Field Study - Indian River Lagoon Dolphins
In this report, I'd like to give you a quick recap and a glimpse of the future of our bottlenose dolphin study.
How many times have we made it on the water in six weeks? Exactly once. The unusually late spring series of cold fronts made it too windy for the photo identification we are doing of dolphins. Also, it's not always easy to get out on the water when the weather is good. If the photo ID project was our only job, we would have been out a lot more often. But Megan Stolen and Rachel Witcher, graduate students, have classes to attend, and Steve Clark, a biologist, only works for me part-time.
Spotting dolphins on the IRL.
When the weather isn't good for boat work, what do researchers do? We can go out to some of the bridges that cross the Indian and Banana rivers and look for dolphins on the lee - or calm and sheltered - side of the bridges. We would see how the dolphins behaved around boats that go under the bridges. Since some dolphins have propeller cuts on their dorsal fins, these observations might tell us how it happens. When the weather is really bad, we stay indoors. Field notes will be typed in the computer; digital photos will be examined and cataloged; and equipment will be cleaned. We'll scan old photos from the 1979 study and work with other biologists to compile a master photo ID catalog for the IRL. There is never a lack of things to do in a study like this one.
Our observation vessel.
Bad weather for our small boat really isn't bad weather for the dolphins. However, because it is so hard to see them, we really don't know if their behavior patterns change during rough weather. Observations from bridges might help a little but we really need radio or satellite transmitters to follow them continuously.
What are we doing with the small amount of data collected so far? We are still in the process of working out the details of our field operations and testing the equipment like the digital camera. We're outfitting our boat. The one good day that we had on the water gave us a good set of photos from the digital camera. It is important to know that the camera works. While I haven't looked at all of the photos in detail, it looks like we have about six dolphins with distinct dorsal fin marks. These will start our new dorsal fin catalog.
Dolphin 56'S Travels
I think that the most exciting thing has been the reports of dolphin 56 in Georgia and South Carolina. While it has probably happened before, this is the first time it has been documented of an Indian River Lagoon dolphin outside the lagoon system - and he was sighted some 300 miles away!
During our one day on the water, we probably saw 20 to 30 different dolphins. But most did not have distinct dorsal fins or we did not get close enough to tell. Other scientists have estimated that between 200 and 500 dolphins live in the Indian River Lagoon.
The IRL study will probably go on for at least five years and probably a lot longer. We'll spend a lot of time during the next several years on the water taking pictures, recording dolphin behavior at different times of the year, listening to their sounds with underwater microphones. (We will also spend a lot of time sitting on shore because of bad weather.) We may even be able to watch the dolphins at night using night-vision goggles. We will find out where the dolphins spend their time in the summer, fall, winter and spring and about their favorite fishing places. We'll note when they have their calves and watch the calves grow up.
The research questions that we asked at the beginning of the study will take a long time to answer. Even if we had been able to get on the water for six weeks in a row, we still would not have enough information to answer the questions. We would have had a lot more photographs and dots on the map where we sighted dolphins, but it will take at least a year before we can even begin to think about some of the answers. Even that may not be enough time!
Science is a big adventure. You never know what will happen next! Like researchers, you can plot the sightings of dolphins on a map in the activity below, using the data we collected in the IRL. And, in the coming months and years, you'll be able to keep in touch with the Indian River Dolphin Project through SeaWorld/Busch Gardens ANIMALS. Stay tuned!