marine Laboratory’s Stranding Investigations Program at 941-988-0212. The program responds to both live and dead strandings of marine mammals and sea turtles. In other locations in Florida, contact the Florida Fish and Wildlife Conservation Commission at 888-404-FWCC.
• Protect the animal from direct sun and keep skin protected with wet towels, making sure to keep the area around the blowhole clear of water, sand or debris.
• Keep pets away and avoid excessive noise or handling.
• To avoid injury to yourself, stay clear of the mouth and tail and observe the animal from a safe distance until the appropriate experts arrive. Even though the animal is probably sick, remember they are wild animals and very strong.