The first few months of 2019 have been sadly busy for us at the Sarasota Dolphin Research Program with the disentanglement of two young male dolphins from fishing gear in rescues we conducted with help from our partners at numerous local, state and federal agencies and organizations.

 

The first rescue took place in mid-March after a dolphin was reported to be entangled in fishing line. Biologists from Florida’s Fish and Wildlife Conservation Commission (FWC) verified a significant entanglement, which included fishing line cutting through each side of the calf’s tail and a second fishing line entanglement forming a bridle through the calf’s mouth. The line was also fouled, which created drag as it continued to cut into the dolphin’s body.

 

After reviewing evidence of the entanglement, NOAA approved of an intervention to help this calf, a young male who was still dependent on mom. On March 11, the rescue team got to work. Under a NOAA permit, we gathered partners from FWC, Mote Marine Laboratory, the University of Florida’s College of Veterinary Medicine, Clearwater Marine Aquarium and Charlotte County Sheriff’s Office to attempt the rescue.

When we found and caught the calf and his mom near Stump Pass, south of Manasota Key in Charlotte County, we discovered that the entanglements through the mouth and the flukes on were nastier than expected and were certainly life-threatening. He also had lost the tip of one fluke, presumably to an earlier entanglement. 

Our team was able to cut the line and pull it free, give the calf an antibiotic shot, take measurements and collect a blood sample and release him. We also had the opportunity to outfit his mom with a satellite-linked tag that will help us monitor the pair’s progress now that the calf is free of the line. Mom’s track is showing us they are residents to the waters near Stump Pass. Unfortunately, they are also still spending time near anglers.

Just three weeks later, we helped a second young entangled male. We first took note of the calf in February, when we saw him with his mother during a routine photographic identification survey — made possible thanks to support from the Charles and Margery Barancik Foundation — because he appeared to be very thin. Mom, who is 17, is a long-term resident of the Sarasota Bay dolphin population known as F199 and she’s been sighted more than 450 times. This is her third known calf.

 

When we saw the pair again during our next set of monthly monitoring surveys a few weeks later, we noted that the calf’s body condition appeared to be even worse. When we were able to analyze our photographs of the dolphin back at the lab, we realized that his flukes were badly entangled in fishing gear, which was heavily fouled, creating drag and cutting deeply through his fluke.

 

We sought permission from NOAA to intervene and, once given the go-ahead, we mounted a rescue that included eight boats and 48 people from SDRP, Mote Marine Laboratory, FWC, the University of Florida’s College of Veterinary Medicine, Clearwater Marine Aquarium and NOAA Fisheries.

 

On Monday, April 1, (no fooling!) the team headed out. Within an hour, we had spotted the young male, who we know as “F316,” without his mom.

The entanglement was caused by poly-filament braided fishing line — a strong, sharp type of fishing line that is extremely deadly to wildlife. The line had cut 85 percent of the way through the right part of the dolphin’s tail and with every tail beat, the line was cutting further and further through. Within 40 minutes, we had removed the entanglement, examined him, given him a dose of antibiotics and released him.

 

We will continue to monitor the progress of both dolphins through our regular photographic identification surveys and satellite-linked tracking.

After disentangling two young dolphins from fishing gear within three weeks, we’re very concerned that we’re seeing the lingering effects of the severe red tide that was along Florida’s Gulf coast for more than a year.

 

We know from the fish surveys that we’ve conducted in Sarasota Bay that prey fish populations have declined by more than 90 percent since last summer. The fish that we are catching are small — too small to be of much nutritional value to the dolphins that need to feed on them.

It’s going to take time for the fish populations to rebuild, but in the meantime, we’re concerned that dolphins and anglers may increasingly come into contact with each other as each are interested in the relatively few remaining fish— with detrimental consequences for the dolphins.

 

During a previous severe red tide in 2005-2006, we lost 2 percent of our long-term resident dolphin population in Sarasota Bay from ingesting fishing gear – bait and catch were very attractive to them. Dolphins were increasingly patrolling near fishing boats and piers. We’re worried that we’re seeing that pattern develop again.

 

But there are things anglers can do to help:

We will continue to keep watch on the dolphins of Sarasota Bay. Please do all you can to help keep them safe!

Wishing you fair winds and following seas...

Randy Wells

Name: F199

Age: 17

Sex: Female

A Dolphin's Life: F199 is the mother of F316, who we disentangled this month. She's been observed more than 450 times since June 2002.

F199 was first observed patrolling — waiting for discarded catch from a fishing boat — just after the persistent and intense red tide algal bloom in 2005-2006. While this is not her primary feeding method, she has continued to be observed around fishing boats off and on since.

She often associates with Vespa who is well-known for spending time around fishing boats. It would not be surprising that F199 had returned to these risky behaviors after this most recent round of intense red tide and associated lack of prey availability. This would increase her and her dependent calf’s (F316) exposure to, and possible entanglement in, fishing line.

The Sarasota Dolphin Research Program (SDRP) is a collaboration dedicated to dolphin research, conservation and education.  

 

It began in 1970 at Mote Marine Laboratory when Blair Irvine and high school student Randy Wells started a pilot tagging study to find out whether dolphins on Florida's central west coast remained in the area or traveled more widely. In 1974, with a contract from the U.S. Marine Mammal Commission, they were joined by Michael Scott and expanded the study with radio-telemetry.

 

Their subsequent discovery of long-term dolphin residency set the stage for today's efforts by demonstrating opportunities to study individually identifiable dolphins throughout their lives in a natural laboratory setting.  

Our work is conducted under the name "Sarasota Dolphin Research Program." This name ties together several organizations dedicated to ensuring the continuity of our long-term research, conservation and education efforts in Sarasota Bay and elsewhere.

The SDRP has been operated by the Chicago Zoological Society (CZS) since 1989. 

"Dolphin Biology Research Institute," is a Sarasota-based 501(c)3 nonprofit corporation established in 1982. It provides logistical support with research vessels, towing vehicles, computers, cameras, field equipment, etc. Since 1992, the program has been based at Mote Marine Laboratory on City Island in Sarasota Bay, with office, lab, storage and dock space and easy access to boat launching ramps within the home range of the Sarasota Bay resident dolphins.