It’s an autumn Sunday, the low clouds and overcast skies promise rain. The Roanoke Sound is calm, though, and a light breeze from the northeast doesn’t seem to be disturbing the waters.
Jessica Taylor, executive director of the Outer Banks Center for Dolphin Research and volunteer Barb Clark go about the business of launching the center’s research boat in a practiced, choreographed way. Once underway on the dolphin survey, Taylor mentions that it’s late in the season to see dolphins in the waters of Roanoke Sound, but there may be some changes in the migratory patterns.
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“Up north in New Jersey and Delaware they’re seeing more dolphins later into the fall,” she said.
Heading south then a little to the east, Taylor makes for House Island, a fairly large marsh island just to the south of the Washington Baum Bridge. After maybe five minutes on the open water, the rain begins — not so much rain, but more like the sky spitting droplets that sting as the boat heads into them.
After 45 or 50 minutes, everything is wet, the rain has managed to seep into the smallest exposed seam in a rain jacket and it is apparent that there are not going to be any dolphins to count today, although that may be as significant as if dolphins had been sighted.
It is a reminder that the nitty-gritty of scientific research is rarely glamorous or spectacular, rather it requires self-discipline, perseverance and often a certain amount of misery.
The center is not a large organization. There’s Taylor, who is the center’s public face, science adviser Shauna McBride-Kebert, a board of directors, some interns and a few volunteers. In the summer there are dolphin tours on Roanoke Sound through the Nags Head Dolphin Watch, a collaborator with the center. There is an annual Shrimp Cookoff with Outer Banks chefs vying for top prize that is the organization’s main fundraiser —but that didn’t happen this year.
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Somehow over the past two years, Taylor, who also teaches science at Manteo Middle School, has had her name on two peer-reviewed articles. Two years ago, she was one of the authors with McBride-Kebert, who was the lead author, on a paper published in the International Journal of Comparative Psychology.
The study, “Common bottlenose dolphin … seasonal habitat use and associations with habitat characteristics in Roanoke Sound,” looked at how dolphins use Roanoke Sound. Noting that Northern North Carolina Estuarine System dolphin are not permanent inhabitants of Outer Banks Sounds, the study’s authors wrote in their introduction, “The dolphin community in Roanoke Sound, North Carolina, primarily exhibits seasonal residency, and there is limited information on their habitat use.”
Concluding that “… the southern region is an important habitat for dolphins in Roanoke Sound, a community for which little is known.”
In the most recent article, published in August in Marine Mammal Science, Taylor was the lead author.
“It’s a pretty prestigious journal. So, I was really excited to publish it there,” she said.
“Skin lesion prevalence of estuarine common bottlenose dolphins (Tursiops truncatus) in North Carolina” is not a title that roles off the tongue, yet the paper examines in detail a phenomenon that is widely observed but little understood by marine biologists.
“With skin lesions, we’ve been seeing them for years … They’ve always been a concern, but nobody has really known what they are,” Taylor said.
The dolphins that the center observes are the Northern North Carolina Estuarine System population. It is not a particularly large population.
“Marine Fisheries Service estimated approximately 823 in the stock the population that we see most often in this area,” Taylor said. “I think that sounds about right.”
What is apparent in the data is that it is remarkably consistent with similar studies. Taylor compared her results to lesion studies done in Charleston, South Carolina, Brunswick, Georgia, and Sarasota, Florida
Taylor’s occurrence of lesions during the study period, 2012-2014, was 45-56% of the dolphins that were observed. The site comparisons were 38-59%.
The study suggests that water temperature is a potential factor contributing to dolphin skin lesions.
Because the Roanoke Sound population is seasonal, comparisons for spring, summer and fall were noted in Taylor’s article. The other study sites with year-round populations were not broken down by seasons. Nonetheless, some of the observations suggest that temperature may play a role.
“It’s taken a long time to compile and process our data to get to this point, and I’m hoping it leads into other papers.”
Jessica Taylor, Executive Director, Outer Banks Center for Dolphin Research
“We didn’t do statistical analysis on that for the dolphins in the Outer Banks and the seasons, but it seemed in the spring we saw more dolphins with lesions,” Taylor said. “Maybe their bodies get stressed to the cold water, and it starts to surface in the form of lesions or diseases, or maybe their immune systems are lower because of that stress.”
There is additional data included in the paper that would seem to support Taylor’s observation that water temperature may be playing a role. Sarasota with the warmest waters, showed the least number of lesions, with 38% of the population identified with lesions.
There is also data that hints at environmental factors as well. Brunswick, Georgia, had the highest incident of lesions with 59% of the dolphin that could be identified showing signs of lesions.
“Brunswick was the most urban study site. There’s been high PCB concentrations in the dolphins. And that’s been a concern,” Taylor said.
Taylor is careful, though, in drawing conclusions, saying in her final remarks in the article, “This study represents the first formal examination of skin lesion occurrence on bottlenose dolphins in Roanoke Sound.” She goes on to call for additional studies of the Roanoke Sound population.
She also acknowledged that for her, it’s important to publish work that could lead to further study of the dolphin population here.
“It feels good to publish. This is the first primary author publication I’ve done since my master’s and the first one that I’ve done for this area. It’s taken a long time to compile and process our data to get to this point, and I’m hoping it leads into other papers … I’m hoping this leads to more,” she said.
