All dolphin photography taken under MMPA Permit #21938-03.
May not be used for commercial purposes.
Hello! My name is Carrie, and I’m a CKDP field assistant this summer. I can’t believe we’re already almost halfway through the field season! In June, thunderstorms kept us off the water for more days than we would have liked, but we’ve still had many field days so far, and have encountered lots of dolphins on each of these days. Thankfully, we have plenty of data to keep us busy in the lab when we can’t go out! I’d love to give you an idea of what a day in the life of a field assistant is like on field days.
Our day starts at 6 AM, when Jolinde, our field manager, checks the weather radar, wind speed and swell height to make sure that conditions are good for spotting dolphins and staying safe on the boat. We then eat breakfast and pack up the equipment. The “data cooler” holds our DSLR camera, handheld video camera, GPS, datasheets, and lots of spare batteries. Another cooler holds our water bottles, sandwiches for lunch, and an abundance of snacks. We pack the coolers, along with acoustic and drone equipment, into the truck, and hook up the boat trailer. We then head to one of our launch locations. This year, we’ve launched from Cedar Key, the Waccasassa river, and Yankeetown. Jolinde chooses our launch location based on a combination of factors, including weather, expected boat traffic, and water depth. The coastal waters in this region are very shallow, so we are often boating in a meter or less of depth while navigating through obstacles like oyster bars and crab pots. When we get to the boat ramp, we load the equipment into the boat, prepare the boat for launch, and then we are off!
While on the water, we’re constantly scanning the horizon for dolphin dorsal fins. We’ve been lucky to have several mornings lately where the water is so calm and glassy that it’s almost hard to tell where the water ends and the sky begins, and cotton-candy-like clouds are reflected onthe water’s surface. When the water is choppier, though, dorsal fins can be camouflaged by the waves. It’s also easy to confuse other animals for dolphin activity. Ospreys and pelicans plunge into the water, creating huge splashes. Cormorants bob on the surface. Fish cause ripples and splashes, and mullets launch themselves into the air. Boulder-like manatee snouts emerge to take a breath, while sea turtle heads poke out of the water like periscopes.
When someone yells, “dolphins!” and we confirm that we have indeed spotted dolphins, we begin to approach them. Boaters are required by law to stay 50 yards away from dolphins, or to continue on their course if dolphins approach their boat. CKDP has a research permit that allows us to approach and follow dolphins at a closer distance. A flag on our boat lets other boaters know that we are performing dolphin research under a permit.
When we arrive at the dolphins, we begin a “sighting,” where we collect photo-ID and behavioral data. Sightings can last from five minutes to an hour, and we usually have multiple sightings per day. During a sighting, one field assistant takes photos, with the goal of taking at least one clear photo of both sides of each dolphin’s dorsal fin. Individuals can be identified using the unique pattern of notches on their dorsal fins, caused by other dolphins, sharks, or boats. They can gain more notches throughout their lifetime, but they don’t lose them (unless they are overlapped by new notches). Their scars, which may fade over time, and dorsal fin shapes can also be helpful for identification. Dolphins with “clean” fins, who are usually calves, are the hardest to identify. Taking photos of dolphins can be extremely difficult, because they only surface for about a second and can stay underwater for long periods of time. Some dolphins are more “photogenic” than others, meaning that they tend to surface frequently alongside the boat, making the camera person’s job easy. Dolphins who don’t surface often or frequently change directions can be very challenging to photograph. Calves are especially difficult to capture, because they surface faster than adults. The more dolphins there are, the more difficult it is tokeep track of where they all are and which fins have already been photographed. We have had many chances to practice this so far, because we’ve frequently encountered large groups of 20 or more dolphins socializing. The camera person and boat driver work together to constantly position the boat in places where we can take photos at good angles.
Another field assistant is in charge of filling out the datasheet. This is also a collaborative process; everyone on the boat discusses what we are seeing. We record information about the time, location and conditions of the sighting. We also estimate the number of dolphins present in the sighting, distinguishing between adults, calves, and young-of-the-year (YOYs), which are calves that were born this year. We estimate these age categories based on the size and behavior of the dolphins. Calves up to three years old are generally no more than half the size of adult dolphins, and YOYs are even smaller. YOYs don’t have fully developed motor skills, so they often stick their face out of the water when they surface to breathe, and they surface very quickly. YOYs also tend to swim in “baby position” alongside their mom. We also record information about how spread out the dolphins are from each other, whether there are subgroups within a larger group, when dolphins join or depart from the group, and how they are moving around the area. We record information about the activities that the dolphins are performing, which could be traveling, foraging, socializing, or resting. My favorite part of data collection is observing and recording specific foraging and social behaviors.
Dolphins in this population have several different foraging techniques, including the cooperative driver-barrier (DB) foraging behavior that is unique to this population, as far as we know. We haven’t gotten a good look at DB yet this season (we are not specifically searching for it this year), but I hope I have a chance to witness it. We have seen other interesting foraging techniques, like “fast swimming,” where dolphins accelerate very fast to chase a fish, sometimes creating a rooster tail at the surface with their dorsal fin. We saw a dolphin named Eller toss a Crevalle Jack fish into the air several times, perhaps to stun it. We’ve seen several dolphins “bottom grubbing,” where they stick their snout into the mud and root around for fish. This requires them to kick their flukes at the surface to keep their body pointed downwards, creating huge splashes. We got to see Nail bottom-grubbing with her YOY watching nearby. My favorite foraging encounter so far was watching Knuckles perform “kerplunking,” where he forcefully dives into the water and holds his body in a curved position so that his tail slaps against the surface as he enters the water, presumably to stun fish. Although this behavior is seen in some other bottlenose dolphin populations, Knuckles is the only individual in this population who has been observed kerplunking. I would love to find out how these dolphins learn these behaviors and how this knowledge is transmitted throughout the population.