Las Vegas Review-Journal (Sunday)
Researchers study dolphins after hurricane
Frequent lesions could be caused by pollution
GALVESTON, Texas — Kristi Fazioli first spotted the pair of dolphins swimming behind a shrimp trawler near Morgan’s Point, eager to get a mouthful of breakfast.
The Houston Chronicle reports they appeared healthy as they popped in and out of the choppy waters typical for a November day on Galveston Bay. But a second glance showed the truth: Their skin was mottled and blotchy, covered in a patchwork of white lesions that stood in stark contrast to the gray coloring characteristic of bottlenose dolphins.
Where some might have winced at the dolphins’ sickly appearance, Fazioli, a research associate at the University of Houston-Clear Lake’s Environmental Institute of Houston, calmly snapped photos of the lesions, documenting the time, date and place of the sighting.
This is the post-Hurricane Harvey reality for the popular bay dolphins, known to swim alongside boats and ferries throughout Galveston Bay. Nearly three months after the storm’s destruction, the more than 500 dolphins she has documented inUpper Galveston Bay still are struggling to recover.
The lesions are nothing new to Fazioli and her colleagues. Dolphins suffered from them after major flood events in both 2015 and 2016.
Scientists often attribute the lesions to extended exposure to freshwater — an inevitability when 51 inches of rain plummets from the sky as it did during Harvey.
But others also believe pollution could be the cause. During Harvey, about 149 million gallons of raw sewage and industrial discharges poured into neighboring communities and waterways. About 100 companies, including Valero Energy, ExxonMobil and Arkema, reported spilling chemicals, some of which undoubtably reached the bay.
A 2012 University of Southern Mississippi study, examining an unusually high number of perinatal dolphin strandings in the northern Gulf of Mexico the year prior, noted that “bottlenose dolphins in colder, low-salinity waters may be prone to severe skin lesions and physiological stress that make them more susceptible to infection or illness from natural or anthropogenic factors.”
Maddalena Bearzi, who wrote about her study of dolphins off the coast of Los Angeles in National Geographic in 2014, noted that almost 80 percent of the dolphins photographed had some type of dermal lesion.
Though she noted salinity and sea temperature contribute to these lesions, “bacterial, viral and fungal infections are also at the top of the list, possibly correlated to bad water quality or contaminated prey.”
Research conducted outside of California, Bearzi wrote, suggests “these issues could be human-induced, likely in relation to poor water quality.”
Pollution’s role in these lesions also had been noted by the National Park Service, which found that about one-third of the dolphins near the Indian River Lagoon System at Canaveral National Seashore in Florida had lesions scientists believed were attributed to pollution.