Work in the field and lab has continued for us this summer, albeit in a socially distant fashion as Covid-19 continues to impact us all. Masks, hand sanitizer, Zoom meetings and other precautions have become our new normal for the foreseeable future.
Fortunately, we’ve been able to continue our monthly dolphin photographic identification population monitoring surveys thanks to support from the Charles and Margery Barancik Foundation, and we have documented the births of 10 calves to Sarasota Bay dolphin residents.
Lightning, FB55, Little Orphan’s Annie, Murphy Brown, Swiss Cheese, Ginger, F219, Nellie, A Little Smart Head and F277 have all given birth this year.
These babies include 8-year-old F277’s first calf and Lightning’s tenth baby. Murphy Brown and FB55 are sisters, and Ginger, FB55, and Nellie were all dolphins that would likely not have survived to become mothers without interventions. We removed a stingray barb from FB55’s head during a health assessment, Ginger stranded on the beach in 2008 and was returned to the wild after rehabilitation and, when Nellie became entangled in plastic line in 2010, we were able to disentangle her. We’re keeping an eye out for Nellie and her new calf, which had an injury in its left flank when we saw first it on July 7.
These young-of-the-year dolphins just learning how to navigate their watery world offer us all a good reminder to slow down and watch out for marine life when we’re boating — which many of us seem to be doing this summer as other recreational activities are curtailed or are altogether unavailable. The Sarasota Police Department’s marine patrol unit reports a significant increase in boat traffic during the pandemic, as compared to the same months during previous years.
During our surveys, we’ve also been noting an increase in boating activity in the home range of the Sarasota dolphin community and we’re detecting it through our Passive Acoustic Listening Station network. Each of the stations in the network includes a hydrophone that records sounds to flash memory cards and/or transmits data via cell phones.
The stations were created in partnership with David Mann of Loggerhead Instruments, Mote Marine Laboratory, New College of Florida and local citizens. They allow us to explore the underwater acoustic environment of Sarasota Bay to better understand the ecological dynamics of the bay and the behavior of its animals, including sound-producing fish, dolphins and manatees.
Because these instruments collect so much data — many terabytes each year — our partners at New College have developed an automated system of identifying bottlenose dolphin whistles. So far, we’ve identified nearly a quarter of a million distinct whistles, and, because of work done by our partners at WHOI and the University of St Andrews, Scotland, to develop a Sarasota Dolphin Whistle Database of the unique identifying sounds that each dolphin makes, we can even tell not just when dolphins are present near these stations, but which dolphins they are.
The image above (left) visualizes the signature whistles of two different dolphins. As you can see, the shape of the whistle produced by the mom is different from that produced by the calf. Since each dolphin has an individual signature whistle, we can use our catalogue of sounds to determine which dolphins were recorded near a specific hydrophone.
We’re working to add new stations like the one in the picture (above right) and improve the capability for people to listen to underwater sounds in real time. Stay tuned for details!
Speaking of partnerships, I’m pleased to report that the Chicago Zoological Society has signed an official memorandum of understanding with New College of Florida to formalize our long-term research and education alliance, which dates back to the 1970s. Together, we will be able to enhance our conservation efforts, undergraduate and graduate student learning opportunities, as well as our ongoing projects on dolphin communication and bioacoustics.
New College is also the location of our 50th Anniversary Symposium, which had been scheduled to take place this year on our Oct. 3 anniversary. However, after much discussion, we’ve decided to err on the side of caution and postpone the in-person event until 2021.
We’re making alternate plans for a different type of celebration to take place this year on or around our golden anniversary and we’ll be sure to keep you posted on the details!
Until next month, I wish you all fair winds and following seas!
Randy Wells
